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View Full Version : Round popping out with open bolt -- technique or mag issue?



EricM
06-25-2012, 01:16 AM
Had something interesting happen at the range today...after inserting a mag with the bolt locked open, I noticed (before sending the bolt forward) that the top round in the mag was pointing up at an angle, just about ready to pop out. Tried a couple other mags as well and found that I could consistently cause one or two rounds to pop out if I slammed the mag in with an open bolt. ("Slammed" is really too strong of a word, I wasn't being gentle but I wasn't going nuts on it either...using a beer can grip, firmly and briskly inserting the mag and then pulling down to make sure it's seated.) Whether the mag was full or only had a few rounds, same issue. Mags in question are 30-round Lancer L5 AWM with an average of 350 rounds through each. I happened to have the unused FN mag with me that came with my SCAR, tried the same thing with it and even if I really exaggerated the amount of force when inserting the mag, the top round didn't budge.

So my question...is this something that is likely to happen with any AR-style mag, such that I should train to insert the mag more gently on an open bolt? Or are these Lancer mags perhaps more susceptible to the issue than other designs? I don't want to go buy a different type of mag only to find that after a few hundred rounds they behave just the same...but if this behavior isn't typical, I have no desire to put up with it. I appreciate your input.

Suvorov
06-25-2012, 08:21 AM
I have never used the Lancer magazines so others with more knowledge on them can say if this is common or not. That said, I have not seen this with Aluminum GI, Thermold, or P-Mags and would consider it a "malfunction waiting to happen" with any of those magazines.

Chuck Haggard
06-25-2012, 08:29 AM
The only time I have seen that is with bad feed lips, or the back of the mag is either cracked (plastic mags) or the weld has popped loose (metal mags).

Al T.
06-25-2012, 09:37 AM
Concur with tpd223. I think your magazines are about shot, no pun intended. :D

Nick
06-25-2012, 10:14 AM
Have you verified that the bolt is locked all the way back? I had a similar issue a long time ago with an AR that probably wasn't cleaned in a long time (it was a rental gun). The bolt locked back on the face of the carrier instead of the bolt so the back of the round would collide with the bolt and pop out. I think the same problem could be caused by a bad magazine with a weak follower spring.

Failure2Stop
06-25-2012, 03:35 PM
Top round popping free is a common problem when slapping the mag into the gun when the bolt is to the rear, especially if the magazine is on it's way to failure.
My rule: don't spank the mag unless it has been bad, i.e.: bolt closed, hammer falls, failure to fire.

You shouldn't need to be gentle during a bolt-lock reload, but over forceful seating can cause this issue.
I had a few old style Lancers and never had this problem, but I wasn't a huge fan of them so they only saw about 10 cycles each except for when I was using them with a 5.45 upper.

EricM
06-26-2012, 02:33 AM
I really appreciate the info guys. I'll take a close look at my mags to check for any premature wear, and compare to a couple unused mags. (And Nick, while I didn't check specifically for the bolt being fully locked back, I did verify at the time that there was nothing at all contacting the rounds when the mag was inserted...thanks for the suggestion, wouldn't have thought of that cause.)

Next time I'm at the range I'll reexamine how much force I'm using as well. At the time I didn't feel like I was doing anything crazy, but thinking further now I realize due to an issue I was having in my first rifle class a couple months ago I may have gotten in the habit of using more force than necessary.

During the class the instructor had us doing retention reloads after most drills, cycling through the mags we had on body. I found that every now and then it was really, really difficult to seat a partially used mag (more difficult than seating a full mag on a closed bolt). After the class that issue didn't occur again for several weeks, but next time it happened I figured out that when a round was chambered, the round below it was sometimes sliding forward enough that the tip of the bullet was over the front wall of the mag. When reusing that mag, it then took a lot of force to seat it under a closed bolt. Not sure if that issue is Lancer specific, SCAR specific, or something that can happen with anything...any thoughts? (and if it's not uncommon, any preferred technique to prevent it, or just slam it in if it happens?)

I've ordered some other mags to try out and I'll see how they compare. I've shot handguns for years but am still getting up to speed on the rifle side of things, I appreciate the help.

Jay Cunningham
07-11-2012, 09:42 AM
Magazines should be inserted into the gun relatively gently when the bolt is locked to the rear. You aren't gaining anything by hammering the mag in and you can pop rounds out and also damage other components. When the bolt in forward in battery the situation is much more forgiving; push/pull still reigns supreme though.