Acer2428

If you EVER shoot an indoor match, it's like cheating. Also green laser + red dot and there's basically never a target/condition, etc that I can't pick up ONE of the dots. I found it much more useful than an offset dot, but I'm also not a GM, so there's that.

Devil's advocate here: Why? Glock mags are well proven and relatively cheap. Lowers can be had VERY affordably as well.

Almost guaranteed with those springs. If anything you should have run the AR-10 springs that come with the MBT to combat bolt speed. By going to a weaker hammer spring you not only had harsher energy transfer (what kills most non-bridged triggers) but you also reduced hammer energy.

2 stage trigger on a USPSA MPX makes no sense. That said, I'm excited for the new Hiperfire MPX specific trigger.

What I described is exactly legal, actually. I never turned it into a pistol. It went from an SBR (short barrel rifle) to a non-SBR configuration, and thus it just becomes a rifle. Which does not require the ATF's blessing to travel between state lines.

As an option, you could sent the bbl+ext. to CLass 3 machining and have them chop/thread to 1/2x28 and pin/weld the taccom extension in one shot. I had that done to one of mine since I wanted a 6.5" bbl anyways.

Get an additional barrel from ILWT or find a factory take-off IMO and then pin/weld a shroud to it. I have two MPX SBR's and usually plan ahead on forms, but on short notice out of state, if you put a 16" bbl in it, it's no-longer in SBR form and no longer requires the ATF's blessing to travel with. Shoot it in 8" config at home, slap the 16" bbl in it if you need to. the shroud really doesn't add much weight and I run the same HG, so it's not much different other than movement/spacing from walls. If that's too much coin, just SBR it for $200, file an E-form 1 and be done.

As a user of previously Colt, then Glock, and now MPX mags, this feels like a solution looking for a problem. Are there Scorpion guys who will want an AR-style gun for USPSA/IDPA without buying new mags? Sure, but seems like an awfully small segment. Not like Glock mags are terribly expensive or that you need more than a few to get started competing. I also fail to see how an MPX mag w/ factory capacity for $10 cheaper is a win. The MPX mag is (arguably) in the top tier of PCC mags ever made, not much to be gained other than cheap mags I can use for practice.

2/3 Sat, 1/3 Sun AM + Prize Table. Having the Prize Table on Sunday sucks for the out of towners who shot Sat (because they need Sunday to drive home). Doing 1/2 of the stages Sunday and THEN doing the drawn-out ceremonies Sunday takes too long. 7-8 Stages Sat, 4-5 Stages Sun AM + Awards and let everyone hit the road would be ideal.

What's the thread pattern for the brake @BC27 ?

Roller locked, so I'm sure there's huge R&D money invested... and they didn't win the .gov contract to pay for it all. Classic Sig move without the Sig swagger/history. For same money you can get an MP5 clone, or slightly more and get a real HK these days.

I can almost guarantee that's what it is. That said, everyone send me $5 and I'll live stream while I do a disassembly on the Cabela's counter (after I buy one).

Already have two Gen 1 SBR's, but kinda want this model. Stock would get traded to someone who wants a tacticool MPX (plenty of them out there) and the trigger would be a hiperfire anyways. Tempting. Anyone have any experience running the PCC/gen2.5/3 uppers on previous gen lowers?

Glad to hear it. I've heard the OG models have been racked with issues.

I have tried many different combos. The Hiperswitches are cheap molded plastic. The edges are hard. When I went to sand the weak-side down to clear my grip, I found a large void in it. No confidence, junk product IMO. I tried Timber Creek, generic ambis, Strike Ind, etc. The Odin Works paddle jobber is what I settled on. Adjustable, had paddles, works well. Only downside is price.

Did you try a control of a different platform with the same ammo? Or even just a different setup to eliminate chrono issues?

How are you figuring a JP recoils MORE? In the scale of recoil from least to most: - MPX - CMMG Guard - HEAVY AR-style - Lightweight AR style JP's are heavy. Thus they generally have less felt recoil. It's just physics.

I'm glad you're happy and you need to pick whichever works best for you, but: .... Did you put it against a timer? Other than reliability, it's the only metric that matters IMO.

Odd. When I ran colt mags I had 4 or 5 of the TF mags that all worked flawlessly, even on crappy Stoner brand 20 rounders.

Yep. I'd be all over it, but too steep for me.... and I shoot an MPX!

My favorite is everyone buying pencil bbls, carbon fiber HG's, MFT minimalist stocks, etc.... and then hanging 1.3 lbs of lead under the gun. Has anyone put a giant stick on the timer? Two 33 rd mags vs. one 60 rd. on the clock? Seems like in a 50+ round stage the time penalty of a reload would be minimal and how much time do you lose in transition/muscling the gun w/ a 60 rd stick in?

Gen 1 has a larger gas port and will run at a lower PF/faster powder. Gen 2's (most of what's out there) can't skirt the PF floor, especially with fast-ish powders without modification.

Seems like a ton of leverage to put on those little pins, but good for table starts I suppose.

A slightly slower burning powder would be idea (assuming you have a Gen2 MPX) Also why can't you do a punk test? Remove the barrel, drop a round in, turn it upside-down.

Yes, tons and tons of info out there. In ye olden days we started with quarters. You can add/subtract to your liking. Then once you get the length you can cut a delrin rod, etc. Thankfully we live in modern times and you can go out and buy a short stroke kit from taccom, JP, etc. If you don't like it, re-sell it for a small loss. If you keep your bolt catch AND full-length travel you WILL eventually break your catch.