.357 mag rifle loads

I run nothing but cast through mine and I find HS6 is my go to powder. Use it for 38 plinking and +P 357 powerhouse loads. Great combo with small groups with my 187 grain mold. Rifle and GP100 have never had a jacketed bullet through them. Gas checked gives all the velocity I need.

I’m running hotter than the Hodgdon on line site calls for but only by a little and I worked up to it carefully. Magnum primers and chronograph average 1100 in the GP 100. Have never chronographed the rifle. These are with my 155 mold which usually casts out around 160. I’ve yet to chronograph the 180 grain mold which casts at 187. NOE always over on weight. I do know the187s knock my 6 inch steel plates off the slip on hanging brackets. I really want a deer with one of these this year. I’m told Longshot will give me more velocity in the 357 and my 10 mm but the accuracy is there on the 357 and I wouldn’t trade that for a little more speed.

cowboy77 said:

. Use it for 38 plinking and +P 357 powerhouse loads. I’m running hotter than the Hodgdon on line site calls for.

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No such thing as +p .357. One issue there is with .357 lever actions is the way they tend to stretch the brass when shot with heavy loads.(think extreme headspace) This is due to the way they lock-up at the rear of the bolt. It is why many manuals recommend only using virgin or once fired brass for upper end .357 loads. This way you don't get case head separation down the road and have to pry a broken case from your chamber after the extractor tears the head off. In a bolt action carbine(i.e. 77/.357) or a single shot, I might consider pushing .357 past some manuals max(Hodgdon already loads hot tho). Not so much for a lever....at least not for my levers.

buck460XVR said:

No such thing as +p .357. One issue there is with .357 lever actions is the way they tend to stretch the brass when shot with heavy loads.(think extreme headspace) This is due to the way they lock-up at the rear of the bolt. It is why many manuals recommend only using virgin or once fired brass for upper end .357 loads. This way you don't get case head separation down the road and have to pry a broken case from your chamber after the extractor tears the head off. In a bolt action carbine(i.e. 77/.357) or a single shot, I might consider pushing .357 past some manuals max(Hodgdon already loads hot tho). Not so much for a lever....at least not for my levers.

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I monitor my brass to make sure I don't get a case head separation. It would make for some cursing if I had to tear a lever action apart because I wasn't being careful.
My general rule is seat it longer if you want to push it harder. This keeps pressure down while allowing more powder.

Most all Hodgdon load levels and most modern reloading manuals are lawyer written. I had to find data for a 180 in a 2nd or 3rd edition Lyman. All loads in it are much hotter than say the Lyman 50th. Reloading for me is not how fast I can push my loads anyway. I load for accuracy. My 7 mm mag is all cable of busting 3000fps but my 3 in one hole group is at 2850fps. Not going to chase the extra 150 or so.

Bfh_auto said:

My general rule is seat it longer if you want to push it harder. This keeps pressure down while allowing more powder.

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I wonder how much, if any, you gain. Would seem to me, that the increase in powder would be offset by the increased case capacity, IOWs, a wash. In .357, bullets you would use for legitimate magnum loads would have a cannelure and thus, unless you crimp outside of the cannelure, you really can't seat longer. Crimping outside the cannelure would mean a less than necessary crimp for slow burning powders and produce slower velocities along with more inconsistency. Most levers are sensitive to OAL cartridge length and thus seating longer may mean unreliable feeding. This is why Hornady uses shortened cases for their Leverevolution ammo when using the longer FTX bullets.

The .357, when loaded as per manual, and shot thru a carbine, is going to give one all they really need. I get just over 1800 FPS from my 20" Rossi lever with a published load, using 158gr projectiles and H110/W296. No need to twerk or fudge OALs and load over max. Guessing at pressure is something none of us can do accurately without the proper equipment. With all due respect, IMHO........if one doesn't think they have enough gun using tested and published loads, they should probably step up in caliber and not just dump more powder into the case. But that's me, others are free to load however they want for their guns.

buck460XVR said:

I wonder how much, if any, you gain. Would seem to me, that the increase in powder would be offset by the increased case capacity, IOWs, a wash. In .357, bullets you would use for legitimate magnum loads would have a cannelure and thus, unless you crimp outside of the cannelure, you really can't seat longer. Crimping outside the cannelure would mean a less than necessary crimp for slow burning powders and produce slower velocities along with more inconsistency. Most levers are sensitive to OAL cartridge length and thus seating longer may mean unreliable feeding. This is why Hornady uses shortened cases for their Leverevolution ammo when using the longer FTX bullets.

