Rifle Barrel Floating

[perfectionist1]

Rifle barrel floating is a very normal thing ( as I gather) in countries with extreme climate and damp seasons.

It is a process of removing and preventing rifle barrel to physically touch and rest on wood, usually happens when wood swells due to moisture, this is done so that the harmonic vibrations of the barrel is not dampened and a better aim and results, specially when long distance placements are achieved. I saw vids where people rub off the wood by sand paper/ filing then re polishing.

This is done on sports rifle.

I got confused, since till recent past, in US till M1 or in UK till SMLE or in Russia - Mosin Nagant in India with police till now, they have full wood cover on all sides of the rifle barrel, then how did they manage the floating.

In the first place why do these rifles as mentioned above were covered fully by wood and how did they manage the floating barrel part?

Please share your valuable knowledge, I admit to be a novice in rifles.

Cheers....

[timmy]

Perfectionist: remember that the military sniper rifle based on the issue rifle is a different animal than the sporting rifle. Te full stock military rifle is meant to endure battle conditions, unlike a sporting rifle. It was also meant to act as a thrusting spear, when coupled with a bayonet.

For example, the bedding of an SMLE is really a nightmare, but the solid but stock attachment makes it an ideal bayonet-use rifle. Similarly, the Mosin Nagang gains a lot of strength I the critical wrist area because the single stack magazine paerves the maximum amount of wood in the stock for strength.

Bedding a Mosin is a dream compared to other designs because of the wood in the action area, and an SMLE is a nightmare. In between are the Mauser-like action. Some complain about the projecting magazine, but the military rifles balance ahead of the magazine, so this isn't an issue for the military rifles.

Even military sniper rifles were not capable of the gilt-edge accuracy we can get from factory rifles today. There are differ techniques for bedding military rifles, depending on type. You'd rally need to examine the techniques for each rifle.

For traditional bolt action battle rifles, the kind of the hill is the Swiss K31 straight pull. It does not hurt, that all of the Swiss ammo is match grade, a big advantage to the target shooter. Right behind are the Swedish M96 Mausere and the Finnish M39 Mosin Nagant. (Mine shoots a lot better than I can!)

As for Garand, M14,m16/M4, someone else can comment on them, as they aren't quite in my line.

[Mark]

Merry Christmas everyone!

I will try to give a short explanation about my current understanding on barrel floating, which is always subject to change as even the professionals cannot agree on what happens.

Anyway, by definition a fully floated barrel does not touch anything except the receiver of the gun. The traditional way of checking whether or not a barrel is floated is to run a piece of paper, money is commonly used as a standard:


Another pic:


The bill should move freely all the way back to the chamber area of the barrel.

If it does not do this, then by definition the barrel is not full floating.

Here is a custom stock for a Ruger 10/22 that can illustrate what the ultimate goal is:



Can you see how the forearm is floated away from the barrel? If you look at a SMLE, you will realize that floating a SMLE barrel is virtually impossible without a lot of extra metalwork.


The same with most rifles that have shrouds (though there are quite a few exceptions to this).

Anyway, I have to go now to the In-Laws so I will cut this short, but just realize that free-floating is just an extra technique that can be used, and is not a mandatory rule for accurate rifles. Indeed, many rifles shoot better with a small pad applying pressure at the end of the stock, and I have not even touched on the topic of "barrel harmonics" which is supposed to be one of the main benefits of floating. Here is an article to read on the how and why of creating a pressure pad:
http://www.shootingtimes.com/2011/01/04 ... hing_0206/

I hope that has answered some of your questions, and if it makes you have even more questions then it is even better!


Regards to all!

Mark

[timmy]

In addition to what Mark said, a composite stock is not so acted by humidity and temperature, so pressure points will not change the point of aim to such a degree.

Also recall tht a military barrel might be expected to be fid under all kinds of conditions, where a hunting rifle might be fired only three or five times at the most. Heating the barrel can change the point of aim, especially if the barrel has not been stress relieved. In such a case, the military barrel can be helped by bedding.

the SMLE has a long thin barrel and the adjustment of the king screw and tensioning screw can help ensure an acceptable level of battlefield expertise.

On the other hand, I have removed the tip pressure point on my Finnish Mosin Nagant M39, and it will shoot Hungarian lead core heavy ball quite nicely in a free floated condition. One of the Finnish improvements to the original Russian design was to shorten and thicken the barrel, and ensure that the receiver is bedded to the stock only in her horizontal plane, under the action. The sides of the action do not touch the stock.

[xl_target]

I got confused, since till recent past, in US till M1 or in UK till SMLE or in Russia - Mosin Nagant in India with police till now, they have full wood cover on all sides of the rifle barrel, then how did they manage the floating.

In the first place why do these rifles as mentioned above were covered fully by wood and how did they manage the floating barrel part?

