Sig MPX FTEject

[Bdh821]

I talked to Rob from ILWT, he recommended HP38 which is W231. I haven’t had FTE issues but sometimes have FTF issues. Not trying to steal the thread but I’ve found this thread to be very helpful. 

 

I used to run 4.0TG under a 115fmj. Everything got really dirty so I switched to plated. Stuff was still getting really dirty so I called Rob and he suggested HP38. It still seems dirty but not as dirty as TG. I tried the whole Blue bullets and ibejihead painted bullets but what a mess. Never again in this gun.  Which sucks as I get discounts thru ibejihead. Oh well...

 

I did just recieve my BCG from ILWT which I haven’t run yet.  

 

Ive found I like how the gun runs with a  1200fps 115, but just want it to be 100%. I’ve tried like 1000 triggers in the gun and so far I keep switching back to the stock timney MPX PCC black trigger.  I bought the timney DH3 which they said it will run in a MPX, but after about 1500-2000 rounds it started not being able to drop the hammer. I adjusted the set screw and it worked, but then it didn’t again. I think they’re sending me a new trigger..

 

sorry I added no value to this topic. I’m just bored with this shelter in place crap

Edited April 1, 2020 by Bdh821

[Chris Keen]

I've used a Hiperfire 24C for 3+ years in mine with no issues thus far. 

[Bdh821]

So I tested out some clean shot yesterday.  I loaded 3.5gr under a 115. Felt very soft. Gun ran 100 rounds flawless. I have about 1000 rounds of my normal hp38 loads thru the gun since I’ve cleaned it. So in other words it was kinda dirty. I’d think it was sub minor as I didn’t chrono because everyone was saying how it’s not an ideal powder for the MPX

[ck1]

This thread kind of put the light bulb on for me as far as running coated bullets through the MPX... never really put too much thought into the gas port in the barrel getting crudded up, but after scraping all the crud off the comp a few times, I think I’m going switch to jacketed only. Makes sense to me that shrinking the gas port while rounds add up doesn’t seem like the best plan lol. Granted, I haven’t had any issues with mine at all (knock on wood), but I’m not a religious gun cleaner either, so I don’t want my laziness to catch up with me.
 

I’ve still got about 600-700rds of the Syntech 130gr kicking around that I’m still going to shoot up, but after that I’m going to jacketed in the MPX (and if/when I can ever buy ammo again LOL that’s what I’ll be buying to feed the MPX).

 

Anyone have any good tricks to share as far as getting the barrel’s gas port nice and fully cleaned out and debris-free?

 

Edited April 2, 2020 by ck1

[inertia]

Shooting the gun clears the port I wouldn't sweat that its were the coating goes after that which causes the problem.

[Bdh821]

3 minutes ago, inertia said:

Shooting the gun clears the port I wouldn't sweat that its were the coating goes after that which causes the problem.

That is exactly what Rob from ILWT said.   Regardless, I abandoned painted bullets for the MPX a while ago.   Plated boolits for me.  Same with my Desert Eagle... Either plated or jacketed soft points..

[GregJ]

This came up on a search, so I thought I would close it up.  I sent my barrel off to ILWT and Rob opened the port to .060.  This, in conjunction with running the PCC/Gen III BCG from Rob in my Gen II, and working up a better load with plated or full jacket bullets, and my Gen II has been running like a swiss watch!!   

 

My load now is plated RN bullets @ 1.100 with 4.4gr of Shooters World Ultimate Pistol.  No more coated bullets in my MPX, they just gum up the plug rings too bad. I did a lot of testing between my usual pistol powders, prior to sending the barrel off, and found that UP was the only powder that consistent locked the bolt back with one round in the mag (LRBHO), though the results were a little erratic - suspect due to the gas port.  If the bolt locked back, then the gas system had enough gas and was working as it should. Since getting the barrel back, I found that I could go quite a bit lower in PF with the UP and still LRBHO.  This again confirms the UP makes more gas than my pistol powders (W231, Clean Shot, Sport Pistol).

 

Thanks all. 

 

[Underwood]

On 4/1/2020 at 7:57 AM, Chris Keen said:

I've used a Hiperfire 24C for 3+ years in mine with no issues thus far. 

Same here, but just installed a elf pcc trigger and it seems to working well. The 24c went into an other AR build

 

Mine also runs 3.7 TG with Zero 124's .. 

[NOSHMJ]

Ive shot the mpx for 4 years now.  I use 147 Blues, and only failure I have has is the extractor springs go flat, and FTE.   It WILL happen at some point.  Change the little springs, and carry extras.  I have mine SBRd, with an original 226 x5  comp on it.  Shoots soft as can be.  

[-JCN-]

On 3/18/2020 at 3:24 PM, 2011BLDR said:

Is the expansion chamber in the gas plug clear? Coated and exposed lead base bullets will fill the expansion chamber in the gas plug causing an over gas issue that results in:

• early extraction while brass is still expanded in the chamber
• extractor slips off the case
• blow back finishes the case extraction but the case never contacts the ejector because it is not on the breach face 
• faster burn rate powders can add to this issue ( pushing gas in to the gas system early in the dwell time at a faster rate / sooner than a  slower burn rate would have)

in my past experience  the expansion chamber in the gas plug clogged with lead/ polymer coating is extremity difficult to clean out even with metal scraping tools.  I gave up on one after 3 hours of work and only 20% progress against the lead fouling, I replaced it and threw it in the trash, I only shoot JHP or TMJ now  with CFE or Sport pistol and bought a good Ultrasonic tank.

Thank you so much for this explanation! I was having such a hard time wrapping my mind around what was happening in my gun (coated bullets or exposed bases) with the intermittent dribble. 
 

But it makes total sense to me in the context of what you’re describing. 
 

I’m thinking of seeing if I can forgo total cleaning as often if I just swap clean plugs and pistons in more frequently. I can do that with barrel still on gun using an extension socket. 
 

Also been experimenting with a mild steel drill bit to clear coked plugs. Seems to be working well. 
 

Thanks again for the knowledge!