Rifle barrels

chipchip · July 9, 2013, 01:06 AM

Is there a reason why some rifle manufactures float there barrels and some don't. Which is more accurate. Does it really matter.

alex0535 · July 9, 2013, 05:49 AM

I only have a basic understanding of barrel harmonics so someone else may be able to better explain this. When you fire a round there is going to be some degree of vibration through the whole system, there is no way to avoid this vibration, the ideal case is to simply have a uniform vibration every time you shoot.

Lets say you have a rifle with a wood stock, or a polymer one that has some flexibility to it. Wood tends to swell and contract with changes in humidity and temperature, if it is not free floated you might get very slight differences in pressure against the barrel, same thing with a polymer stock with flexibility. This variation of pressure on the barrel causes a different vibration and this in turn results in less accuracy.

Free floating provides the barrel enough extra space that the stock will not make contact with the barrel and cause a change in the harmonics of the barrel, it will resonate at its natural frequency.

This all being said, I have heard of rifles that actually benefit from contact between the stock and barrel, but in most cases Free Floating > Not Free Floating. While we are on the topic of contact between parts of the rifle, most bolt action rifles will also benefit from better contact between the receiver and the stock through pillar and/or glass bedding of the stock.

F. Guffey · July 9, 2013, 06:12 AM

“This all being said, I have heard of rifles that actually benefit from contact between the stock and barrel”

http://www.gunauction.com/search/dis...temnum=7309186

“Free floating provides the barrel enough extra space that the stock will not make contact with the barrel and cause a change in the harmonics of the barrel, it will resonate at its natural frequency”

“I only have a basic understanding of barrel harmonics so someone else may be able to better explain this. When you fire a round there is going to be some degree of vibration through the whole system, there is no way to avoid this vibration, the ideal case is to simply have a uniform vibration every time you shoot”

F. Giffey

alex0535 · July 9, 2013, 06:20 AM

^I take it that I explained that pretty well then.

I don't know what I find more strange about that rifle, 3 kinds of wood on it, or that there were 16 bids placed on it. What I was thinking about in the vein of contact between the stock and barrel was shimming it with a section of index card or something of that nature. The guy that did this was of a whole other kind of mindset.

jmr40 · July 9, 2013, 07:02 AM

Generally speaking a standard, or heavy weight barrel will probably shoot better free floated. Some very thin mountain rifle type barrels shoot better with a little forend pressure, others do better floated. They are a little harder to predict.

Some believe that full length bedding to get even and consistent pressure on a barrel improves accuracy. As long as the work is done right both methods will work I think. But it is s lot easier, cheaper and simpler to just free float rather than try to get consistent full length contact with the barrel.

I think full length bedding is best used with synthetic stocks. It is impossible to completely weatherproof wood. Free floating gives the wood a little room to move as environmental conditions change. If you try for full length contact the wood will put uneven pressure on the barrrel as weather conditions change.

alex0535 · July 9, 2013, 07:18 AM

Why not glass bed and also free float? Seems like the best of both worlds to me, especially on a polymer stock. Would provide a lot more rigidity and you still get the benefits of free floating. There isn't any reason why both can't be done, all it would take would be thicker masking along the barrel when you are setting the bedding.

Art Eatman · July 9, 2013, 10:24 AM

The original question was about the manufacturers' choices. As near as I can tell, it varies all over the place. Some free-float, some don't. Some only do it for precision or target rifles.

Whether do-it-yourself or have it done by a gunsmith, glass-bedding the receiver has been a common practice for over sixty years that I personally know about.

As far as the manufacturers choices, I'd sorta guess it has to do with the precision in manufacturing the stocks. But that's just a guess.

eldermike · July 9, 2013, 10:43 AM

From a manufacturers point of view it's most likely improves margin (reduces costs) to add pressure points to the stock. Free floating is part of the accuracy equation and if done apart from the other parts it will often reduce accuracy. That's been my experience and as such this is a guess on my part as to the actual choices made by manufacturers.

Bart B. · July 9, 2013, 01:57 PM

It's interesting that the top ranked, match winning and record setting bolt action rifle shooters and smiths building their rifles for use in competition never have barrels that touch the stocks fore end; they're all free floated. The only thing those barrels touch is the receiver they're screwed into.

