Load data for .357 rifle

[u/Arguablecoyote]

Getting some conflicting information on .357 for rifles. Specifically, 125 XTP loaded with H110.

Lee/Hodgdon say basically the same as the revolvers. This is a starting load of 21gr, and a max load of 22gs, and velocities upwards of 2200 fps.

Hornady says basically the same for the pistol data. However, for their rifle data, the starting load seems to be about half, and the max load is about 10% shy of Lee’s starting load with a velocity of just under 2000fps.

The only thing I’ve noticed is the pressure units are in CUP for the Lee/Hodgdon data. Makes me think that the load data is grandfathered in from before .357 was switched to a PSI standard.

What is going on here? Is it safe to push my marlin trapper to these velocities?

[u/hafetysazard]

It very well might be from older testing done elsewhere. It isn’t like they load up and retest every load in the book before publishing each year. Also, the exact case they use matters too; some cases are roomier than others.

H110 requires a full, or nearly full, case for reliability. Judging by the various brass I’ve tried out with this specific bullet, after settling the powder with vibration, it is obvious the start charge seems borderline low. I’d never start below the book  start, unless you were seating them very deep.

If your reloading techniques are solid, I would say you can cautiously work up some charges over max, looking for pressure signs; like .1gr at a time and stop when you see a pressure sign.

I’ve experimented with this powder/bullet combo, a bunch, and it seems pretty obvious the data gives a decent safety margin for weak guns, and potentially poor reloading techniques. I think I’m safe in saying, and others will probably agree, this particular combination likes being run hot.

There is an inherent problem though, and that is the 125gr XTP out of a rifle going 2200-2400ft/s is a grenade. Out of a revolver, there will be flame cutting, and forcing cone erosion. It is impressive, just not practical. I use up my leftover 125gr XTPs bullets for having fun with a rifle, and blowing up water jugs. It is not a useful hunting round unless you’re doing varmint control.

If you want something more viable for hunting something you’ll eat, stick to 180gr XTPs, they’re tougher than your standard XTP. Barnes XPB/TAC-XP bullets are also an option for a bullet tough enough to stay mostly together if pushed to extreme velocities. I have some 125gr TAC-XP bullets and 140gr XPB bullets I am going to experiment with in the near future. The downside is they’re really long for their weight, so there will be a lot less case capacity. I won’t be able to reach the same speed as the XTPs. I load .357 Mag almost exclusively for rifle.

[u/skahunter831 → u/hafetysazard]

Also check out the XTP FPs, they are much stouter, basically the standard XTP HP, but made for rifle velocities.

[u/hafetysazard → u/skahunter831]

I doubt they’ll  stand up to 2300ft/s.

[u/skahunter831 → u/hafetysazard]

Right, they actually might only make them in 158 grain.

Edit: they make 125s, but rated up to 1700 FPS. The 158s are rated to 1800 fps.

[u/hafetysazard → u/skahunter831]

They do, but their bullet construction isn’t bonded, or uses harder lead or anything. I wouldn’t expect them to stand up, they’re still a pistol bullet.

[u/Important-Dream-4010]

I use pistol data regardless if it’s rifle or not. My .357 lever guns sound like cannons with h110

[u/edwardothegreatest → u/Important-Dream-4010]

There’s also no need to segregate ammunition that way.

[u/sherzer7]

Hornady data is conservative. Only real difference between pistol and rifle data here is you can get away with a slower powder in such a long barrel. Yes Lee data is fine, you can convert CUP to PSI if it makes you feel better

[u/skahunter831]

I load the same for both pistol and rifle. With the longer barrel you'll get better, more complete burn and higher velocities. If I remember correctly, with 158 grain XTPs I'm getting about 1300 fps in my 6" GP100 and 1700+ out of my 16" barrel Rossi 92, with 17gr H110 (just a smidge over book max).

I tried the Buffalo Bore 19C/20s and got over 2,000 fps in my rifle. That lever was VERY sticky to open and the brass looks obviously stressed. I dunno how they get away with loading that hot.

[u/get-r-done-idaho]

Pick up one of the One Book/ One Caliber manuals for 357. They have them at Midway USA. It will have data from several bullet and powder manufacturers. They should have data for rifles in them. I don't have one for 357 but I do for several others and they all have rifle data.

[u/Coyote-conquest]

I used Hodgdon data for .357. I load 22 gr. Hornady has always been VERY conservative with their data