ck1

Doh, 512 not 510, reading is fundamental lol...

https://www.primaryarms.com/holosun-riser-for-hs510c-red-dot-hs510c-riser ...brings it up to a lower 1/3 height. You can also order it through Holosun.com and in my experience they actually ship stuff pretty quick, but they must be redoing their site because right now it’s listed at $99.00 lol!

Nah, it’s not the mag lips, it’s just the magwell being tight with newer OEM mags that bulge a bit when loaded... once the polymer mag bodies wear in a bit they become gtg.

the OEM mags tend to fit tighter and "swell" when there's rounds in them, but the short-term annoyance is worth it IMHO.

The way the Hiperfire triggers work (kinda like a compound-bow), I totally get it affecting or having an effect on pulling back the bolt (this is exactly why they seem to play nicer and not kill themselves so quickly with PCC’s really). It's the same thing with 1911's or tuned-up CZ's where the hammer-spring affects things; I get it. Though really, with a PCC, it’s almost unnoticeable. That said, with the heaviest springs (yielding the lightest trigger pull) once broken-in, mine (I own 3 on a few different guns) all pull just below 2.5lbs and I really have never wished for them to be lighter while still being a total self-admitted OCD/Trigger-snob... (people come up to me almost every time I hit a square range when just testing stuff asking to try my “full auto” which isn't lol)! Not to sound snarky, but I honestly don’t know what going sub-2lbs vs 2.5ish would fix that working on transitions and other fundamentals wouldn't? Pretty sure Max and/or most of the better guys out there aren’t going any lighter than that or that being their "secret sauce", and that'd they would still smoke me or most of us with them running 7lb triggers hahaha... For Long -Range Precision Rifle, at 400+ yards or whatever, I could definitely see trying to go lighter, but for PCC? ...IDK. JMHO.

If budget isn’t a concern, with Glock mags, JP is probably the best IMHO, but MBX and maybe a couple others are probably right there too. If you’re looking to get your feet wet on PCC before going whole hog on some of the pricier complete-rifle stuff, you can build and upgrade as you go: I recommend the FM Products stuff, especially their lower, which is killer for the money (Wilson and a couple other “big names” actually license their design then charge a lot more money).

Hmm, I have a back-up PCC built with the FM Products Upper/Lower stuff and honestly recommend them (especially their Glock-mag lower) all the time due to their quality and tight tolerances (even against upper tier stuff like QC10 etc, incredibly good for the money really). One of the main reasons their lower is so nice IMO is that it holds the mags nice and high and there’s almost no wiggle/play that you usually find in ones that don’t run so great... Mine too was a little sticky with newer OEM 33rd mags (like you, mostly on bolt-closed with rounds still in the mag), but after a bunch of reloads my mags wore in a bit and the issue disappeared... I think once things wear in you’ll appreciate the lack of mag play/wiggle, you might just want to do a bunch of dry-fire reload reps and speed up the process...

I definitely agree with loading newer mags up and letting them sit for a few days, that’ll let them settle in and I bet they’ll run better. All of my mags have the +11 TTI base pad extensions with their included extra power springs and I’ve never had an issue (though I always run them at 40 instead of 41 unless I’m starting a run, because 40 always works on a closed bolt but 41 can be iffy... if it’s a bolt-closed start it’s 40, not 41)

I definitely think so. The two different recoil impulses are radically different back to back: blowback guns are more like a violent “thud/bang” when the action cycles, whereas the MPX cycles more like a fast “sling-shot/poof” type of feel... It’s hard to describe, but you can feel it when you shoot them back to back. You can tune a blowback gun with buffer system stuff and by short-stroking it to be close, but the stock MPX system is pretty much almost always softer and with less dot movement even when shooting higher PF ammo. i should let it be known that I don’t really like Sig very much, and really wish the MPX system wasn’t proprietary, because IMHO, having to deal with Sig if one has issues is probably the biggest con going the MPX route.

I don’t want come across as some JP hater or something... they make some awesome stuff for sure, and I certainly wouldn’t hesitate to recommend one of there rifles (especially if money isn’t a factor). That said, there is a certain amount of “eye of the beholder” involved with some of their stuff just because of what it costs compared to what you actually get (I’d say the same about some others’ like Wilson Combat, Les Baer, etc). That’s really the only thing I was getting at... I am ragging on them a bit about their delay on releasing their slimmer m-lok rail option though (they first teased them 8+ months ago, I mean c’mon man lol, shot show is around the corner so maybe it’ll finally come out, we’ll see).

