[Flskunkape]

Sean, I would agree about the mpx except for the charging handle location, they should have stuck with the side charging like the 550 series had, then I then they would have had the market...

 

[Sean K.]

Sean, I would agree about the mpx except for the charging handle location, they should have stuck with the side charging like the 550 series had, then I then they would have had the market...

Meh...not a fan of the overall AR ergos/layout. I get why....everyone has gotten used to shitty ergos.....the XCR spoils us.

 

[Flskunkape]

Yes it does, I sometimes wonder how I got along before, with just a regular old AR

 

[Rigian]

OK I'm ready for the XCR-P. I have millions of dollars saved up to buy them all . . . in advance if it will help complete the development.

(I dont actualy.)

 

[Chowwow]

OK I'm ready for the XCR-P.

I wish RA would get their ass in gear to have at least a mock-up ready to view. At this rate, the PCC market will be all but gobbled up by the likes of Sig, CZ, Beretta, etc. The threat of a new AWB is also cause for concern; it could stop the sale of XCR-P before it even begins. Would an AWB affect pistol caliber firearms and subguns?

For anyone who has used a CZ Scorpion or any other PCC, does anyone find value in the charging handle that lets you hold the bolt open and do the "HK slap" to close the bolt? I hear a few people who go gaga over that feature but it seems to be a meme to me. I bring this up because an ambi charging handle that lets you slap it closed could be one feature a XCR-P could have that the Sig MPX doesn't. The charging handle style on the XCR works fine to me and I'm afraid having a bolt hold open might add too much redundancy, but I also think it would be nice to have the option to use one handle that can hold open and close the bolt and a little forward assist.

I also did a little look into making a 9mm caliber conversion for the XCR-L for anyone who was wondering: you could bore a 5.56 bolt and extractor to accept the 9mm case and chamber a barrel blank for 9mm, but (taking Sig's MPX barrel design as a hint) you won't be able to install an (appreciable) gas port into said barrel because the barrel extension is covered by the rifle's upper, blocking the part of the barrel that would provide the best gas pressure to cycle a piston. Then you could use an AR-15 magwell adapter to accept 9mm magazines and do something with the recoil spring to get the timing right to cycle 9mm rounds. After all that work, you'd have a straight blowback (see correction) PCC out of the heavy XCR-L. Considering that fact, the expense of chambering a new XCR barrel and the fact that you would have to re-balance the operating system with the recoil spring, and I just don't find it a worthwile project to get into. Even if it did work, you'd be the owner of a heavy, all-metal blowback PCC, which might be the antithesis of the XCR platform.

 

[Flskunkape]

Cmmg makes a 9mm mag that uses a 556 body a lot like how the 22 ar mags are made, to get rid of adapters, and mags that don't fit normal gear, I've never used them, but they look cool and other than the fact that a 556 mag filled with 9mm is kinda size prohibited it looks like a decent solution to the strait mag single feed that glock mags have.

 

[willpgn]

Cmmg makes a 9mm mag that uses a 556 body a lot like how the 22 ar mags are made, to get rid of adapters, and mags that don't fit normal gear, I've never used them, but they look cool and other than the fact that a 556 mag filled with 9mm is kinda size prohibited it looks like a decent solution to the strait mag single feed that glock mags have.

I’ve got CMMG uppers in 9 and 5.7 and both use the “conversion mags” (PMAGs with the “insert”) and both have worked well for me.

I‘d like to see an XCR-P, but I’m not holding my breath!

 

[Flskunkape]

Cool, thanks for the feedback. Do you feel like the mag is reliable enough to offset the added size, compared to glock or colt mag? Also how many rounds do the conversion mags hold?

 

[Sean K.]

I wish RA would get their ass in gear to have at least a mock-up ready to view. At this rate, the PCC market will be all but gobbled up by the likes of Sig, CZ, Beretta, etc. The threat of a new AWB is also cause for concern; it could stop the sale of XCR-P before it even begins. Would an AWB affect pistol caliber firearms and subguns?

For anyone who has used a CZ Scorpion or any other PCC, does anyone find value in the charging handle that lets you hold the bolt open and do the "HK slap" to close the bolt? I hear a few people who go gaga over that feature but it seems to be a meme to me. I bring this up because an ambi charging handle that lets you slap it closed could be one feature a XCR-P could have that the Sig MPX doesn't. The charging handle style on the XCR works fine to me and I'm afraid having a bolt hold open might add too much redundancy, but I also think it would be nice to have the option to use one handle that can hold open and close the bolt and a little forward assist.

