very fast twist too much ?

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Last Post 10 November 2023

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Ken Campbell Iowa posted this 05 November 2023

against my better judgement i was browsing some you-tube gun videos and happened upon a test of light mj bullets in a very fast .... 6.5 twist ... barrel . i heard short bullets don't do well shot fast in a fast twist ... oh well ...

since cast seem to do better the longer they are ... hey, its harder to bend ALL of a longer bullet ... maybe we should all be ordering custom 6.5 twist barrels ... of course this is for our usual 1750 fps loads ....

oh, yep, he wasn't shooting zeros but this is a commercially available plastic gun ... testing relative to longer bullets ...

maybe it would be a sweet spot to choose a very fast twist barrel but chamber/throat it for a desired shorter bullet ... as maybe a 165 instead of a 225 gr. cast in a 30 cal ... hey, lighter recoil for the 8,9, and 10 th shot ....

ken

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Aaron posted this 05 November 2023

Don't you have grass to mow?

With rifle in hand, I confidently go forth into the darkness.

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mashburn posted this 05 November 2023

Ken,

I guess we just aren't open minded. or maybe in our later years, we're just weak in the mind. That is an example of why I don't watch much, or really not any, of the shooting shows.

Another cranky old guy,

Mashburn

David a. Cogburn

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RicinYakima posted this 05 November 2023

Oh, I'm open minded. Does it make a difference if one primer weights more than 0.001 grains more than another? Does BHn of 12 shoot better than 14? How many angels can dance on the head of a pin?

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Ed Harris posted this 05 November 2023

Ric,

It depends upon whether they are the tipsy dancing Irish little people or tee-totalling Bible thumping Southern Baptist or Calvinist Puritan angels...

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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MP1886 posted this 05 November 2023

Bryan Litz told me a long time ago that if he told me how fast the twist would have to be to destroy a bullets accuracy, so he wouldn't tell me. Said I would laugh at him. I would not have. If your bullet is perfect, balanced perfect, gets into the bore perfectly straight, and the bullets composition is up to holding the bullet together in extreme bullet rotation rpms, they just how would it not be accurate?

Personally I've found shorter bullets to be very accurate in my 7 twist AR15's. For me it depends on the brand of bullet and it's shape. Often the shorter ones out shoot the longer ones, but recently I came upon some Speer 70 grain semi points that were extremely accurrate in my AR 15. In fact they were more accurate out of that particular rifle then match hollow point bullets in the 70 grain bracket. A lot more accurate!!

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Hornet posted this 05 November 2023

I know that several years ago I found out that some of those bullets wouldn't shoot groups that would hit the paper at 100 yards. The more fragile ones were coming apart going downrange from a 14" twist .22-250 when I neared full throttle. Cute little puff about 70 yards out and no holes. Occasionally got a little pattern like very fine shot. I imagine that the 6.5" twist would have done the same if the velocity got higher. I learned to make sure that I got the ones rated as high velocity.

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MP1886 posted this 06 November 2023

Hornet I don't think you were blowing bullets up because of the twist or rpm, but rather from the high velocity. For example if you got 4000 fps velocity that's only 205714 rpm which is high, but not that high. To put that into perspective a 55 gr bullet in an AR15 with a 7 twist going 3100 fps is 318857 rpm and they don't blowup.

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9.3X62AL posted this 06 November 2023

The fast twists seem biased in favor of the javelin hurlers in 22-26 calibers. Not a skirt I choose to chase.

My 22 centerfire rifles run the gamut from 1-8" to 1-14" twist. The 1-8 and 1-9 do great work with the 69 grain Matchkings in 223 Rem and all manner of 55 grainers. The 22-250s are 1-12 and 1-14, and the Sierra 60 grain HP runs well in those at 3400-3600 FPS.

Castings in 22 CFs are largely terra incognita to yours truly. 22 Hornet has been decent--1-14 twist in a CZ-527, Lyman #225438 to 2300 FPS and 1.3" to 1.7" at 100 yards. Crosswinds were a PITA for three days of that gymnastic exhibition, there might be more and better there but medical complications have interrupted recreation something awful.

