Accuracy of powder coated vs. conventionally lubed bullets

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Tom G posted this 22 July 2020

I'm just starting with pc'ing pistol bullets. So far, after limited testing on a Ransom Rest with a Browning Hi Power in 9MM, I'm not seeing anything to write home about. 

 So far, I've shot loads with Universal powder from 3.3 thru 3.7 grains with a 126 gr. bullet at 11 BHN hardness.  Groups haven't been as good as with conventionally lubed bullets. Using my Quick Load Program and by comparing velocities of those predicted to those measured, the pc's bullet shoot slower than predicted. I intend to increase the charges up to 4.2 grs. in increments of .1 grain to see if things improve with hotter loads. That will be my next test. 

So far, I've observed that the barrel had no leading at all but was fouled in the first inch and a half in front of the chamber with some unknown substance that came out easily with a few passes with the brass brush. The gun was very sooty around the chamber area and barrel that I don't normally see. This may be due to the cautious approach I made with powder charges that don't burn completely. I dunno.  

Has anyone done an accuracy comparison of pc's bullets vs. regular lubed bullets in the same gun?  Did you get the same velocity?  Was the accuracy comparable? 

My initial impression is that these pc'd bullets don't have the same bore friction as regular bullets. The fact that the don't go as fast indicates that they aren't developing the same chamber pressure due to less initial engraving forces and less friction going down the barrel. 

If anyone has done any kind of a study on these lines it would be good info to share. If anyone is interested, I'll post the results of the next test taking this load up to a full case of powder (100 % load density)  to see what happens. Quick Load program predicts 4.2 grains of Universal to be a full case with 99+ % powder burn in a 4.8 inch barrel. Predicted peak chamber pressure is ~ 25,300 psi. which is way below the 35,000 psi limit for this cartridge. 

This gun has shot groups under 2 inches at 25 yards with the same bullet conventionally lubed. So far, they've been 3 to 5 inch groups with pc'd bullets. 

 Tom

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John Alexander posted this 22 July 2020

Hi Tom,

At last -- somebody doing some experiments to see the effect on accuracy of PC bullets.  I hope others who have done comparison studies, but have kept them to themselves, will contribute their findings so we can at last begin to sort out some answers.  What do we know about this other than PC bullets are pretty?

John

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Tom G posted this 22 July 2020

They are indeed pretty.   I see some advantages right off the bat. 

Your gun should stay cleaner, especially in semi auto pistols where crap blows back into the action during the slide cycle. A lot of that stuff coming back is from the conventional lube. 

They should introduce less lead into the air.  This is especially important on indoor ranges. 

They are nice and clean to handle during the sizing and loading process. I noticed that I didn't have to wipe the bullets clean when inspecting the load rounds.  Just drop them in the ammo box and take to the range. 

The extra slick surface on the noses should help in smooth feeding. 

In reality, it's a pretty cheap process when compared to making your own or buying bullet lube. 

So far, they didn't cause a speck of lead in the barrel. 

There's a lot of speculation in the above statements but I intend to get it sorted out in time. 

Tom

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RicinYakima posted this 22 July 2020

Hoping this lead to a full article in the Fouling Shot when you are done.

This is very popular with those using the big Dillon machines to crank out a thousand a day.

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Ken Campbell Iowa posted this 22 July 2020

.... and it is always good to see any performance testing in 9mm handloads ...

thanks Tom ...

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sghart3578 posted this 22 July 2020

Over on the other cast bullet forum is a 16 page thread about the accuracy of PC bullets in rifle loads over 1800 fps.  It stretches from 2013 to 2020.  Lot's of info, maybe some pertinent to the OP's goal.  Makes for good reading none the less.

I applaud the OP and his willingness to devote his time to expanding our collective knowledge base.  I personally do not PC my bullets.  I am happy with Alox on everything.  But I enjoy reading about advancements and other approaches to the same problems.

Open minds are healthy minds.

