Erratic stripping rounds into battery

[Roslyn]

Wasn't sure how to label this post. I have an Anvil Arms lower in .223, in very good condition. OEM original BCG but upgraded with JP .223 bolt. Using C Products 10 round magazines. This is the problem -- If I insert a new loaded mag into the receiver, and use the charging handle to put a round into battery, frequently the forward motion of the BCG will fail to strip a round from the magazine. Not always, but often. If instead, I pull the charging handle to the rear, engage the bolt catch, then release the bolt catch, the forward motion of the BCG always strips a round into battery. The rifle fires perfectly once the first round has been stripped into the chamber, no failures to feed, extract, eject.

Typically I load the 10 round mags with 9 rounds, but have experimented in trying to correct this problem with 10 rounds, 9 rounds, 8 rounds and 5 rounds, and get the same result. I am conscious of making sure the rounds in the mag are fully seated to the rear.

The obvious questions are: a) is the magazine seated fully into the receiver -- answer is yes, after a failure to put a round into battery using the charging handle, using the bolt catch method the BCG/bolt strips a round without my having done anything to adjust the mag seating; b) am I pulling the charging handle all the way to the rear -- answer is I have looked carefully at the charging motion and the bolt/BCG do retreat behind the magazine sufficiently to capture a round as it/they move forward; c) if I remove the mag after one shot, eject the round then in the chamber, and repeat the process, does the same result occur -- answer is yes.

Thoughts?

 

[propeine]

Are you riding the charging handle? That's exactly what it sounds like.

 

[Roslyn]

Wouldn't have thought so. I pull it all the way back and let it go. Will pay attention there and see if it makes a difference.

 

[smokin.338]

The magazine isn't seated in the well as much as it needs to be from a closed bolt. Might be the mag itself or could be the BCG is a bit off. Simple solution is to keep loading like you have from a open bolt. Or try giving the magazine an extra tap from the base after you insert the mag...

 

[Gunfighter14e2]

When you pull on the charging handle you are tilting the bolt carrier up in the front ever so slightly. The buffer an spring apply pressure evenly. Your problem is a out of spec weapon that just happens to work around it's manufacturing issues most of the time, now. Later down the line, your going to have major issues with it.

 

[ballistic1]

Why not try some other brands of magazines. Perhaps your gun will feed just fine with a Pmag or other..

 

[EXTREMEPREJUDICE]

How did it manually chamber with the original OEM bolt?

 

[Roslyn]

I will try a PMAG.

It chambered fine with the original OEM bolt, using the charging handle or bolt catch, either/or. And it has chambered fine either/or with the JP bolt for the last thousand rounds or so, since I replaced the original bolt.

The problem only came up the last time I shot the rifle. I had cleaned the bolt, wiped out the interior of the receiver, and cleaned the lugs and chamber prior to shooting it. I use Militec as a lubricant, have done for a long time, so that is not a change. Not sure why any of that would make a difference, just adding it in to complete the picture.

The Gunfighter14e2 post about the rifle being out of spec and the Propeine post about riding the charging handle both could be true, TBD. Will be shooting it again this weekend, including with a PMAG and will report back.

 

[Roslyn]

Well... I shot 10 and 30 round PMAGs in this rifle and found that the problem is seating the magazines properly. Simply inserting the mags and/or tapping them until they clicked in wasn't sufficient. I had to put some leverage into the rifle in order to really press the magazines home until they caught. Not sure I explain that better -- when inserting and tapping mags, it sounded like the mags seated correctly, with a noticeable click, and releasing the bolt catch would strip a round properly. But the charging handle on its own would not. I was careful not to ride the charging handle, instead letting the buffer spring drive the BCG forward.

But if I instead pressed again on the bottom of the mags, there was a second, more noticeable click and that put the top most round into position where the BCG moving forward on release of the charging handle would strip a round. This was necessary whether I had 5 rounds in the 10 round mag, 8, or 10 -- didn't matter.

There isn't anything in the mag well interfering with inserting the mags. I both loosened and tightened the mag release button and it made no difference. As long as the mag catch was sufficiently tight to capture the magazine, it still was necessary to really drive the damn mags in to get proper position for the top most round.

If I didn't do this secondary press on the mags, they still would seat (seemingly), would not fall out, would allow the bolt catch to strip a round, and would drop when I hit the mag release.

My sense is that the mag release needs adjusting, but having played with it a good deal not sure what to do next to improve on it. Certainly would appreciate any further thoughts. The rifle operates with this secondary pressure in seating the mags, but the motion and position necessary to make it work disqualify it for anything other than bench shooting.

 

[Gunfighter14e2]

Sounds like the distance between the mag release an bottom of the mag well is to long. Remove the upper and try to lock a mag home, if it will not lock in easily the lower is out of spec. If it locks up w/o issue check your upper for issues. You can remove the excess distance at the bottom of the mag well w/o much effort, or take it to someone that has a mill. In today's world you could buy a spec lower an transfer the parts, cheaper than having it milled unless you know him or own the mill. HTH