The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > The Smithy

Reply
 
Thread Tools
Old January 31, 2010, 10:57 PM   #1
simoncrk
Member
 
Join Date: January 31, 2010
Location: OKLA
Posts: 19
How long should rifling last?

I took my .308 to a gunsmith to have it glass bedded. and he said it is nearly time for a new BBL. Its a Rem 700 with a 20'' Tactical BBL. I reload so I assume the hotter the load the more wear and tear it has on the chamber and rifling. Am I right?????
simoncrk is offline  
Old January 31, 2010, 11:10 PM   #2
noyes
Senior Member
 
Join Date: December 27, 2008
Posts: 1,032
Yes.
http://www.riflebarrels.com/support/boroscope.htm

http://www.rifleshootermag.com/gunsmithing/bore_061405/

http://www.6mmbr.com/hawkeyeborescope.html
noyes is offline  
Old January 31, 2010, 11:23 PM   #3
simoncrk
Member
 
Join Date: January 31, 2010
Location: OKLA
Posts: 19
Thanks.
simoncrk is offline  
Old February 1, 2010, 02:35 AM   #4
Scorch
Senior Member
 
Join Date: February 13, 2006
Location: Washington state
Posts: 11,408
A barrel on a 308 should last at least 7,000-10,000 rounds before being worn enough to require replacement. I know several people who shoot Service Rifle match with 7.62X51mm (308 Win) that have over 5,000 rounds through their rifles.
__________________
Never try to educate someone who resists knowledge at all costs.
But what do I know?
Summit Arms Services
Taylor Machine
Scorch is offline  
Old February 1, 2010, 08:31 AM   #5
thallub
Senior Member
 
Join Date: November 20, 2007
Location: South Western OK
Posts: 2,065
Quote:
A barrel on a 308 should last at least 7,000-10,000 rounds before being worn enough to require replacement.
Indeed it should. One of my Remington 700 .308 guns has over 6,800 rounds through its barrel. The five round groups measure 1.25" or less at 100 meters.

Hotter loads are harder on barrels. A really hot .308 load is a waste in a 20"barrel.
thallub is offline  
Old February 1, 2010, 01:50 PM   #6
James K
Staff
 
Join Date: March 17, 1999
Posts: 19,170
If the OP is loading really hot, or using some types of powders or bullets, or firing rapidly, the barrel will erode/wear sooner. If he is doing all of those things, a barrel might not last 1000 rounds let alone 10,000.

Or the gunsmith wants to make some money. The true story is in the shooting.

Jim
__________________
Jim K
James K is offline  
Old February 2, 2010, 03:57 PM   #7
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 4,457
Top competitive shooters rebarreled their .308 Win. bolt action rifles after about 3000 rounds. They started out with a barrel that would shoot sub 1/4th MOA at 100 yards and under 1/3 MOA at 100 and 1/2 MOA at 600 (1/3 MOA at 100 and 2/3 MOA at 600 for semiauto M1 & M14 service rifles). Their belted magnums lasted only 800 to 1100 rounds.

When these competitive folks started using the .243 Win. in competition, their barrels lasted only 1500 rounds.

A factory rifle will seem to have twice this accuracy life because they're not that accurate to start with. And service rifles used for combat use will have three times those numbers for barrel life.


And rapid fire doesn't cause as much bore erosion as maximum loads do.
Bart B. is offline  
Old February 2, 2010, 07:20 PM   #8
James K
Staff
 
Join Date: March 17, 1999
Posts: 19,170
I don't have any comparison figures for rapid fire vs. hot loads, but I have seen an M1 rifle barrel turn red and droop after about 20 clips fired as rapidly as possible. I suspect it lost its accuracy.

Jim
__________________
Jim K
James K is offline  
Old February 2, 2010, 07:50 PM   #9
Old Grump
Member in memoriam
 
Join Date: April 9, 2009
Location: Blue River Wisconsin, in
Posts: 3,144
Never seen the barrel droop but I can vouch for the fact that the forearm will smoke and burst into flame if you don't pour water on it. Or in my case my lemonade, don't ask. Shot 6" 100 yard groups before and after so apparently the rifling was already kaput and I couldn't hurt it any.
__________________
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters.
--Daniel Webster--
Old Grump is offline  
Old February 3, 2010, 05:15 PM   #10
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 10,195
Back in the late 90's, Sierra ballistic technician Kevin Thomas ran through some .308 stainless barrels to test cryo treating effect and bullet moly-coating effect on barrel wear. He got about 3500 rounds from his stainless untreated barrel and about 4000 rounds from the cryo-treated, IIRC? He was using a special testing set-aside lot of 168 grian MatchKings that are extra accurate. He looks for fliers to start to appear as the indicator the barrel is shot out. Typically, you get one, then, after awhile you get another, and then they start appearing with increasing frequency. They are typically still well-within what hunters consider minute of deer. They just weren't doing 1/4 moa any more, IIRC? It was written up in Precision Shooting. I'm thinking it was like 1998 or so, if you care to go looking?

On the other side of the coin, we have a former Aberdeen Proving Grounds employee on another forum who fired lots and lots testing. He is also a competitive Highpower shooter. He has a long post describing how guns that were mainly fired full-auto (but not to the melting point) actually got substantially longer barrel life than the single-fired barrels. Several times longer. He has a theory about it being related to carbon hardening before being blown through the throat. You can read about it and his reasoning in his post #25, here. Bottom line, I don't know what rapid fire is doing, but its a lot slower than full-auto, so maybe not much?
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Patron Member
Unclenick is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:40 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.08032 seconds with 9 queries