In order to participate in the GunBroker Member forums, you must be logged in with your account. Click the sign-in button at the top right of the forums page to get connected.

300 AAC lessons learned.

bpostbpost Member Posts: 32,664 ✭✭✭✭
It is EASY to make these cases, kind-of. A 25 buck mini chop saw a case jig of some nature and a set of dies is all you need. I bought the Squirrel daddy case jig and it works well. It would be easy to make you own jig with a bit of patience.

It took a bit of experimentation to chop a case, size it and measure it to the rough length needed. I did not feel like shaving .025 off with a case trimmer so I took the time to get the jig clamped where the case was 1.365 after chopping and sizing. Then it was just a matter of touching up the trim to get them to 1.360 where I wanted to start from.

A word of caution; if you can start with US commercial cases your life will be easier. I have ran into about 10% of the loaded rounds being too fat in the neck to chamber, they are all off shore brass cases. All of the fat necked rounds were a real booger to get out of the chamber, is was not in battery and was jammed out of battery at the neck very tightly.

If you have a neck turning tool I recommend running them all through it to get the necks to the recommended SAMMI specs. I do not have the proper Lee auto prime shell holder for the neck turning case clamp so a quick stop at got that rectified. When the shell holder gets here I plan on neck turning every case I formed to get them all the same.

The final step is case annealing, It will help with case life and loading. Do it before you do your final trim, careful to not over heat the case head, it is a short case.

If you want a fun gun buy a 300 AAC upper for your AR or build a lower, I did and it was easy. The round likes Lil-Gun powder, just about every 30 cal bullet weight from 100 to 208 grains can use Lil-Gun. I am shooting 125 Nosler BT's with 17.8 grains and Hornaday 130 grain Spitzers with 17.4. Accuracy is very good. I shot some 180 Speer bullets (14.5 grains of Lil-Gun) and it hit the plate at 175 yards, I did not shoot them on paper. When the book loads are listed from 13 to 18 grains across that many bullet weights you get a lot of BANG out of a pound of powder.

Cast bullets, Lyman 311041 shot OK but did not feed well. I have some 155 Lee cast for the SKS sized to .314 and will resize them to .311 and try them.

This gun and upper is brand new, it needs broke in but the potential for a good short range deer rifle is sure there. Suppressors are supposed to be legal in Ohio next deer season when they allow bottle neck cartridges this will be a formidable tool for deer hunting.


  • Options
    dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    A friend put a cut-off wheel in his drill press and uses that to cut off his brass for the AAC, then sizes and trims [;)]
  • Options
    MobuckMobuck Member Posts: 13,783 ✭✭✭✭
    edited November -1
    I bought a lifetime supply of brass(if I don't lose too many) early in the 300 peak. My initial loading has been with H110 but I do have 8# of LilGun and will give it a try when warm weather allows test firing. I have little interest in sub-sonic and expect 90% of my use will be with 110-125 grain bullets.
  • Options
    v35v35 Member Posts: 12,710 ✭✭✭
    edited November -1
    No free lunch.
    You're dealing with pistol energies here.
Sign In or Register to comment.