Lyman 'accuracy' loads

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  • Last Post 05 July 2011
tturner53 posted this 01 July 2011

Looking thru my worn out Lyman Cast Bullet Handbook #3 I noticed the “potentially most accurate” loads for .38 Special ALL are on the 'max' end of the charge weights, whether WCs or SWCs or whatever. This struck me as inconsistent with what I usually read/hear recommended for target loads in the .38 which usually are low end stuff, around 800 fps. The one thing the Lyman loads seem to have in common acrosss the board is they run right about 16,000 cup for the 'accuracy' loads. I'm trying to dial in a Model 19 6” for PPC and think I can squeeze a little more out of that gun, if not myself. Should I up the pressure, I've been working around half of Lyman's 'accuracy range?

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RicinYakima posted this 01 July 2011

Tim,

Lyman's “accuracy potential” loads are the ones with the smalllest combination of velocity spread and pressure spread. It has nothing to do with where the bullet strikes, since they do not shoot at targets but into a bullet trap.

So if you think small ES's and SD's mean small groups, those are the loads to use. Otherwise, you just have to shoot at paper targets.

Ric

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tturner53 posted this 01 July 2011

Thanks. I thought that might be the case. With umpteen molds and powders to try I have got a big project, probably a thousand possibilities to find the best(most accurate) combination. I have from 100 gr. to 200 gr. bullets, a few that 'should' be target material, others that 'could' be Never know 'til you try. My only true WC mold is a very old Ideal 358432, which is a bust so far. I'm getting the hang of honing out Lee's push thru dies, easy really once you do it, going up in thousandths. My best so far are surprising cheapies, the Lee 140 swc and the TL 158 swc. Still considering store bought swaged wcs since I've heard they are very accurate, but prefer to make my own. Looking at Lee's 6 cav. 148 wc mold, maybe a real soft alloy and light LLA. Yea, that's it, another mold. Maybe I'll even try my LBT 359-200WFN, never know. Works great in the Marlin.

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CB posted this 01 July 2011

Try your Lyman bullets unsized & lightly tumble-lubed.

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tturner53 posted this 02 July 2011

I tried the 358432 as cast, .361 !, with a little LLA mineral spirits mix in .357 cases. Light charges of either Bullseye or SR4756. Not good. I figured that bullet would be a cinch, it's 161.5 gr. RTL. I read about people shooting 2” groups off bags at 50 yds. with 6 shooters, maybe I'm setting the bar too high. Consistent 3” groups would be nice at this point and would be good enough to win me some PPC matches, if I hold up my end. Tomorrow I'll test some more loads using 231 and .38 cases. I'm regretting selling my K38, never thought I'd try this game.  Edit; thinking about it even dependable 4” groups would be a step up. I'll try some swc's too.

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PETE posted this 02 July 2011

Thanks for the heads-up Ric. I've often wondered what criteria Lyman uses to determine their “best” loads since none I've ever tried were even close to the MV's they state.

I think small SD's & ES's are important I've yet to see a rifle shoot the best with that combo. If you get them both below 10 that seems to work for me.

Pete

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RicinYakima posted this 02 July 2011

Pete,

The best explaination I have received is that until the bullet drop difference between the fastest and slowest shots in a group is 1/2 the radius of the horizonal width of the group, it is basicly undetectable. That is why it is important at 600 yards and farther, but not a factor at 100 yards.

Ric

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PETE posted this 03 July 2011

Ric,

Your comments are a good reason to keep, or find, those old Lyman reloading manuals with the “Pet Loads” in them. They at least are a more realistic guide. Altho I've found few that were right on the money for me they were close enuf I could work up an accuracy load without a lot of trouble.

Pete

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tturner53 posted this 03 July 2011

The quest continues for a .38 target load in a .357. I bought some Hornady 148HBWCs to try, for comparison. Not good at all. All my loads this time were with 3.2 gr. W231 in .38 brass. The best group so far was the Lee 158 TLSWC for 10 shots in 2 5/8ths at 25 yds. benched. Several people have suggested working up a load with .357 brass which I will. Is there a trick to determining overall length in a revolver like you do with a rifle? Try seating them out long? Also, is there a gold standard for testing revolver accuracy like there is using Sierra Match Kings in a rifle just to see if the dang gun will shoot in the first place?

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billwnr posted this 03 July 2011

Wonder if the revolvers specific twist rate is the reason for having to push the bullet kinda fast.

I see the .38 revolvers have a twist rate varying from 1:14” to 1:18", depending on manufacturer.

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tturner53 posted this 04 July 2011

Good question. It scattered the 148 HBWCs. I saw a post recently with revolver twist comments including Ed's take. I'll re-read that. It'll be funny if the best bullet turns out to be the humble Lee TL 158 swc.

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Ed Harris posted this 05 July 2011

In .357 Magnum cases you want to use a bulky powder which does a better job of filling the case. If you want a heavy field load, I've had excellent results with the Saeco #348 double-end, bevel-based wadcutter, cast 12 BHN, loaded as-cast and unsized, lubed with LLA and loaded sprue cut-off forward, crimped in the normal crimping groove with the front driving band exposed, using 11 grs. of #2400. Nearly a full charge .357 load and VERY accurate. I have also used 9.0 grs. with this bullet, similarly loaded, but in .38 Special brass, for use in my Ruger Police Service Six .38 Special, or .357 rated revolvers only. This is a +P+ load which exceeds SAAMI +P pressure, but shoots very well in the 18-3/4” twist barrel.

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

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