Shortening a Remmy

[Angel_Eyes]

I have shortened the barrels on a brace of stainless '58 remmy's, no problem.

When it came to the rammers I had great difficulty drilling down the arm.

I removed the catch and spring to use the hole as a guide and burnt out 4 HSS drills in short order.
A friend supplied me with a number of Tungsten drills and I managed to finish the first rammer, not so with the second.

It was like trying to drill concrete agregate, a few millimeters ok, then It was as if the metal had lumps of harder material mixed within it. Two tungsten drills burnt out and nowhere near a result.

Has anyone else come across this problem, or could possibly post a solution?

AE

[Professor Marvel]

Greetings my Dear AE

I trust that Other Wiser heads will chime in, but since no one has stepped up as of yet, I shall "give it a go".
I fear that machining stainless can be problematic. I would opine that you are definitely coming up against galling, possibly overheating, and possibly work-hardening, all in a small blind hole.

2 quotes from machinists:
"Low thermal conductivity of austenitic alloys results in heat concentrating at the cutting edges. This means coolants and lubricants are necessary and must be used in large quantities."

"the work hardens unless you cut very aggressively"

-------------
I can so far recommend the following:
1) proper cutting oil, and copious amounts
2) change you drill speed *and* your feed rate. Slower might prevent galling, faster may prevent work hardening.
3) TiN coated bits seem to work better. Some folks swear by HSS, even over cobalt.

A different solution since the hole is not *too* deep might be using a diamond burr and flushing frequently with oil.
hope this helps.

yhs
Prof Marvel

[clehfeldt]

I have not done any stainless guns but I have run into this problem with regular steel cartridge Remmies by the Italians. I was maching the rear sight notch and groove and ran into all kinds hard spots. Every time I hit one with the milling cutter the mill would jump and sometimes tear the hard spot out of the surrounding steel. Faulty heat treating.
Carlos

[jefff]

slower drill speed more pressure and coolant but i am a blacksmith not a gunsmith.i have thought about shorting a 58 but had planned to cut a piece out of the rammer and reweld it to save time of reworking the lever catch

[Marshal Will Wingam]

I've built a lot of machinery out of stainless. The advice you've been given is correct. The more pressure and the slower you can run your drill, the better. I get the best results using a slow turning drill press and a lot of pressure on the drill. A continuous application of thin tapping fluid or coolant is a must. Don't drill long enough to heat the bit. On the rammer, set your drill depth and work in short steps. Drill a little (maybe 1/8") and back it out to cool, run a little fluid down the bit, fill the hole with fluid and do it again. It's harder to do it with a hand drill but you can make that work if you push hard and don't apply any side pressure when pushing (that will break a bit).

[Angel_Eyes]

Thanks guy's, for all the info.

This project is on the back burner for a while until the pill roller finishes up testing my blood pump.

It's amazing just how much sweat you can raise in the workshop when you are "enjoying" yourself!!

Cheers, AE