I decided to make some M76 guides before I start another rail project since there are a few people looking for them and I need some myself. AKBlue was kind enough to lend me a guide and then I was able to buy one with a demilled receiver off of gunbroker to reverse engineer. I recently bought a kit, scope, mags and Tortort receiver that should be shipping in a month or so.
The material is 4140 alloy steel that will be heat treated to 44-48 Rc.
After saw cutting I square up both ends to a specific length and rough mill in the Bridgeport because I can do this while a part is running in the CNC to save time.
The rivet hole will be undersize because Rforbus informed me that the rivet hole is slightly undersized as is the corresponding hole in the receiver or breech block. The intent is to ream through both at assembly for perfect alignment.
I still have to pick out the corners and cam area so they are the proper radius, angle or square corner.
I will finish one up complete to make sure it is correct and to finish the tooling. I should be able to saw cut the other end, finish mill it and put the radius's on it and do the cam area with the little block fixture.
![]()
![]()
![]()
![]()
![]()
The material is 4140 alloy steel that will be heat treated to 44-48 Rc.
After saw cutting I square up both ends to a specific length and rough mill in the Bridgeport because I can do this while a part is running in the CNC to save time.
The rivet hole will be undersize because Rforbus informed me that the rivet hole is slightly undersized as is the corresponding hole in the receiver or breech block. The intent is to ream through both at assembly for perfect alignment.
I still have to pick out the corners and cam area so they are the proper radius, angle or square corner.
I will finish one up complete to make sure it is correct and to finish the tooling. I should be able to saw cut the other end, finish mill it and put the radius's on it and do the cam area with the little block fixture.
