Converting receiver threads from 6-48 to 8-40

P

P45

Inactive
I have a Remington 700vs .308 rifle. I want to convert the factory 6-48 threads in the receiver to 8-40, to accomadate the 30mm scope I want to mount on it. Can this be done by hand drilling and tapping or does this need to be done on a drill press for best results? What's the best way to do this?
 
tapping

Sir:
If your threads are O.K. now, why go to 8X40 thread - the 6X48 will hold as well!
However, if you do just ream your present holes with a 28 drill and tap for 8X40 - but I strongly advise against it if your present threads are O.K.!!!!!!!
Has some "gunsmith" or "friend" told you that the 6X48s won"t hold? If so they're full of it!
Not only that, but most all bases are made 6X48 and you will need to modify the bases for the larger screws - you will need to order the proper counterbore as well.
Leave those 6X48 holes - they'll work just fine
Harry B.
 
6x48 screws will work for mounting a 30 mm scope, and holding it in place on your rifle. I do it regularly. No need to use 8x40 screws.

Martyn
 
6x48 X 8x40

Sir:
The only place where I fairly regularly redrill and tap from 6X48 to 8X40 is on the Ruger 10-22. Then, of course, you must re-counterbore the base.
I would also consider doing that on any alloy reciever, if possible - although I've never done it.
Harry B.
 
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