Home Forums Hunting & Shooting Gunsmithing Strengthening forend

I am not an engineer not even real dam smart.
A pipe is stiffer than a similar OD solid.
The pipe will resist deflection better, until it
fails, which willeads be catastrophic. The solid willike
bend much easier, but will take more effort to have a total
failure.


For use as a stock stiffener, a good tube will be stiffer, lighter,
and will not be exposed to the forces that would ruin it.

Had a cool old FN Mauser custom 300 Win Mag back in the day with a really nice stick of walnut, it was bedded and floated and began to warp to the side a bit, took it to my 'smith, he milled out a channel in the forend, placed a 6" solid aluminum piece of square bar stock in the channel with epoxy compound, immediately placed the rifle in a vice, used some other attachment to push the forend straight with the barrel, let sit for a couple of days, it was still perfectly straight when I sold it.

At least you provided the disclaimer.

NO! The pipe is not stiffer than a solid bar of the same diameter.

Reading this thread I believe many are confusing stiffer with stronger.
They are not the same.

A 1/4" glass rod is stiffer than a 1/4" steel rod, but the steel rod is stronger.

A solid bar is far stronger then a hollow tube of the same diameter, but the tube will come back straighter if it's bent unless it's bent far enough to kink.

A bar takes more force to bend, but doesn't return to straight as well, ............. alloys being equal between the two.

Welded pipe is often made from 1018 steel and so is hot-rolled as a rule.
If anyone want to test this to be sure, (and not have to believe when they see on the internet my post included), just go get a 1" diameter water pipe (called 3/4" in the plumbing industry) and a 1" hot rolled steel rod. Get them both 4 feet long.

Now clamp them 1 foot from the end in a vice on a heavy duty bench or put them into a buried pipe in the ground 1 foot deep and pull. See which one you can bend easier.

The pipe will flex with just a little effort and come back to straight (or mostly straight.) When you go past the point it can resist, it will kink and break over.

The bar will not bend easily at all, but when (or if) you do get it to bent, it will stay bent about 50-60% of whatever bend you put in it.
Try it yourself and see.

None of this is related directly to the OP question, but may explain the debate so it's easier to understand.
Some are saying "stiff" when they mean "strong", and vise-versa

Young's modulus is the stiffness and for a given material, comparing different shapes of the same weight, the modulus will generally be proportional to strength.

In the elastic region we sometimes call this a spring where in Hooke's law, the stiffness is proportional to the spring constant.

For the same material, comparing hollow tubes to solid cylinders, stiffness is a very good way of comparing strengths.

In accuracy, the stiffness is what counts. Recoil does not break guns, it bends them.

You cannot make an object stronger or stiffer by removing material. Using hollow tubes and flutes allows gains in strength and stiffness relative to mass, not diameter. A solid cylinder of a given outside diameter will be stronger than any tube of that same diameter assuming like material composition. The thicker the walls of a tube, the stronger the tube- again, given the same outside diameter. When the walls get so thick that they touch in the center and you now have a solid cylinder, it has become as strong as possible at that diameter.

True, but fluting allows one to increase OD without an increase in weight.

Rifle barrels are not center-loaded... it is the weight of the barrel itself and the action of pressure behind the bullet straightening the barrel.

That causes the barrel to vibrate as the pressure pulse moves down the barrel..

Yup.

I went through all this with a BC stock and it stiffens the fore end but there was still flex through the action area. I just decided to live with it but if I were to do it over again I wouldn't. I would get a new stock instead or just buy a V-Block bedding cradle and inlet that in. The full length ones stiffen the action and magazine area too. But for the cost and time for this better to sell and start over.