Powder suggestions for 357 Mag

Lil Gun. My experience is it outperforms H110 / Win296 and it does it with lower pressures. It also doesn't leak and fly. Neither one is a flake powder. They're both flattened ball powders but H110 / Win296 has smaller fluffy balls that misbehave. Lil Gun does not do that.

If you read the Internet, Lil Gun will erode your forcing cone and melt your revolver into a puddle of molten metal. The unproven Internet rumor is it has a higher flame temperature and this causes excessive erosion. The truth is all powders have flame temperatures high enough to create a heat affected zone on the inside surface of the barrel. This HAZ is very thin. The destructive temperatures only exist in this HAZ. Heating the huge mass of the whole revolver to 150 deg. F where it's too hot to touch does not do any damage. It's the metal that's closer to 2000 deg F in the thin HAZ that takes the damage and this heat exists on the first shot. Does Lil Gun punish the HAZ more than other powders?

Plenty of people have reported using Lil Gun over the long term with no particularly bad effects. Personally, I don't see how one could expect to shoot a large volume of hot
magnum loads of any powder without enduring some forcing cone erosion. Non-wearing guns don't exist.

Like other magnum powders, Lil Gun cannot be safely used to make light loads. For medium loads, I suggest Longshot powder. For light loads, HP-38 (W231).

Personally, I greatly favor powders and loads that fill the case for safety (prevent double-charges). So I am wary of using powders like Longshot or HP-38 that can be accidentally over-pressure. A good alternative for medium loads that still fills the case with powder is IMR4227. Most data show 4227 at the upper-end of velocities, but my experience is it is a much softer shooting powder. It's single-base with no nitroglycerin, but it tends to blow out powder skeletons.
 
I don't load or shoot 357 so I'm not providing advice or suggestions--I just happen to have the Hornady handbook on the table and can tell you what they say or preferred. Looks like AA9, H110 and 296 for jacketed and Unique for lead were their preferences. But, the Hornady book seems to have been written by folks who don't like to push cast bullets above 900 fps or something, so we also find them running Clays in the 357 at tiny wee loads--something I find surprising (if not bizarre).

What I do have experience loading a lot of is 10mm Auto, and I've used quite a number of powders there, with AA9 now the only one I'll probably ever load in it again. So, given the degree of similarity of some loads (I didn't say they were similar, I said given the degree of similarity) and the recommendation of #9, I would try #9 if I were loading 357--in good part because I now try to keep about 20 lbs of the stuff on hand and don't want to take up a lot more space on the shelves with greater variety, if practical.

I'm very curious about thoughts on 4100...I've not used it at all, but would consider trying it in 10mm just for the heck of it if it's as good as the manufacturer claims it is in 357.

As for leakage: I definitely wouldn't give up a propellant because I had this problem, unless of course I'd exhausted other explanations. I use the Lock-n-Load progressive press, which uses a couple of different schnozzle inserts in the measure. If I were to 'forget' to change the insert (say from loading .45-70 to 5.56 as a silly example), even though I'm running the same propellant for each, I might find I have a big cleanup.
 
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I've used 296 for .357 Magnum revolver loading for nearly 30 years.

It's my go to powder. I've never had a problem at all with it, and will continue to reach for it first.
 
The only powders I use in magnum loads are 2400, H110 and 296. 2400 is especially good for 3/4 power loads and for cast bullets. H110 & 296 shine with jacketed bullets.
 
Bongo Boy, 4100 is an Accurate brand powder that is the same as Ramshot Enforcer, made in Belgium. I have some good shooting loads with it, but the Belgian powders I have like this and True Blue are very fine and leak from sliding cavity type volumetric measures. It is not a deal breaker but can be quite a mess and a waste. It can also jam the measure and produce cases with no powder drop. It should work in my LnL AP but I never tried it.
 
Real Gun said:
4100 is an Accurate brand powder that is the same as Ramshot Enforcer
Click to expand...

They seem to be very close to equivalent, but Western's max loads and velocities for them are slightly different and their online bulk density tolerance is slightly different. Frankly, I'm surprised they haven't just combined the two, but wonder if the deterrent coatings are different. Ramshot brags that theirs don't require magnum primers for uniform performance because of having more modern deterrent chemistry.
 
As UncleNick notes above . . .

4100vs-Enforcer.jpg
 
Poco, I use Unique in my Dillon and it meters just fine. I use it for 357, 44 mag, 45 auto and 9mm. I load the 45s and the 9s to factory specs so as to generate power to eject spent cartridges, but the revolver loads I load down to midrange levels. My revolvers are mostly older so I don't like to push it.

But I also use 2400 when I want more powerful loads. Like, 44 mag out of my Henry lever and old model Super Blackhawk, etc.

And both Unique and 2400 are just fine in my Dillon.
 
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