There is no reason owners of the Gen 1 should have to buy Gen 2 9mm uppers and mags. If you buy a complete Gen 2 upper from Sig, your paying Sig to fix there mistake. Sig screwed up, make them supply and support what they advertised. There is still no 100% guarantee that they will follow through on there promise to support the product, paying false advertisement, bait and switch claims might end up being cheaper then making the parts. See what they show and say at Shot Show about the MPX. They did say different barrels would be available 1st Q 2016.

Why would anyone pay for a Gen 2 9mm upper to replace the Gen 1 9mm upper, there is no advantage to doing so other than relieving you pocket of cash and satisfying a desire to have a gen 2.

The reliability so far seems the same
You can swap caliber for the same $ on either
Gen 1 9mm's fire boolits the same way as gen 2

So whats the real advantage of buying a gen 2 9mm upper to replace a gen 1 9mm upper. I don't see it.

How much support is the Gen 1 going to get in the future is questionable? More of a issue with mags and different barrel lengths. Best thing to do is push Sig into supporting and bringing to market what they advertised.

quote:

Why would anyone pay for a Gen 2 9mm upper to replace the Gen 1 9mm upper, there is no advantage to doing so other than relieving you pocket of cash and satisfying a desire to have a gen 2.

If someone has an 8" gen 1 and wants a 4" bbl, buying a 4" 9mm upper gives them the shorter barrel and an upper that now has bbl and caliber change capabilities. Sure, if you get a .357 sig upper, then you can put a 4" 9mm bbl in that one, but you can put a .357sig bbl in the 9mm upper just the same. BUT, while it probably should be whatever the user wants first, it'll probably come down to whatever SIG releases first.

Does anyone else wish the QD cup on the rear was a limited rotation?

quote:

If someone has an 8" gen 1 and wants a 4" bbl, buying a 4" 9mm upper gives them the shorter barrel and an upper that now has bbl and caliber change capabilities. Sure, if you get a .357 sig upper, then you can put a 4" 9mm bbl in that one, but you can put a .357sig bbl in the 9mm upper just the same. BUT, while it probably should be whatever the user wants first, it'll probably come down to whatever SIG releases first.

That means your have to buy a upper receiver, bolt carrier group, and Gen 2 mags. It was advertised as a modular system. Sig said they would have the shorter Gen 1 barrels 1st Q 2016. Wait and see what happens with the conversions, right now they are not available for either Gen. Knowing Sig we might have to wait for the Gen 3's to get the conversions.

I have talked to Sig CS and they are going to sell the barrels for gen 1 9mm so you don't need to change uppers to accomplish a change

As long as barrels and mags are available to buy a gen 2 upper in 9 mm is redundant and expensive
Jmo

Unless sig fails to support the gen1 interchangeability then we should be fine as gen 1 owners

So Gen1 mags will work with Gen2 uppers, but maximum reliability will be using same Gen mag and upper, correct? I just got a bunch of Gen1 mags as Xmas gifts and Gen2 mpx incoming. Damn it!

quote:

Originally posted by ergoproxy:
So Gen1 mags will work with Gen2 uppers, but maximum reliability will be using same Gen mag and upper, correct? I just got a bunch of Gen1 mags as Xmas gifts and Gen2 mpx incoming. Damn it!

I'll ask SIG how big of a problem this really is, I suspect it's CYA.

If it really becomes a problem, I'm thinking of doing something on or off board where members can trade magazines if it really becomes that big of an issue. My Gen2 T&E MPX came with a Gen1 magazine, so it really can't be that big of a deal.

Thanks LDD. I take it that your Gen2 T&E MPX has been flawless with the Gen1 mags? And it seems like Gen2 mags are only available at the Sig shop right now.

quote:

Originally posted by LDD:


I'll ask SIG how big of a problem this really is, I suspect it's CYA.

If it really becomes a problem, I'm thinking of doing something on or off board where members can trade magazines if it really becomes that big of an issue. My Gen2 T&E MPX came with a Gen1 magazine, so it really can't be that big of a deal.

quote:

Originally posted by ergoproxy:
So Gen1 mags will work with Gen2 uppers, but maximum reliability will be using same Gen mag and upper, correct? I just got a bunch of Gen1 mags as Xmas gifts and Gen2 mpx incoming. Damn it!

I have one Gen 2 mag that came with my Gen 2 MPX. I also have 5 Gen 1 mags. I have run hundreds of rounds through my Gen 2 MPX with the Gen 1 mags without any problems. The only real difference I've experienced between the Gen 1 mags vs Gen 2 mag is I think the Gen 2 mag is a little easier to load due to the extended feed lips.

quote:

Originally posted by ergoproxy:
Thanks LDD. I take it that your Gen2 T&E MPX has been flawless with the Gen1 mags? And it seems like Gen2 mags are only available at the Sig shop right now.

The gun doesn't seem to care if it's being fed with the gen1 or gen2 magazines. Several hundred rounds, No failures to speak of.

