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Louis.J
12-23-2016, 03:32 PM
Is there a need to remove X amount off the camber end of a blank, yes, no and why on either.

JLouis

CMaier
12-23-2016, 05:07 PM
if marked correctly, no.
work is done moving to the muzzle end,
which is typically marked at some point.
makers normally list how much to cut off.

Butch Lambert
12-23-2016, 06:09 PM
I've had very few that are marked. They will be belled a little from lapping on either end. When I can I cut at least an inch off both ends.

Louis.J
12-23-2016, 07:18 PM
Thank you I have seen it recommended have never done so and could not figure why other than say for a 22 rimfire or something else that would not clean it up during chambering or the pilot could not get past.

JLouis

CMaier
12-23-2016, 08:16 PM
the tooling wears as it is used.
a tight muzzle is a good thing,
but a way loose breech is not good.

Louis.J
12-23-2016, 08:29 PM
CM please explain in further detail.

JLouis

Mike Bryant
12-23-2016, 09:27 PM
If you indicate in at the throat, drill and bore out most of your chamber before reaming then there's no need to cut any off the chamber end. If you don't pre drill and bore the chamber and let the pilot follow the bore, then you'll need to cut off any belling from lapping the bore.

CMaier
12-23-2016, 11:15 PM
what mike said

alinwa
12-23-2016, 11:18 PM
I trim the breech end only to set the shank length for aesthetics and stock fit. If looks are less important than length, or if I'm utilizing one of my various 'pull-down tuners' I'll pretty much face the back off leaving the entire shank (I actually go thru the trouble of parting it off generally because for some stupid reason I keep the stamped end in my build-record envelope) and drill/bore ignoring the lapping bell. I run in and map the first 6"-7" of the bore trying to get a feel for how it takes off from the breech end so even with the lapping bell left on I've plenty of clean bore to work with.

If the muzzle wants to finish out long, near the bell, I'll generally upset a lead plug and do a quik-N-dirty tightness check of the muzzle end. Of course on some guns I slug it righteous in which case the lapping bells are kinda' handy to catch and return the slug.

jackie schmidt
12-24-2016, 10:27 AM
The only time I run into this delima is when I am trying to get the maximum length from a blank. The 7mm I just built started as a 31 inch blank from Krieger. I wanted a 30 inch barrel. I cut exactly one inch from the muzzle, and nothing from the chamber end.

From what I see in most Krieger blanks, the bell mouthing goes in about 3/8 inch on each end.This is easy to see with. .0001 indicator.

skeetlee
12-26-2016, 01:58 PM
I have several customers who require me to make a coin out of the breech end. I date the coin and mark the cal. I assume these folks want this information for barrel lot identification?? Lee

CMaier
12-26-2016, 02:12 PM
manufacturers warranty is based on PROOF.
so the cutoff is the closest one can come.
if you have issues with a bbl not a chamber.

Mike Bryant
12-26-2016, 03:29 PM
I have several customers who require me to make a coin out of the breech end. I date the coin and mark the cal. I assume these folks want this information for barrel lot identification?? Lee

Some of the barrel makers require the serial number of the barrel for their warranty. The serial number of the barrel recorded on the invoice should be good enough. Then the barrel maker can look up that serial number and make sure that the barrel they are getting back is what they made. It doesn't hurt to cut a small section of it off with a cut off blade and send it with the barrel. Just less for the gunsmith to keep up with when doing barrel jobs.