Primer Difference?

[Guest]

Hello all.
I was monkeying around with some 8208 XBR in my 223 after posting here and getting some good info a couple months ago. (by the way, thanks for the help on this everyone!)
Have you folks noticed a substantial difference in accuracy in the same load (powder wise) where the only variable is a primer change?
I loaded 25.5 of the 8208 with a 50 gr BT with Winchester primers. Nice load, less than MOA easily with my rifle. Decided to experiment and changed primers to a CCI and the impact area opened up immediately. Still just ok accuracy-wise but nothing too great (more like 1 1/2 to 2" center to center)
Is this common? Not necessarily trying to find absolutes here, just opinions and feelings.
Thanks in advance!

Dewey

By the way, someone asked a month of so ago if I noticed any change in the 8208 with temperature changes and after some fairly unscientific tests (firing at 50 degrees, 20's and single digits) I have to say no, I do not notice any difference. Maybe I will not be lazy and can actually get the chrono out but the cold made me lazy. :lol:

 

[velvetant]

Yes and no, Depends on the firearm.
With my 243 AI groups stay the same but over the chrono I can see the difference.
My NM AR15 I can tell a small difference
My 25-284 went from shooting 1.5"@300yrds to more then 8" at the same distance with just a primer change.

You never know until you try it.
Randy

 

[Guest]

Thanks Randy.
Glad to know it may not :lol: have been me!

 

[DrMike]

Dewey,

It is a good practise to drop back anytime you change a component and work back up to ensure it is safe. There can be some significant changes by changing primers. The oxidant and the igniter is proprietary in the different primers. Consequently, you get differing temperatures, differing flame lengths, etc. Thus, the powder column may ignite along a longer path or ignite over a different time frame. What you are observing is slight differences in pressure generated by using different primers.

 

[corbin9191]

I noticed a big difference when switching from federal primers to the CCI BR-2 primers. I have to drop my charge back by about 2 grains. Nice velocity gain when switching :lol: But I still want to load to be safe. It did switch my POI by 4 inches to the right and 2 inches down.

 

[JD338]

I have seen changes just from the primer. My 280AI started shooting in the .2's when I switched to magnum primers. My 22-250 broke .4 when I ran out of GM210M primers and switched to CCI BR-2 primers. There was not a big difference, but accuracy did improve!

JD338

 

[Guest]

Terrific information guys. Thanks much!
Dewey

 

[Antelope_Sniper]

Yes. Primers can be a big factor.
My .338 win mag: 3" groups with fed215's. 1" with WMRP. that's wth H4350.
7mm STW. pet load, will ONLY group with Fed215. Period. But it's 100 grains of ball powder, so it needs all the flame it can get.

In my .270, there is 12" difference in point of impact at 100 yards when I switch fm cci200's to WMRP's.