Drilling virgin barrel

[bodiebill]

Drilling for an oversize barrel pin (0.301")
Used a "M" (0.295") drill and have a hole that is approximately 0.295".
The barrel pin is 0.301" OD.
Is this too much interference for pressing?
Should I ream? What size reamer?
What do you recommned?

Using a bench mounted drill press that does not always drill an accurate hole. Hate to open it up more and make it loose.

[69Mach1]

Why are you drilling for an oversize barrel pin on a virgin barrel? Typically a "virgin" does not have the barrel pin grove cut yet.

[bodiebill]

virgin bbl drilling

Because the standard pin hole was drilled oversize

[Calif Mini]

........ have a hole that is approximately 0.295".
The barrel pin is 0.301" OD.
Is this too much interference for pressing?

I do think .006" is to much to try to press fit.

Possibly .002" would be the max.

7.6 mm is .299" ??????? Ebay has some for about $10 with shipping.

http://cgi.ebay.com/7-6-MM-GP-Screw-Machine-Drill-HSS-Qty-5-/160472624912?pt=LH_DefaultDomain_0&hash=item255ce9ef10#ht_1531wt_1086

Maybe others who have done this will chime in.

To bad you are so far away.

Ed

[tujungatoes]

I agree that .006" is too much interference. I'd ream to .299".

Here's a reamer from MSC.

[CSACANNONEER]

Something really doesn't sound right. There should be close to a zero chance of having to go with an oversized pin on a virgin barrel. You should be able to use a 5/16th inch end mill followed by a 7mm reamer to do a standard pin. If you need to go bigger, follow that with a .299" or .300" reamer for a .301" pin.

[lelandEOD]

Something really doesn't sound right. There should be close to a zero chance of having to go with an oversized pin on a virgin barrel. You should be able to use a 5/16th inch end mill followed by a 7mm reamer to do a standard pin. If you need to go bigger, follow that with a .299" or .300" reamer for a .301" pin.

Sounds like the trunnion was previously drilled for an oversize pin.

I just built a AK74 with one of those "virgin" Bulgy hammer forged jobs that have the cross pins already cut. The barrel pin notch was waaay off from where it needed to be for proper headspace. I had to ream to .300" and install a .302" pin.

[Psy Crow]

You should be able to use a 5/16th inch end mill followed by a 7mm reamer to do a standard pin.

How is that possible?

5/16 = 0.3125
7mm = 0.27559055

Did you mean 17/64 (0.265625)?
Or I (0.272)?

I must be missing something...

[big ron]

it should of been 17/64 or I then 7mm reamer

[Endofcomment]

When I read "drilling virgin barrel" this is not what I imagined...