CZ Scorpion SBR

[lsufan1971]

I bought a CMMG Mk9 and put a 4.5 inch CMMG barrel with a Sampson Keymod 11 inch rail. The Tirant 9 fits perfect inside the rail.

 

[rcm192]

I bought a CMMG Mk9 and put a 4.5 inch CMMG barrel with a Sampson Keymod 11 inch rail. The Tirant 9 fits perfect inside the rail.

Now thats sexy

 

[rcm192]

I want MPA to fix my goddamned pistol so I can sbr it.

 

[noob]

I want MPA to fix my goddamned pistol so I can sbr it.

Save your money and get a M-10/9 or M-11/9, 1 tax stamp and you will have a machine gun. No separate tax for SBR, b/c machine guns override the length requirements etc.

 

[rcm192]

Save your money and get a M-10/9 or M-11/9, 1 tax stamp and you will have a machine gun. No separate tax for SBR, b/c machine guns override the length requirements etc.

I should before the damn things get more expensive. it just suxks because I bought most of the stuff I need for the sbr conversion for it already...and now its going back to the factory for the 3rd time.

 

[noob]

What's wrong with it?

I remember a few years back when I finally decided to go full auto, the m10's were going for 2300, waited 2 months and it was 2500, waited 6 months it was 3000. Waited a year and it was 3500. By the time I finally decided on which one and had the money set aside. The going rate was 4k, so it's definitely not getting any cheaper. If I told you how much the m16 was, you would mess your pants. So definitely buy one if you ever want to go that route. And it could very well be an investment

 

[rcm192]

What's wrong with it?

I remember a few years back when I finally decided to go full auto, the m10's were going for 2300, waited 2 months and it was 2500, waited 6 months it was 3000. Waited a year and it was 3500. By the time I finally decided on which one and had the money set aside. The going rate was 4k, so it's definitely not getting any cheaper. If I told you how much the m16 was, you would mess your pants. So definitely buy one if you ever want to go that route. And it could very well be an investment

I think the threads werent cut cocentric to the bore.
heres a vid of the piston on the upper and chucked up with a gauge on it. You can see variation. Its causing endcap strikes with the 9mm endcap on my 45 octane. My can runs fine on my G19 though. Also see the target after shooting 147gr and 115gr.
[video]https://youtu.be/dnllJk4xM6Y[/video]

 

[noob]

I had an end cap strike on my Osprey 45 way back when, the issue was how the piston sat on the barrel. I Think with the HK's they sit on the shoulder of the threading where as with the FNP tactical, the piston stops on the tip of the barrel. So they had to design a new piston just for the FNP, and the new piston was marked v2

 

[rcm192]

Turns out Im getting a new barrel. Customer service has been awesome from MPA. read the email and watch the video they made.

Got your upper in earlier this week and finally got a chance to examine it today.



I first grabbed a piece of 4140 bar stock we had laying around and drilled a hole and tapped it ½-28 using the tailstock to repeat your test. While in the same setup, I threaded in your upper and the linked video is of it running on the lathe. I want to stress that the bar had not been removed after machining and prior to the video. If you were to remove the bar (and your test setup from the original video) it would require you to indicate the face and threads back in on most any jawed chuck. Say if I had made the bar a couple of days ago and pulled it out to machine something else . . . for any reason if it came out, it should have been indicated back in to be concentric enough to accurately measure the runout.



https://www.youtube.com/watch?v=E8PVm_FQTBs&feature=youtu.be



The O.D. of the barrel runs out a hair over .0004*

I also checked perpendicularity by holding the barrel after being indicated in and the runout was around .0005*. Being that .0005* is on the edge of the acceptable tolerance we went ahead and replaced the barrel.



There was also some carbon buildup on the shoulder of the barrel when I opened up the box which absolutely would give a false reading. I removed the build-up with a scotchbrite pad and then checked it.



New barrel measures .0003* on the O.D. and .00025* on perpendicularity.



I would still recommend you check the concentricity of the silencer when attached to a known good mandrel and is indicated in. You should check runout on the bore of the front end cap with a dial indicator in the exact same setup that it would be on the Defender: fixed barrel spacer and ½-28 piston in.



Thanks,



Tyler Crawford

Research & Development

Masterpiece Arms

706-783-5091 Mfg Facility

866-803-0000 X100 Sales Facility

www.masterpiecearms.com

 

[rcm192]

Well the MPA shoots like a champ now with the new barrel and endcap. Gotta sbr it soon.

 

[rcm192]

.

 

[rcm192]

Now that I have my scorpion tax stamp in I've been ordering/looking at upgrades. I have the HB Industries mini AK selector and a HB Industries flat trigger forward theta model on order along with a Yeti wurks Switchback grip.

What have yall done to your Scorpions?


This is how she currently sits:

 

[kingfhb]

The Scorpion is a great little platform as an SBR and fits nicely in a tennis racquet case with the stock folded (and suppressor attached) and is super light. Suppressed? It's a mouse fart... Super quiet (With the Hybrid from Silencerco and an adapter). My only complaint is that damn safety drilling into my finger on every shot... easily fixable with several options... but you'd figure CZ would have caught that during development.

 

[rcm192]

The Scorpion is a great little platform as an SBR and fits nicely in a tennis racquet case with the stock folded (and suppressor attached) and is super light. Suppressed? It's a mouse fart... Super quiet (With the Hybrid from Silencerco and an adapter). My only complaint is that damn safety drilling into my finger on every shot... easily fixable with several options... but you'd figure CZ would have caught that during development.

I didn't even shoot it as a pistol while I was waiting for my stamp. It was uncomfortable. When my stamp did come in and the 922 stock kit was installed I knew that the safety had to be changed. Its awful. I'm with you, CZ shouldn't have let that go out the door.

 

[Loudog]

I never found the safety to be an issue after i put the stock on. Shooting as a pistol definitely was annoying.

Got my stamp in last month. It came in right at around 5 and a half months for those with stamps pending.

 

[rcm192]

I never found the safety to be an issue after i put the stock on. Shooting as a pistol definitely was annoying.

Got my stamp in last month. It came in right at around 5 and a half months for those with stamps pending.

Same here. 5 months and 16 days.

 

[kingfhb]

I only shot it as a rifle after the stamp came back... suppressed. Safety was an issue from day one for me. Maybe big hands.

 

[rcm192]

Are you guys going to switch out the forends on yours?

 

[Riceland Guns]

Now that I have my scorpion tax stamp in I've been ordering/looking at upgrades. I have the HB Industries mini AK selector and a HB Industries flat trigger forward theta model on order along with a Yeti wurks Switchback grip.

What have yall done to your Scorpions?


This is how she currently sits:

Just got to play with mine this weekend. Love it, but the trigger needs work. How do you like that HB trigger?

 

[allen1911]

I also run the HB trigger and love it. I stoned the engagement surfaces of the trigger and replaced the springs. Now m trigger measures at about 4.5lbs to 5 lbs. I highly recommend doing this as it really increases the accuracy potential of this platform.