Green Mountain swamped barrels

[Herb]

Terry- finally got through to Jack Garner today. He has swamped Green Mountain barrels in stock and measured the plug depth in the breech. It is 5/8" for a B weight .50 cal. Different larger caliber or straight barrels may be 3/4" plug depth, I don't know. Jack says you have to run a bottoming tap in, but I have them. So I shipped him a walnut blank and ordered a GM swamped barrel from him. I also phoned Green Mtn in Connecticut and they said the B weight swamped barrels have a 5/8" plug depth, I didn't ask about others. Jack says he has been using Long Hammock barrels for 20 years, but the outside at least is not as smooth as the GM barrels.

 

[Terry Zboril]

Herb,
Yes, mine were all .54 C wt's in 38 and 44 inch with 3/4" deep plug holes (entirely too much).

Jack and Steve are good folks. You will be well pleased with the barrel inlet, but you still have to fit and inlet the plug in the barrel and inlet the tang and lug. (He also has the plugs, if you ask.)

If you need to cut off a small amount of breech, the swamped barrel will still "scootch" back, with minor scraping.

I still think it is a shame that a barrel maker of Green Mountain's repute, would leave the breech threads in the sorry condition they do, with everything else being perfect.

Regards,
Terry

 

[C_Laubach]

I still think it is a shame that a barrel maker of Green Mountain's repute, would leave the breech threads in the sorry condition they do, with everything else being perfect.

Regards,
Terry

In the last 20-30 barrels I have gotten from GM I have NEVER gotten one that has a 3/4" deep breech.
They have ALL been 0.621 just under 5/8", and I don't consider this to be sorry breeching!
Sorry breeching is when a barrel maker bores and rifles a barrel and DOESN'T leave enough shoulder for the face
of the breech plug to bottom against! Relying on the threads to seal the breech.Now that is sorry breeching. I also don't see it as a big deal to run a bottoming tap down to the shoulder, it takes maybe 2 minutes?!?
:imo:

 

[Terry Zboril]

Chris,
The 3 GM's that I have done were 2 swamped and 1 straight with breeches of 1 and 1/16" across breech flats on the swamps, and 1" on the straight one.

All in .54 caliber with 3/4" X 16 TPI threads.( standard for the caliber/breech).(I think the industry standard is to cut length to the diameter?)

The threads on this small sample were ALL cut 3/4" deep!, with a couple of threads left uncut. Perhaps my dial caliper is wrong?

You are right that it only takes a small amount of time to cut the threads, IF YOU HAVE THE TAPS!

GM should realize that every gunmaker who buys their barrels, (realizing that every buyer must breech them),may not have a fully equipped shop,(as we do) and at the least, should advise that the breech threads need recutting.(cutting the threads FULL depth in the GM lathe should not take that much longer, if it only takes us 2 minutes, by hand.

The "sorry" portion of my post only refers to my opinion, of the threading of their breeches.

Question? Of the 20/30 barrels you have got from them, Have any had 3/4" X 16 threads?

Perhaps we are arguing apples and lemons?
Regards,
Terry