The .357, when loaded as per manual, and shot thru a carbine, is going to give one all they really need. I get just over 1800 FPS from my 20" Rossi lever with a published load, using 158gr projectiles and H110/W296. No need to twerk or fudge OALs and load over max. Guessing at pressure is something none of us can do accurately without the proper equipment. With all due respect, IMHO........if one doesn't think they have enough gun using tested and published loads, they should probably step up in caliber and not just dump more powder into the case. But that's me, others are free to load however they want for their guns.

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I'm using 360 Dan Wesson OAL length and data. It got me to just over 1800 with a 180 WFN. 158s are over 2000. I modified the lifter, but it still cycles 38s.
I didn't just blindly add powder.

I was going to suggest 360DW cases, but didn't.

I have an H&R 357, and it will easily chamber the 360DW case. Some have suggested reaming to 357 Max, but I don't want/need to.

If I need more than 180gr at 1800fps, I have larger caliber firearms.

Hooda Thunkit said:

I was going to suggest 360DW cases, but didn't.

I have an H&R 357, and it will easily chamber the 360DW case. Some have suggested reaming to 357 Max, but I don't want/need to.

If I need more than 180gr at 1800fps, I have larger caliber firearms.

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I think the steel butt plate would be most unfriendly even it is would be possible to make it a max.
Going to 360 pushed the limits of t-shirt friendly. I shoot mostly 38's, but love the ability to load up if I want to.

OP sorry if I brought it off topic. If so it wasn't intentional.

buck460XVR said:

I wonder how much, if any, you gain. Would seem to me, that the increase in powder would be offset by the increased case capacity, IOWs, a wash. In .357, bullets you would use for legitimate magnum loads would have a cannelure and thus, unless you crimp outside of the cannelure, you really can't seat longer. Crimping outside the cannelure would mean a less than necessary crimp for slow burning powders and produce slower velocities along with more inconsistency. Most levers are sensitive to OAL cartridge length and thus seating longer may mean unreliable feeding. This is why Hornady uses shortened cases for their Leverevolution ammo when using the longer FTX bullets.

The .357, when loaded as per manual, and shot thru a carbine, is going to give one all they really need. I get just over 1800 FPS from my 20" Rossi lever with a published load, using 158gr projectiles and H110/W296. No need to twerk or fudge OALs and load over max. Guessing at pressure is something none of us can do accurately without the proper equipment. With all due respect, IMHO........if one doesn't think they have enough gun using tested and published loads, they should probably step up in caliber and not just dump more powder into the case. But that's me, others are free to load however they want for their guns.

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A pretty good rule is that for each 1% additional case capacity, you get 1/4% more maximum MV. So, in round numbers, if you can squeeze out an additional 5% case volume, you can add more powder to get an additional 1 1/4% increase in MV, or about an extra 16 FPS in a 1300 FPS load.

If you Google for data. The Los Angeles Shooting Club has a write up with data listed on the bottom.
I primarily shoot cast 158s and use a lube groove as the crimp groove. I also use the second groove in the 180 xtp.
I am using 357 brass.

Will your Henry chamber 360DW brass ? If so, try a maximum 357 Mag load, and work up. That would be similar to using max 38Spl loads as a start in 357 Mag

Starline carries 360DW brass.

. 357 load results: my rifle, not yours...... some may be/are over max:

Ruger 77/357
Hornady XTP HP 158 gr
17.5 gr H110
WW lg primer
Velocity: 1815 1862 1861 1849 1858

Ruger 77/357
Hornady XTP 180 gr HP
15.9 gr H110
Federal 200
Velocity: 1671 1160 1639 1617 1623

Ruger 77/357
Hornady XTP 158 gr HP
Federal 200
18 gr Lil Gun
Velocity: 1858 1911 1912 1933 1905 (fired on 5-6-2016)


Ruger 77/357
Hornady XTP 158 HP
Federal GM 200M
18 gr Lil Gun
Velocity: 1976 1943 1927 1982 1906 1922 (fired on 9-12-2016)

This load shot 2” 100 yd groups and was 12” low at 200 yards.

Ruger 77/357
Rim Rock Cast 170 gr LRNFP GC
Remington 7 1/2 BR (rifle)
17 gr H110
Velocity: 1825 1843 1818 1837 1855

Ruger. 77/357
Rim Rock 170 Cast 170 gr LENFP GC
Remington 7 1/2 BR (rifle)
17 gr Lil Gun
Velocity: 1910 1918 1929 1933 1906

Extraction was unremarkable, primers we’re flat but not cratered in the max plus loads. About as far as
I wanted to go with this research. I was hoping to duplicate Buffalo Bore’s 357 loading, but I don’t think it is possible with the powders I used.

As a side note, Federal American Eagle 158 SP’s shoot an average velocity of 1855 from the 77/357 and deliver 1.5” 50 yd groups.