.357 Magnum initial test test results

**Brick** · November 4th, 2018, 07:19 PM

This time out all my testing was with my S&W 627 Pro. Whatever I settle on as a load is going to have to work in both revolver and carbine. PDF attached shows the results of some limited velocity tests made with Hornady's 140 gr. JHP/XTP. I decided to test only 5 for each charge weight. Data used came from Hodgdon's Reloading data. I have to admit to being mystified by the results!
With H110 the highest velocity was with the lowest charge weight, though the SD is pretty crummy. FYI all the charges were thrown then weighed individually and powder trickled in until scale balanced. Pan and powder charge were then transferred to and weighed on a Hornady electronic scale. prior to the start of reloading, I used check weights on the balance beam scale and calibrated the electronic scale. Of the loads tested today H110 at 17.3 grs. came out as the fastest and Win 296 at 17.7 grs. is fastest for that powder and has a more acceptable S.D.

**Hoppy** · November 4th, 2018, 08:45 PM

Interesting stuff. Thanks for sharing it. I'm looking forward to your results in the carbine.

I don't know why you'd get higher velocities with lower charge weights. What is your crimp like? Maybe it's inconsistent?

Everything I've read says H110 and W296 are the same powder so you should be seeing the same results.

It'll be fun to follow your progress.

**Brick** · November 5th, 2018, 06:05 PM

Thanks Hoppy. I'll be sure to post them once I start working with the carbine. I have the loads selected for H110 and 296 with Hornady bullets , but I want to try those powders with Sierra's also and if I can find it A#9 and Blue Dot powders. Not surprisingly the powders tested gave a helluva blast and the "flame" coming out at the cylinder gap was impressive.

**frankski** · November 5th, 2018, 06:52 PM

Are you using magnum primers? H110 needs the magnum primer boost, per the loading manuals.

I think you'll find the H110 loads burn a lot more consistently in the carbine.

**Brick** · November 5th, 2018, 08:29 PM

Oh yeah! Winchester SP Magnum! And the crimp is a strong roll crimp formed by a Lee Carbide Factory crimp. Next round of tests will be the Sierra 140 gr JHP with the same powders. Hopefully I'll be able to get to the range on Thursday, in between raindrops!

**Delkal** · November 6th, 2018, 09:50 AM

If you are using H110 / W296 I think you would be better off with a 158 gr bullet. In general these powders are for max loads with a heavy bullet.

**psweigle** · November 7th, 2018, 09:21 PM

Originally Posted by Delkal

If you are using H110 / W296 I think you would be better off with a 158 gr bullet. In general these powders are for max loads with a heavy bullet.

I found this to be true. I use a powder coated 158gr cast bullet sized to .358 in ALL my 357's, including the coonan and my ruger 77/357 carbine. I use h110 at near max loading with a magnum primer and a heavy crimp. Excellent accuracy in all guns.