7mm PRC and IMR4831

[DEW0341]

Haven’t seen anyone post data with IMR4831 in a 7mm PRC. So this is for those interested. First 50 rounds down the barrel today.

I have a jug of IMR4831 sitting around that I picked up during the Covid era and a 100 gm215 primers from a diff lot I need to burn off. Figured good use of the primers, and powder to get a firing on all the ADG brass I have and get the barrel broke in/sped up.

Of note a little more than half of the factory 175 ELDX I put through it had noticeable stiff bolt lift. Lot number in the photo. I still have 2 more boxes of it. The velocity is got with max charge of 61gr IMR4831 is 100+ FPS slower than Hodgdon’s website.

Plan of attack is shoot all the factory 175’s I have left and the remainder of the IMR4831 and gm215 primers, check velocity to see if barrel has sped up and then start a load work up with H1000 and H4831sc shooting 180 ELD and heavier bergers.

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[Bleeb]

Thanks.

 

[BossGobbler2024]

thanks for the data points. Are you going to use magnum primers in your final workup? I have sufficient amounts of WLR primers but no magnums. In your opinion, does 6 PRC and 7 PRC function equally well without using magnum primers?

 

[DEW0341]

thanks for the data points. Are you going to use magnum primers in your final workup? I have sufficient amounts of WLR primers but no magnums. In your opinion, does 6 PRC and 7 PRC function equally well without using magnum primers?

Yes I have 800 gm215m of a diff lot to use up before I have to switch over to 210’s I have laying around. I think I had seen long range only YouTube post a video their 7prc cartridge guide one, he had said some folks getting excellent results with 210’s. Pretty sure it was that video. I will likely test the two just for fun to see what I can get and then run those until I ran out and switch. I wouldn’t hesitate to use the large rifle vs. magnum large rifle primers if it’s all you have.


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[DEW0341]

UPDATE:

Barrel sped up from 50 rounds to 144 total on it.

Factory 175 ELDX - 2884fps to 2906fps avg

IMR4831 and 180 eldm- 2719fps to 2768fps avg

Hammering with 180’s in a nice tight wad on steel at 600. 175s were a bit bigger groups. At 100 yards 175 avg just over 1MOA in 5 shots so it checks out.


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[doc holiday13]

Would love to see what speeds you'd get throwing some of the 160g Hornady CX's

 

[DEW0341]

Would love to see what speeds you'd get throwing some of the 160g Hornady CX's

I would like to try them eventually. I have a few hundred 180eld on hand. With the prices these days I’m trying to as rational as possible


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[Runolfson]

Last weekend I tested H1000 and fed210 primers. No problems. Decent groups: .75 moa 69.3 grains, 162 eldx, new petersen brass. 20" barrel, average speed was 2857. COAL 3.150

Also shot 70.4 and had some pressure signs (ejector marks and stiff bolt).

 

[Bleeb]

Great info. Thanks.

I managed to get my hands on a brick of Rem 9 1/2M primers, which are the mildest of the magnums. I'm going to use them, and then try WLRs, which are the hottest of the LR primers.

 

[Weldor]

Good info, did not know about the Remington being mild. Good to know, just got 1k for $90 bucks. Been using wlr for my 6.5 PRC, but am running low.

 

[Bleeb]

Good info, did not know about the Remington being mild. Good to know, just got 1k for $90 bucks. Been using wlr for my 6.5 PRC, but am running low.

Ranked in order of power from highest to lowest:

Brand/type Power Average Range Std. Dev

Rifle primers
1 Fed Match GM215M 6.12 5.23-6.8 .351
2 Federal 215 LRM 5.69 5.2-6.5 .4437
3 CCI 250 LRM 5.66 4.5-7.4 .4832
4 Winchester WLRM 5.45 5.1-6.0 .2046
5 Remington 9 1/2 LRM 5.09 3.5-6.75 .6641
6 Winchester WLR 4.8 4.1-6.0 .4300
7 Remington 9 1/2 LR 4.75 3.7-6.25 .5679
8 Fed Match GM210M 4.64 4.0-5.6 .3296
9 Federal 210 LR 4.62 3.7-5.5 .3997
10 CCI BR2 4.37 4.0-5.0 .2460
11 CCI 200 LR 4.28 3.8-4.8 .3218
12 KVB 7 LR Russian 4.27 3.8-4.8 .2213
13 Rem 91/2 (30 yrs old) 4.16 3.8-4.8 .3427

Pistol primers
1 Rem LP 4.47 3.2-5.6 .5171
2 KVB 45 LP Russian 3.89 3.3-4.2 .2232
3 CCI 300 LP 3.18 2.7-3.5 .2406
4 Federal 150 LP 3.11 2.6-3.5 .2090
5 Fed Match GM150M 3.05 2.6-3.7 .2299

 

[BossGobbler2024]

Ranked in order of power from highest to lowest:

Brand/type Power Average Range Std. Dev

Rifle primers
1 Fed Match GM215M 6.12 5.23-6.8 .351
2 Federal 215 LRM 5.69 5.2-6.5 .4437
3 CCI 250 LRM 5.66 4.5-7.4 .4832
4 Winchester WLRM 5.45 5.1-6.0 .2046
5 Remington 9 1/2 LRM 5.09 3.5-6.75 .6641
6 Winchester WLR 4.8 4.1-6.0 .4300
7 Remington 9 1/2 LR 4.75 3.7-6.25 .5679
8 Fed Match GM210M 4.64 4.0-5.6 .3296
9 Federal 210 LR 4.62 3.7-5.5 .3997
10 CCI BR2 4.37 4.0-5.0 .2460
11 CCI 200 LR 4.28 3.8-4.8 .3218
12 KVB 7 LR Russian 4.27 3.8-4.8 .2213
13 Rem 91/2 (30 yrs old) 4.16 3.8-4.8 .3427

Pistol primers
1 Rem LP 4.47 3.2-5.6 .5171
2 KVB 45 LP Russian 3.89 3.3-4.2 .2232
3 CCI 300 LP 3.18 2.7-3.5 .2406
4 Federal 150 LP 3.11 2.6-3.5 .2090
5 Fed Match GM150M 3.05 2.6-3.7 .2299

thank for the list