New barrel maker with new technology

[James Jones]

I can't remember which company it is OTT I think but one of them that makes Encore barrels uses EDM to chamber their barrels , I was kinda hesitant about it but their are severl guys I'v talked to that have their barrels and love them.
I think I'll give it a little more time before I drop the cash on one

 

[Black Diamond 408]

JD,

There would be nothing wrong with EDM for chambering, even with a reamer you have to smooth up the chamber marks, and slightly roughen it. EDM leaves a Kerf behind that needs to be removed. You have to remember that you dont want a polished chamber, this can cause problems. 320-400 grit is about the best. Lots of studies have been done on chamber finish, from just reamer to fine polish. A chamber that has been polished smooth will impart unwanted stress on the locking lugs and the case itself. P.O. Ackley came up with the same conclusions many years ago, the best chamber finish is about 400 grit.

If i can find the artical i will post it.

Dave

 

[dimecovers3]

[ QUOTE ]
I can't remember which company it is OTT I think but one of them that makes Encore barrels uses EDM to chamber their barrels , I was kinda hesitant about it but their are severl guys I'v talked to that have their barrels and love them.


I think I'll give it a little more time before I drop the cash on one

[/ QUOTE ]


This is the guy I think you were thinking of.

http://www.ottllc.com/

 

[Randy338]

Well guys the EDM that would be used in a Barrel Chamber would be a sinker type NOT a Wire EDM..Wire would be used on like a action ,something with a through side to it of closs to equal size...Any kind of EDM-Wire or Sinker type. Can hold very close tolerances...But with any kind of metal removal there is always a drawback...With EDM there is what is known as a recast layer. This is a layer of material that is metalurgically changed after the process. As for a chamber it should work fine but there is an amount of change in the metal structure. Wire EDM has less recast layer on the metal surface than the sinker type. On the sinker a electrode must be made in the male form to burn a hole in the female form. Your tolerance and finish can be controlled by the amount of flushing,Electrical current and material being used for the electrode to name a few..Should work great for a chamber if process is stable enough...Still like the bored and reamed method ..a step better would be a complete ID Grind operation...But who could afford it?

 

[dimecovers3]

In regard to this ability to customize the twist of the barrel, is there a "formula" to spec the theoretical perfect twist for a specific bullet in a specific caliber at a specific velocity?

 

[wapiti13]

Boots is the master of the P&W machine. A lot of todays barrel makers learned from him. /ubbthreads/images/graemlins/shocked.gif

 

[TracySes23]

Agreed


I see two possible soloutions to that problem:

1 - I have heard of some people who are chambering with wire EDM. This would eliminate the problem entirely.

You are mixed up. It's not possible to chamber a barrel with wire EDM. However it's possible to chamber with RAM EDM which would use an electrode shaped like the chamber. The problem with this, is that the electrode erodes away as it's being used. Faster than you can imagine. You'd likely need 3 electrodes to get it done. It would cost more that using a reamer & it likely wouldn't be as precise. It would also cost significantly more. I could go into more detail, but it would be a waste of time. I supervisor in a machine shop at a research facility at the University of Illinois for 22 years. Both of my EDM machines ran constantly.

Spencer

 

[TracySes23]

True enough... I just re-read the specs on case thickness for plasma nitriding stainless. Maximum reasonable case thickness is .008 inches. While sufficient to drastically protect the bore, not enough to lap and have much left.

Ah, well, perhapse just a slightly finer pre nitriding finish to counteract the very slight roughening.

You're talking beyond your experience and knowledge. .008" is the approximate thickness of 2 pieces of copy paper. That is an unbelievable amount to lap by hand.

Spencer