RWS brass and primer issue!

[Ackley Improved]

I currently am doing load development for a 280AI. I am using RWS 280 brass and 215M primers.

When fireforming the primers were very flat, and I put it down to too low a pressure/powder charge. After doing a ladder test and increasing the charge a lot the primer still looked identical to earlier.

What I found is this

RWS 280 primer pocket depth = 3.21mm
215M primer cup depth = 3.26mm

Now, I also had some 210M primers, and those measure 3.21mm.

What I have done is ream the pockets deeper with the Sinclairs tool to 3.35mm. I should not have an issue now.

Now, I am curious.. should the 210M and 215M still measure the same even though the 215M pack more punch, or does that more punch mean deeper primers? Can someone else do a measurement on them?

Next firing since reaming should answer if my problem is solved.. who knows could be caused by something else!

Cheers

 

[Lynn]

Ackley Improved
I use RWS 375 H-H brass and it typically weighs 80-90 grains more than Norma does.I had to cut my load by a full 4 grains to even things out.
Lynn

 

[Greg Culpepper]

AI

Primers are taller than pockets are deep by design and intent. When seated properly, the face of the cup will be several thou below the case head and the anvil will be pushed back into the pellet by the bottom of the pocket to pre-load and sensitize the primer for more uniform ignition and improved accuracy. Stop cutting your primer pockets deeper. Most people find that 210's give better uniformity and accuracy than 215's even in mag sized cases unless you're using ball powder or temps are very cold.

Greg