SIG SAUER MPX (Update: Exclusive Non-NFA version P7)

March 30, 2016, 11:39 AM

quote:
Originally posted by gkgeiger:
quote:
Originally posted by g8rbreath:
Same thing here, rejected today because I had Model as "MPX-P-9" which I chose from the drop down menu using eForms. A note on my disapproved form from the examiner said to change it to "Sig MPX" which looked like it was the only MPX option on eForms (they must have gotten rid of all the other variants). I submitted the new corrected Form 1 within 15 minutes and emailed the ATF Examiner to let her know. My new form was approved within half an hour. Stoked!
I read about this on another forum. It concerned me since I have a form1 in process with the model MPX-P-9. I called the ATF and the lady I talked to said that with SN it is correct. I'm probably going to be denied.

Guess what, Denied.

March 30, 2016, 02:42 PM

gkgeiger

quote:
Originally posted by dwd1985:
quote:
Originally posted by gkgeiger:
quote:
Originally posted by gkgeiger:
quote:
Originally posted by g8rbreath:
Same thing here, rejected today because I had Model as "MPX-P-9" which I chose from the drop down menu using eForms. A note on my disapproved form from the examiner said to change it to "Sig MPX" which looked like it was the only MPX option on eForms (they must have gotten rid of all the other variants). I submitted the new corrected Form 1 within 15 minutes and emailed the ATF Examiner to let her know. My new form was approved within half an hour. Stoked!
I read about this on another forum. It concerned me since I have a form1 in process with the model MPX-P-9. I called the ATF and the lady I talked to said that with SN it is correct. I'm probably going to be denied.

Guess what, Denied.

Easy fix: Call your examiner, explain the situation, provide the old and new document numbers...you will have approval within a day or two.

Can't submit a new form on Wed., so I'll do it in the morning. Thanks,

March 31, 2016, 09:06 AM

gkgeiger

It took less than a hour to get corrected. Yeehaw

Form 1 filed 1/8/2016.

April 04, 2016, 09:19 AM

Brett B

Trying to get caught back up on the MPX stuff. I remember reading a while back that people were getting a lot of gas in the face when shooting suppressed. Has this been resolved? What cans are recommended to minimize this?

I'm looking at the MPX Pistol 9" and am thinking about getting an Octane for it. I am also considering a Hybrid and am wondering if it would cause less gas in face since it's a larger volume and bore.

Lastly, how quiet is the MPX with subsonic rounds? Is it quieter than a 300 Blackout with subs? I'm looking for a quiet backyard plinker that doesn't bother the neighbors. I know it wouldn't be subsonic .22 quiet but I'm hoping it's a lot better than my Sig P220 with an Osprey 45.

April 04, 2016, 12:01 PM

slipjett

quote:
Originally posted by Brett B:
Trying to get caught back up on the MPX stuff. I remember reading a while back that people were getting a lot of gas in the face when shooting suppressed. Has this been resolved? What cans are recommended to minimize this?

I'm looking at the MPX Pistol 9" and am thinking about getting an Octane for it. I am also considering a Hybrid and am wondering if it would cause less gas in face since it's a larger volume and bore.

Lastly, how quiet is the MPX with subsonic rounds? Is it quieter than a 300 Blackout with subs? I'm looking for a quiet backyard plinker that doesn't bother the neighbors. I know it wouldn't be subsonic .22 quiet but I'm hoping it's a lot better than my Sig P220 with an Osprey 45.

Shot 150 of subs through my MPX suppressed and has been cut down to 4.5" yesterday with minimal gas in the face. Not sure about the complaints, only had one person out of at least 10 people shoot my MPX that complained about the gas. And yes, my ear believes it's much quieter than a 300blk and Sig P220 shooting subs. Good luck.

April 04, 2016, 01:50 PM

Brett B

Great thanks for the reply. What suppressor are you using?

Also can somebody clarify for me which is the Gen 1 mag and which is the Gen 2 in the picture below?

April 04, 2016, 02:31 PM

Brett B

Awesome thank you, that's what I thought but didn't want to assume.

April 05, 2016, 10:19 AM

argolfer

quote:
Originally posted by Brett B:
Trying to get caught back up on the MPX stuff. I remember reading a while back that people were getting a lot of gas in the face when shooting suppressed. Has this been resolved? What cans are recommended to minimize this?

I'm looking at the MPX Pistol 9" and am thinking about getting an Octane for it. I am also considering a Hybrid and am wondering if it would cause less gas in face since it's a larger volume and bore.

Lastly, how quiet is the MPX with subsonic rounds? Is it quieter than a 300 Blackout with subs? I'm looking for a quiet backyard plinker that doesn't bother the neighbors. I know it wouldn't be subsonic .22 quiet but I'm hoping it's a lot better than my Sig P220 with an Osprey 45.

Hey Brett - I've never had any problems with gas to the face on the MPX either. I have a Trident9 and an Octane 45. I do think it has more to do with type of ammo. Have you looked at the Obsidian? Initial reviews show it's very good with back pressure.

For my ears, the suppressed MPX is quieter than the suppressed 300blk, though I don't remember shooting them one after the other. I shoot my MPX suppressed in my back yard.