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Ken Campbell Iowa posted this 06 November 2023

...back in the day ... i had just won some big match and a non-shooting friend wanted to observe this miracle of God's creation in person ... so

i picked my trusty remmy 722/222/K10 sporter to aid in my professorial revelation of unmatched shooting skills to my soon-to-be-amazed young student ....

hedging just a little, i set up a 2 foot target at 200 yards ... easy peasy offhand and i figured that my young farmer friend might think that was actually an impressive feat ...

what I didn't figure on was using some untested loads of a giant wallop of Ball C and some old 40 grain Hornet bullets might complicate my Tour d'Force exhibition ......

clear as day I can still remember that about the 7th shot with no hits my new student said something like " hmmmm ... " ....

.... chickens not hatching ... carts before horses ... who woulda thought a lowly 222 could blow up a hornet bullet ? ..... not me up till then ...

that day of Infamy was probably the start of my life of extreme humbleness and a new awareness that actual testing should come BEFORE announcing the success of such testing ...

years later, finding that a hot load in my 257 Weatherby would turn 60 gr. 25-20 bullets to smoke was done in private ...

ken the observor

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MP1886 posted this 06 November 2023

I believe it Ken, as the 222 is just about the equal of the 223. It's a peppy little cartridge and an accurate one too!

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Larry Gibson posted this 06 November 2023

I've seen many of the thinner skinned .224 jacketed varmint bullet of 45 - 55 gr (45 gr Hornet, 50 gr Blitz, 50/55 gr SXs and Speer 52 gr HPs) come apart 40-50 yards down range when pushed above 3000 fps in 12" or, particularly, faster twists barrels. Tried my favorite gas gun 223 varmint load (30 years ago) in my Comp AR with a 9" twist. This load was always super accurate and very deadly in 10" twist Mini's and 12" twist ARs. With the 9" twist Competition Colt Hbar I couldn't get on paper at 100 yards and didn't even see any impacts on the berm behind them. Set up a 25 yard M16 zero target and the first 3 shots Created what looked like a banana with 4 skins peeling back. Actually, they were the only shots fired as it was obviously a waste of further ammo. Did try them also in a Colt AR with a 7" twist and only one of 3 bullets hit the 25 yards target with the jacket peeled back even worse.

I have watched the grey poof many times at 40-50 yards and even some that give a grey "smoke" trace to the target especially with the 50 gr Blitz and 50/55 gr SXs out of 12" twist 223s. Hornady puts a notice in the SX boxes to keep them below 2800 fps in faster twist rifles.

LMG

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

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MP1886 posted this 06 November 2023

Well here's something to ponder Larry. My load for 55 grain bullets in my HBAR 7" twist was full load of 748 Winchester or for 53 grain match hollow points was twenty some grains of H4895. The velocities were slightly over 3000 fps. One day I pulled some 40 grain hollow points bullets from the Winchester brand of 22 magnum and loaded them over that load. I shot them at 25 yards and they were all on the paper. I don't remember what I was trying to achieve. I guess to see if I could blow them up. How can we explain that one? a fluke. 22 mag is one of my favorite cartridges and I have a bunch of it, maybe I should try this again with the same OLD HBAR. Maybe it might be different. If I have the powder I'll even use a load you recomment and I'll put them over the chrono.

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Larry Gibson posted this 06 November 2023

All of the bullets I saw "blow apart" at 40-50 yards would also have been "on paper" at 25 yards........nothing there to "ponder".....

Perhaps you might, if you try it again, see if they make it to 100 yards and if they are "on Paper" at that range. You might also switch to 27 gr H335 or 26 gr AA2230 both of which are better suited to use with that lighter weight bullet.

LMG

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

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MP1886 posted this 06 November 2023

I belive you are right, I'll start at 50 yards. Today, aren't H335 and WW 748 one in the same?

Thanks Larry, soon as I get them pulled and loaded.

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John Carlson posted this 07 November 2023

I just tried some 52gn Watson Match bullets in a Colt Competition HBAR with 9" twist. At 3100fps holes were nice and round but group was just over 2". This from a rifle that routinely produces .75" groups with 69gn matchkings. Might have to try them slower.

John Carlson. CBA Director of Military Competition.

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Larry Gibson posted this 07 November 2023

No, 748 and H335 are not the same. H335 is a tudge faster in burn rate than 4895 whereas 748 is about the same burn rate as Varget or 4064.