Word. The MPX at around 145ish+ power factor still feels softer than 125-130pf stuff in a blowback gun... actually was shooting with a buddy who runs a JP SCS setup tuned in pretty good with his 130pf loads and we were both amazed a little on how much softer the MPX seems against my 145-150pf factory stuff. As an aside, I’ve been running the Syntech PCC-specific 130gr stuff at matches, but I got a hold of a case of S&B 124gr factory stuff that shoots almost identically, and at $0.15 vs $0.20 per round I think the S&B 124’s might just be my new go-to.

I’m hoping someone can confirm if this is just the newer MPX PCC model without the Timney trigger and a different stock (maybe a different muzzle device too) with all the under the hood updates as it seems..? I would really like to grab a backup to my “Gen 3” PCC model I’ve already been running, and this looks very tempting... still pricey, but I’d rather grab a stock adapter etc and ditch the trigger and stock on a $1200 example than do it again on a $1600+ example again...

After contacting JP on questions about various build options on a GMR-15 and having my credit card out and ready to go, I’d say this: maybe get their newer short-stroke bolt and their short-stroke silent captured recoil spring setup, but that’s it, that’s all their innovation right there. Build those things into a quality upper/lower/barrel/trigger and you’ll have a badass PCC. I’m not sure what to think about their PSC-17 side charger option for $700 that sends a chopstick/metal bar towards your cheek/eye lol. From what I’ve gathered they’re fully aware that their handguard, as well as their furniture options and trigger options are outdated (they actually recommended “selling or trading that stuff to a buddy” which is sad). I’m super bummed actually, I’d expected better.

This is why I said “yes and no” earlier about whether a MPX/PCC-specific trigger is really needed vs a standard AR trigger in an MPX, while not MPX/PCC-specific, Hiperfire has it in black and white that they’ll back their “Hipertouch” series: https://hiperfire.zendesk.com/hc/en-us/articles/360024568454-Which-trigger-is-right-for-my-MPX-or-PCC-platform- That said, the upcoming Phantom triggers they’re about to come out with look interesting too... but I’ve got to admit I definitely dig not having to worry about light-strikes with their Hipertouch series, and the Phantom looks like a conventional spring setup, so I hope it doesn’t compromise the harder strike to hit a lower price-point... time will tell I guess.

Yeah, it’ll probably get killed in no time sadly... AND, IMHO, ALL aftermarket triggers are overpriced lol! But hey, a nice trigger is kinda a necessary evil considering how much we spend on all this stuff that doesn’t make you smile as much haha

Yes and no... the MPX design (most PCC’s really, but the MPX is the meanest) cycles so fast that it is way more brutal on the triggers than a typical AR .223/5.56 gun, so that said there are some things to consider: as far as I know Timney with their PCC-specific triggers, and Hiperfire with their “toggle engine” triggers will stand behind them and back them up if (when) they fail and fix/replace them free of charge. I dig Giessele stuff, but their PCC design is wonky and doesn’t make much sense with swapped recoil springs and such to me, so I don’t know about them... Also, 9mm primers on average can be harder compared to a lot of rifle primers, so there’s that; Hiperfire triggers deliver a harder hammer strike by their design, some of the others use lighter springs to get a lighter pull and that can mean light strikes if one is unlucky. I’ve heard of guys going 20k rounds on Hiperfire’s without issues, or some dying after a few thousand... but they stand behind them and will fix/replace them which is what matters most IMHO.

I ran the Timney 683 a bit that came in my MPX PCC when new for a few hundred rounds, and it’s definitely nice enough to stay with, heavier than what I’m used to but it’s reset was pretty awesome, very snappy... I had a Hiperfire Reflex/243G on hand so I switched out to that which I love (and my buddy got the Timney for his earlier Gen2 which he didn’t think he needed until the first pull on it lol). The Timney is like 4.5lbs but crisp enough that it feels lighter, the Hiperfire is like 2lbs in comparison and is just ridiculous fast. So far I’ve had no issues with the Hiperfire through around 7k rounds or so... though I’m aware they can fail, but am reassured knowing if it dies Hiperfire will make it right. Big Daddy Unlimited has good pricing on the Hiperfire’s usually (think I paid $160 IIRC).

Good vid wished you’d gone deeper into that crazy comp/extension though..? Definitely looks nuts lol

I’ve shot 3k of Tula through my PCC’s (most of it through an MPX) and never had an issue. In my experience the Tula stuff has been actually a little hotter than most cheaper brass stuff like Magtech or Blazer Brass, YMMV. I know people talk about extraction issues with steel-cased stuff but I’ve never had any issues with Tula. Wolf or some of the others’ out there may have the sticky lacquer issue mentioned above (I’ve definitely experienced that in 5.56 with AR’s), but I cannot comment on that really because it’s never happened to me in 9mm with CZ’s and Glock pistols, and my PCC’s have only been fed the Tula in steel-case. If anything, steel-case may be slightly harder wearing on extractors because it’s steel on steel (makes sense to me), but again, it’s never hurt any of my guns... and I’ve seen guys blow out an extractor after only a few thousand rounds shooting really well done reloads using brand new brass, so sometimes bad luck is just bad luck. That said, I don’t use aluminum-case stuff ever, because aluminum is so soft that I have had and seen lots of issues with that, mainly the extractor just tearing through the aluminum case rim and causing malfunctions that way. Tula is so cheap sometimes by the case (like $.14 a round) that IMHO I say give a case a whirl and see what you get, for training it might just work fine.