Steve in N CA

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Spindrift posted this 22 July 2020

This is not an easy puzzle to solve. Powder coat is more than just a method of lubrication. It actually slightly changes the geometry of the bullet, due to the added girth on the nose. A simple comparative test, using the same bullet design with PC and lube respectivily, would not necessarily give us the answer; the added coat slightly changes fit, and you have in effect a «new bullet».

 

I have some bullets where PC seems to improve the accuracy potential, others where accuracy is reduced. Imterestingly, my best groups with PC bullets have been with GC designs, PC’ed and shot sans checks. Typical node level +5% relative to the node with the same bullet, checked and lubed. Not enough data to conclude, but will examine this further.

 

My thoughts on the subject

- reduced friction with PC often reduces velocities compared to lubed bullets (with the same load), unless the available friction (pressure) is sufficient for complete burn anyway

- PC, largely, does not alter accuracy potential. But the conditions under which accuracy can be obtained, is profoundly changed. Alloy matters less, and you can load to jacketed bullet levels with no special tricks. 

- The competitive BR shooter, with highly specialized equipment, will probably obtain the best accuracy with lubed bullets.

-The shooter with of-the-shelf equipment who wants to achieve good, practical accuracy with hunting and practice loads, needs reliable cold bore POI in all weather conditions will find PC highly practical

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John Alexander posted this 22 July 2020

Thinking about how pretty most PC bullets are that I have seen reminded me of the two I have seen that aren't pretty at all.  The two most impressive cases I know about for PC bullets in accurate rifle loads have been by Dan Lynch and David Pape.

Dan conduced a major set of experiments of using PC bullets in heavy benchrest rifles at high velocity.  His work was well documented and reported on this forum.  As I remember,  many of his loads were over 2,800 fps and his ten shot groups were approaching the accuracy to be competitive in CBA unrestricted class at the end of his experiments.  Unfortunately,  I believe this groundbreaking work has been taken down, a big loss to CB accuracy.

David has won many of our postal matches using PC bullets in a 223 Tikka T3 Lite.

The reason for my opening remark is that both Dan and David used PC bullets that no one would call pretty. I believe they both used very lightly coated bullets that were ugly as sin but showed very promising accuracy.

John

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Larry Gibson posted this 23 July 2020

Lee 452-230-TC with 4 different PCs vs BAC lubed bullet

 Several weeks ago a member offered to send some of his PC’d Lee 452-230-TC cast of COWW + 2% tin to compare, in a side by side test, any difference in velocity, pressure and accuracy they might have against my own like Lee bullets.  Sounded like a good test so I took him up on the offer.  In due course, after several PMs wherein we cogitated the parameters of the test,  a box of bullets arrives.  I found, just as he promised, there were 4 batches PC’d with 3 different kinds of PC (one batch had a double coat applied) sized .452.  I would load those with my standard 45 ACP load to test against my own TC bullets lubed with BAC. 

 There were also 4 batches of the same PC’d bullets unsized.  I would size those .454 and load over a tested 45 Colt load which I use in my SAAs and M73 Carbine. 

All test rounds were loaded on a Dillon SDB press as that’s how I would use them.  The powder for both the 45 ACP and 45 Colt is Bullseye.  The powder thrower on the SDB was carefully adjusted with charges weighed on an Ohaus 10-0-5 scale.  I loaded 5 gr Bullseye in the 45 ACP and 7 gr Bullseye in the 45 Colt.  The bullets weighed 230 – 233 gr including my fully dressed lubed bullet. 

 I used the following firearms in the test;

Uberti M73 Carbine, 45 Colt

M98 Rhineland conversion, 45 ACP

TC Contender barrel, 45 ACP

TC Contender, 45 Colt

S&W M1917/25, 45 ACP

Colt Series 70 w/Ed Brown Match barrel, 45 ACP

Uberti “Evil Roy” SAA, 45 Colt

 

Pressure testing was done with the TC Contender barrels via an Oehler M43 PBL.  The velocities listed for the Contender tests are muzzle velocities.  Accuracy and functional velocities (screen center was 15’ from the muzzle) were done with an Oehler 35P.  The handguns accuracy (group size) was done with the target at 25 yards.  The 2 rifles were tested with the target at 50 yards.  A two handed hold was used on the handguns with hands braced on sandbags.  The rifles were shot with the fore hand resting on sandbag with elbows on bench. 

