brian45acp

I love that stuff also. I use it as a cleaner but not as primary lube. It keeps things protected but breaks down carbon. Cleaners strip protection off the metal so you have to oil them after throughly. I found that out when I pulled my extractor from the bolt and saw surface rust.

I was using weapon shield. If I oil it Sunday and check it next Friday before Saturday’s match the oil is gone. The stuff is too thin to stay put. It’s really bad in my carry gun and is gone in a matter of days. I have not changed ammo. I have 2 loads that are good which is one being about 1050fps and the other 1150fps using a 124grn jhp. Same bullet I always used

I changed the spring just recently once I started having issues. I did up the weight on it though and have 4 tungsten and 1 stainless. I will go back to 3 T and 1 S. I also switched to bore tech grease which is meant for bolts and slides. I was noticing my oil drying up and I figured maybe it was that so I went to the grease. Possibly it’s allowing bolt to slide more and I’m having bolt bounce? Short stroke kit has been in I think about 2 years now. Only issues I had were dialing in my load with a combination of buffer weights to where the O rings would last longer and not flatten or Frey. But it never jammed on me. I talked to another pcc shooter at this Saturday’s match and he is using the TTI also with good luck. I just hate the company so haven’t considered buying from them.

I think possibly the mags would wear out with the alloy mag catch. But jp is smart and beveled the bottom so I see nearly no wear on the mag notches. I am going to download them more and try new mags. I can’t find a darn thing wrong with the rifle so it’s got to be mags. I’ve always used the Taylor’s and didn’t have issues until now.

Well the idea of the magwell on the lower I don’t believe to be an issue. I have a brand new gmr-13 broken in with few hundred rounds and both my lowers are nearly identical in terms of how tight the mags fits. Both have some movement but nothing crazy so I believe it to be normal. I just realized the spring I thought was the XL was actually not. I counted the coils and it’s 28 and not 34. So either Taylor mixed them up or I did. I’m pretty careful about that so I think it was a package mix up. This doesn’t really change anything though.

My mag doesn’t disengage and never has. I have seen ets fail and crack a few times so I never thought them as an option.

Yeah I know, but I’m in the commie state so wearing out a registered AW lower would make me cry. I don’t think this low round count would eat a lower. That and we hardly ever are doing reloading so the mag just sits there. I’ll ask Jp if they think a new mag catch would tighten up anything.

I had thought the same as well. I was trying to compare if the mag wiggles more than my other back up new gmr 13 and it does by a little. I just took the mag catch out last week to inspect it and clean. It’s alloy so I don’t see how it can wear against a Glock plastic lined mag but maybe it’s possible. The mag chute shows signs of wear but nothing bad or enough to change dimensions I don’t think. Something worn would make more sense to me for sure. It does have a few years of weekly match use. I didn’t keep record of round count but it’s got to be 30-40k.

Posted a bit ago about sudden issues with my gmr 13. I have run the piss out of it for a few years with zero failures and now have some crap going on. Checked the gun over throughly and see nothing there. You guys here helped me with pointing out glock mag bodies swell over time and cause issues due to us running these long extensions and stressing the mags. I thought it was BS but at this point it’s all I can make sense of. I ran a new mag and have not had failures during the stage. But I have had a failure to chamber at make ready. I hope maybe my fault for not charging the handle and letting it rip but I’m not sure. I have the short stroke buffer so no bolt catch meaning it’s possible I just didn’t crank it and let it rip. Today I used another old mag body built with a new spring and used the Goliath XL spring in the standard Goliath extension as to get more spring pressure. I don’t think this helped at all and I had another round jump out of the mag and get pinched against the breech. Last week I ran the same setup and had no issues so I thought I was smart. I will ditch the old mags and use new but I was just trying to prove to myself the theory of swelled mag bodies isn’t a thing and it was lack of spring pressure. Most guys are bitching at me to download the mags and I do download 1-2 rounds but perhaps there is an issue here I’m not aware of. I never downloaded more than 1-2 before and didn’t have issues for years as I mentioned. So I’m back to buying into the swelled mag body theory. Any input is appreciated, thanks guys.

Just came across your post. The buffer that came with the ready rifle is alloy and the snap ring is steel. Your load was too hot for the setup and the O rings will beat themselves thin and the weights begin to get sloppy and shake around making the issue worse in a hurry. This scenario beats the metal snap ring and it is stronger than the alloy buffer. The groove the snap ring rides in gets rounded and your snap ring pops off. The new short stroke kit is an all steel buffer and will solve that issue. It’s also heavy so it’s likely to put you closer to where your weight combo should be with tungsten and stainless weights. Meaning you tuned your buffer system and didn’t realize it. But watch for the O rings getting flat and the weights having slop. When you see this you need more weight so trade a tungsten for a stainless and try again. As you get closer to being perfectly tuned to your load the O rings last very long time. good luck dude

What do you guys think about MBX pcc mags?

thats interesting and I wonder if it’s possible to measure them and see the issue. I suppose I’ll have to toss mag bodies once a year. thanks man

