Colt 9mm Mag Problems

[smith m4]

I just bought a 9mm RRA and it runs fine with the RRA mag but runs like crap with the $60 apiece Colt mags I bought? Anyone got any idea why?

Is there a break in period on new Colt mags?
The Colt mags are 35 rounders. Should I try only loading 30?

This situation has throughly pi$$ed me off since the Clot mags are $60 each and are not working like the $30 RRA mag.


The reason I bought the Colt mags is that the RRA mags do not lock the bolt open after the last round and RRA is out about 10 to 12 weeks on their mags.
Right now the only way you get a mag from RRA is buy a rifle and they send you ONE with your order. I ordered 5 total when my local gun shop placed my order with RRA in March. I did not get my rifle until July and they said it would be 10-12 more weeks before thay finnished filling my order for mags. So I canceled my mag order and bought Colts. I am starting to think it was a mistake.

[chrismartin]

I posted this in the other 9mm thread where you posted:

Depending on the position of the mag block, the magazine can sit a little high or low causing feeding issues. CProducts 9mm (I have 4 CProducts 9mm mags and they have worked well in my AR.) mag discussions on arfcom go into this a little bit. Some one else will have to pipe in on the RRA block, but I think you can loosen the set screw a little, move it a little and tighten it back down.

That's just what I've read though, I have a hahn block.

Also, if you are looking for other mags, CProducts makes some sweet 9mm steel mags patterned after the colt (10, 20, and 32 rounders). They also are willing to help out if they don't work in your AR. Options from walking you through adjusting the mag catch hole on the mag, adjusting the mag block, etc.

ETA: It would also help if you posted the nature of the problem you are having. I'm assuming that you have feeding issues.

[LukeMacGillie]

Ive never seen 35 round Colt Mags. Were they experimental? My Agency uses the Colt SMG and we only have 20 and 32 round mags, and have had very little luck with getting any new mags out of Colt. Perhaps your problem is rounds number 33, 34, and 35.

[Jinete_Palido]

As Chris Martin posted, the RRA block is somewhat adjustable, and I have found that the Colt mags run best with the block sitting as low as possible in the mag well (i.e. closest to the mag well opening). You should be able to loosen the allen screw in the bottom of the block, hold the rifle right side up, and re-tighten the allen screw as gravity pulls the block down in the mag well. Hope this helps.

Edited to add: Saw Grant's post in the other thread, looks like he has had the same experience as me with lowering the gas block for the Colt mags. Hope it works for you.

[SuicideHz]

I have a 20 round Colt mag that jams a lot.

My slotted Uzi mags work flawlessly.

[LukeMacGillie]

Ive been working on a few early Colt SMG's where the block is one piece, and held in by only 2 roll pins and a ball detent that excerts force on the front of the magwell to hold it in place. What I and other armorers are finding is that this system over time is cracking the mag well.

We have removed the ball detent and have no issues with only 2 roll pins, but will eventually switch the entire fleet over to the multiple piece, 3 roll pin model of block.

Only with time will we know if all of these drop in blocks will cause the same issue. Ive decided not to get the conversion parts to make my SBR a SMG just for this reason. Putting the parts in a non SBR is just not worth it in my opinion.

As to Colt mags not feeding, yes it happens, but not very often. Most of the mags that have issues are ones with AWB markings and are in the 5-7 years of service mark. Not to pull an "H&K" answer, but mags are cheap, and expendible, and not designed to function forever.

You have to look at more than just the cost of a gun, but at repair parts, and mags and ammo to see if a weapon is worth putting your hard earned dollars into.

[khc3]

Ive been working on a few early Colt SMG's where the block is one piece, and held in by only 2 roll pins and a ball detent that excerts force on the front of the magwell to hold it in place. What I and other armorers are finding is that this system over time is cracking the mag well.

We have removed the ball detent and have no issues with only 2 roll pins, but will eventually switch the entire fleet over to the multiple piece, 3 roll pin model of block.

Are these blocks different from the ones that are tightened in the mag well by a hex screw on the bottom?

[LukeMacGillie]

Are these blocks different from the ones that are tightened in the mag well by a hex screw on the bottom?

Its a combo block, one piece, with 2 roll pins and a hex screw with a ball detent exerting the force on the front of the magwell block.

Urban ledgend around the shop is that the multiple piece block with 3 roll pins is the result of our compaining.

[williejc]

I lack the qualifications to be as knowledgeable on this topic as you guys, but I
can't resist adding my meager suggestions. If you haven't already, you can disassemble the Colt mags and inspect for burrs and structural or dimensional
defects.

Can you detect binding of the mag spring? Might the higher capacity ones exert such a strong upward pressure that feeding is unreliable? When the mag sits even slightly on the high side, the extracted empty case can catch on the lip of the top round.

You may benefit by using a spray graphite lube on the mag's interior.

Call Colt on their dime and sweet talk'em. You may get new springs and mag followers along with some technical specs on the mags.

Sometimes, Brownell's techs can help.

Williejc

[The Archangel]

I lack the qualifications to be as knowledgeable on this topic as you guys, but I
can't resist adding my meager suggestions. If you haven't already, you can disassemble the Colt mags and inspect for burrs and structural or dimensional
defects.

Can you detect binding of the mag spring? Might the higher capacity ones exert such a strong upward pressure that feeding is unreliable? When the mag sits even slightly on the high side, the extracted empty case can catch on the lip of the top round.

You may benefit by using a spray graphite lube on the mag's interior.

Call Colt on their dime and sweet talk'em. You may get new springs and mag followers along with some technical specs on the mags.

Sometimes, Brownell's techs can help.

Williejc

Good recommendations Williejc.