April 05, 2016, 11:55 PM

HRK

Took the MPX to the range for the fist time with the collapsible stock, 150 rounds worked great but now the button to collapse the stock won't go down and it's stuck in the extended position

Anyone else experiencing this? If so what's the fix or is it call sig time.

April 06, 2016, 03:08 AM

LDD

quote:
Originally posted by HRK:
Took the MPX to the range for the fist time with the collapsible stock, 150 rounds worked great but now the button to collapse the stock won't go down and it's stuck in the extended position

Anyone else experiencing this? If so what's the fix or is it call sig time.

The A3 style stock is retained by two set screws that can be accessed from the underside of the stock body.

Turn the stock upside down and you'll see a small screw you can extract with an allen key (We'll call this one Screw #2). Underneath that screw is an identical screw (Screw #1). It's Screw #1 that controls the "tightness" of the struts (I think it may actually control how much the top release button can depress--if it can't depress far enough then it won't release). Back #1 off until the stock slides as you'd like it to, then re-install #2 to lock #1 in place.

Self diagnostic: If #1 is too tight, then the struts lock and you can't open or collapse the stock tail. If #1 is too loose, you get excessive play between the locking piece and the struts (and the stock feels wobbly).

I guess you could use loctite on #1, but be conservative and use blue loctite, not the red or purple stuff.

April 06, 2016, 11:10 AM

HRK

Thanks

I'll look at it this evening, prior to shooting it moved fine, I"m guessing the vibrations from shooting caused the set screw to turn in.

I'll put a dab o blue on it so it doesn't move in the future.

April 06, 2016, 06:40 PM

D4Heavy

Has anyone tried a Liberty Mystic suppressor on the MPX?

April 06, 2016, 07:29 PM

immawake

quote:
Originally posted by D4Heavy:
Has anyone tried a Liberty Mystic suppressor on the MPX?

Not yet, but soon. I have one in jail for my MPX. It should be out in a couple of months. I wanted a Thompson SG2, but couldn't find one anywhere. I got the Mystic X because it seemed to be a close alternative.

April 06, 2016, 08:43 PM

D4Heavy

I have the original Liberty Mystic and will try it once I get my MPX (bought from a forum member here) Seems the rail diameter is 1.76 so the Omega might even work with its 1.56" Dia. Just need to find a thread adapter.

April 06, 2016, 10:36 PM

ftttu

quote:
Originally posted by LDD:
quote:
Originally posted by HRK:
Took the MPX to the range for the fist time with the collapsible stock, 150 rounds worked great but now the button to collapse the stock won't go down and it's stuck in the extended position

Anyone else experiencing this? If so what's the fix or is it call sig time.

The A3 style stock is retained by two set screws that can be accessed from the underside of the stock body.

Turn the stock upside down and you'll see a small screw you can extract with an allen key (We'll call this one Screw #2). Underneath that screw is an identical screw (Screw #1). It's Screw #1 that controls the "tightness" of the struts (I think it may actually control how much the top release button can depress--if it can't depress far enough then it won't release). Back #1 off until the stock slides as you'd like it to, then re-install #2 to lock #1 in place.

Self diagnostic: If #1 is too tight, then the struts lock and you can't open or collapse the stock tail. If #1 is too loose, you get excessive play between the locking piece and the struts (and the stock feels wobbly).

I guess you could use loctite on #1, but be conservative and use blue loctite, not the red or purple stuff.

I originally thought I had the adjustment down but I don't as of yet. There is a screw directly under the button and then the two hex screws below that.

I originally adjusted the two hex screws but they loosened after shooting. I took it apart again and just srewed the button screw all the way in, and then just tightened the two hex screws to where the small one is flush.

It retracts/collapses as "advertised" but I will see how long it lasts after shooting sessions.

April 07, 2016, 12:13 AM

HRK

Fixed mine tonight will take it back to the range hopefully it's good to go appreciate the help

April 07, 2016, 08:40 AM

slipjett

quote:
Originally posted by D4Heavy:
Has anyone tried a Liberty Mystic suppressor on the MPX?

I have the titanium version of the Mystic, the Infiniti. Use it almost exclusively on my MPX, sounds great, but protrudes way out even with my cut 4.5" barrel.

April 07, 2016, 09:20 AM

D4Heavy

quote:
Originally posted by slipjett:
quote:
Originally posted by D4Heavy:
Has anyone tried a Liberty Mystic suppressor on the MPX?

I have the titanium version of the Mystic, the Infiniti. Use it almost exclusively on my MPX, sounds great, but protrudes way out even with my cut 4.5" barrel.

I guess there is always a trade off between sound suppression and length. If you want it short and compact it's going to be louder.

April 07, 2016, 01:48 PM

slipjett

quote:
Originally posted by D4Heavy:
quote:
Originally posted by slipjett:
quote:
Originally posted by D4Heavy:
Has anyone tried a Liberty Mystic suppressor on the MPX?

I have the titanium version of the Mystic, the Infiniti. Use it almost exclusively on my MPX, sounds great, but protrudes way out even with my cut 4.5" barrel.

I guess there is always a trade off between sound suppression and length. If you want it short and compact it's going to be louder.

The trade off does have me seriously thinking of a SilencerCo Omega 9K...