View Full Version : Shooting off the deck with Noveske Gen 2 Lower ?
I recently purchased a factory assembled N4 with one of their newer gen 2 lowers with a flared mag well.
Today I wanted to zero the rifle and every thing went ok except when the my magazines were being used as mono pods the bolt would not lock to the rear.
The mags were black PMags that should have plenty of life left in them. The ammo was PMC 55gr.
The bolt locked to the rear every time when I did no have the mag pressing against the ground being used as a monopod.
Has any one else had a similar experience with gen 2 lowers ?
Did you try swapping to known good USGI mags?
Do the PMAG followers go all the up? both normally and if the feed lips are slightly squeezed in?
I no longer own any USGI mags but will pick up a couple and try them on this rifle. This is the first rifle I have owned that had this issue shooting off the deck. Its not a huge deal as long as it consistently locks back in every other position but it would be nice to hear from others with the same lower.
Check to see, with the upper off, if the forward right edge of the bolt catch rubs on the back of the PMAG rib, right near the 'U'. I have found that on all my PMAGS, if I pushed the bottom of the mag up and forward, I could get the bolt catch to contact the mag rib, thus stopping correct movement of the bolt catch. I have since shaved just about 1mm depth off that little section, just to the right of the 'U' on all of my PMAGs. Voila, fixed. It was a very real situation with pressure on the mag. Easily duplicated in multiple lowers and multiple PMAGs. Threads all over TOS on it as well.
Anyway, something to check.
Check to see, with the upper off, if the forward right edge of the bolt catch rubs on the back of the PMAG rib, right near the 'U'. I have found that on all my PMAGS, if I pushed the bottom of the mag up and forward, I could get the bolt catch to contact the mag rib, thus stopping correct movement of the bolt catch. I have since shaved just about 1mm depth off that little section, just to the right of the 'U' on all of my PMAGs. Voila, fixed. It was a very real situation with pressure on the mag. Easily duplicated in multiple lowers and multiple PMAGs. Threads all over TOS on it as well.
Anyway, something to check.
I second this. While shooting my most recent BCM build off the bench using the magazine as a mono pod I experienced the same thing with the bolt failing to lock back.
filthy phil
08-07-12, 04:55
get a harris ultralight bipod and use 20's
Its really not a big deal. I think it might have something to do with the flared Mag well allowing the magazine to shift more while the weight bears down on it. I will verify what other posters have stated above later today.
Normally when I shoot prone I use my elbows and keep the mag off the deck.
I could have swore I read somewhere(in one of the stickies on this forum) that if using the mag-monopod method the bolt should lock back the rear on last round. If it won't there is some type of problem. I'll see if I can't locate where I found it.
Aaron
It sounds like a stupid solution, but I experienced a similar problem with 30 round worn PMAGs while resting the mag on the deck with an LMT lower.
I just brought my AR back from a stay in California, so I had replaced the mag release button with a bullshit button for CA compliance. I guess I was a little lazy tightening it down when I returned it to how God and Gene Stoner intended, so when I tightened the mag catch another turn; that solved the problem.
There apparently wasn't enough tension on the mag catch spring and the PMAG wobbled a little when the weight of the rifle was on it. With GI mags, there wasn't a problem, but the maybe the fit is a little more rigid than with the plastic mags.
I've had similar problems with the bolt not
Locking back when on the deck using popular brand
Milspec lowers and different brand lpk's including colt, Issue for me was the bolt carrier binding on
The mag when pressure was applied, p mags and usgi mags.
Some carriers would cycle smooth others would not.
All popular milspec bolt carrier groups. Check and hand cycle the
Bcg while applying some pressure to an empty magazine in your rifle Might be
A little rubbing that's causing it not to cycle completely.
So here is what I have learned.
1. If you press down and pull back while the PMAG is on the deck it will not lock to the rear. Pushing the magazine forward is what induces this.
2. This issue does not occur with USGI metal magazines.
3. The bolt will lock to the rear when shooting from any other position.
4. The bolt will lock to the rear if you are using the magazine as a mono pod but so long as you are not pulling it into your shoulder and causing the magazine tilt back.
So this issue appears to be particular to only this flared mag well lower I have. I tried tightening down the magazine catch but it made no difference. None of the other lowers/rifles have had this issue.
I am just glad I figured out how to induce it so I don't keep doing it if I ever have to shoot off the deck like that.
justin_247
08-07-12, 16:25
This is one of the reasons many advise that you shouldn't use the magazine as a "monopod." Generally, doing so should not cause a malfunction, but it may cause a malfunction to those using out of spec magazines or out of spec magwells. It's just better to not use it at all.
Since I turned 21 and bought my first personally owned AR15 I have only ever used PMAG's. They are awesome but this has prompted me to want to add some USGI's to the mix.
I found some NHTMG mags for a good price and I'll see how they work out with this rifle.
This same thing happens with my Noveske chainsaw gen 2. Thought it was my H3 buffer but it happened with H2 and standard buffer.
I have a Noveske Gen 2 Lower build with a BCM Upper, which is fed with P-Mags almost exclusively. From the prone position, I use the mag as a monopod. When I first used this rifle from the prone, I was curious if the flared mag well would present an issue while using the mag as a monopod. I have not had any issues with the bolt failing to lock back on an empty P-Mag.
Interesting to read about this. I was thinking of buying a Noveske Gen II to SBR, but I'm now having second thoughts if there's a potential downside relating to function.
So here is what I have learned.
1. If you press down and pull back while the PMAG is on the deck it will not lock to the rear. Pushing the magazine forward is what induces this.
2. This issue does not occur with USGI metal magazines.
3. The bolt will lock to the rear when shooting from any other position.
4. The bolt will lock to the rear if you are using the magazine as a mono pod but so long as you are not pulling it into your shoulder and causing the magazine tilt back.
So this issue appears to be particular to only this flared mag well lower I have. I tried tightening down the magazine catch but it made no difference. None of the other lowers/rifles have had this issue.
I am just glad I figured out how to induce it so I don't keep doing it if I ever have to shoot off the deck like that.
My FFL does the same thing. They are proprietary lowers and may indeed have little quirks. This is one of them.
Hmm I'll have to check this out today or tomorrow.
I've just about completely rotated out of Pmags. I keep a few on my pack because the covers are nice for keeping dirt out. But I bet I have less than 10 anymore.
Somebody needs to take a pic of what the did to the PMAG to fix...
Interesting to read about this. I was thinking of buying a Noveske Gen II to SBR, but I'm now having second thoughts if there's a potential downside relating to function.
Buy the complete firearm from them if you must that lower. Here's why: https://www.m4carbine.net/showthread.php?t=129128
I have some kind of Anchor Harvey upper on my Noveske Gen II FFL Lower and I also have to tap in the receiver pins. But if fits super tight with no slop and shoots like a dream.
I shot from the prone a good bit last weekend, pulling it into my shoulder. However I was using Lancer AWM 30rd mags, not PMAGs.
No problems.
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