I'm loading 25-20 single shot using 86 gr. cast bullets from Missouri Bullet, and bullet length is .6965. I Tried 2400 starting with 6.0 gr. and worked up to 8.0 gr. The loads at 7.5 gr. and above exhibited primers pushed partially out of the case. Upon checking, when a case is fully inserted into the breech, there is .012 from the face of the case bottom to the breech face. Friend told me I need to seat bullets to a little less depth to let them contact the rifling, thus eliminating the .012 depth problem and getting case flush with breech face. Block locks up solidly, and there is barely .001 gap between block and breech face.

Am I taking the correct approach? I did Chrony the loads and can furnish the data if necessary, but fastest load was 8.0 gr. at 1787 F.P.S. 

I have not found a SAAMI spec for this round - not sure there is one, but a suspected "factory" round I started with measured 1.9250" OAL. Not sure it's right or not.

1787 fps seems awfully fast for this cartridge.

marlinguy wrote on Nov 13^th, 2015 at 10:41am:


Yes, obviously, using plain base bullets.  In the '30s Allyn Tedmon wrote an article about boosting the .25-20 up to 1800 fps. and beyond with jacketed.  I read it, and for some years I used a Stevens 44 1/2 in .25-20 on chucks.   I was using 11 grains of 5744, which is OK in a strong action, but I'd say not in a Model 44, especially a loose one. 

Hard cast GC bullets ought to handle 1800 fps easily.

The Lovell 22-3000 wildcat used .25-20 cases at pressures that would make you stare.  Obviously not in weak actions, and they complained that case life was two or three loadings.  

I suggest the O.P. try this trick:  Fire a primed but otherwise empty case in the rifle, and see how much primer setback you get.  The will be a pretty good indication of your headspace.  If you've really got 0.012", the barrel needs to be set back.  

What brass?  I seem to remember that somebody in recent years was selling brass with a thin trim.  

8 grains of 2400 should get you about 1750 fps, as calculated in Quickload.  I would go that far with a properly breeched 44, but no farther.   A bit much in an old, loose one.

beltfed wrote on Nov 15^th, 2015 at 10:27am:


The Jamison brass is quite strong, but sadly out of stock everywhere.  They promised me a year or more ago that they would run it again in 2015, but here it is November and nothing yet.   We may have to go back to making it by crushing and machining .223 brass, which is even stronger, but has the thin rim problem.  Or settle for RMC which is machined from solid, but it's the wrong alloy.   

Quote:


I'm wrong!    Just checked Captech's site, and they have it again.   

Price is a bit steep, but it's there!   

Another pic

Do you happen to be able to post a pic of the case(s) where the primer backed out?

6.5 gr. 2400