AR-MPR Build - Determining Max COL with Hornady Lock-N-Load OAL Gage

[AndrewTannerCA]

How would you do these measurements on a rifle without access through the rear / chamber? Specifically for the M1 Garand.

[shaunpisk]

Is that round at that length going to fit into your magazine? I'm currently running the Sierra 55 grain HPBT and setting it to factory 2.240 COAL. I have a 24 inch E.R. Shaw HBAR on a Daniel's Defense upper and I'm getting maybe at this time a .25 center to center group. I think you might run either into a feed problem(canting the bullet on feed, losing the bullet out of the case all together, or a stovepipe). Bolt rifles are good for lands loading. I don't know if an autoloading AR will be.

[gavintoobe]

@shaunpisk - Totally agree- towards the end I mention that you want to be .020" off the lands, and may have to go deeper to get cartridges to fit the magazine.

[shaunpisk]

@gavintoobe You do have a pretty kickass gun though. Let us know how it shoots in the end and let us know about the "lands" experiment works out for yah. If it warms up enough, I have built up 69 grain loads with Varget in the case. I'm going to see my AR likes the Varget 69 grain Sierra combo and see which grain of powder works the best if at all (.2 grain increments from 24 to 26 grains). I'm running TAC behind the 55 grain Sierra HPBT and it shoots well.

[soldout83]

Cool

[badjeep02]

Nice video, very interesting .

[macman30331]

FIRST