TGibe

Thread is at https://www.ar15.com/forums/AR-15/Thoughts-on-the-CMMG-Guard-/15-713060/?page=8

I also start with my biggest mag, but I have a 27 rounder and a 19 rounder on my belt pouches.

Sent pics last night and woke up to an RMA with shipping label from them. I called and talked to them and they think the buffer tube it out of alignment either due to the tube or the lower. They have a test fixture, but it seemed like they only do random checks so this one may have slipped through. Shipped it off today and will wait and see what they find out.

Talked to CMMG and will send them pictures to look at, but the next step will be to return it to them unless they see something obvious. I couldn't see anything when comparing the buffer tube angles between the 2 lowers, so if it's off it isn't by much... They said they will make it right, which I believe, but it's a bummer though as this is going to stretch well into January now...

The guard doesn't use an ejector like a straight blowback. The ejector is part of the bolt.

I was only trying an upper from another complete PCC build to try and diagnose the issue with the complete CMMG guard build I'm working on. No ramp should be needed on the Guard. Sorry for the confusion...

My JB welded Taccom ramp interferes with their LRBHO linkage and the upper won’t close. Good idea though. I thought about seeing if I could remove the linkage, but want to check with them first. Thx!

Thanks. I’m sure they’ll help me out and get me going.

I even removed the trigger in case that was somehow interfering. It still binds.

I received my back ordered CMMG Guard 9mm lower today to match up with my CMMG upper ordered last month. Originally I thought I could use my Spartan lower with it but couldn’t get the bolt to clear the mag. Anyway, after snapping the two together tonight I couldn’t pull the bolt back more than halfway without it binding up hard. I took out the buffer and spring and everything looks ok (although the buffer rattles). The bolt goes into the buffer tube fine (spring removed) without resistance. I put the CMMG upper on my Spartan lower (after removing the ejector) and the bolt cycles fine (no mag of course) with no abnormal binding at all. If feels just like cycling the PSA bolt on the PSA upper. Could the buffer tube tube is misaligned? Could the upper be the problem even though it cycles fine on the Spartan lower?Has anyone else seen anything like this? Am I missing something I should try? I plan to to call them tomorrow and am hoping for a quick resolution but wanted to gain as much info as possible. Just sucks having paid transfer fees etc, waiting a month and having it fail hard. LOL thanks, Allen

https://www.cmmginc.com/product-category/uppers/9mm-guard/ This is where I ordered mine.

Lower http://www.joeboboutfitters.com/Spartan-Complete-9mm-Billet-Lower-Receiver-V2-p/jb-spartan9-v2.htm I decided on this upper because it came with a Hyperfire ETD installed. I have since swapped it out for a Hyperfire 24 3Gun trigger, but can't really tell much of a difference. Upper http://palmettostatearmory.com/psa-16-9mm-nitride-1-10-13-5-m-lok-railed-upper-with-hybrid-bcg-ch-516446602.html This is the one marked for PCC competition and I am able to run my OAL at 1.130-1.135" with any issues at all. Feed Ramp https://taccom3g.com/product/taccom-glock-lower-feedramp/ This is one of the most important parts even though it's only $20. It was super easy to install, but I did have to grind a small amount off of my bolt to keep the bolt from hitting the ramp. Ammo: I'm running Montana Gold 124g RN FMJ @ 1.130-1.135" at around 140PF. I case gauge every round and discard any that don't fit the gauge (I either pull the bullet or use them during practice or sight in) Other Mods: It doesn't impact reliability, but I swapped out the buffer and spring for a Kaw Valley 4.3 oz one http://www.kawvalleyprecision.com/KVP-Heavy-Tungsten-Carbine-Buffers-p/buffer.htm and a regular carbine spring. This softened recoil a good bit.

Will do shortly.

Ok. Once again I’m wrong... the ejector does stop the mag from over insertion on my NFA. Sorry for the confusion, but sometimes I can be dense...

Maybe my Spartan lower is not an NFA then because while the ejector will eventually stop the mag it is high enough where I can go past the mag release a good distance if I hold the mag release down. No biggie either way was just trying to clarify the CMMG lower mag stop... thx, Allen

Is the LRBHO tab the only thing keeping the mag from over insertion on the CMMG lower? Or am I not seeing it...? My CMMG lower is backordered and when I tried the CMMG upper on my NFA lower I noticed that I had been running the NFA lower without any over-insertion protection all along. Thanks, Allen

I have one and haven't been able to part with because it's so much fun. I prefer AR9 for competition though, but as Eric says, the reloads on a mechtech are so easy.

I can't say enough good things about the PSA upper I purchased. 4th match in a row without a single failure. I also think that the Taccom ramp is helping, but I absolutely hate failures of any kind. I expected a failure or 2 per match for such a bargain PCC, but this has exceeded my expectations.

I had click models on my open guns (sold them) and picked up a standard model for my PCC. I think I prefer the click and if I purchase another it will be a click model because I like the "locked in" feel of the click. IT seem like on the regular one it take me longer to get the dot right...

I'm looking forward to the evolution. I ordered the CMMG Guard because I can't stop tinkering and like to try new stuff (a common theme here LOL), which will be my third PCC but certainly not my last. I guess PCCs are like potato chips...

Very nice. I really like the red parts on the black one.

While I'm sure I could get my NFA lower to work with the mod, I ordered a lower from CMMG yesterday. This way I can leave my current PCC as is for a spare... maybe eventually sell it as a complete unit.

Good coverage. Looked like a lot of fun.

Ordered my upper this morning. Was hoping for some discount code or something, but didn't find anything... Fingers crossed that this thing runs well.

What if it is a complete CMMG upper?