45° helical end mill

[precisionworks]

Of the 100+ solid carbide end mills in the cabinet there was not one that would work on a new job. A slot will be milled into an aluminum Picatinny rail section to match the bottom profile of a Trijicon ACOG:

Thankfully the ACOG base is a standard 45° on each side & 45° end mills aren't uncommon. Some are chamfer only & come to a point - these are used only to mill an edge profile. Others like the one above are helical or tapered & cut the bottom profile as well as the sides. Pricey for a small tool but it works well.

 

[wquiles]

Hopefully you will get to use the new cutter more than once

 

[precisionworks]

LOL, three jobs so far & the first job pays the cost of the tool. I never buy any specialty tooling unless it makes at least a small profit.

 

[StrikerDown]

Any reason you cant use a TA 51 mount?

Or is this going on a Competition upper/Pic and you don't want it too high?

 

[precisionworks]

Excellent question. The owner wants to eliminate the TA51 to get the optic as low as possible. He's planning to mount a MRDS on top of the ACOG & hopes he can raise his head slightly for the red dot or keep it low & use the magnified optic.

Rifle is a MSAR STG-556 & the pic rail extension is elevated quite a bit:

Barry Milton
Precision-Gunsmithing.com
iPhone5 voice recognition

 

[Toaster79]

Some are chamfer only & come to a point - these are used only to mill an edge profile. Others like the one above are helical or tapered & cut the bottom profile as well as the sides. Pricey for a small tool but it works well.

Bollocks! We use these for hardcore center drilling, slotting and chamfering.

 

[precisionworks]

The larger one in your link is $102 for the head & $270 for the shank. At that price it should work very well.

 

[StrikerDown]

That is making more sense now. The rail looks about as high as a Competition AR 15 upper's rail.
http://www.brownells.com/rifle-part...-m16-competition-upper-receiver-prod5604.aspx

Kind of an interesting looking B/Pup, Wonder how it shoots.