.357 reduced cast loads accuracy

[relic]

I've been chasing accuracy in my 357 win 73 and a model 92 both the new Mirokus. Boolit is RCBS 158, sized ,358 and LBT soft blue lubed. One load is 10 grs alliant 2400 which averages 1268 fps, no fillers. Sometimes I get nice 2 inch 50yd groups with semi buckhorn rear sight, 77 year old eyes. The other load is 6.2 gr Unique, same boolit no fillers,1284 fps avg. Both light crimp from Lee collett die. These averages are from the 73 with 16 inch barrel. The model 92 20 inch barrel is 1316 fps average with 10 gr 2400 and 158 rcbs boolit. These are very pleasant loads to shoot and I have no reason to change,But accuracy is or hasnt been consistant. Well after spending hours on this forum I think I finally found my problem. I think it is inconsistant alloy. Tested today and yesterday with two known alloys. What I did was use boolits from 2 specific alloys as a base. I have literally thousands of cast 358 boolts BUT they are not all the exact same alloy. I found excellant accuracy using the same exact alloy for my testing. My problem is my own doing, I was not using the same exact ingredients in my alloys, so each batch of boolits were just a little different. I have the cabin tree tester and thats what i have been using to sort my alloys kind of by hardness, so I have several jars of boolits but each a little bit different, enough to affect accuracy at 50 yds. So, I have a couple hundred pounds of ingots and I'm going to mix them all together to make one large stable alloy. Why didnt I do this years ago? Just didnt read and research enough. I dont want to remelt all the boolits I have so I will just load and shoot and keep good notes for each batch. Crap, I thought if the hardness was the same they would all shoot the same but it looks like I may have been wrong, what do you guys think? I guess alloy matters too.

[Mr_Flintstone]

I’m glad your research paid off for you. I’ve had similar issues in the past. Right now I’ve been struggling to replicate a very accurate stout 38 special load of 158 gr cast and 9.7 gr IMR 4227 in .357 cases for my Henry by bumping up the powder just a tad. They just don’t seem to function the same in .357 magnum cases. I may “borrow” your recipes and give them a try.

[relic]

Those loads work really well for me as long as I stay with the same batch of alloy. Live and learn. Everytime I re load a batch I include a note about what powder, primer case and boolit. Should have included the info on the lead.. will do that from now on. I just never could understand why I would get excellant accuracy one day and then it would change. Hope I'm on the right track now. Going to do more testing and stick with one batch of alloy and then switch to another. I was jumping around to much. Will update as I move along. Also as an aside I have 4 25-20s and drove myself nuts with those trying to work up good loads, now I know why. I also load cast in 30-30, 32 win special, .348, .35 Rem and 45-70. I do stay with reduced loads in all cause I'm old and tender now.

[robg]

7gr of true blue with a 158rnfp boolit works well in my win94 as a light load.

[trapper9260]

This good to know what the OP stated. I also found out some I had cast by bottom pour of my Lee 10lb pot and ladle pour that the BHN had change on me. The one with the ladle was softer then the ones that was bottom pour. I had some else test them they told me to send them to see what there test was and some was different but also for how I had my Lee tester set up was different too. I need to change that. As for alloy mix is what I learn also that the BHN can be the same, but the alloy mix will not be. Just to let know for what I learn not too long ago. That is from a member on here that help me.

[RedHawk357Mag]

I have experienced this as well. I just used up the last bit of 200 lbs of accuracy challenged alloy. Thought it was a number of things before suspecting alloy being the drama. Thought cases were worn, thought maybe die adjustment was contributing, powder section, load levels, sights on firearms, bench/shooting/range of target vs eye sight acuity. Considered type of bullet mold. Got sorta frustrated and ordered some commercial bullets from several different sources and did get some better results. I did some limited testing using PB aluminum GCs and accuracy did a measurable improvement. That led me to start looking at my alloy. Sent a sample of to Rotometals to test. It tested at 94.366 Lead, 4.176 Antimony and 1.207. My next course of action is to test two different certified alloys, I bought 30 lbs of 94-3-3 and I am gonna mix up a alloy of 1 lb Lino and 3 lbs pure to make a alloy similar to wheel weights minus arsenic. Definitely going to test my large batch alloy before I use it make projectiles again. I sadly admit that I had to work through 200lbs of alloy to come to your deductions. Fortunately I recover most of my lead so I get an opportunity to tweak it again. It's funny how some folks can reach into a brass bucket and grab a fistful of brass, and throw a bunch of WWs in a pot with valve stems, razor blades, orphaned lug nuts, tobacco chaw, and whatever else the tire jockies toss in there and get acceptable and claimed repeatable results. I just haven't seem to replicate their outcomes and results. Thanks for sharing your experiences.