Man... I’ve always dug MP-5’s and love the way they feel when shooting them (mostly friend’s that are older registered full-auto, and cost as much as a few old sports cars I might like to have instead lol)... That said and besides, I think I’m too spoiled at this point having been able to run great triggers (Hiperfire, Timney) to see them really having any real place as a good modern PCC these days, and that’s not even mentioning their slow quirky reload manual of arms... They’re definitely cool, but their design shows it’s age IMHO if you’re looking at them against an MPX or GMR-15, especially at like $2.5-3k. Make no mistake though, if I hit the lottery I’d grab 2 so I could dual-wield like in Golden Eye

I’d vote 510 over the Venom, not because it’s a bigger window, more so because it’s just easier and faster to get your eyes behind. That said, I don’t really buy the “more FOV” thing... shooting both eyes open it doesn’t really matter. I totally DO buy getting behind the optic and picking up the dot faster... and a 510 with a 30mm window, or even a Aimpoint micro sized 20mm sized window when mounted right just seems easier than any “handgun-sized” optic I’ve ever tried. ...but most of the handgun-sized optics I’ve tried on PCC-type guns were just thrown on with whatever mount was in the box or some riser that wasn’t really dialed to the stock/cheekweld. There’s no real reason the Venom would be worse IMHO if one were to really spend/experiment with where/how to mount it though...

Which adapter is better, TTI vs KAK I cannot comment on; because I only have experience with the TTI one (which is solid). The KAK one looks solid too. I was more trying to point out that how you mount it up (the stock adapter), height-wise, matters a bunch more than maybe first glance as far as feel and optic height are concerned. The MPX receiver is different enough from how a “normal” AR-9/15 sits that optic height and feel is definitely different depending on how one chooses to mount their optic/stock; it’s not apples to apples. The MPX’s are a little wonky in that regard, and are actually closer to a CZ Scorpion than an AR variant in most ways... for optic height and cheek-weld. The MPX can be a bit tricky coming from a more traditional AR-9 platform, but it’s not as simple as “just get a low mount” or whatever, because how high you mount the tube on the back of the receiver changes things. I can say this after fumbling around with it and trying and buying different stuff: IMHO, mounting the stock adapter 1 pic notch down seems best, it’s naturally more in-line with the bore, but it means using a 510C specifically (which was my favorite) is out unless you prefer a lower 1/3rd height setup, because that’s as low as that sight can be mounted. Adapter mounted 1 pic notch down with an MRO on Trijicon’s stock low mount equals an absolute cowitness height, and feels exactly as an absolute cowitness on an AR platform. An H1/T1/Holosun 20mm sight on a factory low mount will be too low (shotgun height), and so an ADM low mount or maybe Midwest (which is a bit higher and about equal to Trijicon’s MRO low mount) is needed to bring it up to an absolute cowitness height... this is all after seeking a traditional “absolute cowitness” feel and cheek-weld on the MPX. Phew, I know, confusing AF LOL

I think you really shouldn’t worry about it, I’ve shot a bunch of the Syntech poly coated stuff through various PCC’s and it’s never been an issue. If the comp looks a mess, cleaning it only adds a few minutes. For me, what kind of IS an issue with the JP’s is paying top dollar for a handguard/stock/grip most of us are going ditch as soon as possible, just to get the rest of the rifle; their proprietary handguards and available furniture choices are weak and one would have thought they’d have addressed that by now... JP’s rifle builder should have options when you get to handguard/stock/grip where we can select “nope/nope/nope”... their rifles are awesome, but a lot of thier original equipment options are behind the times and kinda lame IMHO... Not trying to sound snotty, but I’m a guy about to click “buy” on a new dual-charge JP, and have a hard time getting my head around paying around $2500 for a gun that’ll immediately need a new handguard at minimum, and probably a grip and stock as well, and maybe a trigger swap to a Hiperfire if the stocker has light-strike issues like a lot of them do...

Any plans or anything out there as far as shrouds to bring MPX’s up to 16” with weirdo 13.5x1LH..? Seems like there’s a few out there, but info on getting one is sketchy... I’ve got a buddy looking to bring a 10” Gen 2 MPX “pistol” up to spec for USPSA PCC, and I might want one to build a backup off a Gen 2 pistol, or even cut down my “3rd Gen” PCC model if I like it better...