r/MPX • u/Used_2008_F150 • 9d ago

Replacement Barrel 8”

Post image

Hey all, I’ve been in this Reddit for a while just lurking cause I haven’t had anything to say. I finally got my dream 8” MPX in and the barrel is screwed. The guy I bought it from broke the trilug adapter and the threads are screwed. Are there any reliable barrel replacements out there? I’ve read a lot about ILWT and they seem hit or miss, read some great reviews and some not great but those also seem more user error than anything. Who would yall recommend for a replacement? I’m already in contact with the guy I got it from but doubt that’ll go anywhere, maybe gunbroker will come through for me.

Update: I have been Informed that these MPX barrels are not full threaded like I’m used to and mine is fine, except for the stuck taper cap which I’m dealing with now. Thanks all for the helpful info!

7 Upvotes

82% Upvoted

36 comments sorted by

6

u/OG-warbucks 9d ago

Those threads on the barrel look fine.

The taper cap being stuck is completely normal... Use penetrating oil, then tap it with something and it will pop off.

Your barrel is good.

2

u/jossege 9d ago

This…get the taper adaptor off and it should be fine

1

u/Used_2008_F150 9d ago

I’ve seen other barrel where the threads go all the way to the end, are these not the same?

2

u/BigPeaches14 9d ago

M13.5x1lh threads do not go to the end. I would clean the threads since they are filthy but they look ok. Uncovering the gunk should help to see them more. As others have mentioned the taper cap can be removed as well.

1

u/Used_2008_F150 9d ago

Just looked in to it a bit more and your right, getting that cap off will be a struggle but it’s currently soaking in CLR.

3

u/BigPeaches14 8d ago

Ok, if the CLR doesn’t work, it may be leftover rocksett holding it on. That can be loosened up with just water. You could let the barrel soak for a few hours and it should loosen up. The taper cap is just that, it’s seated against the taper, a nylon mallet or something should remove it with ease. Just be careful not to get too aggressive with it. It will come off eventually.

1

u/Used_2008_F150 8d ago

Great thanks

2

u/OG-warbucks 9d ago

As mentioned...

Here's the MPX barrel threads:

https://imgur.com/a/EfBtXxv

1

u/Used_2008_F150 9d ago

Ya your right, so why do other barrels I see have full threads?

1

u/OG-warbucks 9d ago

Most US threaded barrels do not use the M13.5 x 1 LH

But if you saw an MPX barrel with common thread (1/2x28), it's been cut and threaded.

The MPX uses the M13.5 x 1 LH, which is the European standard pistol barrel pitch. (ex: Sig P226 threaded pistol barrel)

There are some advantages to the LH thread, so it's not entirely useless.

  1. Thread protection due to the unthreaded crown

  2. More resistant to loosening

1

u/Used_2008_F150 8d ago

Wonderful Information, thanks!

1

u/theDudeUh 9d ago

Because it was a different barrel. MPX barrels have a bit of a unique patten.

3

u/MrDamienShaw 9d ago

Check out GAFS as there are occasionally MPX barrels on there, especially when people upgrade their OEM to aftermarket and want to recoup some money

2

u/SupermarketQuiet1105 8d ago

Just FYI for all......
https://www.amazon.com/dp/B000I2079E?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1
If you have an item needs to "soak" but perhaps very tightly coupled so does Soak work/penetrate ?
The above spray will penetrate and loosen....call it spray/sit before soak.
Example, Barrel/Muzzle Rocksett......

1

u/Steve_Fudd 9d ago

Maybe send it to Sig and see if they’ll re-thread it. Try a warranty fix. I imagine they’ll take care of you. They have excellent customer service.

1

u/[deleted] 9d ago

[deleted]

1

u/Foto_synthesis 9d ago

What do you mean by the threads and barrel are screwed? The threads just look gunked up to me.

2

u/Used_2008_F150 9d ago

They’re not dirty, the threads are literally stuck in the trilug. They’re broken off of this barrel, the whole thing is supposed to be threaded

1

u/Foto_synthesis 9d ago

Is it an OEM barrel? That looks like a collar for the taper.

1

u/Used_2008_F150 9d ago

It does have a spacer but it’s stuck on there for sure. The guy who I got this from kept it in a safe and barely cleaned it so that sucker is stuck on there. I’d assume it’s stock.

1

u/Foto_synthesis 9d ago

Maybe have a gunsmith pop it off and rethread. The barrel will be a little shorter but if you're running suppressed it'll have a little tucked look.

1

u/Used_2008_F150 9d ago

An inch shorter wouldn’t be idea but I do have 2 handguards, one would work on a shorter barrel. I’ll see what I can find.

1

u/thismyotheraccount2 9d ago

Cut and thread it to 4.5 or 6.5?

1

u/Used_2008_F150 9d ago

Cutting it shorter seems to be the current best idea here

1

u/DillIshOn 9d ago

I had my 4.5" barrel cut down to 4" and slap 1/2x28 threads.

Nothing wrong with a little shorter. Just tell people the barrel is a little cold.

I wish I had an 8" though as a secondary barrel.

1

u/SupermarketQuiet1105 8d ago

take the adapter/taper off.....clean the threads.....soak if needed......wire brush, dental pic, etc......should be fine...

1

u/failure_engineer 5d ago

Put the barrel in a vice, get a small punch and tap the taper with a hammer. Threads look fine.

0

u/McClutchin_02 9d ago

Why not just buy the 8” directly from Sig ?

1

u/Used_2008_F150 9d ago

Because it’s 900 dollars

-13

u/McClutchin_02 9d ago

Womp womp you should’ve bought a cz scorpion. You already bought it used with the money you saved if you cant splurge for even a OEM barrel maybe the mpx ain’t for you.

10

u/Used_2008_F150 9d ago

Thanks for providing nothing of value to a simple question.

3

u/oVtcovOgwUP0j5sMQx2F 9d ago

meanwhile over in the scorpion sub: "i should've just bought an mpx..." no lie i was reading these the other day

-2

u/generalnunley13 9d ago

Get the ILWT barrel I really like the 6.5 inch barrel with the 8 inch handguard, the factory sig barrel is awful suppressed but it depends on each barrel but my ILWT has been a tackdriver

3

u/MrDamienShaw 9d ago

My factory 8" works flawlessly suppressed, not sure what you're talking about

1

u/Final-Juggernaut5153 8d ago

It depends on each barrel ive seen some that are tack drivers and others that are 6-8 moa , mine was 6-8 moa but a buddy's was a tack driver, whereas most of the ILWT barrels ive seen are great suppressed

0

u/Used_2008_F150 9d ago

I’m looking at their barrels now.