I also did a little look into making a 9mm caliber conversion for the XCR-L for anyone who was wondering: you could bore a 5.56 bolt and extractor to accept the 9mm case and chamber a barrel blank for 9mm, but (taking Sig's MPX barrel design as a hint) you won't be able to install an (appreciable) gas port into said barrel because the barrel extension is covered by the rifle's upper, blocking the part of the barrel that would provide the best gas pressure to cycle a piston. Then you could use an AR-15 magwell adapter to accept 9mm magazines and do something with the recoil spring to get the timing right to cycle 9mm rounds. After all that work, you'd have a straight blowback PCC out of the heavy XCR-L. Considering that fact, the expense of chambering a new XCR barrel and the fact that you would have to re-balance the operating system with the recoil spring, and I just don't find it a worthwile project to get into. Even if it did work, you'd be the owner of a heavy, all-metal blowback PCC, which might be the antithesis of the XCR platform.

I know you're new but this is just how things develop at RA. It's a slow process....and yet, name one other company that has done all the caliber conversions, different monolithic uppers, bbl lengths, upgrade of the ambi controls, bigger BHO, etc. that RobArms has. No one.

The threat of the newest restrictions on just pistols, should have RA cranking out 16"+ compliant uppers....as well as stock 'tails' to replace pistol braces that currently have Tailhooks attached. Frankly, if more money is going towards the P, the threat of a new AWB should have RA focused on 16"+ rifles. With braces coming under fire and likely banned....the current PCC market is largely going away if you can only do it via NFA. I mean, what's the point of a 16" PCC?

I have a Scorpion EVO....the HK slap feature is not something I use much at all. It's too easy to reach up with your left thumb while inserting a new mag for that to make sense from a speed perspective. Some people love it....but it's not that big a deal to me.

Not following on your BHO comment. The XCR's charging handle CAN and DOES release BHO and offers forward assist.

 

[Chowwow]

you could bore a 5.56 bolt and extractor to accept the 9mm case and chamber a barrel blank for 9mm

Correction: You can't make a blowback bolt if the bolt is designed to rotate and lock into the barrel extension. So to get a blowback PCC, you need to design a new non-rotating bolt and/or a barrel extension that doesn't let the bolt plunge into there (GAH!). Alternatively, you could try using a barrel with the shortest gas length available, (long enough for the Micro length piston for Blackout) and try to cycle the gas that way; but I don't think siphoning gas from the round as it's traveling out of the barrel would give it enough muzzle energy in the end and/or give it enough gas to cycle anyway. In short it's a lot of work for something I know is going to be underwhelming, lol.

Cmmg makes a 9mm mag that uses a 556 body a lot like how the 22 ar mags are made,

I actually did consider that Cmmg mag but I noticed that it set the cartridge far back on the magazine and thus you would need the bolt to travel as far back as it would for 5.56 to pick up the next round. Considering gas constraints I wanted to reduce the needed bolt travel as much as possible. The magwell adapters also have a brass ejector that helps get the 9mm brass out of there.

I know you're new but this is just how things develop at RA. It's a slow process...

I know, I know. But hope springs eternal, right?

 

[Flskunkape]

Makes perfect since, on length of bolt travel. I didn't realize that the round seated at the rear of the magazine. I wonder if you could make the bolt non rotating, perhaps with a split pin like a ar bolt uses to hold in the firing pin. Then mill out all of the barrel extension and re contour it to look like a flat faced 9mm AR barrel extension, but recessed into the barrel extension so the barrel would still maintain proper lock up into the receiver.

 

[willpgn]

Cool, thanks for the feedback. Do you feel like the mag is reliable enough to offset the added size, compared to glock or colt mag? Also how many rounds do the conversion mags hold?

9mm = 30 rounds
5.7 = 40 rounds

I’ve had no trouble with these feeding reliably for many hundreds of rounds through both types...matter of fact, I’ve had more trouble with my Glock and other pistol mag PCCs, though they probably haven’t been the mags causing all the issues. Size between AR pattern and a Glock mags (of the same capacity 32 rd) don’t bother me. Weight is about the same between the two fully loaded. If we are talking about mag possibilities for a future XCR-P, I’d like to see a CZ style (PSA clones are excellent and cheap) or an MP5 style mag. Also, looks of a Glock or stick Colt mag in an AR style gun aren‘t pretty...obviously, looks are secondary, but if you have a choice, make it look good as well!

 

[Sean K.]

If we are talking about mag possibilities for a future XCR-P, I’d like to see a CZ style (PSA clones are excellent and cheap) or an MP5 style mag.

