I understand that you would have to open up the gas port to make a reliable 12.5in mid-length setup, but what exactly would be so bad about it?
People keep mentioning this as a deterrent to using this setup, but I am not sure why.
As long as it cycles reliably, what's the big deal?

i think the question you should be asking why would you want to go with gas length that's unproven at that barrel length? i know some ppl say mid length shoots softer, but not sure if it's worth the risk you would take going with mid length gas when carbine length gas works great.

also, i have read some posts about some of the SBRs being more prone to reliability issues (i have not experience this) so probably best to stick with more time tested formula to minimize any potential issues?

Truth be told, I'm never buying a middy again. Everyone blathers on about the decreased pressure, but I've never had any AR break because of the gas system length.

In fact, the only functional issues I've had were using lower power ammo that wouldn't cycle a middy, but fed in a carbine length just fine. Don't drink the internet bandwagon kool aid. It may look and smell good, but the aftertaste is regret.

maybe YOU had a problem, this doesnt mean JACK. I have a Mid and it has NEVER had a single issue. this is since 2005. and it gets the most work out of all my rifles.


open up the gas port a few thousandths at a time, its not hard to do. lock it up in a V-block and go slow.
it will look like a mini Dissipator.

Have a 16" middy and two 14.5" middies that run any and everything like a champ. Never even seen a slight hickup. I would trust my life with any of those rifles.

Sorry I went off topic pertaining to the OP's question, but to trash the mid length gas system in general is ill-informed. 14.5" and 16" middies shoot like a dream, and are every bit as reliable as carbines. And while there's a bit less of a difference with 14.5" barrels, the difference is even more noticeable with 16" barrels.

Agreed as far as the 12.5" is concerned.

My comment was solely directed towards you sounding to throw middies in general under the bus. I was simply giving my experiences that with 14.5" and 16" configurations, a middy is every bit as good, and even better than a carbine.

What your missing is that reliability has far more to do with gas port size than location.

I have quite a few different gas systems and most the time I haven't had to touch the gas port.

16" barrel rifle gas rifle buffer - Runs 5.56 and brass (standard pressure) .223 without issue but doesn't like TULA - I haven't opened the gas port on this one yet.

20" barrel rifle gas rifle buffer - Runs 5.56 and .223 including TULA - but doesn't lock back after last round with TULA - This is a FN barrel and BCG

18" barrel rifle gas rifle buffer - Runs 5.56 I have never experience a failure but it has failed to lock back on some .223 - I haven't had this out in a awhile and the failure to lock open could be magazine related - I need to take it back out and play with it again

16" barrel carbine gas standard buffer - I haven't run any TULA in this one yet - the gas port is pretty small .065 IIRC

15.4" barrel carbine gas Spikes T2 buffer - Runs everything including TULA and locks back at the end of the mag.

14.5" barrel Mid length gas H3 buffer - Runs everything and locks the magazine back on everything. This barrel came with a gas port on the larger size of spec. Originally had some issues with a standard buffer while running full auto, but the H3 fixed it.

10" barrel carbine gas H1 buffer - Runs 5.56 and .223 including TULA without failure - always locks open at the end of the magazine and works suppressed and unsuppressed.

12.5" barrel Mid length gas - This is a 6.8 that I am putting together pretty soon. All the parts are waiting for me when I get back - this is a factory AR Performance barrel and I don't expect issues


People hark on dwell time, but IME gas port size is far more important than dwell time or buffer.

Or this rail on a 12.5"

12.5 Middy AR That Works

I just wanted to post this (goofy) review of the Warsport 12.5'' middy. I haven't gotten to put rounds through this one yet but everyone I know that has seems to like it. Just throwing it out there.....