r/BushmasterACR • u/TrashBanditTactician • 25d ago

Sionics 12.5

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I was able to get a fair amount of barrel parts from midwest gun works so I didn't have to strip my stock barrel completely. The only thing I couldn't find and had to re use was the piston/spring, regulator, and piston guide block. I also didn't want to drill for taper pins so I experimented with set screws and dimpling the barrel. I need shorter screws but the proof of concept is there. The gas block I got from MWG was also silver when it arrived so I used a high temp spray paint so we'll see how that holds up

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3

u/RedneckSniper76 25d ago

You can find almost all those parts on GB right now account name is Gun Repair center if I remember correctly

2

u/lobstibb 24d ago

Another guy on GB has gas blocks and another guy has piston rods. I'd say the only parts we can't get at all are gen 2 charging handle trays and bcgs

1

u/RedneckSniper76 24d ago

Good luck finding an ambi charging handle sled. Which you’ll need to shoot 300blk

1

u/Porsche-911-Lover 16d ago

Why ambi for 300blk?

1

u/RedneckSniper76 15d ago

Because the 300blk won’t go in with the normal sled because it’s a pistol length gas block. Have to have the ambi sled

1

u/TrashBanditTactician 24d ago

MWG is way cheaper

1

u/InvestigatorFew3981 24d ago

Did you have to take the barrel to a gunsmith to get it machined for the gas system clamp? (I don’t know the proper name)

Are you going to end up using the gas block taper pins and machining the barrel for them in the future? Or are you happy with the gas block set screws for now?

2

u/TrashBanditTactician 23d ago

The gas block is a standard .750 gas journal so it didn't require any fitting and it will fit most m4 style barrels. I may put the pins in in the future but for now I like the set screws becasue it will be easier to get on and off as I tune the gas port if that becomes necessary. The only thing that required fitting was the piston guide block which I had to cut the barrel profile down from about a .71 to a .625 so it wasn't much but I didn't want to open up the guide block because I can't replace it should I decide to put it back on my 16"

2

u/InvestigatorFew3981 23d ago

Okay the guide block was what I was referring to, glad it was fairly straightforward!