k2pichu Posted September 17, 2022 Share Posted September 17, 2022 Gun: SIG MPX PCC Competition/Gen 3. Issue: Failure to eject/Stovepipe. The spent casing is extracted, but doesn't eject causing the next round to jam up. Round count: I purchased a new MPX 8 months ago and have about 8-9k rounds through it. I've experienced hundreds of these malfunctions, all identical. The malfs occurred fairly early on, but I didn't know enough about firearms at the time to realize it was not normal at the rate I was experiencing them. Mods: MPX is stock except for the Radian charging handle, grips, red dot, and magwell. Thing's I've noticed: Inconsistent ejection, both in direction and distance. Sometimes the casing is sent 5-7 yards away at 1:30, Other times, it dribbles out 1-2 yards away at 3:30. The eject cases seem to be spinning a lot. The orientation of the jams also seem to indicate the case is spinning more than it is being sent out of the port. The anondizing/paint is worn on the inside of my upper receiver. I seem to have around a 1% malfunction rate. It's often enough to occur almost every match, but not often enough to easily debug. I've participated in about a dozen local matches this year and have had at least one malfunction in two thirds of them. I've done two majors and had malfunctions at both of them. Cleaner and Lube: Hoppes 9 cleaner, Hoppes Elite Cleaner, C4 Boretech carbon remover, Hoppe's elite oil Troubleshooting so far: Read all the forum posts and internet resources on this issue Fully cleaned and lube BCG/Upper receiver and cleaned gas system, checked correct gas plug depth. Still malf within 50-200 rounds. Mix of 115/124g FMJ factory new brass from Blazer, Federal American Eagle, Sellier and Bellot, and Fiocchi. Malf experienced with all brand/project weight combinations I've tried. I also tried Brian's MPX GM Loads but had 2 malfs at that at Area 7. Different (all Lancer) magazines. Malfunctions occurrence is spaced out in the mag. Sometimes it's happens in the first few rounds, sometime at the end, with no observable pattern. I tried brand new magazines with no real improvement. New Gas plug + tappet from ILWT. Installed this before Area 7, 20 rounds of zeroing, two malf's in first 5 stages. No malfs in second 5 stages. New extractor and spring, rubber insert, and donut o ring from ILWT. Experienced malfs within 100 rounds. Sent back to Sig for warranty, the customer service agent was friendly and the gunsmith replaced the extractor and spring. Malf within 30 rounds, 3 more malf's in the next 350 rounds during practice. 2 malfs experienced at Area 7 (~350 rounds). Sent back to Sig again for warranty, they told me they shot another 60 rounds and saw consistent ejection pattern and that the malfunctions were caused by user error. The same customer service agent I talked to suggested I had a "limp shoulder" ("limp wrist", but for rifles???) and that I should try shooting other people's MPX to see if I get the malfunction there and have other people shoot my MPX to see if it happens to them. Makes sense to eliminate the variable of the shooter vs gun, but logistically and cost wise that's not really practical. On the call, the customer service agent seemed very annoyed at me and pretty much told me to f*#k off and if I tried to send it back they would charge me for shipping, gunsmith time at $75/hr and ammo used. I'm honestly out of ideas at this point and tired of trying to debug this thing. I know ILWT sells and adjustable gas plug and variable spring rates, but I have no clue if my problem is too much gas or too little gas or what direction to even go in. With my tests and discussions with other local MPX users, I'm confident my issue is not with cleaning or ammo related. Depending on the price and cost, I'm considering: Buying a new upper assembly. Ideally I buy just the part that's not working, but I don't know how to tell if it's the receiver, BCG, or gas system on the barrel that's causing the issue. Selling my MPX and buying a new one. I've never done this before and don't have any idea on the process, valuation, and laws surrounding this so I'm a bit weary of this option. Depending on how much I can sell it for, it might be more cost effective than buying a new upper assembly. I've invested a lot into this platform with magazines, loader, mag carrier, etc. and I really enjoy the platform so I'd prefer to stay with the MPX if possible, I just don't know what to do to make it reliable. Sending it to the ILWT guy to see if he can gunsmith a solution to this. I don't know what the problem is and I'm not sure if he offers services for this or not. Link to pictures: https://drive.google.com/drive/folders/1e3LH4-6kmrcGPKEbwNRV3MOENZ8SKLYO?usp=sharing If you guys have any additional insight or suggestions, it would be greatly appreciated. Thanks! Quote Link to comment
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