 The cartridges were loaded with my standard loads on the SDB with Dillon SDB 45 ACP dies. A taper crimp was used to straighten out the case mouth flair.  The 45 Colt cases were sized in a RCBS steel dies then lube cleaned off.  They were loaded on the SDB with the Dillon sizer removed.  A slight role crimp was applied to case mouth crimping into the forward edge of the front drive band just behind the start of the ogive.  

 

The loads are as follows;

 45 ACP: 

Lee 452-230-TC cast of COWW + 2% tin

Bullseye powder at 5.0 gr

A WLP primer

Remington R-P cases

OAL; 1.199”

45 Colt;

Lee 452-230-TC cast of COWWs + 2% tin

Bullseye powder at 7.0 gr

A WLP primer

Winchester W-W case

OAL; 1.588”

All tests were 10 shot test strings (both for pressure and accuracy/velocity testing).  The barrels were cleaned between tests and 2 foulers fired prior to record testing. 

I completed the rather extensive test (350 rounds “for record” + foulers) of the PC'd bullets in both the 45 Colt and 45 ACP cartridges.  Four different firearms (Contender for pressure, Colt M1911, S&W M1917/25, and M98 Rhineland rifle) were used for the 45 ACP tests.  Three different firearms were used for the 45 Colt (Contender for psi, Uberti SAA "Evil Roy" and Uberti M73 Carbine) tests. 

In this test I found only one of the PC'd 452-230-TC bullets that performed as well accuracy wise as my own with a naked BAC lubed bullet.  That PC coating was the Cardinal Gloss Black.  None of the other PC’d bullets were found to be more accurate out of any of the Those other PC’d bullets would start out, in several of the firearms giving excellent accuracy but around rounds 6 – 8 the fliers would start.  In a couple cases it appeared so bad I began questioning my shooting ability.  However, when I shot the Cardinal Gloss Black PC’d bullets and the naked BAC lubed bullets accuracy was as it should have been. 

When cleaning I found fouling (PC buildup and leading) to be a problem with two of the PC coatings (both the Sherman Williams coatings and the Cardinal Pearlescent Steel Gray) in several of the firearms, particularly the 6 1/2" barreled M1917/25 and both rifles.  The fouling was both from a heavy build up of the PC in the bore and several instances, leading also. Here is some of the leading and PC buildup removed with a Lewis Lead remover after one test string. The leading removed in this picture when the Cardinal Pearlescent Steel grey was shot in the S&W M1917/25. 

 

 

 

Concealment is not cover.........

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Larry Gibson posted this 23 July 2020

Continued;

The Sherman Williams, both 1 and 2 coats, left PC deposits in all the barrels after 6 - 8 rounds with flyers then occurring.  They also left leading in the S&W M1917/25 in 45 ACP and Uberti SAA in 45 Colt.  The PC fouling could be cleaned out easily with a bronze bore brush and Hoppe's #9.  The leading required a Lewis Lead Remover to remove as pictured above.  This picture shows the PC residue buildup when the Sherman Williams PC was used, particularly the 2 coated bullets.  

As to reducing pressure I found only one of the PC'd bullets demonstrated a measurable (outside of lot to lot variation probable) less psi that the lubed bullet in the 45 Colt but that PC’d bullet gave the highest psi in the 45 ACP, higher than the naked BAC lubed bullet.

Additionally I found one of the PCs (Cardinal Gloss Black) to leave a residue on the firearms (revolvers) worse than regular lube does.  There also was considerable residue blown back on the case with the 45 Colt load.  Other than that the Cardinal Gloss Black 1 coat worked well in all the firearms and rivaled the naked BAC lubed bullets for accuracy.  It gave slightly less psi and slightly less velocity in all the firearms too.  However, as mentioned, there was a considerable blackish deposit left in the chambers, on the cylinders of the revolvers and around the carrier of the M73.  That did not seem to affect the accuracy and no fouling occurred in any bores.  It cleaned off the firearms as readily as the residue from naked BAC lubed bullets.

