In 6XC can primer cause a 50fps difference? Update it can cause 30fps

[Shawnba67]

So I am playing with a new 6Xc I built. I shot an ocw test. I then realized I was out of CCI br2 primers. So I picked up some 210M primers. Reshot the ocw and noticed I seem to be 40-50fps slower with the 210's.
H4350 powder. Just curious if any one else has had similar results. Or my shooting chrony is suspect!
Thanks for any input.

 

[Nomad47]

Switching from 210M to 215M primers (6SLR & H1000) got me the same results as adding .5 grains of powder.

 

[WyleWD]

So I am playing with a new 6Xc I built. I shot an ocw test. I then realized I was out of CCI br2 primers. So I picked up some 210M primers. Reshot the ocw and noticed I seem to be 40-50fps slower with the 210's.
H4350 powder. Just curious if any one else has had similar results. Or my shooting chrony is suspect!
Thanks for any input.

It's my guess that your chrony is pretty much right. When I switch from BR2s to Remington 9 1/2 I gain an average of approximately 30fps.....but accuracy falls off. JME.WD

 

[jaygorski]

No way. http://bulletin.accurateshooter.com/2017/04/ultimate-large-rifle-primer-shoot-out-16-types-tested/

 

[Shawnba67]

It's my guess that your chrony is pretty much right. When I switch from BR2s to Remington 9 1/2 I gain an average of approximately 30fps.....but accuracy falls off. JME.WD

My accuracy improved! Lol but I was slower. And my low ES node moved a little. So much to learn! Thank you

 

[Zero333]

I worked up a load for a 300 wimag with cci250. 208eldm right at 3,000 fps. Tried the same load with 215m and got almost 30 fps avg less, the groups got much smaller, but about 20% of the time I could feel the bolt lift was a little stiffer.

 

[ballisticdaddy]

No way. http://bulletin.accurateshooter.com/2017/04/ultimate-large-rifle-primer-shoot-out-16-types-tested/

No way? I have seen more than a 30 fps variance by staying with the same primers and just switched to a new lot.

 

[AckleymanII]

My accuracy want to simply unbelievable when I went with a 7 1/2 in Palma brass, and brass did not show pressure signs till I got to 3270 in my 31" barrel, which was the top end accuracy node. Never even thought of full length sizing at 3150, the next node down.

 

[Shawnba67]

Well back to the drawing board, i shot a seating depth test of what i thought was a node at 39.6gr of h4350 with the 210s. It had showed sub 20ES first round this round for 5 ,5 shot groups 33 was lowest es. NO BUENO! Couldnt match the accuracy of the first test either.
At 39.8. The BR2 had 3 different bullets with 3 shot groups with ES of 8. Now a 3 shot wont show a great load, it will show a bad one!

 

[Shawnba67]

So today at the range I tried 4 each of identical loads except the primer.
210M 39.4gr H4350 3035fps ave ES 14fps. 4 shots
BR2 39.4gr h4350 3066fps ES 14fps. 4 shots Same bullet, same seat depth groups right after each other.