I am confused...PB over 1,000 FPS and no leading??? HOW????

  • 2.5K Views
  • Last Post 21 September 2011
Southern Shooter posted this 01 December 2010

I was under the impression that velocities over 1,000 FPS in cast bullets would surely begin to lead. Please look at the reference below. Could this be the case? I am confused.

http://www.handloads.com/articles/default.asp?id=24>http://www.handloads.com/articles/default.asp?id=24

"The mid-1950s were another fertile period for the .38 SWC with the introduction of the K-framed S&W Combat Magnum and the Ruger .357 Blackhawk. Velocity was the selling feature of the cartridge and Lyman chose to capitalize on that feature, while simultaneously capturing those features that Keith and Sharpe had espoused in their designs, with the 150 grain 358477 (cataloged in 1957). With this bullet it was easy to achieve 1500+ fps from the .357 Magnum and 1000 fps from a .38 Special, and do both with superb accuracy and no leading. For my money, the original 150 grain 358477 is the finest .38 Special bullet ever designed. Loaded over 5.4 grains of Unique, it generates 982 fps from a 6” K-38 Masterpiece with exceptional accuracy.”

The BIG question: How do you get a Plain-based bullet to travel over 1,000 FPS without leading? I am especially interested in doing this with .357 Magnums at 150-180 grains and .44 Magnums at 240-250 grains.

Thanks

Attached Files

Order By: Standard | Newest | Votes
jimc posted this 01 December 2010

Without going into a lot of detail, the right alloy mix and the right lube and you can shoot cast bullets up to Mach II(2200+ FPS).

Attached Files

billwnr posted this 01 December 2010

My .44 Mag began leading once I passed 1250 fps. I polished the barrel but haven't done shot any full throttle lead bullets since. 1000 fps wasn't any problem.

I should mention this was with no gas check.

Attached Files

corerf posted this 01 December 2010

lee 158 358 plaim based with std lube groove, White Lable Lube Carnuba Red 2700+, easy to get 1200+ with a barrel you can eat out of (dan wesson 8 inch model 15. Mould was lapped upon arrival to get an extra .001 diameter out of it. Loaded with several powders, generally slower ones. No RED DOT's and Uniques. Sized in .363 so it gets lubed but not sized to get me AS CAST

Just my personal experience.

Attached Files

RicinYakima posted this 01 December 2010

Dr. Fryxell, PhD, Materials Engineering, lives in the Tri-Cities, WA. It he writes it, you can take it to the bank. HOWEVER, you have to copy his work exactly as written. You can read his whole series of articles on the LASC ( Los Angles Silhouette Club) web site. HTH, Ric

Attached Files

Ed Harris posted this 02 December 2010

As a general rule plainbased bullets in rifles are likely to start giving problems as you approach about 1400 f.p.s. That figure isn't an absolute, due to variations in bore smoothness, bullet fit, chamber pressure and alloy strength, but as a simple rule once you get above that everything must be perfect, bullet fit, lube, alloy, etc.

The reason plainbased loads such as .357 and .44 Magnum which shoot well in revolvers often fail to do so in rifles is because you pick up 150 f.p.s. or more in the longer rifle barrel. For dual-use in revolver and cowboy rifle you have better luck if you limit your revolver loads to about 1100 f.p.s. so that they are less likely to exceed 1400 f.p.s. in the rifle length barrel. 

As for plainbase in rifle calibers, most of the successful blackpowder rifle cartridges, such as the .32-20, .32-40, 44-40, .38-55, .45-70 and the like all used soft alloy bullets of about 10 BHN at velocities around 1300-1400 f.p.s. If you stick to those general parameters getting good results is relatively easy. Once you get above 1450 with plainbased bullets is where witchcraft and skullduggery come in...

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

Attached Files

Tuner posted this 28 December 2010

A lot has been learned about leading in handguns since the mid 50's when much of the concentration was on lubricant and alloy.  When I first started casting bullets if you got leading the cure was to go to a harder alloy.  Since then a lot of research has been done on the problem and what has been found is that critical dimensions in a revolver and the size of the bullet have more impact on leading then hardness or lubricant.  There is also a relationship between bullet hardness and pressure, the lower the pressure, the softer a bullet should be.  The three dimensions that are important in a revolver are the cylinder throats, the forcing cone section of the barrel, and the bore diameter.  The main cause of leading is hot gasses from the powder burn passing down the side of a bullet that is too small to seal the bore.  This can happen because a bullet has been sized too small for the particular handgun, or because there is a constriction in the forcing cone that squeezes a bullet down.  When this happens once the bullet is out of the constriction gasses will blow past the bullets, cutting lead which is deposited on the barrel.  If throat, forcing cone and bore dimensions are correct and a bullet is sized too small, but soft enough for the load pressure the bullet can be “bumped up” by the pressure generated and leading eliminated.  In this case a bullet that is too hard for the pressure could actually increase the potential for leading.  As other posters have said with the correct dimensions cast bullets are capable of some pretty impressive velocities without leading a bore.