LMG

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

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MP1886 posted this 07 November 2023

That is what I've always though and I also believe, the two being very close in their early initial manufacture, that 748 was better or a better grade then 335.

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Larry Gibson posted this 07 November 2023

&48 is a completely different ball powder developed by Winchester in conjunction with 76 and 780 powders. the line of powders intended for loading into all Winchester commercial cartridges. H335 was a milsurp powder produced for loading the 5.56 cartridges (M193) and then was produced commercially. Winchester 748, even the original 748BR, was always a bit slower than H335, even a tudge slower than BLC2.

In pressure testing both powders (H335 & 748) it takes about 1.5 gr to 2 gr +/- more of 748 in the 223/5.56 under 55 gr bullets to achieve the same velocity and psi as with H335.

LMG.

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

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Ed Harris posted this 07 November 2023

H335 is milsurp WC844.

BLC2 was originally milsurp WC846 but now may be newly manufactured.

H322 was originally milsurp IMR8208M and now is newly manufactured.

H380 was originally WC852. Now is newly manufactured.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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MP1886 posted this 07 November 2023

That's the way I heard it Ed, but I'll try go one step further. When they were developing 844, and they just didn't hit the nail on the head the first time, They had a batch that was better then the other batches. The two were very similar, but the better batch went on to become 748. The other batch become 335. 748 was 846. What I had read said that 748 was better powder. Most all my 5.56/.223 loads are loading with 748 except when I'm shooting match bullets. Just my two cents and that doesn't make it right!

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Bud Hyett posted this 07 November 2023

I apologize but I've got to tell a tale on bullets blowing up.

In the 1950's, a Western Illinois varmint shooter was looking for a ground squirrel bullet for his .30-'06. He happened on some Norma 93 grain .30 Mauser soft-points. He loaded them to a maximum velocity and shot at 100 yards getting 1 1/2 inch five-shot groups that were adequate. Testing them at 200 yards, they did not hit the paper. But there was a strange rough surface to the paper. He surmised the bullets were blowing up and put a five-gallon bucket at 175 yards. The bucket had slight dings and paint scratched off. These made a devastating ground squirrel load.

The Rivoli Rifle Club at New Windsor, Illinois has a fun Turkey Shoot every November. One event is five shots at 200 yards, offhand, unsupported at five balloons each on a three foot string. In the Fall winds, this was a very competitive target. Two balloons often won a turkey and three balloons were almost guaranteed to win.

Knowing of Loren's load, I purchased and loaded some 93 grain Norma .30 Mauser bullets. The day of the match, my first shot burst a balloon. My second shot burst a balloon. The scorekeeper said I was well on the way to getting a turkey. My third shot burst two balloons. The scorekeeper asked to see my loads. Unfortunately, I had bought the bullets from him and he instantly surmised the scenario.

The next year, the club added the phrase "No Specialty Loads" to the event.

Farm boy from Illinois, living in the magical Pacific Northwest

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MP1886 posted this 07 November 2023

Bud I have a similar story. About a farmer up northeast. He had a huge groundhog problem. Called this gentleman that was suppose to be very good at clearing your farm of groundhogs. This old ruddy guy shows up with an old 1903 Springfield. He done almot the same thing as you mentioned on loading the 93 grain 30 Mauser bullets, except his were 90 grain FMJ 30 Luger bullets. They didn't blow up at any distance, but the groundhogs sure did!!

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muley posted this 08 November 2023

Ed, what is WC820 compared with ??

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Ken Campbell Iowa posted this 08 November 2023

Bud .. in 1960 we loaded up those Norma 93 gr 30-06 loads for a friends Rem 760 as a jump-em-up jackrabbit gun .. 1.5 groups ... oh, about 60 gr. BallC ... heh ... worked outstanding at up to 100 yards ... never tried them at longer range.

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Eutectic posted this 09 November 2023

Why do bullets wait until 40-50 yards to blow up?

It seems to me if rotational speed was too great they ought to come apart at the muzzle.

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RicinYakima posted this 09 November 2023

My guess, for what it is worth, is that it takes that long for the heat to get through the guilding metal jacket.

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MP1886 posted this 09 November 2023

Question was asked why does it take a bullet so many yards to blowup. Well there is a lot of heat from air friction. Maybe some of you airforce boy can tell me if this is true or not, but I was told or read where the wings, possibley the fuselage, can get up to a 1000 degree and they are supposed cooled some how.

