Gen 1 mags fail to feed about 5 times out of 20 rounds - I'm shooting 115 gr at COL 1.115". Have loaded some 147 gr at COL 1.169" - probably try those within next several days. The Gen 2 mags fed the 115 gr and 124 and 147 @ 1.169. I bought the gen 1's on sale - doubled one with a Gen 2 to make a 70 round mag for 3 Gun PCC class.

quote:

Originally posted by dwd1985:

quote:

Originally posted by 911Boss:
Can gen 1 magazines be used in a gen 2 gun? Any problems? They seem to be a lot cheaper than gen 2 magazines.

There really shouldn't be any issues/ differences between Gen I and Gen II magazine use in either generation weapon. Nearly everyone has reported that both generations work just fine when interchanged.

Cool, just ordered 5 at less than 1/2 the price of gen 2 mags. Just the deal I needed to get me off the pot to order my pistol. Kinda surprised a local dealer had the best price on the pistol, not in stock but should be here next week, can't wait!

This message has been edited. Last edited by: 911Boss,

In a strange turn of events.... The ATF is faster than Sig at delivering things filled out on the same day. (Form 1 vs 4in barrel)

What do you guys like in the collapsible stocks? I have a sig folding stock right now. Its nice, but I really want to try a collapsible stock. Not looking for a M4 stock setup.

quote:

Originally posted by g8rbreath:
So called Sig customer service to check on my MPX K handguard I ordered Feb 2016, they said approximate ship date is July. At least my Omega 9K is about to clear! Can't believe it's taking so long for a part...

Sig just charged my Credit card $129, looks like the 4.5" handguard is shipping soon! woo hoo! hope it's not a false alarm...

They also charged my card for the 4.5" handguard on Saturday. I ordered it in January of 2016. Now just waiting for the shipping email - very excited for it to arrive!

ETA: Still no email from Sig, but I did receive a notification via my FedEx account with tracking info for an incoming (SmartPost) shipment. Shows it as in transit from SSI - Newington, NH.

This message has been edited. Last edited by: Cntrl23,

quote:

Originally posted by Cntrl23:
They also charged my card for the 4.5" handguard on Saturday. I ordered it in January of 2016. Now just waiting for the shipping email - very excited for it to arrive!

ETA: Still no email from Sig, but I did receive a notification via my FedEx account with tracking info for an incoming (SmartPost) shipment. Shows it as in transit from SSI - Newington, NH.

I got my shipping notice last night, checked FedEx and package is in transit for delivery Monday!

quote:

Originally posted by Smokey99:
Gen 1 mags fail to feed about 5 times out of 20 rounds - I'm shooting 115 gr at COL 1.115". Have loaded some 147 gr at COL 1.169" - probably try those within next several days. The Gen 2 mags fed the 115 gr and 124 and 147 @ 1.169. I bought the gen 1's on sale - doubled one with a Gen 2 to make a 70 round mag for 3 Gun PCC class.

I am running 115 gr. RN bullets (xtreme bullets) at that same length and have never had an issue with any of them, gen1 or gen2. Might be something with your gun, or with the cases having bulges perhaps. Hope this helps.

quote:

Originally posted by Smokey99:
I've bought 3 sets so far (have them on AR's also). Run about $195.00. Trigger pull 2.5-3 with the springs for lightest setting. 24C comes with three sets of springs so you can select what weight you want.

Very happy with the 24c trigger! Now if I could only reload as fast as I shoot the bullets I would be all set!! It did take about 200 rounds for me to get adjusted to it (or maybe it had to break in a bit too).

quote:

Originally posted by mpxgeek:

quote:

Originally posted by Smokey99:
Gen 1 mags fail to feed about 5 times out of 20 rounds - I'm shooting 115 gr at COL 1.115". Have loaded some 147 gr at COL 1.169" - probably try those within next several days. The Gen 2 mags fed the 115 gr and 124 and 147 @ 1.169. I bought the gen 1's on sale - doubled one with a Gen 2 to make a 70 round mag for 3 Gun PCC class.

I am running 115 gr. RN bullets (xtreme bullets) at that same length and have never had an issue with any of them, gen1 or gen2. Might be something with your gun, or with the cases having bulges perhaps. Hope this helps.

I'm running the identical bullet. I'll try the other Gen 1 I have. My MPX is a Gen II - but that should not be a different barrel/barrel extension than Gen 1 MPX. My failures with Gen 1 mag is bolt over bullet when feeding (20 round mag - maybe spring too strong?)

quote:

Originally posted by Smokey99:

quote:

Originally posted by mpxgeek:

quote:

Originally posted by Smokey99:
Gen 1 mags fail to feed about 5 times out of 20 rounds - I'm shooting 115 gr at COL 1.115". Have loaded some 147 gr at COL 1.169" - probably try those within next several days. The Gen 2 mags fed the 115 gr and 124 and 147 @ 1.169. I bought the gen 1's on sale - doubled one with a Gen 2 to make a 70 round mag for 3 Gun PCC class.

