Loads for JP GMR-15 Steel Challenge

[DIYguy]

Variations on this topic but asking again.

Picked up a JP GMR-15 dual charger, just started running it in Steel Challenge and probably later in USPSA. I've been working on testing loads with mixed results.

I started using Power Pistol powder several years ago for all my pistol loads. Had a chance to buy several jugs on sale so ended up with 16# of Power Pistol. Thought I would have a life time supply loading +/- 5g per load. Short lifetime. Almost ran out, bought another 4#, now I'm down to little over 1# again. I've loaded over 10k Acme 147g FP rounds for USPSA. Tried some of those loads with the JP, discovered I had to load the rounds even shorter for the JP than what I run in my Shadow2. I was having issues with the rounds hanging up in my Glock mags so getting failures to feed. I have a couple thousand X-Treme 124g RP plated bullets that I started testing with descent results, have maybe (500) X-Treme 147RN bullets I haven't tested. So far the 124RP loaded to 1.146 are running OK in the Glock Gen4 and Gen5 mags.

So much for that, now for the question. Power Pistol is a dirty powder. I have to do more cleaning with my CZ S2 but not a big deal, ultrasonic cleaner etc. With the blow-back system for the PCC my brass is pure black and rifle shows the carbon pretty quick. Lot more work to clean.

* What powder works best with the JP since I need to get more powder?

* 124 or 147? X-Treme has RP and I like X-Treme better than Berry's.

The coated FP rounds seem to have more feed issues but may have been those loads. I like to load heavy bullets and run sub-sonic which dictates the powder.

Any help?

[philmadxx]

I like Vihtavuori, specifically N320. Burns really clean, very accurate and meters well. I do 3.6gr @ 1.118 oal RMR 124gr RN. No feeding issues ever. This is for my GMR, works great in the JP5, and can go down to 3.2 with full reliability and reasonable cleanliness. I only use FMJ bullets, RMR is close enough in cost to plated or coated that I stay with them for everything 9mm

I hear good things about sport pistol powder but I haven’t used it.

[DIYguy]

I've seen other posts that like N320. I'm going for speed and accuracy with low recoil so looking for that magic perfect powder. Meter well in a Dillon progressive,consistent powder drops,  burn clean, shoot soft, low recoil, subsonic etc. Right next to the purple unicorn that $h!+s rainbows.

I did check with my local dealer and good news is N320 is available which is critical. Doesn't mater if a powder is the purple unicorn if it's also impossible to find.

[DIYguy]

Another powder that's available that seems like a potential is CFE Pistol. Any opinions on that one?

[xjwalt666]

20 hours ago, DIYguy said:

Another powder that's available that seems like a potential is CFE Pistol. Any opinions on that one?

In my opinion CFE pistol is kind of slow for PCC. It's another one of those powders that doesn't burn all the way at low charges. The best I have seen that is actually available is N320. I just discovered sport pistol right when the availability dropped off. Picked up a 4# jug off a local guy that doesn't use it anymore. N320 is really clean, meters great, and shoots soft. 

[dmshozer1]

Winchester Super Target works for me,

Ball powder, meters perfectly, very clean and available.

It is supposed to be temperature sensitive.

Don't believe it.

I ran my chrono on two different days using 2.8 of WST with a 147 gr. bullet.

Temp. in my cellar was 58 degrees. That is where I do my reloading.

Fired 10 rds. Held a hair dryer on the next 10 rds.

They were exactly like the cold ones.

Did the same thing a few days later. Same thing.

Nice powder.

 

 

[Chills1994]

On 8/9/2024 at 11:23 AM, DIYguy said:

Variations on this topic but asking again.

Picked up a JP GMR-15 dual charger, just started running it in Steel Challenge and probably later in USPSA. I've been working on testing loads with mixed results.

I started using Power Pistol powder several years ago for all my pistol loads. Had a chance to buy several jugs on sale so ended up with 16# of Power Pistol. Thought I would have a life time supply loading +/- 5g per load. Short lifetime. Almost ran out, bought another 4#, now I'm down to little over 1# again. I've loaded over 10k Acme 147g FP rounds for USPSA. Tried some of those loads with the JP, discovered I had to load the rounds even shorter for the JP than what I run in my Shadow2. I was having issues with the rounds hanging up in my Glock mags so getting failures to feed. I have a couple thousand X-Treme 124g RP plated bullets that I started testing with descent results, have maybe (500) X-Treme 147RN bullets I haven't tested. So far the 124RP loaded to 1.146 are running OK in the Glock Gen4 and Gen5 mags.

So much for that, now for the question. Power Pistol is a dirty powder. I have to do more cleaning with my CZ S2 but not a big deal, ultrasonic cleaner etc. With the blow-back system for the PCC my brass is pure black and rifle shows the carbon pretty quick. Lot more work to clean.

* What powder works best with the JP since I need to get more powder?

* 124 or 147? X-Treme has RP and I like X-Treme better than Berry's.

The coated FP rounds seem to have more feed issues but may have been those loads. I like to load heavy bullets and run sub-sonic which dictates the powder.

Any help?

How short did you have to go on your OAL for your Shadow 2?

 

How about TiteGroup for a powder?

[DIYguy]

7 hours ago, Chills1994 said:

How short did you have to go on your OAL for your Shadow 2?

 

How about TiteGroup for a powder?

For OAL, I'm loading Acme 147FP at 1.156 Originally spent a lot of time doing the barrel plunk test to work of loads that fit and then loads that would feed.

Haven't tried TiteGroup. Had a Stop the Bleed class yesterday and wanted to stop by my local reload supplier after the class but closed early on Saturdays. We do have a Sheels on that end of town so stopped by to pick up a pound of N320 to test. Ran into two guys picking up power that definitely knew a lot about loading, impressive credentials while we chatted. They talked me into trying CFE Pistol so I picked up both.

[z40acp]

Sure is strange that N320 powder is cheaper than WST. How did this happen? I use 3.6 grains N320 with an Everglades 124 grain version 2 plated RN. Everglades on sale frequently for $160 per 2000 shipped. Helps keep rifle clean.

[DIYguy]

Loaded up (30) rounds each of the N320 last night at 3.7, 3.9 and 4.1. under X-Treme 124g RN. Will try and make it to the range today and chrono and test for grouping and function.

[DIYguy]

Range report

Loaded (30) rounds each of the following and ran three strings of ten to test:

3.7    Avg 1022.35     Avg SD  23.6

3.9    Avg  1086.47    Avg  SD  17.5

4.1    Avg  1132.54     Avg   SD  24.0

 

Load does seem to burn cleaner, I inspected my fired cases and with the JP blowback system had 1/2 of one side black, rest, not too bad. This is much cleaner than the Power Pistol powder. With such a small charges velocity does swing so not as consistent and higher SD's. Will load another batch with 3.5 and 3.7 again and compare.