IMR 7828 in the 6mm AI?

[Tyler Kemp]

Hodgdon has load data for the 6mm Remington and shows 48 grains under a 100 grain bullet as a compressed load and at 48,000 CUP.

With my Ackley I am at 48 grains and am having a soft brass issue. I got this brass in bags and it is older, there seems to be a couple slightly different headstamps, some of them show extractor marks for no reason when the primer is fine:This is with RL 22 but it is pretty similar, 45 grains is a lightish load and it gives me the most pressure signs. Stars denote the most evident signs and the slightly different headstamps.

Can I continue in the 6mm Ackley until I recieve primer flattening, or I get a really compressed load? Is anything hurt by lots of compression of powder? I am already nearing the case neck, and then a 105 Amax on top of that goes into the powder some. Much more powder and I believe it will be in the case neck before bullet seating. Is that a no-no?

 

[Ernie]

Have you measured the changes in the diameter of the case head?
Primer pockets?
I would pay attention the brass more than the primer myself.

 

[Tyler Kemp]

Primer pockets are nice and tight, I will measure case head changes next time I shoot.

 

[HarryCallahan]

If your 6mmAI has a short throat or tight neck or you're using different bullets than what Hodgdon used, your pressure will be different. Try chrono-ing the load and see what your velocity looks like as you get close to these max loads. Try some different loads with the bullet Hodgdon uses and see if you still get brass flow. Measure your fired case neck and compare that to a loaded round in the same type of case to make sure the case has enough room to release the bullet. Compressed loads are fine unless they push your bullet back out of the case. Check if this is happening by re-measuring OAL some time after loading and before firing.

 

[Tyler Kemp]

My 6mm Ackley is standard throat and stuff, I just figured since I have 9.5% more capacity pressures wouldn't be near enough to cause brass flow. Some cases show signs and some don't...can I continue further or should I stop? I was originally thinking 50 grains as a max, but with 48 showing pressure signs (on the brass at least) I may be able to go no further with good case life.