What the twist does, or more accurately, the rifling cuts into the jacket and weakens it.

Ricin the bullets main source of high heat is the friction of it going down the bore in conjunction with heat from the powder burn.

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RicinYakima posted this 09 November 2023

The time it takes to get to 40/50 yards.

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Larry Gibson posted this 09 November 2023

RicinYakima is correct. In the microseconds it takes for the bullet to spin apart the bullet, at 3000 +/- fps has traveled the 40 - 50 +/- yards. Simple as that.

LMG

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

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MP1886 posted this 09 November 2023

Larry would say a 40 grain Hornady V Max bullet doing 3803 fps spun at 391,166 rpm would blow up? Well it doesn't. Hodgdon's reloading data has lots of bullets in the 30 to 40 grain bracket loading data. If they blow up that easily why would they provide data and not mention that? They have 30 and 35 grain loads exceeding that velocity above, albeit some are copper bullet with a tin/copper alloy. I think there is more to bullets blowing up such as a combination of extreme heat, velocity, and rpm, not excluding air damage from friction heat and stress force.

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Hornet posted this 09 November 2023

Some of the jackets are much thinner than others. Try pushing a Hornady #2230 45 grain Hornet bullet at the 3808 fps speed of that V-max and bad things will happen. I seem to recall that the jacket on them is about 0.007" thick. Throw in some stress risers from the rifling making grooves and the material gets thinner. Add the material strength reduction from the frictional heat and you pass the stress to failure limit. It happened with the original cup-and-core bullets in the .30 Newton and with the original 0.007" thick jackets tried for the .303 British at even lower velocities. Newton went to a paper-wrapped core to help keep it from melting and the brits went to a 0.014" thick jacket to increase the stress to failure. This isn't a new development. It's both heat and rpms and the rifling form may also have an effect.

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Larry Gibson posted this 09 November 2023

MP 1886

Larry would not say that because Larry knows better. If you'd bother to read my previous post you'd find I referred to "thin jacketed" bullets and gave examples of those that blow up. The Sierra 50 gr Blitz, the Speer 52 gr HP, the Hornady 50 and 55 gr SXs and the Hornady 45 gr Hornet bullet Hornet mentions are examples. Those were all made for 12 to 16" twists with velocities upwards of 3400 fps. Put any of them in faster twists at 3000 + fps and they begin to come apart as mentioned.

All the older manuals had plenty of data for their thinner jacketed bullets for use with those slower twists for which the bullets were made. Hornady 4th Edition, Vol I, page 114 states; "When using a 223 with rapid twist barrels (as in Ruger Mini-14s,or Colt AR15A2) do not use SX bullets. The rapid twist can cause these fragile bullets to come apart in flight, especially at maximum velocities."

The question was; "Why do bullets wait until 40-50 yards to blow up?" It is not asking what makes them blow up but why they "wait until 40-50 yards before they "blow up". As I mentioned in answering that actual question; "In the microseconds it takes for the bullet to spin apart (i.e. "blow up") the bullet, at 3000 +/- fps has traveled the 40 - 50 +/- yards. Simple as that." Indeed, it is that simple.

LMG

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

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MP1886 posted this 10 November 2023

I know all that, but some of those bullets like the V Max are built to explode. The A Max is that way too. I shot a milk jug full of water with a 7 twist AR14, the bullet was a 65 grain A Max. It never made it through the jug. There were particles of the jacket and the lead alloy core and none were any larger than a #6 shot. I mention this because a broadside lung shot coyote went 1/2 mile before he collapsed. That's why I shot the water jug to see what the bullet might have done. Now I know, it blew up. The jug was at 80 yards and a 65 grain .224 bullet isn't exactly a light weight bullet.

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Larry Gibson posted this 10 November 2023

MP 1886

Yes, most al varmint bullets are built to rapidly expand, explode, come apart, etc. on impact. The thinner jacketed ones especially. However, other than those mentioned and perhaps a couple others, all the varmint 224 cal bullets these days are built to withstand the higher velocities and centrifugal forces of faster twists used in rifles today.

There is little if any correlation between what causes a bullet to "explode" on impact and what causes the bullet to come apart inflight.

LMG

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

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