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[relic]

Now I know I'm not the only one. I am going through the same as you. I have several batches of similar alloys, what I mean is they all test close to the same BHN. I have no idea what their composition is, so this does show us that big batches may be best or we need to keep really good notes on what we smelt, but in order to do that we need to know what we are starting with. Oh boy, what a black art we are into. I like your idea of sending a sample of a good shooting alloy in to be tested and go from there. It sure is frustrating to put 30 rounds into one large hole at 50 yds and the next day its a shotgun pattern. I am trying to stay with the RCBS 158 flat based boolit and the powder loads I mentioned in the OP. I have got excellant accuracy with those combinations so I know its just a matter of getting the alloy right. I'm heating my pot right now and i'm going to do like you and start over with a known #2 alloy I have on hand. If the certified alloy shoots good I will follow up.

[dverna]

Brinell = 8.60 + ( 0.29 * %Tin ) + ( 0.92 * %Antimony )

I use commercial alloy (92-2-6) and it has 3 times the Antinomy as Tin...as it is a cheaper way to get hardness
My Linotype alloy (84-4-12) has Tin and Antimony at the same ratio.

I suspect that that 3:1 ratio of Antinomy to Tin is important to the ability of the alloy to "work" properly. But may will get different mechanical properties (malalbity/brittleness/ability to fill, etc) with alloy of the same hardness and different composition.

Both these alloys should test the same for hardness.
95-5-0 = 10
97.7-1-1.3 =10

I doubt they will both yield the same bullet performance.

I believe many problems are caused by "mystery alloys" so I agree with your conclusions. For accuracy testing, I use 92-2-6 as it is my known alloy. I use other alloys for plinking bullets.

[RedHawk357Mag]

Another thing I noticed was kicking the speed up on my problem alloy also helped close groups. I was originally loading at 1000 to 1050 fps. I moved to 1150ish and got tighter groups with my bullets. I would say definitely keep good notes from here on out. My labeling of casted projectiles definitely has improved. That is significant in tracking trends of accuracy. Great post.

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[Black Jaque Janaviac]

I don't know whether to laugh or cry. Laugh because I have a potential solution to accuracy problems or cry because there is yet another nit to pick. Trying to control the variables is like picking stick-tights out of a wool sweater.

So is the conclusion that some alloys are junk and others good? Or is the conclusion that if you mix bullets from different casting sessions you' ll ruin accuracy?

[charlie b]

.....Both these alloys should test the same for hardness.
95-5-0 = 10
97.7-1-1.3 =10

I doubt they will both yield the same bullet performance.

I believe many problems are caused by "mystery alloys" so I agree with your conclusions. For accuracy testing, I use 92-2-6 as it is my known alloy. I use other alloys for plinking bullets.

Different alloys may produce the same hardness if cooled the same (ie, slow air cool), but, they will respond much differently if they are heated differently or cooled at different rates. Casting may be different, with different shrinkage. Yield stresses will also be different resulting is a different friction as it engraves the rifling and travels down the bore. Amount of bullet 'upset' will be different.

It is always best to stick with one alloy when working up loads. As noted, changing the alloy will change the performance of the bullet, even if they are the same hardness.

Going from pistol to rifle changes several things as well. I quit with the pistol carbines just because I needed different loads to get decent results from them vs pistols.

Some alloys may be 'junk' for various reasons. They don't cast well, too soft, too hard, etc. Most can be made to perform adequately with a change in load, but, some need to be changed by adding other components, such as tin or antimony. And do not rely on hardness to tell what you have got. That's why when I had a mystery metal I would leave it for plinking loads.

[relic]

Well, I just tested some loads with a known alloy that performed well in the past. The alloy is Missouri #2. I also took some of the #2 and mixed some pure soft sheet lead to get to about 10-12 BHN, both shot well yesterday. But, but, I also deep cleaned the rifle, I shot at different times of the day with the sun in a little different position, even the temp was a little different. I got good satisfactory groups I'm happy with but I have all this mystery alloy that I want to use, so its all going into one big batch and I'm sending off samples of the mystery and the alloy that shoots good and then compare them. I'm going to figure this out. I'll report back. Oh, another thing I found is shooting with iron sights is not the best indicator, but whatever I'm still going to do the alloy tests.

