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snowhack
05-05-2007, 01:27 PM
I have a question about the OAL of the seated cartridge. I read on this forum somewhere it shoild be 2.26" and Accurate's load data says 2.265". I read somewhere else it was suppose to be 2.10", I forget where. The load data for .223, for which will be the magazine used, says COL from 2.10" to 2.26" depending on bullet used.
I'm using Hornady 180 gr SP and the 2.10" is perfect for the canalure location on the bullet. 2.265" puts the canalure way high. I trim cases to 1.35" and I know .05" off the lands is good for my bolt gun, but I'm going w/ Mod 1's AR kit.
Ultimately I will try for the .05" off, but should I just seat the bullets to the canalure and forget it? I'm not taking the gun to sniper school, I'm just paper punching. seating to deep raises pressures and I'm already nervous about the new gun and my use of trimmed GI brass. (.330" seated neck diameter)
What would be a good starter OAL that is safe and does anyone w/ a Mod 1 kit have any advise? Thanks.

I guess I should have posted this on the reloading topic....

pug
05-05-2007, 07:30 PM
snowhack I have gone from 2.050" to 2.260" so your range sounds ok. The pressure does go up the deeper you seat the bullet but as long as you are using reputable source of data then you should be fine. There is nothing wrong setting the cannelure higher if you choose to. If you do have a .330" loaded neck diameter I have not heard of any 300/221 chamber that you should have a problem with. You only need one to two thousandths clearance for the neck to open up.

too_many_hobbies
05-06-2007, 12:10 AM
...I trim cases to 1.35" and I know .05" off the lands is good for my bolt gun, but I'm going w/ Mod 1's AR kit.....

I have read that you are limited by the maximum magazine length in an AR-15, which is 2.260". I have 2 fire-formed cases at Hornady now to have a modified case made for their OAL Guage. I have been setting the seating die for an OAL of 2.250" which is working, but I will actually measure the distance to the lands when I get the modified case back.

sniperx
05-06-2007, 12:35 PM
You will have to test chamber each different bullet. Mark it with a marks alot
and chamber a unprimmed dummy load and set it back until it clears and chambers correctly. I have played with quite a few and most all have a different seating depth.

snowhack
05-06-2007, 04:51 PM
I kind of knew the answer prior to posting, I mean like I said...I have to shoot for .05" off rifleing, but I was curious about the AR platform w/ regard to pressures and magazine limitation and all. I know the crimp is important w/ the autos and heavey bullets and I've only messed w/ bolts. The canalure being so far off got me second guessing myself.
I browsed the archives about this question and got more info than I need, thanks to all who posted.