Slivers of Cork + Mosin

[rojocorsa]

The Box of Truth has a tutorial on improving a Mosin's accuracy by putting a slice of cork between the barrel and the furniture.

http://www.theboxotruth.com/docs/edu63.htm

My question: Scientifically, how/why does this work?

Have any of you ever tried it?

[sorensen440]

Maybe a reduction in vibration ?

[Rover]

Tighter fit between barrel and stock, it's why no high end stock ever fits well from the factory and you have to sand it away to get the fit perfected. Less wobble between what you're holding (the stock) and what you're shooting (the receiver and barrel)

[someR1]

that is retarded....there is no proof that the cork actually improved the accuracy. Could of been shooter error or even wind....too many variables

note to self: do not modify a perfectly accurate weapon with retarded theories

[jtv3062]

that is retarded....there is no proof that the cork actually improved the accuracy. Could of been shooter error or even wind....too many variables

note to self: do not modify a perfectly accurate weapon with retarded theories

OK , It's a know fact that putting pressure can improve accuracy in some rifles with thin barrels. Most hunting rifles already upward pressure on the barrels, so No it's not retarded

[Lucky Scott]

I am a big fan of the box of truth and tried the trick on my Mosin.
Seemed to help.

[SilentScream]

You should think before you speak "someR1", the technique described above will work on some rifles but not on all, this has to do with natural vibration frequency of the barrel, (as the powder ignites in the chamber shock waves are send trough the barrel and will vibrate it) most of the time removing stock contact will improve accuracy (thus free floating the barrel works really well, freeing the barrel to vibrate with out interference from the stock) but sometimes putting a consistent pressure and/or weight on the barrel at a specific point will do the same here is product that work on the same principal in modern firearms

http://www.limbsaver.com/2009/products/firearms/barrel_deres/index.php#two

for a Mosin give it a try it might work… It worked for me but bedding the action and free floating the barrel worked better.

http://www.theboxotruth.com/docs/edu75.htm

[someR1]

OK , It's a know fact that putting pressure can improve accuracy in some rifles with thin barrels. Most hunting rifles already upward pressure on the barrels, so No it's not retarded

CAN improve, not guarantee .....

I still think the cork idea is a fluke

[coop44]

Either full bedding or upward pressure work on the barrels that tend to "whip" both are very old school techniques, and work very well. Smle #1mk3's with their light barels have a spring loaded tensioner under the barrel. I have personally seen both german 98's and us 03a3's with layers of paper, and in one instance a piece of tin can wedged between the stock and barrel.

[NeoWeird]

It's not so much about vibration but consistancy. Accuracy is not determined by how small of a target you can hit at a distance but by your ability to repeat previous shots with consistancy. You may be able to hit a dime at 1,000 yards with your .223, but if it takes you 1,500 rounds before you do it then your rifle is not that accurate. That's why long range shooters laugh at 3 round groups; because you should be able to put ALL your fired shots into a group that small if you're rifle is THAT accurate - not just the best three you can muster out of a day of shooting. You're rifle may shoot 16 feet to the left, but if EVERY shot goes 16 feet to the left, than it's more accurate than a rifle that shoots it's bullets within a 1" circle concentric to the bore.

That is why free floating is so popular. There are many variables that come into play, such as stock fit, bedding, etc and by removing those variables you make the barrel rest that much more consistantly. If there is nothing touching the barrel, it will naturally want to rest with its center of gravity at it's lowest point.

Now you go to barrels that have thin barrels relative to ratio of length (a .5" barrel 2" long will be more rigid than a 1" barrel 6" long). These barrels will whip when fired. The cork, or other form of bedding, essentially acts as an anchor, like on a suspension bridge. The result is like cutting the barrel in half and creating a more rigid platform while at the same time forcing the barrel to rest above it's natural point of rest. It is forced to the same point each time; ie it returns to rest consistantly in the same place.

The vibration absorbtion comes into play with rapid strings of fire. When the barrel vibrates with each shot, it causes a small wave to travel the length of the barrel which causes it to, for fractions of a second, to point in different directions until the wave stops. This will obviously through off point of impact. By absorbing the vibration quickly, it causes the barrel to return to natual rest more rapidly so follow up shots will be held closer to point of aim.

It's not snake oil, hog wash, or hocus pocus magic. It's science and it's done for a reason.

[cryoguy]

It's not so much about vibration but consistancy. Accuracy is not determined by how small of a target you can hit at a distance but by your ability to repeat previous shots with consistancy. You may be able to hit a dime at 1,000 yards with your .223, but if it takes you 1,500 rounds before you do it then your rifle is not that accurate. That's why long range shooters laugh at 3 round groups; because you should be able to put ALL your fired shots into a group that small if you're rifle is THAT accurate - not just the best three you can muster out of a day of shooting. You're rifle may shoot 16 feet to the left, but if EVERY shot goes 16 feet to the left, than it's more accurate than a rifle that shoots it's bullets within a 1" circle concentric to the bore.

