.300 AAC factory crimping

[07JKX]

I guess this really does not apply to just .300 AAC, but I just loaded a dummy round and have been playing with my lee factory crimp die.

First I noticed that if I set my col at 2.250 (pretty close to as long that will fit in the mag with the hornady sst) and chamber a round, the jumps out about .05

I put a light/medium crimp on it and it is a bit less of a jump but the bullet still moves.

Question is, do you crimp for your ar's? Medium light heavy?


Seems like the bullet jump is consistent, I suppose I could load, set the col to about .03 of where I want it and then crimp to compensate for bullet jump...


Any input?

 

[b.a.customkydex]

That seems long. But I'd add some more crimp to it

 

[07JKX]

Yeah they are just dummy with 150 grn projectiles. I will be loading with 125 so my col should be shorter. Just getting into the caliber so everything is new from forming brass to new powders. Just taking it really slow since I am stepping out of my .308 comfort zone.

 

[b.a.customkydex]

Yeah they are just dummy with 150 grn projectiles. I will be loading with 125 so my col should be shorter. Just getting into the caliber so everything is new from forming brass to new powders. Just taking it really slow since I am stepping out of my .308 comfort zone.

If you are comfortable loading 308, no problems loading 300blk, it ain't much different.

I need to either repossess my chrono from a buddy in Norcross or find someone close with one I can borrow.

 

[ngcsugrad09]

Seating depth is critical in the Blackout to ensure proper function with an AR. Seating where the bullet diameter of .250-.260 is touching the rib seems to be the ticket for reliability.

As far as crimp, I've got a Lee factory crimp die with a light kiss that seems to work just fine without bullet movement.

 

[07JKX]

Going to play a bit more tonight. Looking at some more published data, I should be able to move those 150grn SST in to about 2.105. That should give me more bullet in the neck and with a light crimp should solve my jump problem.

should.. lol