[dverna]

I don't know whether to laugh or cry. Laugh because I have a potential solution to accuracy problems or cry because there is yet another nit to pick. Trying to control the variables is like picking stick-tights out of a wool sweater.

So is the conclusion that some alloys are junk and others good? Or is the conclusion that if you mix bullets from different casting sessions you' ll ruin accuracy?

BJJ

Do you have any alloy that is consistent? Can you obtain that same alloy in the future? If you answer yes to both, use that alloy for load development. As I stated in the previous post, I do that with 92-2-6 as it is a standard commercial alloy that I have the most of and I can easily replace. The other advantage is that most commercial cast bullets are made from it, so a lot of range lead should be close.

Once you have a good load with your known alloy, try your "mystery" alloy and see how it performs. For plinking loads it may not matter much.

In my case, If my "good" .38 load groups 1.5" from my carbine at 50 yards, I am ok with 2.5" groups using "mystery" alloy . I am not a good enough shot for that to make a difference. If that same "good" carbine load shoots a 2.5 " group at 25 yards out of my pistols I am done. I can live with 3.5" groups our of the pistols with "mystery alloy". That becomes "My Load" forever.

If I hunted with cast bullets, I would never change alloy once a good load is found. Hunting is important. When I shot Bullseye I did the same. The load and alloy was tailored to the gun.

But I have three rifles and four pistols in .38/.357 and I will not work up the ideal load for each gun. Too much work for too little gain IMHO for what I need.

Charlie b makes a good point about how casting methods can affect results. I do not like water quenching due to the mess it makes, and I will not take the time to heat treat bullets.

IMHO cast bullets are not worth my time for critical applications like hunting. When I shot Bullseye I used factory 148 gr HBWC at 50 yards as I could never approach their level of accuracy with my casting skills. My practice load was cast bullet that shot to the same POI but groups about 3/4" larger.

You can get anal about casting or decide good enough is good enough. People are wired differently and have different needs. You should decide which camp you want to be in. I am in the anal camp for HV rifle performance and shoot jacketed; in the good enough camp for cast bullets in pistol calibers.

[Black Jaque Janaviac]

No I don't have a consistent alloy. Except for muzzleloader roundballs which I try to keep as close to pure as possible (plumber's lead). The rest is sort of a mish-mash of wheel weights, range scrap, and other odd scraps (once people learn you cast they tend to give you all sorts of "finds").

On occasion I've gotten some really nice groups, then can have a bit of trouble trying to reproduce that some time later. It may be because of alloy. But I think it would be easier to melt all the lead together to produce one consistent alloy for the entire big batch than it would be to try to keep track of numerous alloys. I would of course reserve the plumber's lead for muzzleloaders which I already do. But I could melt all the wheelweights I have on hand together with the strange scraps and make one, big, consistent batch of muffin-tin ingots. Then I could cast from that batch, while accumulating more scraps and wheel weights, then just before the first batch runs out I'd mix up the next batch. I would have to re-visit the loads developed with the first batch and perhaps raise or lower the powder charge a tad to dial in the loads for the next batch.

However, if it is not as simple as tweak the charge to match the alloy that could stink. If some alloys just plain can't shoot well that would really bite if I made a mix of crappy alloy. If one alloy will perform well with H4227 but another needs H110 that would be even more maddening.

[curioushooter]

I believe many problems are caused by "mystery alloys" so I agree with your conclusions.

I believe this to be true as well!

I never got what I consider good enough accuracy from any rifle until I started working with pure lead, pure tin, and roto-metals superhard and mixing them with carefully weighed amounts. It is still important to have a big enough pot that you can make 100 or so bullets and not run the pot down to below 1/4th full so the alloy is nice and consistent through the casting session.

With handguns, the inherent inconsistency/lack of a scope makes it so you basically cannot tell as long as the alloys are reasonably close. Unless your casting hollowpoints...then the alloy is of the upmost importance as the performance of the projectile can vary wildly depending on its composition.

[onelight]

If I got 2" groups at 50yards with semi buckhorn sights I would call that excellent and I'm a young 65 year old

[Outpost75]

100-Yard Accuracy Results of Selected .38 and .357 Magnum Cast Loads in a BSA Single-Shot and Marlin Cowboy


The proof of the pudding in any long gun is it will do at 100 yards. Not all handgun loads provide linear dispersion in proportion to the range, when fired from rifles, you need to test. Wad cutters do well at 50 yards, but not at 100.

