I have been working on load development for a JES bored 38-55. Anyone have a cast bullet sub 1100fps load(s) to share? My efforts thus far have produced lots of okay loads but nothing that seems to be the one. I have gone through various bullet diameters from 375, 376 and 377, shows slight preference to .377. (JES bores are modern 375-376’ish) Powders tested: Titegroup, unique, Trailboss and 4759. Mostly with pistol primers.Traditional speed loads have shown the rifle can shoot well. Slow from the big case is the challenge. Thanks

I assume this uses a Large Pistol primer.

you might try CCI or Federal Premium Large pistol Magnum primers for better SD numbers.

Dennis

The correct primer is large Rifle. I was experimenting with the pistol primers due to essentially testing pistol powders and typical pistol charge weights. I agree, different primers could very well lead to lower ES/SD and contribute to better accuracy. Magnum pistol is on the menu as well is standard rifle. Thanks Dennis

I have the Deluxe Uberti 1894 with a 26" barrel. This is what I use for chickens and pigs. It is subsonic but it whacks the daylight out of those two animals.
Starline short brass, Accurate 38-245D in 20-1 alloy, White label lubes NRA 50/50 , 7.5gr of Trailboss and a CCI#350 primer.
Using the CCI#300 primer the 100 yard groups were 6 to 8 inches.
Using CCI#200 primers were better, maybe 4-5 inch 100 yard groups.
The Large pistol magnum primers turned it into a dream come true.

The bullet in the image is my 290gr wheel weight alloy for the rams. I just grabbed it for a reference.
Nine shots at 100 yards using a front rest, Lyman 17A front sight and an MVA Vernier tang sight.

This rifle shoots 1.5in groups like this every time I put it on paper. If I do my part I can watch the animal fall through the rifle sights. I constantly get teased about the tremendous recoil that I am forced to endure. It works, it is very mild shooting and that 20-1 alloy bullet leaves a mark that any spotter could see.

DavidMagnum, fantastic!

Excellent information - thank you

Have you tried stuffing some dacron over the pistol powder to tighten up the ES? Or try Trail Boss if it ever shows up again.

edgehit wrote: Tue Feb 04, 2025 1:21 pm Have you tried stuffing some dacron over the pistol powder to tighten up the ES? Or try Trail Boss if it ever shows up again.

If I'm not mistaken, I believe that his post on Nov 3rd said that he was using 7.5gr of Trailboss.

I wish I could find some trailboss...dreaming