Federal GM210M vs CCI BR-2 LR Primers

[THOMAST]

I was running low on Federal GM210M primers (stupid stupid!) and the local dealers were out of stock also, so I tried a packet of the CCI Bench Rest primers in my 7mm08.(Been using Federals since day one, about 15years ago and figured if it aint broke , dont fix it!)
I loaded 30 rounds, 20 with the Federals and 10 with the CCI primers, keeping the rest on the load identical.
Shot 2 10 shot groups at 200 meters with 2 minutes cooling time between shots, one group with CCI and another with the Federals.
I found the the CCI bench rest primers gave me a tighter group than the Federals, about 1.4 inches 10 shot group with the CCI and at 1.9 inches with Federal at 200 meters(219 yds)
Is this the norm, or just luck? One cannot really form an opinion from just 20 shots, So I'm asking for your opinions please.

So which primers do I go for?

[sewwhat89]

I played with different primers with my 300 RSAUM shooting 185 gr Berger VLDs. The velocity variation between WLR, BR2, GM210M, RP9.5M and WLRM was less than 30 fps. There was a difference in groups. I too was shooting from 200m, but I was using 3 shot groups. I got the tightest group with the RP9.5M primers.

With my 300 WM, I loaded up some 175 gr SMKs, and the BR2s shot tighter groups, but with the 190 SMKs, GM210M primers shot best groups. The 190 Berger VLDs shot best with RP9.5M primers.

Bottom line, you have to test until you are satisfied that you have done sufficient work on your "best" load. I would use the BR2s if they shot better. Your 1 10-shot group would be fine with me to switch, but I would continue to watch and see if it holds to make a pattern of supremecy. There's my opinion.

[royinidaho]

[ QUOTE ]

Is this the norm, or just luck? One cannot really form an opinion from just 20 shots, So I'm asking for your opinions please.
So which primers do I go for?

[/ QUOTE ]

One cannot really form an opinion from just 20 shots? Sure you can!

So which primers do I go for? Of the two you mention I don't think it makes much difference. If you're shooting longer than 300 yds the primer producing the smallest ES and SD would be the selection.

You may want to try CCI-200s and see what they do. you may be supprised......

[davewilson]

I'm with Roy, group size is only half of the equation.i'm more partial to ES.

[Meister]

I've tried the BR2's in several calibers and they seem to really shine in the 308 cart. Everything else seems to like the GMM the same or better. I've been told that the CCI's are harder and have a milder but more consistant charge. My testing did support this info. I know I've shot groups of 5 with velocity spread of 8fps, and that was what sold me. The lot to lot variation seems to be smaller as well. I don't reccommend them with slower powders, never had good results. My 308 rifles really like the BR2's with 44.6g of Varget. This is a warm load so please reduce and work up to it for safety's sake.

[halvey]

[ QUOTE ]
My 308 rifles really like the BR2's with 44.6g of Varget. This is a warm load so please reduce and work up to it for safety's sake.

[/ QUOTE ] What brass are you using for this?

[Meister]

Federal GMM or Lapua... 175 SMK's as well