The Sherman Williams, both 1 and 2 coats, left PC deposits in all the barrels after 6 - 8 rounds with flyers then occurring.  They also left leading in the S&W M1917/25 in 45 ACP and Uberti SAA in 45 Colt.  The PC fouling could be cleaned out easily with a bronze bore brush and Hoppe's #9.  The leading required a Lewis Lead Remover to remove.  There will be a couple pictures of that in the article. 

The cardinal Pearlescent Steel Gray performed well in all the handguns both ACP and Colt but was pretty inaccurate in both rifles. 

Colt.  The PC fouling could be cleaned out easily with a bronze bore brush and Hoppe's #9.  The leading required a Lewis Lead Remover to remove.  There will be a couple pictures of that in the article. 

The cardinal Pearlescent Steel Gray performed well in all the handguns both ACP and Colt but was pretty inaccurate in both rifles. 

I’m not going to draw any conclusions; I’ll let each of you do that by scrutinizing the data.  Here are the correlated data for each cartridge:

45 ACP/452-230-TC/5 gr Bullseye/WLP/R-P Case

Sherman Williams

Metallic Silver 1 Coat

Firearm…………… Grp @ 25 yd……..Velocity……SD……..ES……psiM43)…..SD……ES……..

TC Contender………3.9”..(8 in 2.8&rdquo……1019 fps….11 fps…35 fps…..20,200…….900…...3,300……

S&W M1917/25…….4”…(8 in 3&rdquo……….890 fps….15 fps…54 fps…....

Colt Gvm’t M1911….5.5”…………………919 fps…..12 fps…42 fps……

M98 Rifle..(50 yd).....3.2”..(7 in 1.1&rdquo…….1046 fps….17 fps….58 fps…..

Sherman Williams

Metallic Silver 2 Coats

Firearm…………… Grp @ 25 yd…..Velocity…….SD…….ES………psiM43)…..SD……ES……..

TC Contender………4.6”……………..1006 fps……19 fps…58 fps……19,400…...1,200….3,400…

S&W M1917/25……5.4”..(9 in 4&rdquo…….903 fps……14 fps…41 fps

Colt Gvm’t M1911…6.5”………………919 fps…….19 fps…54 fps

M98 Rifle…(50 yd)…5.25”……………1044 fps……10 fps…33 fps

Cardinal Pearlescent

Steel Gray 1 Coat

Firearm…………… Grp @ 25 yd…..Velocity….…SD…….ES………psiM43)…..SD……ES……..

TC Contender………4.4”……………..1002 fps……14 fps…53 fps……19,900……1,500…4,000

S&W M1917/25…….4.9”………………895 fps...…17 fps…54 fps

Colt Gvm’t M1911….5”………………...917 fps…...10 fps…35 fps

M98 Rifle..(50 yd)…5.2”………………1038 fps…...13 fps…48 fps

Cardinal Gloss

Black 1 Coat

Firearm…………… Grp @ 25 yd……Velocity……SD…….ES………psiM43)…..SD……ES……..

TC Contender………2.2”………………996 fps……16 fps…..61 fps……18,700……1,200….4,100

S&W M1917/25……2.2”………………886 fps……16 fps…..43 fps

Colt Gvm’t M1911…3”…………………917 fps……9 fps…...31 fps

M98 Rifle…(50 yd)..3.6”…(8 in 1.4&rdquo…1035 fps…...14 fps….43 fps

Naked Cast w/BAC Lube

Firearm…………… Grp @ 25 yd….Velocity…..…SD…….ES………psiM43)…..SD……ES……..

