Developed a new load for my 38-55 today, how and why

[KirkD]

For my old vintage Winchesters, I like to stay near the original velocities, and bullet weights. I had a custom mould made by Accurate Moulds, that gives me a 262 grain gas-checked bullet sized and lubed, using pure clip-on wheel weights. The original black powder velocity for the 38-55 was somewhere in the neighbourhood of 1,300 fps.

I had developed a load, using 16 grains of 5744 and a tuft of cotton filler, that gave 1,307 fps. The groups were okay at 100 yards (five shots into around 2") but at 200 yards, the groups were a bit looser (10 shots into 7"). I upped the charge to 16.5 grains of 5744 and a tuft of cotton filler to keep the powder against the primer, and was able to put 7 shots into 5" at 200 yards. 100 yard groups tightened up to under 2". The problem was that my velocity was now around 1,350 fps. I can live with that (and the slightly higher pressure), but what this told me was that I was probably on the edge of the kind of peak pressure I needed to properly bump up the bullet to completely seal the bullet into the grooves. I decided to drop the velocity slightly, but raise the pressure, which meant I needed a faster powder.

2400 gives roughly the same pressure curve as FFg for the old black powder rifle cartridges, so I figured if I worked up a load that gave me 1,300 fps, I should also have a similar pressure curve as I would with black powder, which should have enough of a spike to properly bump up the bullet just like black powder does.

I started with 11.5 grains of 2400 and a tuft of cotton filler. Stepping out into the back yard, one shot over the Chrony gave me 1,215 fps.

12.0 grains of 2400 with a tuft of cotton gave me 1,247 fps and 12.5 grains and a tuft of cotton gave me 1,280 fps. I figured 13 grains plus a tuft of cotton should give me what I wanted, so I loaded up five rounds and put all five over the Chrony.

Result:

13 grains of 2400, plus a tuft of cotton for filler, under a soft cast 262 gas-checked bullet gave me 1,307 fps with a five-shot extreme spread of only 17 fps and a S.D. of only 6 fps.

Boys, I've got me a load. This load gives me the exact same velocity that 16 grains of 5744 and a tuft of cotton gave me, but since 2400 is a faster powder, it will give me a higher pressure spike, closer to and maybe slightly higher than the 16.5 grain 5744 load. Your results may vary depending upon bullet hardness, bullet diameter vs. groove diameter, and length of barrel.

I hope to try it out at 200 yards this week.

P.S. The stump in the back yard is now 2,096 grains heavier than it was this morning.

[Old Savage]

Look Kirk - that is all just dandy BUT - I want you do develop loads without the filler. I do not want to introduce that variable. Pictures????

[Nath]

Thanks Kirk,,,,as it happens I just got me a can of 2400 because I am having no joy with H110 in my 357m 94ae.
Seem to have a load to suit me,,,need a little more time to comfirm. The H110 does not work untill I am way over book!

Nath.

[missionary5155]

Greetings
I know many moan and groan about BP being so "Dirty" but why not give 3F a try. Have 3 94's in 38-55 and all give the best groups with 3F that is poured slowly into the case and compressed about 1/8 inch with the seated bullet. Plain base or GC.. they all shoot better compared to any smokeless load. My lube is 45% oilive oil and 55% beeswax. If your bullets do not have deep enough grooves then dip the nose in some warmed lube.
Load 10 and give it a try. Worse thing can happen is you will enjoy 10 rounds of the "real McCoy" 38-55 ammo.
Mike in Peru

[Pitchy]

Sounds like ya nailed it pard, grats.

[KirkD]

Look Kirk - that is all just dandy BUT - I want you do develop loads without the filler. I do not want to introduce that variable. Pictures????

I checked through my records and, to my surprise, I have not done any loads without filler in this rifle! I've done them in the other 38-55's I've used, but not this one. I will see if I can figure out a load with no filler this week. I will use 5744 since it is the least position sensitive powder I've used, judging from the relatively low extreme spreads in velocity compared with other powders.

Problem with cotton filler: I am finding that it is a bit tricky to seat the bullet without some of the cotton fibres getting caught in between the gas check and the case wall, which makes a slight bulge in some of my cases. This can make for a little snugger chambering, which makes for a little higher pressure, which changes the POI down range. I've been carefully tamping down the cotton all around the edges and most of the bullets seat without the cotton getting caught, but still some do. If the no-filler option works fine, then I'll be happy to dispense with the cotton filler.

The black powder option might be an interesting experiment to compare with.

[Shasta]

Very good report, Kirk. I hope your new load pans out as well on targets as it has over the chronograph screens. I very much look forward to some pictures of tight groups from your .38-55!

As for the use of filler with smokeless powders, I too used to be of the opinion that fillers could cause pressure problems and were to be avoided, but reading of your success with filler in the Winchester 1876 in .45-60, I followed your lead and discovered that you do indeed know where of you speak! One half of a square of single ply toilet paper folded loosely between the powder and bullet gained me nearly 200 fps in velocity as well as lowering the extreme spread of five-shot tests. Now I know that when properly used in straight walled cases, filler can improve accuracy. I too have experienced problems with cotton or dacron fibers having wild strands that stick out, making it difficult to seat the bullet. I like the TP better.

