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Posted: 7/13/2020 9:30:03 AM EDT

I built a 300 blackout with an Aero Precision lower, and only certain magazines seem to fit into the mag well without resistance. When I hit the mag release button, most magazines don't budge and there is a good bit of friction when inserting. The only magazines that seem to fit for the most part are Pmag M3's, M2's have the issue mentioned above, as do the few promags I have and hex mags. Has anybody else ran into this issue? Is there an easy solution to the problem other than just buy M3's?

Posted: 7/12/2020 5:35:36 PM EDT

[#1]

More often than not it's the magwell dimensions.

Posted: 7/12/2020 5:53:59 PM EDT

[#2]

What mags have you tried so far?

Posted: 7/12/2020 6:32:51 PM EDT

[#3]

Quoted:
I built a 300 blackout with an Aero Precision lower, and only certain magazines seem to fit into the mag well without resistance. When I hit the mag release button, most magazines don't budge and there is a good bit of friction when inserting. The only magazines that seem to fit for the most part are Pmag M3's, M2's have the issue mentioned above, as do the few promags I have and hex mags. Has anybody else ran into this issue? Is there an easy solution to the problem other than just buy M3's?

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A simple test...

Try one Okay Industries magazine, EVERY Okay Industries magazine is checked on an insertion jig to ensure proper sizing. If it doesn’t fit properly, it’s your receiver.

Posted: 7/12/2020 9:34:19 PM EDT

[#4]

Quote History

Quoted:

A simple test...

Try one Okay Industries magazine, EVERY Okay Industries magazine is checked on an insertion jig to ensure proper sizing. If it doesn’t fit properly, it’s your receiver.

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Quote History

Quoted:

Quoted:
I built a 300 blackout with an Aero Precision lower, and only certain magazines seem to fit into the mag well without resistance. When I hit the mag release button, most magazines don't budge and there is a good bit of friction when inserting. The only magazines that seem to fit for the most part are Pmag M3's, M2's have the issue mentioned above, as do the few promags I have and hex mags. Has anybody else ran into this issue? Is there an easy solution to the problem other than just buy M3's?

A simple test...

Try one Okay Industries magazine, EVERY Okay Industries magazine is checked on an insertion jig to ensure proper sizing. If it doesn’t fit properly, it’s your receiver.

Just purchased 2 of these and will see what happens when they get here.

To answer the other question above, I’ve tried gen 2 and 3 Pmags, pro mags, hex mags, and some random metal magazine that came with my AR I bought many years ago. Only the gen 3 pmags have dropped free and inserted without resistance.

Posted: 7/12/2020 10:04:45 PM EDT

[#5]

I have a Spike's lower that's pretty much the same - M3's (and Emags, if anybody remembers those ;) ) drop, M2's don't. Not uncommon, from what I've heard.

Posted: 7/12/2020 10:08:15 PM EDT

[#6]

My Defender lower hates M2s. I had to weed out near 2 dozen as the mag dimensions were all over the place. M3s were 90% or better, think I dumped 2.

USGI aluminum are 100% in it.

I have zero use for mags that do not drop free in all of my lowers.

Posted: 7/13/2020 3:15:59 AM EDT

[#7]

Okay Ind. mags are the most consistent mags I've found dimension wise. I had to pay close attention when I was running a Scar16 a few years back. Not only are they consistent, but they are reliable. Okay and M3 Pmags are all I buy, but anymore Okay usually gets my money. Your receiver may be on the tight side but the Okay mags you purchased should be a good tell. If you find there is an issue, I would contact Aero.

Posted: 7/13/2020 5:55:41 AM EDT

[#8]

Way back in the old days of the late 80s my first AR was built on a OLY/SGW receiver. That one was very picky with magazines. No go with Thermolds back then, any USGI did work which was good as I had two footlockers full of them.

CD

Posted: 7/13/2020 6:25:45 AM EDT

[#9]

Quote History

Quoted:
Way back in the old days of the late 80s my first AR was built on a OLY/SGW receiver. That one was very picky with magazines. No go with Thermolds back then, any USGI did work which was good as I had two footlockers full of them.

CD

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I work with a guy that has an OA gun, even aluminum mags give the guy fits.