TC Contender………2.1”……………..1004 fps……12 fps….40 fps…..18,900…….900……2,900

S&W M1917/25……2.25”…………… 917 fps……..9 fps…..30 fps

Colt Gvm’t M1911…2.75”…………….922 fps…….12 fps….37 fps

M98 Rifle…(50 yd)…2.2”……………1060 fps…….15 fps….45 fps

45 Colt/452-230-TC/7 gr Bullseye/WLP/W-W case

Sherman Williams

Metallic Silver 1 Coat

Firearm………………. Grp @ 25 yd….Velocity………SD…….ES……psiM43)…..SD……ES

TC Contender………….2.8”……………..1080 fps……10 fps….34 fps…..14,800……800……2,900

Uberti Evil Roy SAA…..3.6”……………..896 fps……..12 fps….34 fps..

Uberti M73 Carbine..(50 yd)..3.6”………...1153 fps……12 fps…41 fps

Sherman Williams

Metallic Silver 2 Coats

Firearm………………. Grp @ 25 yd….Velocity……..SD…….ES………psiM43)…..SD……ES

TC Contender…………..3.1”……………1070 fps…….12 fps….39 fps…..15,700……500……1,700

Uberti Evil Roy SAA…..3.6”…………….900 fps……...8 fps…...24 fps

Uberti M73 Carbine..(50 yd)….2.8”..……1142 fps…….8 fps……27 fps

Cardinal Pearlescent

Steel Gray 1 Coat

Firearm………………. Grp @ 25 yd….Velocity………SD…….ES………psiM43)…..SD……ES

TC Contender………….3.9”…………….1070 fps……..7 fps….20 fps……16,000……600……1,700

Uberti Evil Roy SAA…..5”……………….899 fps……..18 fps…59 fps

Uberti M73 Carbine.;(50 yd)..4.2………...1135 fps………5 fps…17 fps

 Cardinal Gloss

Black 1 Coat

Firearm………………. Grp @ 25 yd…..Velocity…..…SD…….ES………psiM43)…..SD……ES

TC Contender…………..1.8”……………1066 fps…….11 fps….31 fps……15,900…..500……1,700

Uberti Evil Roy SAA…...2”………………896 fps……..10 fps….31 fps

Uberti M73 Carbine..(50 yd)..2.5”………..1134 fps……13 fps…..49 fps

Naked Cast w/BAC Lube

Firearm………………. Grp @ 25 yd…..Velocity……SD…….ES……..…psiM43)…..SD……ES

TC Contender…………..1.8”…………….1078 fps….9 fps…….35 fps……16,700……900……2,900

Uberti Evil Roy SAA…..2”………………..902 fps….12 fps……44 fps

 

Uberti M73 Carbine..(50 yd)..1.7”………..1135 fps…..5 fps…….15 fps

Larry Gibson

Addendum; From the above test and numerous other rifle handgun cartridge tests with a variety of PC'd cast bullet which gave basically the same results you understand why I have not yet began using PC'd bullet.  So far [guess there's always hope]  PC'd bullets have shown me no advantage.  That included "less smoke" and clogging up dies.....the smoke doesn't bother me and my lubed bullets don't clog up dies. 

LMG

 

Concealment is not cover.........

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Ross Smith posted this 23 July 2020

Holy Moses Larry, That was some post!

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lotech posted this 23 July 2020

That testing is to be appreciated by many of us. I've never used a coated bullet, so can't comment from experience, but it's hard to imagine how the coating process could produce a more accurate bullet than a conventionally sized and lubed bullet of proper alloy and fit. There are few shortcuts when seriously working with cast bullets. 

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Geargnasher posted this 26 July 2020

Hmmm.

I began powder-coating my cast bullets several years ago because the method virtually eliminates lead accumulation in my silencers. I soon found the coating has many ither advantages as well.

