M92 38/357 Lead Bullet Accuracy Loads

[GasGuzzler]

...as the speed picks up?

Explain that because it would seem the soft lead would proof it. I might have read it wrong.

[Cheyenne4090]

What I'm getting at is why does this 158 semi wadcutter and a fairly long one at that stabilize so well out to 200 meters going a thousand feet per second when the other 158 type bullets won't stabilize until they get way up in speed with the one in 30 twist. For instance the Lee 158 round nose flat point stabilized well but it was going way over 1700 feet per second. I've shot bullets in the 13 to 14 hundred feet per second range and the groups opened way up. Just wondering if it has to do with the fact that those Targetmaster 158s are soft lead or does it have to do with shooting them at such a low velocity that they stabilize? Probably still clear as mud!

[donhuff]

Wow, that is really small in diameter. I have no idea how that stabilizes at all.

Those slugs, like most factory lead ones, are probably swaged lead. And you are right about them being soft. Since they are swaged, they use pure soft lead wire for the swaging process. I'll bet that it is so soft that the case is swaging it down even more when it is pushed down into it. They more than likely started out with a .357" or bigger bullet, but after loading, it got smaller.

May be that because it is so soft, it gets bumped up in size at firing, so that it fits the barrel. But why it WILL stabilize at that slow of a speed, but then a slightly longer one wont, is beyond me. I do understand that if you try to push that soft of a bullet much faster. Then you start having problems with the pressure of the faster round causing problems with the bullets base. Or the pressure can run up the side of the bullet and cut it causing problems. Put a gas check on that bullet, and then you can push it harder, and still keep the accuracy. Or use a harder bullet and keep the accuracy at higher pressures.

Those Lee 158rnfp bullets were likely cast from a harder alloy that could take the pressure of the faster load.

That Remington bullet looks a lot like the old Lyman/Ray Thompson 358156 which has been around forever, and has always been a very accurate bullet. If you like it and want to try it at higher speeds, I can send you a hundred to try out. They will be powder coated and plain based as I reamed out the gas check shank portion on my mold.

I think you are really just wanting to understand bullet weights, lengths, rifling twist, and how it all effects accuracy, right??????? So do I! Along with that 156 bullet, I also cast the 358429swc which is a long swc that weighs 170 grains. It works great in almost anything you shoot it in, except the Rossi. In it, you have to shoot it as fast as possible to get any kind of accuracy out of it. And it still is not what I would call great. Then I have the 358311RN that weighs in at 160+ and is also pretty long. You can shoot it and almost any speed out of the rossi, and it has decent accuracy I have no idea what's going on! Then the Lee 125rnfp just dang out shoots any other cast bullet I have put down the rossi's barrel. WHY? is it weigh? is it length?

I think you said once, that you were shooting "gong matches"? Do you need a heavier bullet for this, is the 125 not enough? are you like me and just curious?

[Cheyenne4090]

Thanks Don,

Yes like you just curious I guess and no don't need a heavier bullet just need to hit the gong to get a point. I'm sure the 125s will work along with the 158 RNFP's. Now of course I want to find the perfect bullet load combination for this game!

Never gave the Rossi much thought until recently. I tried various loads several years ago and the Remington's shot by far the best and I left it at that but now my supply is running low. Remington used to sell these bullets for reloading in a box of 2,000 but can't find them anymore. Speer sells a nearly identical bullet in a box of 500 so I have some and am going to try to duplicate the Remington load as a fall back. Anyway when I decided to develop a load for the rifle I thought why not shoot something that was not only accurate but with a flatter trajectory and minimal wind drift. Well that opened up a whole new can of worms because bullets going really slow, below 1,000 fps, have minimal wind drift but lots of drop. The same bullet going faster has more wind drift and less drop. It not till the bullet gets going really fast by .357 standards that the drift starts getting smaller.

For example the Speer swaged 158 LSWC has a BC of .135 per Speer (I used this BC because the bullet is very similar to the Remington factory bullet). At 1032 fps it has 16.6 inches of wind drift at 225yd in a 10 mph cross wind. At 1200 fps it has 20.5 inches of drift and at 1700 fps it has 23.7 inches of drift! My understanding of this phenomenon is that wind drift is worse at the speed of sound and the farther away from the speed of sound you get, faster or slower, the less wind drift. I'm sure its much more complicated...
It not until the velocity increases to 2425 fps that the wind drift is once again 16.6 inches. I guess that's one of the reasons why target 38 and 22 ammo is sub-sonic.