With the current powder shortage we have, I am interested in knowledgeable research such as yours that may allow use of a broader range of the powders I have on hand. Thanks for another great post!

SHASTA

[Griff]

Be careful Kirk... Not sure I'm remembering this correctly, but don't fast smokeless powders give spike pressures of a sort not attainable with BP even at equivalent velocities with the BP load. I mean to say, a sharper, faster spike to the pressure curve than with BP. So even if you're meeting that pressure ceiling of the BP round, the pressure spike occurs much faster with smokeless and can lead to damage from such repeated fast spikes. I should think that in lieu of matching the BP velocity, with a fast powder, you'd want to be slightly under that BP velocity and ensure that your pressure curve doesn't spike too fast.

[Nath]

Be careful Kirk... Not sure I'm remembering this correctly, but don't fast smokeless powders give spike pressures of a sort not attainable with BP even at equivalent velocities with the BP load. I mean to say, a sharper, faster spike to the pressure curve than with BP. So even if you're meeting that pressure ceiling of the BP round, the pressure spike occurs much faster with smokeless and can lead to damage from such repeated fast spikes. I should think that in lieu of matching the BP velocity, with a fast powder, you'd want to be slightly under that BP velocity and ensure that your pressure curve doesn't spike too fast.

Not in a 94 action Griff surely?

N.

[rbertalotto]

Have you ever tried unique? I get amazing accuracy with 9 grains of unique under a 250 grain bullet.

[KirkD]

Be careful Kirk... Not sure I'm remembering this correctly, but don't fast smokeless powders give spike pressures of a sort not attainable with BP even at equivalent velocities with the BP load.

That is correct. Fast powders will give a higher pressure spike than, say FFFg and slower smokeless powders will give a lower pressure spike (peak pressure) than, say, FFg. The crossover point is roughly Blue Dot (for FFFg) and 2400 (FFg) all other things being equal (velocity, bullet type and weight, case capacity, etc.). So for black powder rifle cartridges, the same velocity, with the same bullet will give the same pressure spike using 2400. For smaller black powder cartridges, such as 44 Russian, 45 Schofield, 45 Colt or 44-40, the powder to use to mimic the same pressure spike as FFFg would be Blue Dot.

It is only for those criterion that one can use matching muzzle velocities to get matching pressure curves. One must never do that for faster powders such as Trail Boss, Unique or Bullseye. For slower powders than 2400, one can match the muzzle velocities and usually do it at a lower peak pressure than FFg, but other problems may develop such as failure to bump up the cast bullet to seal off the throat, or failure to seal the case walls against the chamber walls, resulting in sooty cases.

My bigger concern is the problem of the cotton fibres getting caught between the base of the bullet and the case wall, creating a small bulge in the finished case right where the base of the bullet is. On the one hand, I haven't worried about this if the cartridge falls into the chamber with no resistance, but I do worry about this if the cartridge is slightly tight. My worry is that the small bulge creates a stress concentration against the chamber wall at that point during ignition. Perhaps my worries are unfounded, since I've fired countless cartridges with a slight bulge in the case due to tight cases and large sized gas checks, or cotton fibres caught between the bullet and the case wall, but I do worry enough about this that I think I'm going to experiment with no filler loads to see if I can find something accurate and with an acceptably low extreme spread. A solution to the caught fibres is to use the commercial filler Polyfill, but that raises the cost of my reloads, which I try to keep down.

[Lefty Dude]

How about SR4759 for the 38-55 ?

Any load development with this powder ?

Just asking you understand.

[KirkD]

How about SR4759 for the 38-55 ?

Any load development with this powder ?

As a matter of fact, I really like SR4759 for two reasons. First, it has more bulk to it so it fills the case better. Second, it has a burn rate not too much slower than FFg, so it is good for reloading in black powder cartridges. I have played with various loads of SR4759 in various 38-55's. For a rifle I had, 18 grains of SR4759 (no filler) under a 255 grain cast bullet gave me 1,300 fps with an extreme spread of 57 fps (11 shots) and an S.D. of 18 fps. The same load in an original SRC 38-55 gave me 1,235 fps with an extreme spread of 81 fps (10 shots) and a S.D. of 29 fps. The high E.S.'s are due to not using any filler, so burn consistence drops. Not a problem at 100 yards, but you will start seeing significant vertical spread at 200 yards.

[Griff]

Be careful Kirk... Not sure I'm remembering this correctly, but don't fast smokeless powders give spike pressures of a sort not attainable with BP even at equivalent velocities with the BP load. I mean to say, a sharper, faster spike to the pressure curve than with BP. So even if you're meeting that pressure ceiling of the BP round, the pressure spike occurs much faster with smokeless and can lead to damage from such repeated fast spikes. I should think that in lieu of matching the BP velocity, with a fast powder, you'd want to be slightly under that BP velocity and ensure that your pressure curve doesn't spike too fast.

Not in a 94 action Griff surely?
N.

My concern is mostly reserved for those actions that don't have a nickel steel barrel.

[MikeNV]

I found that 26 - 26.5grs of H-322 is a low pressure load but will still drive a 245 bullet through more than 20" of penetration on an antelope and is very accurate. I think this load is in 1300-1400fps area. I also found that 9.5grs Unique was also very accurate out of my Marlin.