After many thousands of rounds fired in everything from .223 semi-auto and bolt actions to .308 and most of the popular handgun and revolver calibers, most at full copper-jacketed velocities, here is a copy of my list of conclusions so far, from a very lengthy and ongoing thread on another cast bullet board:

"1. The coated bullets don't need lube up to and beyond equivalent jacketed bullet speeds. 2. Full-power, full-pressure loads can be used in ordinary, production-quality barrels without leading or fouling, provided the bullets are sized as the coating requires (it's different from ordinary cast bullets), the coating is properly cured, and the bullets have relief ("lube") grooves. Light carbon-fouling akin to shooting jacketed bullets is all I get at high-velocity, one wet and two dry patches gets it all out (eight rifles tested so far, repeatedly). 3. The first shot from a CLEAN barrel goes in the group, usually in the center. Very predictable. 4. Powder coating allows full-power rifle loads with reasonable hunting accuracy in ordinary hunting rigs using bullets of HALF the BHN normally required, making for more effective expansion at extended ranges. This of course extends the minimum hunting range if you don't want excessive meat damage. Air-cooled clip-on wheelweight alloy plus 1.5% tin is good for 1.5 MOA or less for ten shots to the pressure limits of the .223 and .308 in standard, oriduction barrels. 5. Powder-coating drastically reduces the lead fouling of muzzle brakes and suppressors and virtually eliminates leading of both piston and DI gas systems. 6. The coating hasn't proven any gilt-edged, match-winning accuracy for me yet, but then again I haven't (nor am I inclined to) pursue it to that level just yet. This quest was for usable hunting accuracy with appropriate alloys and particularly for semi-automatic rifles which we don't see at many cast bullet shooting matches. And for the biggie.....After all this testing at both extremely low and high velocity, I consider the Quest for Extreme Bullet Lube 100% fulfilled. Our dear departed friend Felix Robbins was right all along when he kept indicating that some sort of polymer was the solution to the bullet lubrication challenge. Who knew all those years ago that it would take the form of a TGIC-crosslinked coating?"

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Geargnasher posted this 26 July 2020

There are some other things that are important to understand when developing loads with powder-coated bullets, so a short list may save all of you some time.

First, like I told Ric Bowman a while back when he dabbled with this, you need to forget everything you think you know about loading cast bullets and start anew, tabula rasa, or you're going to have troubles with powder coat.

The coating is indeed slippery and extends the initial pressure rise somewhat. This can easily be seen when comparing recorded velocities between coated and uncoated/lubed bullets in otherwise identical loads. As a rough average I'm seeing a need to increase powder charge 5-8% by weight across the board to achieve equal velocities with coated bullets.

If the coating gets scraped off in the throat it won't work very well, so make sure that your static fit is a little loose, i.e. size your bullets at least half a thousandth smaller than throat entrance diameter. Again, as a rough guideline, size your bullet's body diameter halfway between a commercial jacketed projectile's and what you would normally size a lubricated, cast bullet and adjust from there if you see a need. All eight of my sundry .45 ACPs (revolvers, rifles, pistols) dote on powder-coated bullets sized .4515". All of my .30-30s and .308s prefer .3095" except the one .308 with a .3088" throat entrance, that one gets .3085" bullets.

Don't make the bullets too hard. You do not need any alloy harder than 14 BHN, PERIOD, unless you're trying for 3000 fps in 6mm without a gas check as Dan did.

Speaking of gas checks, your rifles need them for top-end loads. My .458 Socom did not need them for 35K PSI subsonic loads.

Make CERTAIN the coating cures properly. Don't guess. Use a contact probe on a sample bullet in your batch to measure actual bullet surface temperature, and cure your bullets according to the paint manufacturer's schedule.

I also find it slightly helpful to size my rifle bullets in a form die similar to a "bump" die. This cleans up any "warts" or parting lines on the noses and sizes the nose and body together in a concentric fashion.

One characteristic of the coating which IS similar to traditionally-lubed bullets, pertaining to rifles, is the form and factor of proper FIT of the bullet to the throat. While the sort of fit that gives me most satisfactory results is still a highly unpopular one here, it does bear mentioning. A dynamic fit of bullet to throat involving some degree of initial freedom, a gradual take-up of clearances and incremental increase of engraving resistance allows the bullet to find the middle of the bore better than you can force it to with a hard jam and matching tapers, and minimizes the damage and distortion that the bullet's back end receives when it is loaded tight and started against a hard jam resistance. The coating is slippery and almost as tough as copper, so it increases the bullet's ability to guide to center in the throat without damage. However, if you fit it to perfectly match the throat angles and fill all available space, the base will rivet, the coating will scrape off along with a base layer of your bullet, and you will have a mess.