The other way to reduce wind drift is to increase the BC although there's only so much that can be done with a .357 bore and a 1 in 30 twist. One possibility is a bullet like the RD-175. It has a listed BC of .1946 on one of the drawings I saw. At 1700 fps it has only 16.3 inches of drift at 225 yds and it is reported to be accurate and it feeds in the Rossi. If I could find some in a plain base tumble lube I would love to try them but hate to invest that much in a mold if I'm not sure it will work.

Here is a pic (left to right) of the Remington 158, Speer 158, Lee 158 and Lee 125.

[donhuff]

Dang, I did not know that about the wind drift. And yeah, trying to get a 357 over that 2425 threshold would not be reasonable.

I wish lee made a stretched version of their 125 bullet. Say 150 to 170 grains would be great. And move the crimp groove back some.

I'm betting something like this one from accurate would work good for you. http://www.accuratemolds.com/bullet_det ... 170Z-D.png
He also has a 35-168Z that looks good. They say he will make the any diameter you spec.


Also, what about 147 bullets for 9mms? I tried some but did not have any luck with them. But they were sized for 9mm @.356 and I think that is what was hindering my success with them. I thought about getting a mold and making my own, that way I could make em larger for the rossi. They worked great in 9mm and 38 super. But I did not try shooting them at distance other than hitting soda cans at 100 yards.
http://www.snscasting.com/9mm-147-grain ... ed-1000ct/

[donhuff]

Can you use round nose bullets?

I see on Lee mold that they list their 158 swc at .117 bc and their 158 RN at .207. That's a huge difference!

I can't find the bc of my 358311 RN.

[Cheyenne4090]

http://precisionbullets.com/store/ Check out the .38 - 147gr bullet. Prices include shipping very reasonable. This looks similar to the SNS 9mm bullet you mentioned. I will post a pic of the target in a minute.

[Cheyenne4090]

Here's a target shot with the 147 precision. Its a hard bullet swaged with 6/2 alloy per the manufacture.
I have no idea of the BC but I need to experiment with it more for sure and I need to try it at 200. Scroll down on the pic to see the data on the load. I have some RN bullets but none of them seem to do to well in the Rossi. I did notice they have a higher BC and that's why I tried them, guess higher BC is not that important if they don't also group well!

[cdmajesty]

I agree that the pure lead swaged swc bullet you mic'ed is being swaged down when seating it in the case. And, yes, it is probably be bumped back up, or else your accuracy would be non-existent. The phenomenon of why the bullet stabilizes at such a slow speed is probably because the pressure is low enough to not distort the bullet. Everything is sound and right for a good launch. And then, when pressure is increased (remember, it also matters where and when peak pressure takes place, as to the bullet in the bore) accuracy goes to crap. I've experienced the same thing with the MP-358-180-rf (same as NOE 360-180) in it's HP form with a vary low charge of Red dot or Unique for only 800-950 fps. Accuracy at 100 yards (furthest tested) was very good. Increasing the powder to obtain 1000-1050 fps caused erratic behavior of the bullet flight. Another 50-100 fps and they weren't even hitting the paper. The bullet was 8.5-9 bhn.
I should have tried more powder just to see what happened, but I stopped there.

I also shot the 360640 at 1000-1400 fps, or so. It was interesting how there was occasional unstable bullet flight in the 1100-1200 or so range, but then things came together well at 1300 fps. The tipping (yawing) went away. But the 360640 has quite a bit of unsupported nose weight that I think needs a enough spin (velocity) at the 1-30 twist to properly stabilize.

The greenhill, etc formulas for applying bullet weight (length) to twist/velocity does not take into account bullet fit, pressure, peak pressure (where in the bore it happens), etc. It's never a black/white game. Too many variables that can affect the outcome.

As to the wind drift dilemma, I very much doubt that it works quite like what was described. I'm pretty sure (it's been my experience) that more velocity equals less wind drift, period, as long as the bullet is stable in flight.

IMO, the OP is overthinking this by some measure. My experience is that you need to choose a proven design that will allow you to load and shoot with ease. The less hassle with lubing/sizing, and especially gas checks, the better. The more you can load the more you will be able to shoot. And no matter how perfect the bullet design is or how well it works in your smoke pole, that will not be a reliable substitute for time behind the trigger and rounds sent down range. Once confidence is established after the first 1000 or so rounds sent down range, small variations in BC or wind drift from one bullet to another will most likely be totally immaterial and forgotten.

[GasGuzzler]

From what little I know it seems the peak pressure point in ratio to barrel length and twist rate is where this mystery could be solved...by someone else.

I have Lee 358158TL but couldn't get good bullets from it so it's with a friend that knows a lot more than I to see if it's me or the mold. If it proves to do OK I could send some from it later when it comes home (ASSuming I want it back).