Your "Go To" primer for the Grendel

[tackdriver]

Maybe it was the temp, it was 123 scenars w/31.0grn of Lvri would guess temp was 20-25degrees warmer outside. Accuracy didn't fall apart but my firing pon paid the price.

[Bwild97]

CCi 450, Fed GM205m, are my current go to primers. I have a brick of Rem 7.5s to try out soon.

+1 to what Drifter said.

[Blacklab]

mainly been using cci 450 but I'm going to use BR cci the next time I'm at the loading bench.

[waveslayer]

Has anyone ever found that using a certain primer actually was the culprit making a load inaccurate in their grendel? Just the primer change, nothing else at all.

I did some load work up using 123 AMAX and XBR powder using CCI 450's.... wow switched to Remington 7.5 primers to just see. Shrunk my group down by a whole inch at 200 yards! It's now my PET load. .5" at 200 yards now.

So my experience has been, yes, it can make a big difference. I just worked up a load and then I used that same load using different primers. That saves time and money and doing that I stumbled upon a awesome load.

[NugginFutz]

I did some load work up using 123 AMAX and XBR powder using CCI 450's.... wow switched to Remington 7.5 primers to just see. Shrunk my group down by a whole inch at 200 yards! It's now my PET load. .5" at 200 yards now.

So my experience has been, yes, it can make a big difference. I just worked up a load and then I used that same load using different primers. That saves time and money and doing that I stumbled upon a awesome load.

WS - did you note any changes to MV? Was the primer the only change to your load?

[waveslayer]

WS - did you note any changes to MV? Was the primer the only change to your load?

Yes there was a small change, I will have to get my reloading data and update this post. It wasn't much from what I remember.

Update. I had a 15-22 fps change. The Remington 7.5 being a tad faster

[SG4247]

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While not shown here on the chart, I can say the CCI #41 is intended for auto loader rifles like ARs and I have found it to be the most reliable and least likely to pierce in high pressure loads.

I have ruptured cases in my Grendels and had the #41 stay intact.

Hope this helps...

[SG4247]

Also think the #41 is .025" thickness. Much like the 450 and BR4 but maybe different and harder material.
From thier site:
Quote on #41 primers;
•Mil-spec sensitivity
•Initiator mix optimized for ball/spherical propellants
•Available in large (No.34) and small (No. 41) rifle
•Use the same data as CCI Magnum primers

[Dos Perros]

FWIW, I have found CCI's BR4 to get flattened quite easily compared to others. Have also had some doubles and slam fires with them. I don't think they are the best for AR type applications. I do use them with great results in a bolt gun, though.