.38-55 Heavy Bullets

[ajj]

I'm going to try long, heavy 340 gr soft cast bullets in my .38-55 Highwall replica. These are meant for black powder silhouette and long range target shooting. I'm going to use smokeless and hope someone here has loading experience or data to share. Thank you.

[marlinman93]

Have you checked your twist rate, or do you know what it is? Most modern repros are 1-20" or 1-18", and they wont stabilize bullets that heavy. You'll need something in the 1-16" or faster to use 330 grain bullets with any accuracy.

[ajj]

It's a 15. I'm getting the impression that the Schuetzen folks just use the old standbys like 4227 and 4759 in somewhat lighter charges, say in the 16 grain area. If that sounds wrong, please let me know. Thanks.

[Maxd]

I would say you are real close on the estimate, I would start with about 14 grains of 4759 and start watching the bore, adding a half a grain until the burn cleaned up. That would be looking for an accurate load...

The rifle that I use anything similar in is an old perry slug gun barrel on a hiwall action. It's not quite a .40 cal but larger that the 38, say a 39 cal.  I use as 38-72 case and breach seat a 330 grain bullet over 18 grains of 4759.

[marlinman93]

That's good advice from Maxd. RCBS cast bullet manual lists a 260 grain bullet at a starting load of 20 grains of 4759, so I'd say the 15-16 grain charge of 4759 for your 330 grainer should be a good start.