Bought a new ATI Galeo 13" SAR chambered in 5.56. I watched a video talking about headspace and it got me to thinking. The guy seated his bbl and headspaced it. He had his bolt a little tight and he made a statement about it loosening after some firing and "settling in". Made me wonder if it is tight on 5.56 and would settle in would it, in theory, be "better" to break in for settling in with .223 with shorter case neck?  Or would you want to break in with 5.56 and then rock on with .223?  Maybe this is stoopid or a silly question. Just tryin to learn....

Think you're over thinking it. Put 500 rounds through it and see what you get. I used steel because I reload and since they're usually over gassed anyway it still seemed to work harden the steel receiver.

Better get to shooting before the warranty runs out

Clean & lube it and go shooting.
Save your brass and take a look at it for anything abnormal.


If headspace "grows" quickly its usually a sign of something wrong.
Bad bolt fit / lug contact, receiver hardness, etc.

Sometimes I need someone to help me realize I am suffering from analysis paralysis....Thanks!!

.223 and 5.56 cases are identical.

Slightly tight headspace is ok.  Long headspace could lead to case ruptures and be dangerous.

Thanks. I fired it a few times the other day and d no issues. Then the freakin rain set in. Pretty sure we have had a legit 10" in the last few days. Range has to dry now.

@MSOGDAWG

How's it running? I'm interested if you'll be the first one on here that hasn't had to send his back.

The few times Ive fired it it has been fine. So far it has been with Tapco mags only. Learned a few weeks ago my Pops has cancer so range time has been limited. Hope to get it out for longer more rapid strings of fire. Will report back tho.

bump

Mine throws brass so far down the range, forward and to the right, that I'm consistently hitting adjacent targets. I think I am more accurate with the brass than with the projectiles.

Bought a used one yesterday, then went behind the store to range to shoot it.  Fired with both Tapco and surplus mags. No jams, to issues. I grew up with 20 inch barrels, then shot everything from 21.5 inch, 18 inch, and 16 inch, but this was my first with such a short barrel. Even compared to "Enforcer" M-1 Carbine pistol, it was....Loud and percussive! Perhaps attaching a stock and SBR'ing it will reduce the perceived percussion.