I just bought a used McGowen barrel in 6BR. It is an 8 twist.
Anyway, on the chamber end there are some numbers stamped. The 243 is obvious, as is the 8. But it is also marked 237. Can anyone tell me what that is measuring?
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I just bought a used McGowen barrel in 6BR. It is an 8 twist.
Anyway, on the chamber end there are some numbers stamped. The 243 is obvious, as is the 8. But it is also marked 237. Can anyone tell me what that is measuring?
look down one.
Actually -I think it should be the minor diameter, or the smallest diameter of the lands. The neck diameter on a 6mm round should be anywhere from .262 to .272ish +-
+1
I just visited the Mcgowan web site and they list .237 as the bore diameter. Follow this link;Quote:
Originally Posted by claysshotgunner
http://www.mcgowenbarrel.com/catalog2.htm
Thanks guys. I should have just looked on the McGowen site. lol
That lettering shouldn't of been left on there, when it was chambered it should of been faced off square with the bore.
My McGowen 6br has the same lettering.
Several of the barrel makers stamp the barrel after chambered. I know all of my Shilens and McGowen that they chambered are. My gunsmith also marks the barrel with stamps here as well as on the outside (only if I request it). TimQuote:
Originally Posted by sinman
If its the markings from being a blank there shouldn't be there and I'm pretty sure that's what they are talking about
Shilen will remark theirs the same blanks plus the chambering and neck. SM 17 30BR .330 = Select Match, 1:17 twist, 30BR, 330 neck. It has the same info as the blanks I have got from they plus the chamber and neck. At least mine do.... Tim
I think on the McGowen "drop in" barrels, they leave them stamped on purpose. Mine is also, bought new through Northland:
[img width=600 height=450]http://i490.photobucket.com/albums/rr268/slowpokeslim/P1050331.jpg[/img]
I believe it would only be faced off the chamber end if it was originally bought as a blank, and finished by a smith.
The barrel(s) that you have pictured that are "drop-in" barrels most likely are some of Northlands old inventory. Our previous gunsmith felt that the customer should see the stampings on the end of the barrel so they know exactly what they are getting. Since that gunsmith left us we have changed this policy and all barrels coming out of our shop are milled off on the end of the barrel. This stamping, while it doesn't look great, has no effect on the barrel that I am aware of. The headspace is set by the cartridge & bolt face and not the end of the barrel. What the stamping means is the smaller of the two numbers, in this case 237 that is the bore diameter and the larger number is the groove diameter .243, there are usually two other marks, one is the rifling twist and the other is the material either "C" for chrome moly or "S" for stainless. All the barrel ends are squared to the bore prior to stamping.