I just put in a Black Rain Ordnance trigger (super short reset) so next test is as-fast-as-you-can-shoot-em, but I don't expect the results to be any different (really was not happy with the factory trigger's weight or reset).

I don't have a Gen1 gun to test, but I do know Gen1 MPX owners with multiple Gen2 magazines and they've reported no issues. I don't think SIG would send a T&E gun out with the "wrong" magazine--they knew who they were sending it to.

I have two gen 1 mags and 3 gen 2 mags. The only failure ive had was with Armscor ammo. A friend bought a box on my last range trip since he didn't want to use up all my ammo. In the MPX, It wouldnt feed at all - the nose would catch on something and the bolt would push the round causing some major bullet setback. I swapped back to federal and had no issues. We used the armscor in my G19 and had a couple issue there, too.

Thanks LDD and immawake. I guess, I'll just hang on to the Gen1 mags I have.

Did it happen to both gen of mags or just a specific gen?

quote:

Originally posted by PorterN:
I have two gen 1 mags and 3 gen 2 mags. The only failure ive had was with Armscor ammo. A friend bought a box on my last range trip since he didn't want to use up all my ammo. In the MPX, It wouldnt feed at all - the nose would catch on something and the bolt would push the round causing some major bullet setback. I swapped back to federal and had no issues. We used the armscor in my G19 and had a couple issue there, too.

quote:

Originally posted by ergoproxy:
Did it happen to both gen of mags or just a specific gen?

Gen 1 mag. I didnt try it in the gen 2 mags. Should have.

It happened twice on the glock, too. It was weird ammo. The range sold it to us for $11.97 a box? Yellow and black box.

Hello,
Okay, I am considering an MPX for an SBR project. My buddy checked one out last night at the local gun store. Here's my concern that I don't know about and was told about (I have only handled one MPX rifle before and this is the first I've heard about this particular issue):

Rumor has it that the rifle has a serious issue. The issue is with the bolt cam. Supposedly, the cam is marked to go into the bolt ONE WAY ONLY. It is super easy to put the cam into the bolt any way (meaning the "correct way as marked" or "backwards"). If the weapon is fired with that cam installed, not the correct way, supposedly the rifle will lock up and could completely destroy the rifle internally.

Is this true? If it is, that is a real serious problem with this weapon I would think. Even if I installed it correctly, I would worry that it wasn't in there correctly. It's something I would worry about ALL THE TIME.

So, let's have it. True or untrue? I hope it's untrue as I was really leaning toward the SIG MPX over the CZ Scorpion. If it is true, I'm going CZ.

Thanks in advance.

quote:

Originally posted by Tiger 2 Tank:

So, let's have it. True or untrue? I hope it's untrue as I was really leaning toward the SIG MPX over the CZ Scorpion. If it is true, I'm going CZ.

Thanks in advance.

Well, no one is going to knowingly install the cam backwards and shoot the gun in this condition, so I doubt a private owner will be able to tell you if your hypothesis is true.

I did unknowingly install an MPX cam pin backwards and it locks up the BCG, so yeah, that is potentially bad. But it only locked up the BCG in such a way as to prevent me from easily taking the BCG out. The bolt could still rotate and partially unlock, it just wouldn't fully unlock--not sure if the incorrectly assembled BCG would simply stay in battery and just fail to load the next round or force-unlock with the cam pin then gouging the sacrificial plate in the receiver. Obviously I didn't fire it in this position.

You can tell from the outside that there's a problem because you won't be able to pull the charging handle back all the way. Going from memory the stroke limitation is pretty severe. You probably wouldn't even be able to pull the CH back far enough to get the bolt to strip a round off the top of a magazine--so blowing up your gun would be quite a party trick.

Once I finally got the BCG out there was no visible damage to the inside of the upper.

It's pretty easy to assemble correctly, just line up the two dots (one on the cam pin, one on the carrier). You can visually confirm that the cam pin has been installed in the proper orientation. The instructions are quite explicit on this matter.

If you insist on assembling your MPX incorrectly, I suppose anything could happen.

I've seen all sorts of issues with guns put back together sideways--it can happen with any platform and any assembler so long said assembler can gather a sufficient amount of incompetence together in a single sitting (yours truly not excepted). I've seen SIG PRO's with the slide stop lever spring installed under the lever (so that the slide locks back every time the gun was shot), ARs, with the firing pin retaining pin inserted before the first collar on the firing pin, AR hammer springs backwards, takedown pin going the wrong way, rifle buffer in a carbine tube, etc.

If I'm reading correctly then it sounds like it is easy to install the cam incorrectly, but an operator won't be able to pull the charging handle back to get the bolt carrier group cycled? So, it may not be possible then to fire it with the cam installed incorrectly? If that's the case, that's okay. I am just concerned that you could accidently install the cam in the bolt incorrectly and not realize it, fire the weapon and have a catastrophic and permanent failure.

finally got my tracking number for my stock.
should arrive on monday.
7 months and a week after I ordered it - and only because I called bitching and got my part# changed.