That is why free floating is so popular. There are many variables that come into play, such as stock fit, bedding, etc and by removing those variables you make the barrel rest that much more consistantly. If there is nothing touching the barrel, it will naturally want to rest with its center of gravity at it's lowest point.

Now you go to barrels that have thin barrels relative to ratio of length (a .5" barrel 2" long will be more rigid than a 1" barrel 6" long). These barrels will whip when fired. The cork, or other form of bedding, essentially acts as an anchor, like on a suspension bridge. The result is like cutting the barrel in half and creating a more rigid platform while at the same time forcing the barrel to rest above it's natural point of rest. It is forced to the same point each time; ie it returns to rest consistantly in the same place.

The vibration absorbtion comes into play with rapid strings of fire. When the barrel vibrates with each shot, it causes a small wave to travel the length of the barrel which causes it to, for fractions of a second, to point in different directions until the wave stops. This will obviously through off point of impact. By absorbing the vibration quickly, it causes the barrel to return to natual rest more rapidly so follow up shots will be held closer to point of aim.

It's not snake oil, hog wash, or hocus pocus magic. It's science and it's done for a reason.

I agree and very well explained. Thank you for the info.

[reidnez]

Ahh, the technical wizardry of Mosin gunsmithing...there's also a method of doing a trigger job which involves using a flattened piece of soda can as a shim.

You know you have a grunt's weapon when it can be improved with cork and a soda can.

[rojocorsa]

It's not so much about vibration but consistancy. Accuracy is not determined by how small of a target you can hit at a distance but by your ability to repeat previous shots with consistancy. You may be able to hit a dime at 1,000 yards with your .223, but if it takes you 1,500 rounds before you do it then your rifle is not that accurate. That's why long range shooters laugh at 3 round groups; because you should be able to put ALL your fired shots into a group that small if you're rifle is THAT accurate - not just the best three you can muster out of a day of shooting. You're rifle may shoot 16 feet to the left, but if EVERY shot goes 16 feet to the left, than it's more accurate than a rifle that shoots it's bullets within a 1" circle concentric to the bore.

That is why free floating is so popular. There are many variables that come into play, such as stock fit, bedding, etc and by removing those variables you make the barrel rest that much more consistantly. If there is nothing touching the barrel, it will naturally want to rest with its center of gravity at it's lowest point.

Now you go to barrels that have thin barrels relative to ratio of length (a .5" barrel 2" long will be more rigid than a 1" barrel 6" long). These barrels will whip when fired. The cork, or other form of bedding, essentially acts as an anchor, like on a suspension bridge. The result is like cutting the barrel in half and creating a more rigid platform while at the same time forcing the barrel to rest above it's natural point of rest. It is forced to the same point each time; ie it returns to rest consistantly in the same place.

The vibration absorbtion comes into play with rapid strings of fire. When the barrel vibrates with each shot, it causes a small wave to travel the length of the barrel which causes it to, for fractions of a second, to point in different directions until the wave stops. This will obviously through off point of impact. By absorbing the vibration quickly, it causes the barrel to return to natual rest more rapidly so follow up shots will be held closer to point of aim.

It's not snake oil, hog wash, or hocus pocus magic. It's science and it's done for a reason.

Thanks, well done.

Does this trick only work for long-barreled guns such as the 91/30? I figure I'd ask because the M38/44/53/59s have carbine length barrels.

[NeoWeird]

Thanks, well done.

Does this trick only work for long-barreled guns such as the 91/30? I figure I'd ask because the M38/44/53/59s have carbine length barrels.

It, and other 'tricks' work with ANY gun. It's not some secret science that is only taught by master gunsmiths to their apprentices; it's simple application of basic principles. Bull barrels are relatively more accurate because they are more rigid and more massive so they are less influenced by outside forces. Trigger jobs help with accuracy because it takes less force to fire the weapon, so less force is imparted to the weapon to push/pull it off target.

Consisntancy is the key to accurate shooting. It's why pillar bedding and torque drivers are so popular with long range platforms. Use what you know, and think about WHY things are there and you will figure out things that can be done to improve your firearms. Things like leverage, pressure, influence of moisture, surface finish, etc etc all come into play and can be used to aid yourself. You just have to think of how to use them.

[rojocorsa]

Don't mean to resurrect my thread. OK, I do. But....



How much cork are you supposed to put in that spot? Do you want it to fit snugly in between both surfaces, or what?