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7mmfan Rookie Member
Joined: Jan 12, 2008 Posts: 8
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Posted: Wed Feb 13, 2008 7:21 pm Post subject: 4 Land |
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I'm having a Rem. 700 rebarreled in 7mm STW and going to a 4 land Lilja barrel. How much velocity increase should I expect in going from 6 lands to 4 lands?
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1895ss Super Member
Joined: Jul 21, 2005 Posts: 2612 Location: Not Here...!!
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Posted: Wed Feb 13, 2008 8:33 pm Post subject: Re: 4 Land |
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Welcome aboard 7mmfan, I would check with the people at Lilja, they should know something folks here don't.
_________________ A cruel truth is much more desirable than a really nice lie.
'Tis far better to walk alone than to follow a crowd or an a**hole going the wrong way.
Last edited by 1895ss on Thu Feb 14, 2008 2:39 am; edited 1 time in total |
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Pumpkinslinger Super Member
Joined: Sep 22, 2007 Posts: 5001 Location: NC foothills
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Posted: Wed Feb 13, 2008 11:27 pm Post subject: Re: 4 Land |
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I wouldn't expect any velocity increase. Am I missing something?
_________________ Mike
"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle |
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1895ss Super Member
Joined: Jul 21, 2005 Posts: 2612 Location: Not Here...!!
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7mmfan Rookie Member
Joined: Jan 12, 2008 Posts: 8
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Posted: Thu Feb 14, 2008 5:20 am Post subject: Re: 4 Land |
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Maybe I am thinking about this all wrong but, it would seem to me that if you are digging 1/3 less grooves into the bullet then for a given barrel length, powder charge and bullet weight the resulting reduction in friction/restriction would have to result in increased velocity .
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Pumpkinslinger Super Member
Joined: Sep 22, 2007 Posts: 5001 Location: NC foothills
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Posted: Thu Feb 14, 2008 6:42 am Post subject: Re: 4 Land |
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Fewer lands but I bet they are wider. Either way I wouldn't expect any appreciable increase. If you find out different let us know!
_________________ Mike
"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle |
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mikeleduc Member
Joined: Jan 23, 2008 Posts: 69 Location: Phoenix, AZ since 1972
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Posted: Fri Feb 15, 2008 7:11 pm Post subject: Re: 4 Land |
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I don't think the original 2 land 30-06 barrels had any advantage in velocity over the later barrels.
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Dimitri Super Member
Joined: Nov 25, 2005 Posts: 5944
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Posted: Fri Feb 15, 2008 7:41 pm Post subject: Re: 4 Land |
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The barrel lands are propotional in general, and after the initial shock of forming at the throat of the chamber it really doesn't effect anything all that much I dont think. And as Mike mentioned the "cheaper" 2 land barrels produced by various militaries for different firearms in times of war shot the same as the non-wartime production 4 grove barrels, but required less cutting passes to cut hence the money and time savings.
Dimitri
_________________ A thousand hills, but no birds in flight, ten thousand paths, with no people's tracks. A lonely boat, a straw-hatted old man, fishing alone in the cold river snow. |
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7mmfan Rookie Member
Joined: Jan 12, 2008 Posts: 8
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Posted: Sat Feb 16, 2008 7:37 am Post subject: Re: 4 Land |
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I took 1895SS's advice and emailed Dan Lilja. Pumpkinslinger was correct in that when they reduced the number of lands they kept the nominal about of bearing surface the same so there will be essentially no net gain in velocity. However, there is a slightly longer service life due to the lands being wider and that is important with an overbore like the 7mm STW that I am going to.
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