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View Full Version : Muzzle brake: barrel to thin

johnsopi
11-21-2003, 08:16 PM
Just got 2 M.B 74 type.Problem is the barrel on the sar2 is to thin .508
the M.B slips over top. No way it can be threaded.The sar1 barrel is .556 and should be fine. I was going to do both gun and then have my smith blind pin them.The inside of the M.B is @ .516. Do all SAR 2 have thin barrels. I never
thought to see if would fit. A AK brake goes on a AK barrel. The M.B are the 14x1mm. Anyone else run in to this.

Paul I
Packrat
11-21-2003, 10:02 PM
The AK-74 brake screws onto the front sight base; a 1.5cm diameter by 1mm pitch, right-handed, I think. AK-47/AKM is 1cm x 1mm , left-hand.
JA
11-22-2003, 11:07 AM
I have installed AK-74 style muzzle brakes on the barrel of a SAR-2 rifle and CUR-2 rifles by threading the barrel 1/2x28. Which is the standard barrel thread size for M-16/AR-15 rifles. AK-74 style muzzle brakes can be bought that are threaded 1/2x28 for use on AR-15 rifles. I turn a piece of welding rod or a nail in a drill press then use a file to get the diameter down so it will fit into the muzzle brake retaining pin hole in the front sight base. Cut a piece of the turned down rod to .551"/14mm then put the spring of a Bic Click ball point pen into the hole followed by the pin to have a functioning MBR pin. Then tack weld the muzzle brake to meet the legal requirements for threading the barrel of a post ban AK rifle.
A real AK-74 muzzle brake screws onto the front sight base of AK-74 rifles. The AK-74 front sight base is cast with a exstention on the front of it that is threaded to accept a muzzle brake.
http://www.k-var.com/product.asp?0=216&1=235&3=239
The Romanian AK-74 uses 22x1.5mm threads and the Russians/other combloc countries use 24x1.5mm threads. The AK-47/AKM rifles barrels are threaded 14x1mmLH.
CAMPYBOB
11-23-2003, 08:47 AM
the correct threadings are:

ak-74: 22mm x 1.5mm right hand for romania
24mm x 1.5mm right hand for russia/bulgaria

ak-47 and akm: 14mm x 1mm left hand


the sar-2 may be threaded 1/2" x 28 threads per inch pitch and an adapter used to bush up to the larger commie ak-74 brake threadings.