Recently purchased a second hand LMT MWS off of gunbroker. I am pretty sure it is the older model, it has a quad rail and single ejector. I have been away from firearms for quite some time while in school so these issues might just be me shaking off the dust so please bear with me.
So far I have noticed:
The mags are more difficult to insert than I remember in previous AR15s i’ve owned.
The mags also do not drop free. I need to strip every mag by hand before reinserting a new mag.
I cannot press check. It is EXTREMELY difficult to bring the bolt partially back to see brass. I need to muscle it so much that most of the time I pull the CH back all the way and eject the round.
Other than these things the rifle ran great… Are these normal quirks of the Ar10 platform? I have been using Hex mags and Pmags with ZQI brass. Unfortunately I live in Jersey and am limited to my mag selection.
I have an early LMT MWS (2010) and seeing your post, I got mine out and tried several different magazines. I don’t have any Hex mags…mostly PMags and a few IMI. I have a lone KAC Metal mag as well. I tried various configurations…loaded, unloaded, bolt closed, bolt open. The only mag that dropped free was the lone KAC mag. The PMags didn’t drop free at all, nor did the IMI. I am not bothered too much by this, I don’t use my LMT as a run and gun platform anyway. If you do contact LMT, let us know what they say. Thanks.
Thanks for bringing yours out and testing. The mags not dropping free don’t bother me to much. I don’t get to do to much running and gunning either. The press checks bothers me a bit for some reason. I have a feeling it’s the pressure the extractor puts on the casing that makes it hard to pull the charging handle back.
I’ll get in contact with LMT and see what they say. Will keep you guys posted.
I also tried a press check with a full PMag, a full IMI mag and I was able to pull the charging handle back fairly easily with a round in the chamber. How much difficulty are you having pulling the CH back? I realize this could be difficult to quantify but if the BCG is rubbing or grinding against something, I suppose it should be somewhat obvious. If the gun cycles just fine when firing, I would be interested to know why the CH is so difficult to pull back. On my MWS, the press check feels exactly the same as charging the gun with a full mag and the BCG full forward…if that helps.
I strongly suspect that the reason for the difficulty with “press checks” has to do with either the tightness or dirtiness of the chamber, or that the bullet is engaging the lands in the barrel. You can check the chamber by cleaning and polishing it to see if that changes anything for the better, and you can check for the bullet engaging the lands by very carefully comparing an extracted round to one that’s never been loaded.
With PMAGS of the day I had some issues of them not dropping free as well, but only with a few of the ones that I had. I solved this by taking a sander and sanding down the sides of the mags a hair (just 2-3 seconds a side with 200grit sand paper IIRC) and the problem was solved. All of the mags are still in rotation in my inventory with no issues.
Have you adjusted the mag catch? Assuming that you are having a difficult time seating the mags
Thanks for responses. All excellent ideas. Tried seating a round in the chamber and dropping the mag then press checking. Still had difficulty so it’s not the bolt hanging up on the mag or any other rounds in the mag. Actually never cleaned the internals of the rifle. Only lubed and shot it. Suspected chamber dirtiness might be playing a role. Will try adjusting mag catch, cleaning out the chamber and report back.
So I just gave it a good scrubbing. Its got dual extractors so it must be the newer model. Fitting the pin into the extractor is a lot more difficult than I remember. After fighting with it for 20 minutes I knelt on my extractor to get enough pressure on it to finally fully insert the pin. Wish I was kidding.
Still had issues with press checking. Seated a round and extracted, there are visible lines on the bullet once extracted so I assume thats from the lands.