Primer test - surprising result (to me)

[roklock]

Hello,

Let me preface this, I am not new to reloading but I am new to precision reloading 1000 yard bench rest & both F Class ranges. (about 1 year now)

Load:
Fire formed BR Peterson brass => 6 BRA
H4895, charges from 29.9 through 30.9, 0.2 increments
Load is jammed +.005

I had, Federal 205, CCI BR4, and CCI 450 to do the test with and was extremely surprised that the BR2's showed pressure signs (bolt lift and extractor mark) at "standard loads" and velocities. Especially when I didn't see any pressure signs from the 450's or 205's through the entire powder charges.

Any thoughts around this, especially where I didn't have any pressure from the magnum primers?

Thanks,

Steve

 

[rsmithsr50]

so you need to test the brs at lower powder levels to eval.
to test the primer do not limit the powder

 

[roklock]

so you need to test the brs at lower powder levels to eval.
to test the primer do not limit the powder

Yes, understood but I have a known node load that performs well and was just doing a primer test. Was actually using the federal 205M in the load and was just doing some playing since all matches are cancelled. Between the three the CCI 450's improved the load performance, based on my limited knowledge.

So for instance, my current load is 30.7 grains with the 205M primer, the 450 primer seemed to give me a wider node 30.3-30.7 and a tighter vertical on the target. I do plan to do another test with the 450's to see if I can repeat it.

With the CCI BR4 I started to see pressure at 30.3 grains, definitely saw it at 30.5 and didn't shoot the 30.7 or 30.9. Was shocked to see the BR2's have such pressure at those powder charges.

 

[KY_Windage]

Maybe the combination of the BR's and being jammed .005?

 

[ppaul]

what bullet r u using?

 

[roklock]

what bullet r u using?

Bart hammers

 

[roklock]

Maybe some clarification, I was wondering if anyone else has experienced a "standard" primer to show more pressure than a magnum primer?

 

[Zero333]

This is not unheard of.

I thought I read or heard from one of the powder makers about this happening when switching from Magnum primers to standard primers. Might of been directed towards pistol cartridges, but can't say for sure.

The closest thing to this scenario I've had happen was with a 300winmag. Worked up a load with cci250's, and then tested Fed215m's and the 250's side by side.
The 215m's showed the odd pressure sign and velocity was down by 20+ fps compared to the cci250's. But with the 215's the groups were half the size !

 

[rsmithsr50]

THE NODE is at a velocity, not a pressure,
can you get the velocity with the br and less powder.
( but if you have an answer, you like well go there)

Yes, understood but I have a known node load that performs well and was just doing a primer test. Was actually using the federal 205M in the load and was just doing some playing since all matches are cancelled. Between the three the CCI 450's improved the load performance, based on my limited knowledge.

So for instance, my current load is 30.7 grains with the 205M primer, the 450 primer seemed to give me a wider node 30.3-30.7 and a tighter vertical on the target. I do plan to do another test with the 450's to see if I can repeat it.

With the CCI BR2 I started to see pressure at 30.3 grains, definitely saw it at 30.5 and didn't shoot the 30.7 or 30.9. Was shocked to see the BR2's have such pressure at those powder charges.

 

[roklock]

THE NODE is at a velocity, not a pressure,
can you get the velocity with the br and less powder.
( but if you have an answer, you like well go there)

yeah, so I had pressure at 2930 with the BR4s, the node is closer to 2955-2960

 

[urbanrifleman]

Maybe some clarification, I was wondering if anyone else has experienced a "standard" primer to show more pressure than a magnum primer?

If by "showing pressure" you mean flattening, this is totally normal because the cci450 has a thicker cup and will not flatten and Pierce when the thinner cups will.

 

[roklock]

If by "showing pressure" you mean flattening, this is totally normal because the cci450 has a thicker cup and will not flatten and Pierce when the thinner cups will.

what I experienced was heavy bolt left and extractor marks

 

[Liven The Dream]

H4895 Pressure Problem ??

 

[Northridge]

was this the same outing? meaning all brass in same cycle only thing being different would be primers. in regard to 6dasher or 6BRA often the 205 federal for me will give a indication of heavy bolt before the BR4 and or cci 450 in every action I have regardless of firing pin diameter. was the BR4 your last ladder of the day?

Shawn Williams

 

[roklock]

was this the same outing? meaning all brass in same cycle only thing being different would be primers. in regard to 6dasher or 6BRA often the 205 federal for me will give a indication of heavy bolt before the BR4 and or cci 450 in every action I have regardless of firing pin diameter. was the BR4 your last ladder of the day?

Shawn Williams

yes, same outing, all brass and same number of firings, Powder weighed by Fx120, Bullets seated with arbor press.

fired all three powder weights before moving to next weight...so, 29.9 (205m, br4, 450) in that order for all charges except for the br4’s I didn’t shoot any after 30.5.

 

[urbanrifleman]

what I experienced was heavy bolt left and extractor marks

Well that's different

 

[ppaul]

IIRC, BR4 are a different formula than the 450. Where for instance federal's match primers are the same just made by the more experienced people.