I shot a 1-1/4" 100-yard, 5-shot group just two days ago, from a Mossberg MVP 5.56x45, with the Lyman 225415, and 24.5 grains of H335, at 3,016 FPS, SD 8.7. That's over 241,000 RPM for those who prefer to view performance from that perspective. Alloy was air-cooled, straight wheelweights which at my house are about 2.5% Sb/.5%Sn and just about 12 BHN. I would post a photo but the software here doesn't support that feature when posting from an Android device.

It's been a while since I contributed here or read the rules so I don't remember if links to threads on other boards are acceptable, but if so I can put a couple of really good ones here which should advance the knowledge base of this group considerably.

I also noticed a CBA match in March was won by a gentleman using powder-coated bullets. I'm surprised that didn't get any press here.

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mashburn posted this 26 July 2020

Hello Gearnasher,

Thanks for your post. You have given possible answers to questions about powder coated bullets that have been floating around in my head since I first heard of powder coating. A lot of things that you brought up were possible solutions that I had thought might work. I haven't been coating long enough to really test a lot of ideas but you have helped me save some testing of ideas I have.

Thanks again,

Mashburn

David a. Cogburn

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mashburn posted this 26 July 2020

Hello Spindrift,

Glad to see you making another post.

Mashburn

David a. Cogburn

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John Alexander posted this 26 July 2020

Geargnasher,

Thank you for taking the time for your long and helpful posts on powder coating.

You offered to post helpful links on the subject.  I look forward to following them to more on powder coating.

John

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Geargnasher posted this 27 July 2020

Here's one documenting some of my work from the very beginning. It gets sidetracked with me wrestling with a rifle that wouldn't shoot very well with any kind of projectile but did as well with PC'd cast as anything else and compares jacketed bullets to powder coated ones:

https://www.artfulbullet.com/index.php?threads/my-quest-for-speed-and-accuracy-with-powder-coated-cast-bullets.4143/

Here's one showing the group and MagnetoSpeed data I mentioned previously: https://www.artfulbullet.com/index.php?threads/hey-walter.5185/

This one, particularly posts 20, 74, and 80: https://www.artfulbullet.com/index.php?threads/effect-of-powder-coating-on-bullet-velocity.5784/

That's a start, I'm still looking for more involving my PSA LR-308 which has exceeded my every expectation with powder-coated cast bullets.

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Spindrift posted this 27 July 2020

Mashburn, thank you for your kind words! 

Just returned from the range, where I (among other things) shot some PC bullets through the .35 Whelen barrel of my Rem 700 (switch-barrel custom job). 1:14 ROT.

I have chosen the CBE360-300 for my moose bullet. It is 310grs in my alloy. It drops undersized bullets, the nose is .3475 and the bands .358 (bore-rider). Which would probably be very bad with conventional lube (never tried)- but it makes room for powder coat! The finished bullet is sized .360 on the driving bands, and .351 on the nose. The .351 bushing not so much size the nose, as even out the high spots.

Load development has been ridicilously simple, considering this was a completely new cartridge to me, when I got the barrel this spring. 3 different loads (45-47grs) with a total of one powder (Vihta N150). Some expansion/penetration testing to establish suitable velicity for this alloy.

I made a mistake when editing the photo. The powder is N150, not N140. C-C is 21mm, range 100m, approx 0,7MOA.

Included is also a photo of the bullet before and after it was shot into water containers. V0 is about 2060fps.

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Geargnasher posted this 28 July 2020

My dinosaur 2006 laptop with 1 gig of ram actually managed to upload these photos.  

