[Lexington]

Howdy,

I recently picked up a nice XM16E1/early M16 rifle. She has no case deflector. As a lefty shooter, I was concerned about brass but I had a "slickside" AR years ago that never hit me so I took a chance. Turns out, this one hit me every time in the cheek with spent brass shooting .223! On a hunch, I switched to some Federal M193 5.56 and all was well.

So, brass hits my face with .223 but sails safely to three o'clock with 5.56.

Obviously, I plan to shoot 5.56 only with this rifle. But I'm curious as to whether this indicates anything I can do to make her less picky with ammo. Does this suggest my ejector spring or buffer spring are worn? Has anyone had a similar experience?

Thanks and be safe!

 

[DesertDew]

Howdy Lexington. I have modified my AR-15 by fabricating and positioning a homemade deflector, before any were available on the market. You can go that way or purchase a Caldwell universal brass catcher. The Caldwell attaches with two Velcro mounting straps and is easily installed / removed. I like mine and you don't have to pick your brass.

To address the characteristics of .223 vs 5.56, if you're using .223 in a rifle chambered in 5.56 it can be problematic. While the case dimensions of .223 vs 5.56 are the same, the firearm may just be chambered for 5.56. The .223 is loaded for higher pressure in chambers with closer tolerances. The 5.56 chamber, "has more generous" tolerance and military ammo is loaded differently, (powder amount / burn rate), such as the M193. Shooting the .223 in a 5.56 chamber causes the brass to expand considerably and causing a more violent cycling rate. More than likely the cause of the wild ejection.

An AR-15, with a Wylde chamber will comfortably use .223 and 5.56. Hope this helps.
DD

 

[M92PV4U]

Does this suggest my ejector spring or buffer spring are worn?

No.

5.56 it typically a hotter round than .223, I would try a lighter buffer for the .223 loadings and the factory one for the 5.56 loadings.

I have no research to back this up it's only theory.

 

[Lexington]

Thanks.

No doubt 5.56 is a bit "hotter" when loaded to spec. I've noted the difference in recoil and muzzle blast when shooting back to back, in various 5.56 rifles.
I guess it didn't occur to me that a weaker recoil impulse would cause brass to go straight back, as opposed to 3 o'clock. Since I never had an issue with my old slickside, I assume I must have fed her only M193. Of course, that was in the good old days (2002-2005?) when Federal 5.56 was still $3.99 a box!

 

[HB of CJ]

I'm a Lefty. The BEST cure is a left handed top assembly. Watch some slow-mo vids of the M16 cycling. Lots of ejection gas hitting the lefty's face and eyes. Adds up over 1000's of rounds. Also like already said, seems your rifle likes 5.56 ammo and NOT .223.