Attached Files

frank l jr posted this 29 December 2010

lee 166 swc,flat base,L B T lube,.359, 6% com. alloy,8"dan wesson,fire lapped barrel,cyl throats uniformed to .3595,case full AA#9,fed reg primers,1000=1150, depending on amount of #9, you are on your own as to amount. 10.0 ++.bullets can be cast softer, but i had troubles with dia. if softer.i e too small with the softer alloys. shoot all day with very little problems. 40 round matches,10 per min,4 relays. barrel get plenty hot here in deep east texas in summer. just my 2 cents. see ya

              frank l jr

Attached Files

runfiverun posted this 29 December 2010

in my leverguns 1600 or more is easily attained with plain based boolits. the trick is to use enough lube groove. and a boolit that resists slumping. in the revolvers getting there is not so much the lube but the fit and the smoothness of the transition. i also had to use a harder alloy, to handle the extra pressure, and the transitions better.

in the rifles 38-55, 25-20 going over about 1400 with a plainbase didn't leave leading but the accuracy was lost, i found it again in the 25-20 going up to 1700 with even better accuracy. but had to go to gas checks in the other rifle rounds.

Attached Files

Daryl S posted this 29 December 2010

I hold my plain based revolver loads to 1,300fps or under - no leading problems - straight ww alloy and either SPG, Lyman Moly lube or Lyman Black Powder Gold - they all work for me in .357/.38 and .44 mag. I shoot bullets .002” large than goove diameter, which makes they very snug, almost engraving the handgun's cylinder mouths in the 3 handguns I shoot with these loads.

Attached Files

BCB posted this 16 January 2011

I am shooting the 45-270-SAA in a Blackhawk @ 1068 fps to 1218 fps using 300-MP (don't like the stuff--no data) and H-110 at the top end of velocity...

Wheel Weights is the alloy...

I can shoot a box (50) and get very minimal leading. Actually only a bit of “streaking” on the bore side of the rifling...

That is acceptable to me...

At lower velocities, I get almost no leading at all...

Good-luck...BCB

Attached Files

CB posted this 17 January 2011

Bullet fit is the most critical aspect to shooting lead in pistols.

SA guns needs to be groove diameter ie: 1911 Colt groove dia = .452 then the bullet needs to be at least .452 or slightly larger like .4525

Revolvers - bullet dia should be the same size as the forcing cone on the cylinder. One also needs to check that all of the forcing cones on the cylinder are the same diameter. If they are not there will be accuracy problems and possible some leading if one is larger than the rest.

After all of this has been addresed then you can begin looking at alloy strength (hardness) and lube..

Attached Files

Catshooter posted this 16 August 2011

I agree with Mr. Bowles, except to me and my guns, 'fit' means as large as will chamber.

I shoot the 45 ACP for the most part. For most of them I load .4535 bullets and the bores are usually .451 to .452. Zero leading.

I have a S&W Shorty 45 Performance shop pistol. Match grade barrel that is .451. A .4515 bullet will lead with the first round. .452 leads less, where .4535 shows zero leading.

The bigger the better.

Cat

Attached Files

mikld posted this 21 September 2011

For my revolvers (.38/.357 and .44 spec. and mag.) I size the bullet to the same size as the cylinder throat. Since I have slugged my barrels and throats I know that the throat diameter is larger  than the groove diameter by .002” to .003". So, as in my .44s with throat diameters of .431", I size my bullets at .431” and they are over the groove diameter by .002” to .003” which is a good fit. I get no leading with wheel weight alloy and home made lube. My last loads of .357 magnum were 158 gr. LSWC over max. (pretty hot) loads of True Blue with no leading to speak of.

Attached Files

Categories
Search
Popular Tags
This Weeks High Earners
Hot Topics
Close