Guide me to 38-55 velocities for silhouettes

[sd5782]

I’ve posted on the single shot forum earlier about my Miroku 1885 high wall in 38-55. I am shooting some casual silhouette shoots at ranges out to 400 yards. I’m not using black powder yet, and my heaviest mold is an Accurate 285 grain. Barrel twist is 15.5”.

I’m asking here as I am wondering about the sort of velocities I should be trying to get for the 250 gr and my 285 gr. I know the heavy 300-330 gr is best, and I will perhaps keep an eye out for one. I know that is a simplistic way to look at it, but for my smokeless development that may save me some experimenting if I had some idea of what might work best.

I know there is a stability problem with bullets passing through the sound barrier. Would 1300 FPS on the 285 keep it above that area out to 400 yards? Would starting it at say 1150 be foolish then at long ranges? Perhaps 1350 on the 250gr ones?

I know with black it is a matter of filling up the case and having long heavy bullets. I also have been stepping up my game for reloading and casting. I won’t be competitive, but I was hoping to have fun and perhaps get up to a 50% score. This isn’t a cheap discipline to get started in, but it sure is fun making a hit at 300-400 yards.

[greenjoytj]

Looking in some of my manuals that have ballistic charts it looks like a 250 gr bullet with an MV of 1300 fps would pass the 1125 fps sound barrier at about 135 yds from the muzzle.

At 1400 fps MV the 250 gr bullet would cross the sound barrier at about 190 yds from the muzzle.

A 310 gr bullet retains MV about 60 yds further out.

With smokeless powder a 270 gr round nose with a BC of .253 and MV of 1700 fps will reach the sound barrier at about 270 yds.

My data is from Lyman Cast Bullet Handbook 4 th edition
Black Powder Cartridge Reloading Primer by Steve Garbe & Mike Venturino
Hornady Handbook Of Cartridge Reloading 4 Ed. Vol2 Tables and Charts

Knowing your bullet BC is important for ballistic table data look up.

Knowing just how much kinetic energy is required to knock down the various steel targets would help. In the Steve Garbe book he says he has occasionally seen 500 meters rams fail to tip over with the 38-55.
So with the 38-55 (a great ctg by the way) the long range steel game is more that hit or miss just making a clang doesn’t cut it.

[country gent]

I would shoot for velocities in the 1150-1200 fps range. A few more points if elevation but thats where I normally find best accuracy at. Where hes shooting they se swinging targets so all he needs is a wiggle and a ding. Use the 285 grn until you find the heavy bullet. My shooting partner had a 15 twist 38-55 it was marginal with the 330 lymn but really liked the 302 rcbs bullet. I wouldnt give up accuracy for the sake of velocity, You need to hit them first before anything else.

Once you establish the load and zeros its just a matter of sight alignment reading wind and holding hard.

[sd5782]

Thanks folks. Ive been playing around with ballistic charts and plugging in different ballistic coefficients just to get somewhat of an idea. It would seem that except for a very low initial velocity, the bullet has to pass through the sound barrier at these target ranges. Am I wrong to guess that the longer bullets are less likely to be disrupted passing through that zone? I don’t know anything about black, but my understanding is the velocity you get is more or less dictated by the case capacity and of course bullet weight.

So basically the great bullets have shown themselves in black as long as twist, capacity, load consistency, etc match? Then, with smokeless I guess I am exposed to a bit more trial and error. My home range is 200 yards, so if my velocities lead me to believe it is subsonic there and has good accuracy there, I have a better chance for accuracy at 300-400yds?

[country gent]

Let the rifle tell you what it wants. Experiment with different bullets and powders. Neck tension is another area but with smokeless and the air space the light to none wont work,Black Powder and the wad fill the case to the bottom of the bullet keeping it from moving. Smokeless Powder and Black Powder produce velocity at different levels per grain.

If you have access to a lab radar chronograph it will give you 5 velocities between the muzzle and 200 yds, you want the muzzle and 200 ys wiyh these you can use a ballistic program to figure your bullets actual BC With this BC you can then make very accurate "drop" charts.

This is from memory but when I did the 330 lyman it was around 1230 at the muzzle and 1100 at 200 yds. I seem to remember that Speed of sound at Camp Perry was said to be 1100 fps, it varies with elevation.

With some load development Black Powder is capable of single digit extreme spreads.

[Gunlaker]

Don't worry about the sub-sonic, supersonic thing in the slightest. Every year thousands of bullets get fired at 1000 yard targets from bptr rifles. They pretty much all start supersonic and end subsonic. I can only recall one rifleman who's rounds are supersonic at 300 yards. You can tell by the painful crack as it passes. That was Kenny Wasserburgers .45-110 with over 100 grains of powder :-).

Worry more about wind effect. A heavier, more efficient, bullet will help.

With black powder you also have to become very proficient at fouling control. Fouling control is not just about being able to chamber the next round, it has a huge effect on accuracy at range. The difference between good fouling control and so-so can mean cutting in half your vertical dispersion at distance.

I know that some people are fans of lower velocities, but my rifles have always worked better at distance using heavier loads with plenty of velocity to reduce vertical dispersion.

Either way, Country Gent's advice of letting the rifle tell you what it wants is spot on. Your rifle will tell you better than we can :-). Shoot it often, as far as you can, and in various winds.

Chris.

[sd5782]

Thanks for that. I did have promising results at 1245 muzzle velocity at 100 yards. I will try at 200, and maybe up or down a bit.

[Gunlaker]

If you can get it shooting well at 200 with really tight vertical then you'll probably be ok.

Chris.