So today’s match I tried the questionable mag with new spring and same s#!t. Lucky for me it jammed up 3 times while trying to make ready so I just went for my other mag to start. I continued the match with the new mag and had no issues. While making ready a round jumps straight up and gets pinched at a 45 degree angle at the top of the upper and between the bolt. As soon as I remove the mag another round jumps completely out of the mag. So my thought is internal drag causing loss of spring tension and rounds are jumping out. So I have it narrowed down to mag body for sure. I wish I could see what the issue is but I’m not certain. I’m going to remove more of plastic flashing that’s stuck to the mag body at the transition from mag to extension. I always sand them and smooth it out but I’m going to actually remover the excess plastic that extends up the metal liner. I saw comments about mag bodies wearing out primarily on pcc so that must be a good observation too.

Just want to update everyone in hopes it might help. I put the gun back to the way I had it in terms of buffer setup and started over. It has ran thousands of rounds no issues so it didnt make sense to chase ammo or setup combos. I used a brand new mag with a new Goliath extension which was my back up mag to the same combo which was used the past 2 years. I had 2 matches with not a single problem and I can feel feeding being more smooth. No more noises of bolt to closing then springing shut when moving port to port like before. Next step will be a new spring in my original mag and run it some more to narrow down the issue. But for sure its with the mag and not the gun. Now the next mission is what part of the mag is giving me issues. I suspect spring length has nothing to do with spring "health". It must be fatigued and tossing round out of the feed lips during recoil which is why my jams are always a live round pinched between bolt and chamber.

Thats the odd part. The springs are nearly the same and not even half a coil difference. But I have inspected the s#!t out of this gun and it can't be the gun. I ran the potential bad mag yesterday just in practice which is 51 rounds. I shot it off my shoulder and from low ready etc just to see if my issues were from a weak shouldering etc. The mag might just be bad for reasons I can't explain but running the new mag for a while will tell me if thats the case of not. I returned my buffer back to the way I had it with 4T and 1S but but I did bump my load so my 124grn jhp are doing average 1150fps

This makes the most sense. After JP mentioned issues with too fast of a bolt I started thinking along the same lines. Additionally I switched to a very slick light grease from bore tech so I think that increased the bolt speed as well. So the extractor issue was diagnosed after I started thinking it was a cold weather and not enough lube issue which is when I switched to the grease. I think you may be on to something that makes the most sense to me. I will put the weight back to what it was and see what happens. I never had issue with spent case so that last part doesn't apply so much. I also dropped a quarter in the buffer tube to preload the SCS assembly to help keep the bolt closed a smidge longer. I have always done that since I got the rifle and I think it helps.

I loaded a mag and stripped them one by one by hand and in the rifle. eventually I’ll figure this out and report back so it helps others. This has to be a good one because it sure isn’t obvious what’s wrong.

I checked those. No presence of rubbing of the ejector on the bolt. No wear marks on ejector top or underside of bolt. I’ll check them again. I didn’t actually wrench on them. I did pull on the ejector and tap it and checked for movement or signs of rubbing.

Called JP and we can’t figure it out either. I’m going to put my buffer system back to what it was and start over. If I change 1 thing at a time I should figure this out. One thing I didn’t think of is they mentioned reducing weight and increasing charge of my ammo could cause bolt to hit limiter and bounce which would induce feeding issues. The timing would be off and cause problems. maybe it’s possible as I changed my load and SCS weights I created more of an issue. The original problem for sure was a filthy extractor that was all caked up. But once I changed it and still had a failure maybe something was wrong with a particular round and not something bigger. But my changing things sent me down the wrong path.

Looked hard at those mags but I live in the communist state. Trigger issues wouldn’t cause misfeeds would they?

Mag issue makes a lot of sense. 2 rounds didn’t come out at once. One round never made it into the chamber and got pinched between bolt face and breech face/barrel. I never saw a spent casing stuck and it’s always a live round. Extractor was changed to new 2 weeks ago. Checked ejector position and it has never moved. Ejector looks the same as my 2nd brand new GMR. The recoil spring was changed 2 weeks ago as well. this crap is driving me nuts

No new changes for about 10k or more rounds I would say. I was wondering about high mileage wear and tear. How would the bolt wear out? Looking at it I can’t seen anything but it would be logical that all these parts have a life expectancy.

I’m going to reduce buffer weight and send it next Saturday and see what happens. All that makes sense to me is short stroke causing the round to get stuck. I will report back and hope it helps others

Unless this mag suddenly went bad in about a year and a half then I dont know why it would suddenly be the problem but I do agree it seems mag related. I measured the feed lips and they are the same as a new mag. I inspected the heck out of it and can't see anything either. But running the new mag a few matches will tell the story I suppose. I like to figure things out and learn so this I dont like this. Just to write something off as mag related and not understand or see the issue doesn't satisfy my understanding of the issue.

I didnt change anything and started having issues suddenly. This is what is driving me nuts because I felt I was way past needing to dial anything in. I never had issues and stayed with what worked. But now there is something wrong so I am having to figure it out.