When the rifles that you have mentioned, like the SMLE and the Mosin were designed, a common infantry tactic was volley fire. Volume of fire was used to substitute for accuracy. Extreme accuracy was not needed for the average infantryman's rifle as the tactics didn't dictate that requirement. However, a rifle that was very robust (as Tim has mentioned) was required. It had to be capable of providing a mounting point for a bayonet. The butt plate would also be used as a striking object in the event of hand to hand combat. It was desired that the stock be robust enough to handle that kind of use.

Recently standard infantry rifles have become very accurate. In fact, in the US military's involvement in the semi urban and urban environment of Iraq, the surprising accuracy of the US's standard military rifle has come to light. The large numbers of head shot enemy, in Iraq, caused the US Army to suspect that soldiers were executing insurgents. However, it was proved that the introduction of optics (as standard issue) in combination with the M4 rifle was allowing soldiers to make consistently accurate shots, from a distance, to dispatch the enemy. The military issue M16 or M4 is not free floated. You can make it free floated but the standard handguard touches the barrel. As Mark mentions, it is just one of the things you can do to make a rifle more accurate.

However in the wide open spaces in Afghanistan, the 5.56 cartridge doesn't seem to retain the energy to produce fatal hits past around 300/350 yards. The US army is evaluating the effectiveness of the M4 rifle.
http://www.foxnews.com/politics/2010/05 ... ghanistan/
http://www.armytimes.com/news/2010/05/ap_m4_052110/

As Tim mentioned, sniper rifles were a whole different animal. They were put together by armorers, with accuracy in mind. A lot of work usually went into them, sometimes a lot of hand work with filing and matching of parts. However, often it was the shooter and not the rifle that accounted for the sniper's accuracy. Carlos Hathcock's Winchester M70 (which was a modified sporting rifle) in Vietnam was a 2 MOA rifle but it's zero never shifted. Still Carlos was extremely effective with it.

Match shooters and some hunters do everything they can to make their rifles more accurate so match rifles and some hunting rifles are often free floated.

[Arien73]

Hello members,

As follow up to this post , free float barrel is just one factor,accuracy of a rifle depends upon the having a bull barrell, heat treated, hammer forged, smooth bore, and reciever being steel and glass bedded, and having a weatherproof stock which is resistance to humidity and heat,or cold..and above and most important all, a fixed magnification high end rifle scope.... i am writing with personal experience as my real cousin who is sniper us marines(USMC) and he served in iraq and afghanistan,and i had chance to go with him ,at his camp and inspect their sniper rifles chambered in .308, they use fixed magnification (u.s optics) scopes..and that is their secret sucess,, he being instructor told me that even dumbest of dumb person shoots fine with this rifle, and fine snipers are produced who understand the calculas of ballistics.. which is not that hard but requires sharp memory and is possible..
apart from all of above , a fine accurate rifle can be made by civilians too, with availble materials in market..

regards....arien 73

[perfectionist1]

Dear Timmy, XL_target & Mark,
Thanks for great deal of insight. Really helpful information.

Cheers....

[timmy]

Perfectionist:

Please take a look through these articles. There is a lot of interesting information what has been written here:

http://www.riflebarrels.com/articles/default.htm

[xl_target]

Thanks Tim, for those links. Very illuminating.

Perfectionist, as you can see by reading those links; ( unlike what has been mentioned above) hammer forging is not the only way to make an accurate rifle barrel. Lilja barrels are renowned for their accuracy and Dan Lilja's button rifled barrels barrels are in great demand by shooters who demand the ultimate in accuracy. He also talks about cut rifling. The object is to make a bullet spin at a certain rate. How it is done shouldn't really matter that much.
Some Glock pistols (and some other manufacturers) have polygonal rifling in the barrels that are unlike the traditional lands and grooves. However, polygonal rifling is nothing new. See: this article and this one

Read the article on the rigidity of a barrel and it's effects, from those links posted by Tim. Much food for thought there.

[timmy]

Yes sir! The idea of the barrel being a water hose and harmonically vibrating when fired, and with vibrations determined by length, thickness, and stiffness of the barrel helped me understand the idea of bedding a lot better. The SMLE's unique two piece stock requires additional techniques, where the critical areas are where the fore end joins the buttstock socket and where the fore end wood around the trigger slot beds to the receiver. then there is king screw and forend tension to consider.

[perfectionist1]

Thanks Timmy, XL_target,
Gone through the links, very informative.

regards

[only32owner]

[quote="perfectionist1"]Thanks Timmy, XL_target,
Gone through the links, very informative.

regards[/quote

OOOH,

You seems satisfied,
But Please let us know. What you are going to do with your rifle. If you have any?

Regards.

[perfectionist1]

Dear only32owner,

Thanks for your comment, sarcastic though.
As I have admitted on the onset that I am novice to rifles and I certainly do not own one, it is a learning curve.
Sure, you might have gone through it some time, maybe long back.
I am aware that you are an experienced rifle shooter.

Would look forward to you for sharing great knowledge about the subject.

Cheers..

[only32owner]

I respect your sentiments.
Its same for me also , just learning and trying hard not to hurt anyone.

Regards.

[perfectionist1]

thanks sir