Across all the rest of the rifle buyers, shooters, fixers, bedders, testers and whatever across all shooting disciplines, there's a wide range of beliefs and processes that makes each barrel profile shoot most accurate. All sorts of barrel to stock touching and pressure arrangements are thought to be the best.

I think the second paragraph above is why many manufacturers put a bit of up pressure at the stock's fore end tip against the barrel. It's a decades old method of improving accuracy with sloppy inletting of the stock around the receiver. Therefore, as most customers like that idea of a pressure point. they get what they think is the best.

Which group do you think knows best? The ratio of "top ranked" to "all the rest" is about 1 to 10,000; maybe more.

Erno86 · July 9, 2013, 03:43 PM

If you unscrew the front receiver screw...and the barrel rises up above the rifle forearm, your rifle is probably in need of a bedding job.

F. Guffey · July 10, 2013, 07:02 AM

Akex0535, nothing has changed, when the M1917 Remington listing hit the forums not one single member looked at the rifle with an open mind. I purchased the rifle for the parts but hoping there was an outside chance the builder knew what he was doing. I could not see how anyone could build a rifle in that configuration without knowing what they were doing. The receiver and barrel is bonded to the stock as one piece, the receiver does not have a recoil lug, the recoil lug is the the bonded stock, it does not have a trigger guard with a magazine (no floor plate), the magazine was formed when bonded, complete with spring and bullet guide.

Money? The rifle has a Timeny trigger, I took the rifle to the range with 120 rounds, I used 12 different loads of 10 rounds each, new cases, once fired cases, military cases etc., with total disregard for the chamber length, different bullets, different powders, no patterns, just groups, nothing larger than a quarter, no excuses but the low stock and high rings made it difficult when aiming. There was nothing I could do to improve the accuracy outside of taking more time.

Touching, floating, bedding and harmonics, this rifle has an exemption, there is a member of this forum that has said “ Do not build it ugly just because you can”, I did not build this rifle, I could improve the looks, at the risk of losing accuracy, I won’t.

F. Guffey

July 9, 2013, 01:06 AM	#1
chipchip Senior Member Join Date: December 21, 2005 Posts: 247	Rifle barrels Is there a reason why some rifle manufactures float there barrels and some don't. Which is more accurate. Does it really matter.

July 9, 2013, 01:57 PM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	It's interesting that the top ranked, match winning and record setting bolt action rifle shooters and smiths building their rifles for use in competition never have barrels that touch the stocks fore end; they're all free floated. The only thing those barrels touch is the receiver they're screwed into. Across all the rest of the rifle buyers, shooters, fixers, bedders, testers and whatever across all shooting disciplines, there's a wide range of beliefs and processes that makes each barrel profile shoot most accurate. All sorts of barrel to stock touching and pressure arrangements are thought to be the best. I think the second paragraph above is why many manufacturers put a bit of up pressure at the stock's fore end tip against the barrel. It's a decades old method of improving accuracy with sloppy inletting of the stock around the receiver. Therefore, as most customers like that idea of a pressure point. they get what they think is the best. Which group do you think knows best? The ratio of "top ranked" to "all the rest" is about 1 to 10,000; maybe more. Last edited by Bart B.; July 9, 2013 at 02:04 PM.

July 9, 2013, 03:43 PM	#10
Erno86 Senior Member Join Date: September 22, 2012 Location: Marriottsville, Maryland Posts: 1,739	If you unscrew the front receiver screw...and the barrel rises up above the rifle forearm, your rifle is probably in need of a bedding job. __________________ That rifle hanging on the wall of the working class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there." --- George Orwell

July 9, 2013, 05:49 AM	#2
alex0535 Senior Member Join Date: November 4, 2012 Location: Georgia Posts: 908	I only have a basic understanding of barrel harmonics so someone else may be able to better explain this. When you fire a round there is going to be some degree of vibration through the whole system, there is no way to avoid this vibration, the ideal case is to simply have a uniform vibration every time you shoot. Lets say you have a rifle with a wood stock, or a polymer one that has some flexibility to it. Wood tends to swell and contract with changes in humidity and temperature, if it is not free floated you might get very slight differences in pressure against the barrel, same thing with a polymer stock with flexibility. This variation of pressure on the barrel causes a different vibration and this in turn results in less accuracy. Free floating provides the barrel enough extra space that the stock will not make contact with the barrel and cause a change in the harmonics of the barrel, it will resonate at its natural frequency. This all being said, I have heard of rifles that actually benefit from contact between the stock and barrel, but in most cases Free Floating > Not Free Floating. While we are on the topic of contact between parts of the rifle, most bolt action rifles will also benefit from better contact between the receiver and the stock through pillar and/or glass bedding of the stock.

