Rigid reaming on CNC lathe

[hunter686]

Hi,
I'm looking for some advice. I have the use of a CNC machine and I'm looking to ream my first chamber.

My plan is to mount an aluminium block into a holder and then bore and ream the block in order to mount the reamer and then set the tool to zero. I'll then clock, drill and pre-bore the barrel before the reaming process.

My question is; how do I go about the actual process of reaming the chamber? Do I run a drilling cycle and peck? Or do I set up an boring process and manually set the DOC and passes? And if so what feeds and speeds should I be looking at?

I don't plan to have any pressure flushing system as it's not really worth my while setting one up for the sake of one barrel every 18 months unless I need to to run rigid. The most likely outcome will just be a honeymoon style job. Just retract, wipe, lube, reinsert.

Any info is appreciated

 

[Dusty Stevens]

If youre not going to have thru barrel coolant youll need a peck and retract with the regular machine tool coolant spraying the chips off

 

[linebaugh]

Can you not set up with a floating holder? just curious

 

[Walt Krafft]

I talked with somebody whose company tried this. After breaking several reamers they decided to ream on a manual machine. If I was to try it, I would want the pilot to always be in use and not predrill or bore. A rigid 6 flute reamer is like playing Russian roulet, which flute is going to act like a boring bar? And through barrel coolant is really needed. The more you peck, the more chances for things to go bad.

 

[hunter686]

I talked with somebody whose company tried this. After breaking several reamers they decided to ream on a manual machine. If I was to try it, I would want the pilot to always be in use and not predrill or bore. A rigid 6 flute reamer is like playing Russian roulet, which flute is going to act like a boring bar? And through barrel coolant is really needed. The more you peck, the more chances for things to go bad.

That makes sense. Would I be better just setting up a flush and doing it in two hits? Say one big hit to .30 off, measure, then a final plunge after to size?

 

[Walt Krafft]

Your luck will be better with chambers that require little material removal. 300Blk or 9mm Luger you could almost 1 hit if you could figure out how deep to go. 300 Win Mag not so much. Also depends on the reamer. Feel tells you how it is cutting. You don't have any feel on a cnc.

 

[akajun]

I believe John Scandale at Keystone accuracy chambers on Cnc hass lathes maybe ask him

 

[shortgrass]

Make sure you set the rapids @ 100% before you hit the green button!