This is my universal .308 Winchester hunting load, details on the targets.  The powder charge had to be reduced to 34 grains in some brands of military brass due to primer flattening, ejector swipes, excessive case head expansion, and velocity increase which corresponds to a QuickLoad prediction of excessive pressure.  With the water volume of my tested lot of R-P commercial brass, 36.0 grains of Reloder 7 is predicted to run right at 50,000 PSI and the velocity prediction is within 20 fps of actual measured muzzle velocity.  My LR-308 has an 18" barrel and mid-length gas system.  My Savage 111 has a 24" barrel.  My M1A, not pictured, has a 22" steel "pencil" barrel and runs this same load at about 2540 fps if I recall correctly.

The whole reason for using Reloder 7 instead of a much slower powder was that I wanted to keep muzzle blast and pressure to a minimum in the LR-308 which sees service as a wild pig hunting rig, suppressed.  The relatively short barrel doesn't make use of a full charge of any powder more slow-burning than Reloder 7, anyway. so there is no velocity advantage to using a slower powder.

Checking the load in these two rifles side-by-side.  The Savage has a small throat entrance and doesn't shoot as well as it can with the load made for the LR-308, but still gives acceptable hunting precision. 

This is the MP 30-180 "Silhouette" hollow point, designed by 45 2.1, which shoots so well in all of my .308/7.62 NATO rifles.  I install and crimp the gas checks, push through a .309" Lee sizing die, powder coat via the "Airsoft BB shake and bake" method, stand the bullets on non-stick aluminum foil, and bake at 400 degrees F for 22 minutes.  Alloy for the hollow points is 2.5/2.5 Sb/Sn, air cooled from the oven, running about 14 BHN after a month.  As a final step after coating I nose-size the bullets in a custom form die which cleans up the very front part of the nose in concentric alignment with the body portion and does not ruin the delicate angles the designer put there.  I load these to a common OAL, just off the lands, .005" to .020" depending on the rifle.  Forgive the ring from the Forster seating die, I haven't fully fixed the top punch to fit these yet.

 

This is my universal .45 ACP load.  Straight wheelweight alloy, Lee TL452-230TC, coated and sized in a .451" Lee push-through die resulting in a final .4515" diameter.  Loaded to 1.208" OAL and taper-crimped to .468" at the mouth, these feed and shoot very well in all of my pistols, revolvers, and my AR-15 with DI upper receiver.  To quantify "very well", my AR-15 variant stacks the bullets into 3" or less at 100 yards using a Bushnell TR-25 4 MOA red dot, so it groups smaller than the dot with the aim point being the center of a piece of typing paper.  I don't claim that the coating has any accuracy advantage when compared directly to plain lead bullets in the .45 ACP, but since I have both pistol and rifle suppressors in .45 caliber (one of which cannot be disassembled for cleaning) the coating allows me to shoot inexpensive cast bullets rather than copper plated or jacketed, with the same results.  The coating also tolerates high temperatures and does not melt in the sun or in a hot vehicle, so is as durable as jacketed bullet ammunition.  I have several hundred rounds through the carbine (probably closer to 1000 than 500) and have not cleaned the bore once since developing the load.  There is absolutely zero fouling from the coating and only a light carbon fouling in any of my guns.  One patch dampened with Ed's Red and two dry patches clean up the handguns completely (including revolver cylinders), verified with an endoscope camera.  I do not know what was causing Larry Gibson's issues but I surmise his bullets were sized too large for the throats and the coating was terribly under-baked.  The two causes of the coating causing difficult fouling in the bore can almost always be traced either to insufficiently cured powder or a bullet which is too large for the chamber throats, and has occasionally been linked to using grooveless bullets at high velocity in smallbore rifles.  

 

 

 

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Redleged posted this 28 July 2020

Hi Gearnasher. The links in your post about documentation aren't working for me. BTW, my results are similar to yours where I've had no leading issues with PC'd bullets (unless I fail to expand the cases properly and scrape it off while seating them.) I'm kind of on the fence with respect to PC vs HiTek coating. The PC is easier, but I really like the results of the HiTek (if done correctly.)

Ed

Growing old is mandatory, growing up, however, is totally optional!

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