Chamfering, counter sink, counter bore Where to get 'em?

[projectnut]

Mickri said: I have been looking for a 60* piloted countersink with changeable pilots that doesn't break the bank cost wise. I want to use this to cut counter bores ( wrong term??) to match 60* dead and live centers when turning between centers. I have found some 45*.

I think what you're looking for is a set of center drills. They do cut at 60*, and also relieve a hole for the the point of the live or dead center so it isn't damaged and doesn't support the entire load when turning.

Here's an example of what I'm referring to:

SHARS 15 HSS COMBINED CENTER RH DRILL DRILLS COUNTERSINKS SET NEW ^} | eBay

I'm not aware of any that have interchangeable pilots

This is a link to a set of counterbores with interchangeable pilots. They're primarily used to allow socket head bolts, or the heads of shoulder bolt to be flush with or below the surface of the material they are fastening.

39 Pcs/Set HSS Interchangeable Pilot Counterbore Set in wooden box #510-IDX | eBay

They also come in sets with a single arbor with interchangeable cutters and pilots, as well as one piece ones with fixed pilots.
Fixed pilot style:
4-Piece Set High Speed Steel Socket Cap Screw Counterbore #8 #10 1/4 3/8 | eBay

Single arbor with interchangeable cutters and pilots:
Interchangeable Pilot Counterbore Set 21pcs/set, short style #Z-3620-0121-new | eBay

As an FYI I see that ACHiPo made a post at 9:10 Am this morning. It wasn't online when I posted at 10:37. I did see a notice that said it could take up to an hour before a post went online, but in this case it was closer to an hour and a half

 

[mmcmdl]

I have a few hundred down the basement . Decide what you need then give me a shout out .

 

[mickri]

I now realize that counter bore is the wrong term. I will be chambering several barrels this winter as part of my small ring mauser projects. I will be doing this between centers. To ensure that the 60* centers are truly centered in the bore of the barrel it is best to use a 60* countersink with a pilot that matches the bore of the barrel. I will most likely have to make the pilots.

 

[mmcmdl]

They are known as barrel plugs . Make sure you turn bore 60 degree angles and DO NOT depend on a center drill for being concentric to the plug . They also make carbide and ceramic center laps if needed . We used to make prototype guns for the gubmint at AAI .

 

[mickri]

I have read about brass plugs for barrels to protect the rifling and muzzle crown. Looked for them on Brownells and didn't find any. Searched online and didn't get even one hit. I am probably using the wrong search term. Not important to protect the rifling when chambering. The muzzle end will get cut off and the chamber end will get bored out when chambered. Brownells has piloted countersinks. The cost is $140 and you only get pilots for one bore size. More than I care to spend. Probably just have to live with what I have.