I am reloading the 357 rem max in a nef single shot rifle for my uncle. I am using new Remington brass, hornady 357 diameter 140 gr flex tips. 22.4 gr of w296 powder. rcbs dies and grouping very well at 50 and 100yds however I am getting a split case about every 10-15 shots. just curious if I am doing something wrong, bad brass or what. in load development I had cases split at grain increments of 20.5, 21.5, 22.4, 22.9. If the split cases were on the hotter end of the spectrum I would understand but my third shot with the 20.5 split and the splits are occurring mid case and only split to where the bullet is seated to. this is my first go around with pistol caliber reloading so any help is appreciated. thanks

mite be a bad chamber .make a casting . and mike it

Could be work hardened brass if the chamber is OK. After checking the chamber I would try annealing the cases to see if this helps. For a single shot not much neck tension is needed so you could back the dies out and size less possibly. If you have an over sized chamber and or under sized dies ether sending them back to the manufacturer or polishing them yourself could help.

ilikeguns :Had the same gun. I have four question for you. Where are the splits? Do the fired unsized brass go in to the chamber with little effort? Is the brass nickle plated? Do you sizes the whole length of the case? If the splits are at the neck and the fired cases go back into the chamber with little effort than you only need to size the case down to the point where the base of the bullet sits. Its like necksizeing just the upper part of a rifle case neck.. If the splits are are at the neck they need to be annealed or replaced. If the cases are nickle plated just poup-can them as annealing them can make them harder than barrel steel.

Can you Try a heavier bullet with your 296. Do you have any 180’s.
Also try Partially sized case just past the the bottom of a seated bullet.
Check the chamber for flaws.

I have a MGM 357 Max barrel. Fired couple hundred rounds with mostly Lil Gun, some 296, AA1680 and CFE black. Never spit a case. And I’ve pushed until I seen pressure signs.

I wouldn’t do that. WW296 just like AA9 it’s always been stated that a heavy roll crimp was needed for proper ignition in magnum loads.

Swifty52: You are thinking 4" to 6" revolver. This is most likely a 18"rifle that is not vented (cylinder gap). When I had a 357 Max rifle (17.5") I found that all pistol powders had 100% burn by 14" on QL.

Any updates??


I've owned several NEF/H&R, Encore, and Traditions rifles all rechambered to 357 Max and none of them had the same preference for crimps. One would prefer a heavy roll crimp and the next one would not. Testing is needed as there is no firm rule in a single shot.


What I haven't read is how the barrel was rechambered or is it a factory Maximum? Those 357 Mag chambers have a factory "Linda Lovelace" throat that, in some cases, can chamber Maximum brass. I had one that brass stuck upon firing as it was flowing into the throat area. I suspect a light (short) bullet would allow this easier than a heavy longer bullet. I trimmed .010" off the brass and that problem went away.

Don't expect those 140gr FTX bullets to penetrate deeply or hold together if they hit bone. I tested them in wet newspaper at speeds up to 2500fps. While they held together they didn't penetrate far with a 50yd impact distance. Think archery shots right behind a deer's shoulder and they should be fine.

Thanks, Dinny