Chambering questions

[Samdweezel05]

For the guy like me that will chamber one or two barrels in any given caliber, is it necessary to use a rough in reamer first or can the entire job be done with a finish reamer? Maybe something like a .338 Lapua would need a rough in reamer but a .22-250AI could be done with just a finish reamer? I am going to chamber, thread and crown my own barrel at some point but need to know how much I really need to buy the first time around to get the job done. Also wondering if a floating reamer holder is as good of an idea as it sounds or if I need to find a different way to hold the reamer in the tail stock. Thanks guys.

 

[Bob3700]

There are many ways to skin the cat and in the end, the cat is skinned.

I don't use a roughing reamer, I pre-drill and then bore the rough chamber (.010" smaller than the shoulder diam. ) in place. Final is the finishing reamer.

Some sort of floating reamer holder is used. You can make your own. do an search and you will find the "Pusher type" of reamer holder. They work just fine.

Good luck,

Bob

 

[Samdweezel05]

I really did want to make myself sound stupid by asking if I could drill and bore to rough in a chamber but now we can both sound stupid together, lol. I witnessed what I think is a pusher reamer. It was a reamer being held in a normal tap holder but there was a square slot in the end of the tap holder and a square bit in the tail stock. The slot was made with some "play" in it. Reamer with tap holder was placed the the chamber and the tail stock was brought up behind it. It was all brought together and then backed out of the chamber .010" and the lathe was turned on. Tap holder was held against the tail stock and slowly turned into the chamber.. I think .050" was cut and it was all taken back out, cleaned and started over.

 

[butchlambert]

+1 on what Bob said.
Butch

 

[Samdweezel05]

So after you drill and bore how do you keep the reamer true with the bore of the barrel? I have to assume that the pilot bushing on the end of the reamer won't be in the bore until you start to chamber further than you drilled. Unless I am missing something. Also, where do you find specs for case head protrusion?

 

[butchlambert]

It would be easier for you to search this subject on the this and BR.Com forums. Basically you indicate the bore, drill, and bore. Your bored hole will be dead on with the bore if you use good machine shop practice. Remember your bushing is quite a bit forward of the chamber, but it don't matter as your precision bored hole is guiding the reamer.
Butch