^This. I get the decision to use Glock mags....but still. The CZ Scorpions or PSAs are SOOO freaking good and inexpensive. For 9mm it makes more sense. I wonder...if RA does a .45 or 10mm....won't the lower have to be different considering the glock frame sizes are different for the larger calibers?

 

[Flskunkape]

Thanks for the report! I agree that the scorpion mags in a sub gun look great and seem to function very well. All this talk about pccs has me wanting a stribog with the lingle industries lower and acr stock/brace, it certainly has the right look to be paired with an xcr.

 

[Flskunkape]

Sean I wonder the same thing about multiple sized pcc lowers and it not really falling into the "eXchangable Caliber Rifles" concept... Although the desert tech MDR has the ability to change from 556 to 308 in the same receiver. So maybe there are more advanced designs Alex has up his sleeve that my simple monkey brain has not considered.

 

[Chowwow]

Not following on your BHO comment. The XCR's charging handle CAN and DOES release BHO and offers forward assist.

What I meant was when I have to engage BHO on my -L when I want to clear it, I have to pull back the charging handle and then use my trigger finger to lift up the bolt catch. It's not a huge deal but it would be nice to have to do that all with the charging handle. I typically go to an outdoor range and the RSO wants everyone to empty their guns and hold their bolts open before posting new targets, so I find myself having to engage the BHO a lot, lol.

EDIT: Now that I think about it, a Scorpion-style charging handle would lose the FA. Oh well, can't have it all. I still think it would appeal to the current PCC/subgun crowd.

^This. I get the decision to use Glock mags....but still. The CZ Scorpions or PSAs are SOOO freaking good and inexpensive. For 9mm it makes more sense.

The curve of the Scorpion mag seems to work great for feeding 30+ rounds of 9mm reliably, shame a similar design hasn't been adopted for 10mm or .45 ACP, though there is probably a reason for that. One thing about the Scorpion mag though, it loads by way of a lug at the back of the magazine that is caught and secured by the magazine release; the same release that occupies the space behind the magwell that the XCR family puts the bolt catch foot. Internally and externally, the systems would get in the way of each other.

https://hbindustries.net/store/wp-c...roStock-Magazine-Release_3-e1528843350342.jpg

I wonder...if RA does a .45 or 10mm....won't the lower have to be different considering the glock frame sizes are different for the larger calibers?

Sean I wonder the same thing about multiple sized pcc lowers and it not really falling into the "eXchangable Caliber Rifles" concept... Although the desert tech MDR has the ability to change from 556 to 308 in the same receiver. So maybe there are more advanced designs Alex has up his sleeve that my simple monkey brain has not considered.

I would guess that RA would do what DT did with the MDRX, make the gun support .45 ACP natively and use magwell adapters that allow support for the smaller calibers. Alternatively, they could make the magwell bigger than any of the calibers and require the installation of one of three magwell adapters for each caliber mag, that way they can add other necessary features. I don't expect the pistol calibers to be different enough to warrant a different brass extractor, but a specific brass extractor could be screwed into the corresponding magwell adapter if need be. Hopefully the same feed ramp can be shared across calibers, but if necessary a specific feed ramp can be also included with the magwell adapter.

I've been following the design of the Sig MPX and I find it as a great opportunity for RA to learn from Sig Sauer's ideas and mistakes as it's essentially what RA wants to do with the -P. One issue that has cropped up is the fact that apparently, MPXs have been chewing up their triggers because the bolt assembly on the MPX moves too fast and hard. Part of that may have been due to Sig wanting to reuse as many parts from the MCX line as possible and initially ended up with bolts that were too light and springs that are too rigid that caused said issues. Being over-gassed from the factory and the gas valve not being adjustable by default are also suspected causes. In RA's case, it would seem tempting to reuse the same parts from the -L and use them in the -P (I certainly thought they could get away with that too), but I believe the end product will resemble the operating system in the present XCR family but smaller/optimized for pistol cartridge pressures. The fact that the -P is likely to have one recoil spring versus the MPX's two should make the bolt travel less violent and avoid the trigger reliability issues that the (older gen anyway) MPX line suffers.

 

[Sean K.]

What I meant was when I have to engage BHO on my -L when I want to clear it, I have to pull back the charging handle and then use my trigger finger to lift up the bolt catch. It's not a huge deal but it would be nice to have to do that all with the charging handle. I typically go to an outdoor range and the RSO wants everyone to empty their guns and hold their bolts open before posting new targets, so I find myself having to engage the BHO a lot, lol.

EDIT: Now that I think about it, a Scorpion-style charging handle would lose the FA. Oh well, can't have it all. I still would think it would appeal to the current PCC/subgun crowd.