July 9, 2013, 06:12 AM	#3
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	“This all being said, I have heard of rifles that actually benefit from contact between the stock and barrel” http://www.gunauction.com/search/dis...temnum=7309186 “Free floating provides the barrel enough extra space that the stock will not make contact with the barrel and cause a change in the harmonics of the barrel, it will resonate at its natural frequency” “I only have a basic understanding of barrel harmonics so someone else may be able to better explain this. When you fire a round there is going to be some degree of vibration through the whole system, there is no way to avoid this vibration, the ideal case is to simply have a uniform vibration every time you shoot” F. Giffey

July 9, 2013, 06:20 AM	#4
alex0535 Senior Member Join Date: November 4, 2012 Location: Georgia Posts: 908	^I take it that I explained that pretty well then. I don't know what I find more strange about that rifle, 3 kinds of wood on it, or that there were 16 bids placed on it. What I was thinking about in the vein of contact between the stock and barrel was shimming it with a section of index card or something of that nature. The guy that did this was of a whole other kind of mindset.

July 9, 2013, 07:02 AM	#5
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,805	Generally speaking a standard, or heavy weight barrel will probably shoot better free floated. Some very thin mountain rifle type barrels shoot better with a little forend pressure, others do better floated. They are a little harder to predict. Some believe that full length bedding to get even and consistent pressure on a barrel improves accuracy. As long as the work is done right both methods will work I think. But it is s lot easier, cheaper and simpler to just free float rather than try to get consistent full length contact with the barrel. I think full length bedding is best used with synthetic stocks. It is impossible to completely weatherproof wood. Free floating gives the wood a little room to move as environmental conditions change. If you try for full length contact the wood will put uneven pressure on the barrrel as weather conditions change.

July 9, 2013, 07:18 AM	#6
alex0535 Senior Member Join Date: November 4, 2012 Location: Georgia Posts: 908	Why not glass bed and also free float? Seems like the best of both worlds to me, especially on a polymer stock. Would provide a lot more rigidity and you still get the benefits of free floating. There isn't any reason why both can't be done, all it would take would be thicker masking along the barrel when you are setting the bedding.

July 9, 2013, 10:24 AM	#7
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	The original question was about the manufacturers' choices. As near as I can tell, it varies all over the place. Some free-float, some don't. Some only do it for precision or target rifles. Whether do-it-yourself or have it done by a gunsmith, glass-bedding the receiver has been a common practice for over sixty years that I personally know about. As far as the manufacturers choices, I'd sorta guess it has to do with the precision in manufacturing the stocks. But that's just a guess.

July 9, 2013, 10:43 AM	#8
eldermike Senior Member Join Date: January 24, 2013 Location: NC Posts: 545	From a manufacturers point of view it's most likely improves margin (reduces costs) to add pressure points to the stock. Free floating is part of the accuracy equation and if done apart from the other parts it will often reduce accuracy. That's been my experience and as such this is a guess on my part as to the actual choices made by manufacturers.

July 10, 2013, 07:02 AM	#11
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Akex0535, nothing has changed, when the M1917 Remington listing hit the forums not one single member looked at the rifle with an open mind. I purchased the rifle for the parts but hoping there was an outside chance the builder knew what he was doing. I could not see how anyone could build a rifle in that configuration without knowing what they were doing. The receiver and barrel is bonded to the stock as one piece, the receiver does not have a recoil lug, the recoil lug is the the bonded stock, it does not have a trigger guard with a magazine (no floor plate), the magazine was formed when bonded, complete with spring and bullet guide. Money? The rifle has a Timeny trigger, I took the rifle to the range with 120 rounds, I used 12 different loads of 10 rounds each, new cases, once fired cases, military cases etc., with total disregard for the chamber length, different bullets, different powders, no patterns, just groups, nothing larger than a quarter, no excuses but the low stock and high rings made it difficult when aiming. There was nothing I could do to improve the accuracy outside of taking more time. Touching, floating, bedding and harmonics, this rifle has an exemption, there is a member of this forum that has said “ Do not build it ugly just because you can”, I did not build this rifle, I could improve the looks, at the risk of losing accuracy, I won’t. F. Guffey