Best powders for 357 Mag (170-180gr) 10-13" barrel

With heavy slugs and a long pipe, IMR4227 comes to mind first, then H110/W296. Single shot pistol, I'd consider Lil' Gun also, not so much with a revolver.

i use blue dot for my 1200fps 180 gn lead loads. i find h110 a bit slow. hs-6 also works well for heavy bullets at high velocity in the 357 magnum.

murf

AA#9 and 2400 work for me. I use Li'l Gun in my carbine, has a rep for forcing cone erosion in revolvers.

I've never had much luck with blue dot. It reaches unacceptable pressures before it makes acceptable velocities in my experience.

Nothing beats Power Pro 300 MP for max loads. Check out pages 4 and 5 of this PDF from handloader magazine. Some of those 357 magnum loads have over 850 pounds of muzzle energy from a 6" barreled GP100. The 44 magnum loads with heavy bullets are also impressive.

http://ps-2.kev009.com/ohlandl/310/357-44_Bain_Davis/Handloader_274_Oct_2011.pdf

Harry1969 said:

Nothing beats Power Pro 300 MP for max loads. Check out pages 4 and 5 of this PDF from handloader magazine. Some of those 357 magnum loads have over 850 pounds of muzzle energy from a 6" barreled GP100. The 44 magnum loads with heavy bullets are also impressive.

http://ps-2.kev009.com/ohlandl/310/357-44_Bain_Davis/Handloader_274_Oct_2011.pdf

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Harry1969 beat me to it. I have had great luck with 300MP in .357. The only place where I have had issues with it is on minimum loads in cold weather. It seems to have some ignition issues under those circumstances.

For mid to max loads, it is great stuff and, since most folks don't really know about it yet, it hasn't been too hard to find.

It's cheap too, I bought a pound for $19.99 and it works with a standard primer.

Nothing beats Power Pro 300 MP for max loads. Check out pages 4 and 5 of this PDF from handloader magazine. Some of those 357 magnum loads have over 850 pounds of muzzle energy from a 6" barreled GP100. The 44 magnum loads with heavy bullets are also impressive.

http://ps-2.kev009.com/ohlandl/310/3...4_Oct_2011.pdf

Click to expand...

Wow, I'll have to look this stuff up. Never heard of it. Thanks. Best I get with a 180 is from AA#9, 1400 fps, 785 ft lbs from a 6.5" Blackhawk.

Been wanting to try 300-MP real bad. Saw it in a store, looked it up when I got home and by the time I got back to the store (several days) it was all gone and hasn't been seen since.

Back when handgun powders were hard to find, 300MP was the only thing on the shelves for magnum handguns. I was tempted to try it also, but initial reviews from others on it was either a love it or hate it. Good friend of mine tried some and said he saw no performance difference between it and H110/W296 in .357mag and did not like it in .44mag. Since I still have plenty of H110/W296 on hand, I've yet to try it. Maybe I should give a pound a try.

Load data is scarce but the Alliant site, Hornady 9th edition reloading manual and the Lee modern reloading 2 revised edition also have load data for pp 300 mp.

Lil gun is another top performer for magnum handgun cartridges as well as AA9 and AA4100/ Enforcer. For everything other than max loads 2400 is still my favorite.

H110/W296 are already mentioned, and I use them on heavy 357 loads.

I also recommend Vitavouri N-110 for long barrels:
See HERE

I prefer 2400

I use 2400 for heavy loads, like my Elmer Keith style load and 231 for light loads.

With heavies in 357 (ie 170 to 185 grs) I always had the best luck with H-110. The extra resistance provided by the heavy for caliber bullets always makes H-110 perform very consistently.

Mark in GA

I did some heavy bullet tests with W296/H110 and Lil'Gun and shot them in a 18.5" levergun. I didn't use 2400 with the heavy bullet because it's faster than the other powders but i did use it with lighter bullets up to 158gr. Lil'Gun delivered ~100 fps more then the other powders.

Here are the results:
Using a 180gr Hornady XTP bullet:
15.0gr Lil'Gun - CCI-550 primer - AV=1584 fps
13.6gr W296 - CCI-550 primer - AV=1495 fps

Using a Cast Performance 180gr WFNGC bullet: (Hard Cast)
14.8gr Lil'Gun - CCI-550 primer - AV=1657 fps
13.7gr H110 - CCI-550 primer - AV=1547 fps

I also tried a 170gr Sierra JHC bullet and liked the results.
17.0gr Lil'Gun - CCI-550 primer - AV=1793 fps (that's amazing velocity!)
15.5gr H110 - CCI-550 primer - AV=1699 fps

Just to add some info for a 125gr Hornady XTP/HP bullet even though I didn't use Lil'Gun, the velocities were scary!
17.7gr 2400 - Win WSP primer - AV=2055 fps
22.0gr H110 - CCI-550 primer - AV=2239 fps

xphunter said:

Do you think 1500 ft./s is realistic with the 170 grain Sierra in a 12.5-13" barrel with H-110?

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Different manuals show approximately 1700fps possible with that 170gr pill outta a 18.5/20'' carbine barrel, so 1500fps outta a 13'' may be possible, but realistically, maybe not probable.

With a full charge of Li'l Gun, I get 1900 fps out of a 20" barrel and a 165 grain SWC. I load it a might lighter and still get over 1800 fps, which is what a full charge of 2400 gives me mid 1800s fps and isn't as hard on brass, which is what I was looking for. Brass life is significantly increased and I have all the power I figure I need with the Li'l Gun load.

The problem, as I've previously stated, with Li'l Gun is that it's slow burning and has a reputation for top strap cutting and forcing cone erosion in revolvers. Not a problem, of course, with rifles. I still load 2400 and that bullet for revolvers for a general purpose load, but load AA#9 for a little better results behind the 180 Hornady XTP in my Blackhawk.

xphunter said:

Do you think 1500 ft./s is realistic with the 170 grain Sierra in a 12.5-13" barrel with H-110?

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I'm not sure because I never tried it and I'm not good at guessing how much velocity is lost with shorter barrels.

While 2400 is the classic small rifle and magnum powder I do not feel it delivers top performance with heavier bullets in the .357 Magnum. Even though it's a real magnum powder it is on the faster side on the magnum powders. I feel the same about AA#9. In the 44 Magnum with heaver bullets you will find IMR4227 and Accurate 4100 will deliver better performance than 2400 too because they are slower powders.

W296/H110, Lil'Gun, IMR4227, AA4100 and Power Pro 300-MP are all slower powders than 2400 and will deliver higher velocities than 2400 can with heavy bullets in the .357 Magnum... (IMO of course)

300-MP is awesome but it does have a bit of muzzle flash. This is an almost max load from a snubbie. Kind of shakes up the place!