I tested ordinary .38 and .357 handgun ammunition for which I had previous 50-yard accuracy data. These included match-grade Norma 158-gr. lead round nose factory ammo from the 1980s, handloads with Speer swaged lead round nose and semi-wad cutters and handloads with cast lead, flat nosed cowboy slugs cast from wheelweight metal. All were standard velocity loads fired from my BSA Martini with 6X Unertl small game scope for five consecutive 5-shot groups at 100 yards. The best loads in the Martini were tested again in the Marlin 1894 with 2.5X Weaver scope.

Norma .38 Special 158-gr. LRN factory loads averaged just less than 3” at 100 yards from the BSA. Handloads with swaged lead round nose and semi-wad cutter ammo in .38 Special cases didn’t shoot quite as well, but did stay under 4 minutes of angle, having useful field utility.

The most accurate 100 yard cast loads used the Hunter’s Supply cast 190 LFN of 92-6-2 alloy, sized .358 from Midway, with 4.3 grains of Bullseye in .357 cases. They averaged 2.18” in the BSA and 2.36” in the Marlin. This is the same bullet as Accurate 36-185E. http://www.accuratemolds.com/bullet_...=36-185E-D.png

I cast some of those also from wheel weights and tested them, getting comparable results as long as velocities with softer wheel weight alloy were subsonic. I normally use 3.5 grains of Bullseye in .38 cases and from 4.0 (if low noise is important) up to a maximum of 4.3 grains in .357 cases based upon accuracy results. In my experience supersonic loads do not group as well at 100 yards as slower ones, due to transonic buffeting as projectile velocity decays below the speed of sound.

My advice is not to magnum-ize it, but keep it handgun-caliber lead loads for rifles slow, accurate and quiet. A good working velocity range is from 950 to 1050 f.p.s. In a 24” barrel this gives a peak decibel noise level of less than 90dB, measured 10 meters from the muzzle, and there is no sonic crack to disturb the neighbors. A big flat-nosed bullet is effective on groundhogs, wild turkey and larger edible critters raiding your garden. Bon appettit!

[PAndy]

I have messed around with a few subsonic loads in a levergun this winter. Not sure if I learned much. Two things I suggest are 1). Shoot ten shot groups to see what's going on and 2) be extra careful with brass prep, neck tension, and crimp. 3) it's fun.
I wound up settling on a load that is mild (1200 fps) but supersonic...Shooters world ultimate pistol powder under a 140 flat point cast. It's position sensitive in the .357 case, but I think I can manage that . Accurate so I'll make it work.
Subsonics with a 180 wfn are extremely fun for ringing steel.

[Thin Man]

The story of alloy hardness came home to me recently. I have been testing various boolit loads in a Savage Sporter 25-20 for a while and got pedestrian groups. Jacketed bullets were the same story. Then came the day I tried water dropping my casts which exit the mold at .259" diameter. Applied gas checks and sized-lubed at .259" (in a .257" die I had honed out oversize, diameter confirmed with pin gauges). Groups were immediately excellent, good enough to stop there but, you know, the testing will continue. Contrary to conventional experimentation I had changed 2 variables at the same time: (1) diameter increase from .257" to .259" and (2) water dropping for increased hardness. Was it one or the other change that gave me a smile? Don't know and at this point it really doesn't matter. I am close to where I want to be with this rifle and could leave it alone but will experiment further with the powder charges to see what that will do.

As for the pistol cartridges in a lever rifle, last year I was searching for a cast boolit load for a Winchester 94AE Trapper in 45 Colt. My boolit was a Lyman 452664, alloy was ACWW, sized .452" with LAR45's BAC lube. This boolit allows smooth feed-up in my rifle. Powder charge was a heavy charge of H110 (not over published max allowed loading). This combination produced the tightest group I have ever received from a lever rifle and has earned a visit to the deer camp this coming season. This is the first heavy loaded handgun cartridge that has grouped tight for me and will be at the top of my preferred loading list for this rifle.

[relic]

Yes I have shot some 2 inch groups but not every time. If the temp is right, the sun shinning at me from off to my right if i am using the Win 92 with the green Williams front fire sight and the good proper load then I can get a good group. If you have been following my posts you will see I'm having a little difficulty staying consistitent. I really should have said 2-3 in would have been more realistic, but I may be expecting to much from a Winchester 73 16 inch barrel trapper and a Winchester 92 20 inch barrel rifle. Maybe pinpoint accuracy isnt possible with .357 158 gr cast lead at 1200-1300 fps.