I am running 115 gr. RN bullets (xtreme bullets) at that same length and have never had an issue with any of them, gen1 or gen2. Might be something with your gun, or with the cases having bulges perhaps. Hope this helps.

I'm running the identical bullet. I'll try the other Gen 1 I have. My MPX is a Gen II - but that should not be a different barrel/barrel extension than Gen 1 MPX. My failures with Gen 1 mag is bolt over bullet when feeding (20 round mag - maybe spring too strong?)

Mine is a Gen2 gun, but I have only used 30 round mags. Now that I think of it, I have had a few instances of the first round not feeding properly, but that has always been my fault for not seating the mag in fully. I re insert the mag with a little more force and no issues.

How much powder are you running in your loads? I wonder if it's not enough to cycle the bolt all the way back and you are short stroking the bolt? I am running 4.6gr of titegroup. I run 4.2 for my pistols but thought it would be good to have a little more combustion to cycle this gun so I went with that and seams to be fine. I don't have a chrony available but no signs of over pressuring. I also cleaned the gas valve recently and the port was almost completely shut off by a big chunck of lead, which took about 2 hours to remove (I had been running a moly coated bullet in the beginning and believe melted lead to have caused this, I'm not running those in this gun anymore lol).

Keep me in the loop if you figure this out, I am interested to see what the issue has been. Good luck!

I'm running 1265 fps. With Gen II mags it runs everything. 147 gr (1.167 COL) at 800 fps also.

Finally received my 4.5" MPX K handguard yesterday! Luckily it came pretty quickly...only had to wait 439 days from when I placed the order.

I have a 4" barrel, cut and rethreaded by ADCO in January 2016, and TROS USA 3-Lug. I use a SilencerCo Octane 45 HD with Griffin 3-lug connection. I picked up an extra MPX front sight for the 4.5" handguard last year, so I can quickly swap between the two setups. The 4.5" handguard also has the Sig foregrip/hand stop installed. All I can say is WOW is the MPX tiny with the 4.5" handguard and a 20rd mag. Pictures just don't do it justice. Can't wait to get it out to the range!

Here is my MPX with the 4.5" handguard vs 8" handguard;






And the 4.5" vs 8" w/suppressor;






Sig item numbers:

Sweet! I just got my K handguard too. This gun fits PERFECT in my Crye AVS 1000 pack I bought just for this setup! The cool thing about the pack is you can put a armor plate in it too.

Very nice! I like that pack, fits that setup perfectly.

I also had the folding stock in the safe, never preferred it much with the 8" setup w/suppressor. So it mostly sat, swapped it out here and there. However, man does it make the K configuration TINY. When it's folded, it's just so compact.






Compared to a 9.7" iPad;

Wow, with the folder vs the telescopic that's got to take another 2-3" off OAL? I might have to look into that setup too.

I'm still not convinced the plastic Sig vertical grip is durable and that might be the first thing I have to switch out.

That front grip is such garbage.
I bought one - and was VERY disappointed in pretty much everything about it.
It's made of flimsy plastic - not a nice sturdy polymer.
It's too damn short - I end up with 2 fingers hanging off the bottom.

Great looking setups guys, such a compact little gun with the 4" barrel.

I heard the Sig grip was cheap too so ended up trying to the BCM KAG hand stop and so far I really like it.



I am also currently trying out the KM side folder since it saves 2-3" of OAL compared with the telescoping stock. I found that mine fits perfectly in the Hazard 4 Rocket pack with the side folder. With the telescoping stock it was too long. This Hazard 4 seems like a great pack for the MPX if you don't mind the tacticool look.

quote:

Originally posted by g8rbreath:
Wow, with the folder vs the telescopic that's got to take another 2-3" off OAL? I might have to look into that setup too.

I'm still not convinced the plastic Sig vertical grip is durable and that might be the first thing I have to switch out.

Yeah, looks like the folder comes in at 13" OAL, and the collapsible is just over 16.25" OAL. Like I mentioned, with the bigger MPX setup I preferred the collapsible...but the folder on the K is something else!

I agree with you and creslin about the Sig vertical grip, not super impressed with it. I like the form factor of it with the small setup, but it sure doesn't feel all that solid. Not a lot of room on this small rail though, that will likely narrow down the options for a replacement if you're looking to install and hand stop and vertical grip.

Brett B:
Thanks! You've got a nice looking setup as well. I recently picked up the BCM KAG for my 8" .300 blk SBR, I really like it. Minimal, solid, and great design.

WooHoo! I've officially joined the club. Just took delivery on my Gen 2 MPX.

Thanks to spaladin226 for a great deal and fast service!