Gunsmithing What size drill bit is needed to drill out a 6.5 cm brake to a 308
- Thread starter Kawi
- Start date
You would probably want to use a boring bar vs. a drill bit. It may be beneficial to try to verify that the 6.5mm opening is concentric to the threads also before boring it out. If you wanted to play it safe, you can bore it out to around .320" or even .338" would still give you decent performance. But if you want it as close to .308 as possible it should be measured and indicated on a lathe and bored on it also.
You could always have a Smith bore it for you if you have someone that can do it for cheap? It's really hard to use a drill bit for this, even on a press. Plus the drill bit wont drill a very good hole through a brake. 6.5mm to 7.62mm+ is quite a bit to bore out.
You could always have a Smith bore it for you if you have someone that can do it for cheap? It's really hard to use a drill bit for this, even on a press. Plus the drill bit wont drill a very good hole through a brake. 6.5mm to 7.62mm+ is quite a bit to bore out.
Unless you have a lathe and are doing the work yourself it may be cheaper and better advice to just buy another brake and sell the one you have.
I have two 30 cal brakes I will be getting rid of soon since I can't stand the noise and blast from brakes and I'm sure there are numerous others to be found in the PX for a good price.
I have two 30 cal brakes I will be getting rid of soon since I can't stand the noise and blast from brakes and I'm sure there are numerous others to be found in the PX for a good price.
I would recommend the purchase of a new brake.
But if you want to do this modification at home I would use a piloted reamer. This would allow the pilot to
follow with the material that is available the original bore.
Is this ideal No but this would work much better than a drill bit which is free to wonder on its own course.
By the time you purchase the reamer(s) you may be more cost effective to buy that new brake.
JMHO
Good Luck!
But if you want to do this modification at home I would use a piloted reamer. This would allow the pilot to
follow with the material that is available the original bore.
Is this ideal No but this would work much better than a drill bit which is free to wonder on its own course.
By the time you purchase the reamer(s) you may be more cost effective to buy that new brake.
JMHO
Good Luck!
Buy a ream or use a boring bar. Drills just make a mess in existing holes.
I agree with your best bet is going to be buying a new brake. But I figured I would throw out the info out there in case you know someone that has a machine shop.
I'm in a place where there just aren't many machinists or shops so I have to either find ways to do it myself or send it off. If you have or know someone with a lathe and they know how to use it, it's not a hard job to do. But if not, best bet is to sell your 6.5mm brake or post a WTT ad here when you have the post count.
I've found a lot of great deals on here, a lot of good guys and good shooters here that have been doing this for years and may have the brake you want or may trade?
I'm in a place where there just aren't many machinists or shops so I have to either find ways to do it myself or send it off. If you have or know someone with a lathe and they know how to use it, it's not a hard job to do. But if not, best bet is to sell your 6.5mm brake or post a WTT ad here when you have the post count.
I've found a lot of great deals on here, a lot of good guys and good shooters here that have been doing this for years and may have the brake you want or may trade?
If you happen to have any machinist friends, get one to do it for you. I do all of my own but am a journeyman machinist(25 years) with access to all the right equipment.
Most recommend a minimum of .03 over. In your case, 11/32(.343) is right on and would work perfectly.
Most recommend a minimum of .03 over. In your case, 11/32(.343) is right on and would work perfectly.
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