How would you bore this?

[mikey]

Offer $50. I have one. Great boring bar.
https://www.ebay.com/itm/CIRCE-CARB...265172?hash=item1ca7eac4d4:g:oLEAAOSwXHRa0TA7

Awesome price, especially if he takes a lower offer. If I didn't already have two, I would buy it.

 

[ericc]

Would it be possible to make some sort of piloted D-bit to do this specialized job? I don't have any experience making tools like this, but it sounds like it should work.

 

[derf]

A 3/16" endmill works quite nicely. I use a 3" solid carbide 3/16" 4 flute end mill to make the final cut on muzzle brakes.

 

[pontiac428]

I understand wanting to keep your parts count down, but is it really worth the effort? Having the cones and spacers as separate parts allows you to tinker with tuning (via spacing and changes in spacing along the length). The cone mouth on most modern cone-baffle designs is neither round nor concentric, and there is good information on that particular facet of suppressor design on the web. Anyway, extra effort is warranted when there is something to be gained, but unless you really have fun doing it, make the job easy on yourself!

 

[cdhknives]

Tradeoffs...LOL. Separate cones makes for double the interface surfaces that need to mate up. Yes I SHOULD be able to machine to that close of tolerance but the difficulty goes up no matter what. Making the spacers different length for tuning has been considered and is interesting. FWIW I am fully engaged over at silencertalk.com but for basic machining help I feel I do better here. Ultimately the cones will be clipped, but that is the final op...and might get done on the belt grinder since all I have for milling is the Atlas mill attachment and no jig for holding fragile cones.

My fear of baffle strikes and the federal laws concerning (forbidding without expensive licenses if you take a strict interpretation) repairs have me being VERY cautious with alignment and concentric bores.

 

[cdhknives]

The little micro 100 boring bar is proving to have a LOT of uses. Thanks again for the heads up guys!

 

[killswitch505]

Sooooo..... would this work? Could you not drill a hole, use a chuck reamer and ream it, range it like a barrel and cut the outside diameters?

 

[killswitch505]

Turn it on centers cut the od to be concentric to the ID?

 

[cdhknives]

Separate cones and skirts wins...too much trouble to deep bore those cone internals. That little Micro 100 boring tool did yeoman's duty on this little project, doing all the internal cone work in addition to the center bore. Nice tool!

 

[pontiac428]

Did you end up turning those off of the 3-jaw chuck in a single (fixing) step?