The curve of the Scorpion mag seems to work great for feeding 30+ rounds of 9mm reliably, shame a similar design hasn't been adopted for 10mm or .45 ACP, though there is probably a reason for that. One thing about the Scorpion mag though, it loads by way of a lug at the back of the magazine that is caught and secured by the magazine release; the same release that occupies the space behind the magwell that the XCR family puts the bolt catch foot. Internally and externally, the systems would get in the way of each other.

https://hbindustries.net/store/wp-c...roStock-Magazine-Release_3-e1528843350342.jpg




I would guess that RA would do what DT did with the MDRX, make the gun support .45 ACP natively and use magwell adapters that allow support for the smaller calibers. Alternatively, they could make the magwell bigger than any of the calibers and require the installation of one of three magwell adapters for each caliber mag, that way they can add other necessary features. I don't expect the pistol calibers to be different enough to warrant a different brass extractor, but a specific brass extractor could be screwed into the corresponding magwell adapter if need be. Hopefully the same feed ramp can be shared across calibers, but if necessary a specific feed ramp can be also included with the magwell adapter.

I've been following the design of the Sig MPX and I find it as a great opportunity for RA to learn from Sig Sauer's ideas and mistakes as it's essentially what RA wants to do with the -P. One issue that has cropped up is the fact that apparently, MPXs have been chewing up their triggers because the bolt assembly on the MPX moves too fast and hard. Part of that may have been due to Sig wanting to reuse as many parts from the MCX line as possible and initially ended up with bolts that were too light and springs that are too rigid that caused said issues. Being over-gassed from the factory and the gas valve not being adjustable by default are also suspected causes. In RA's case, it would seem tempting to reuse the same parts from the -L and use them in the -P (I certainly thought they could get away with that too), but I believe the end product will resemble the operating system in the present XCR family but smaller/optimized for pistol cartridge pressures. The fact that the -P is likely to have one recoil spring versus the MPX's two should make the bolt travel less violent and avoid the trigger reliability issues that the (older gen anyway) MPX line suffers.

Good point on the mag release for a CZ mag. However, you are going to a much smaller magwell....and should be able to have the mag release in that extra space, but it all depends on how the lower is actually designed. The actual claw on the BHO that actuates the mag follower would likely be the bigger issue since it would have to be longer to reach to the mag itself.

Whatever though...the PCC XCR isn't something I'd buy anyway. I'd much rather have the AK-V.

 

[Flskunkape]

I feel like if one was so inclined a hybrid BHO between a XCR and scorpion. Similar to what Sean just said if the magazine sat forward in the mag well there could be room for the xcr style hold open modified to grab a scorpion magazine.. and just make the area directly in front of the trigger guard/hold open get skinny and stretch it out enough the paddle mag release could fit.. although the idea may well be cost prohibitive.

 

[Chowwow]

Whatever though...the PCC XCR isn't something I'd buy anyway. I'd much rather have the AK-V.

I feel like a kid who has been told that his dad was with someone else before he married mom on the rebound. How unfaithful!

Seriously though, if RA builds the -P in the way I believe they would (at least in the manner they've made the entire XCR family so far), I think it would be the only PCC that I would actually buy. According to my research, the Sig MPX is the only gas operated PCC that's in mass market and RA is in the position to avoid the MPX's problems and occupy a very unique niche with simpler design. Though I fear the result would be the XCR line's dirtiest gun; being 9mm rounds are what they are and that the gas block would be so close to the chamber that it would be venting gas inside of the gun like any blowback PCC. Even if they open up the upper a bit for us to get at the gas block, not even Sig found a way to keep the MPX's internals from getting fouled.

although the idea may well be cost prohibitive.

Honestly, I cringe at the idea that RA will have to introduce a new gun with a new set of logistics on top of what they already have to do. If the -P is gonna work properly, it's going to need a unique bolt, barrel, op rod, piston, recoil spring etc, I don't think it'll be sharing many parts with the -L or whatever. It must be a hassle to have to manage building parts for the -L and the -M already, let alone the M96 whenever they have to do that. Is RA still making the old types of parts for the older generations of the XCR? For a company that works like RA, it's got to be a mess. The retooling is probably what's holding back the launch of the -P.

 

[SheffieldTactical]

What do you know:

Look how far back that gas port is. I guess there isn't that much gas to take advantage of. I wonder if we can replicate this with our XCR-Ls with a barrel blank and one of the shorter pistons?

What xcr/barrel combos are considered low gas that you would want to move the piston?