We have to find out - casting a barrel in concrete

[jackieschmidt]

I’m curious what was inside the tube? Is that rail gun still around?

The tube is filled with pourable Devcon. The trick is to get the barrel exactly in the middle of the tube.

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Tomorrow, I will make you a pencil sketch as exactly how I did it.
yes, I still shoot my Rail Gun, only with a standard V-Block.

 

[jackieschmidt]

Here is how I constructed the barrel encased in a SS tube using pourable Devcon.

Devcon Aluminum Liquid (F-2), 1 lb, Aluminum, 1/EA

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[ricco1949]

The tube is filled with pourable Devcon. The trick is to get the barrel exactly in the middle of the tube.

Devcon Plastic Steel Liquid (B), 1 lb, Can, Dark Grey (1 EA / EA)

Can be machined to close tolerances|Hardens in about an hour|Ideal leveling compound for machinery and equipment|Low viscosity and high compreh...Click For More

factorysupplyoutlet.com

Tomorrow, I will make you a pencil sketch as exactly how I did it.
yes, I still shoot my Rail Gun, only with a standard V-Block.View attachment 1612064

Jackie did you give up on your experimental long bedding lug? IIRC that was on your rail.

 

[jackieschmidt]

Jackie did you give up on your experimental long bedding lug? IIRC that was on your rail.View attachment 1612697

Yes I did.
I could not get it to shoot at a competitive level.

I’m not sure why. I thought I had every base covered.
I still have all of the pieces. Additions to my ever growing menagerie of failed ideas.

 

[davidjoe]

Jackie, per your diagram, you used an already very stout barrel, similar to 1.4 inch straight 6mm I have. Your additional steel tube and devcon contribute their rigidity to the barrel’s, and almost certainly negate its resonance tendency, as it does for the outer tube. Together though, they probably are still lighter than a steel barrel of that outside diameter, and possibly a bit more flexible. I think the main difference though is that I’m planning to put this on a base that supports it as much from the front as from the rear, trying to eliminate any effect of a cantilever design.

I’m curious if the concrete will crack from shock and moderate width barrel expansion. I don’t think it will noticeably recoil.

I have been under a deluge of work but considering how I could keep this project somewhat mobile.

If it is mobile, then it needs to be capable of reliable and precise aiming.

~220 pounds is my calculation of the reinforced concrete poured project, plus separate base. A “down and dirty” way to consider its recoil is to assume recoil is a linear function, such that this would roughly equate to 10 F-Ooen rifles weight.

Rather than trying envision 1/10 of a .308’s recoil in an F-Open rifle, I believe it is valid to mentally substitute a cartridge of 1/10 its potency in energy, shot from an F-Open rifle, perhaps something like a .32 or .380 ACP, or possibly the actual mark is even more like a .22 Win Mag Rimfire from an Open rifle.

A major issue is where and how to affix a scope. The action will be centered directly behind a cylinder of concrete approximately 11 inches in diameter.

 

[davidjoe]

Yes I did.
I could not get it to shoot at a competitive level.

I’m not sure why. I thought I had every base covered.
I still have all of the pieces. Additions to my ever growing menagerie of failed ideas.

If you ever want to clear some space, I can assist you with that. I go to Houston every now and then.

 

[davidjoe]

Well, I called in my inquiry for an opinion, preproduction. The “fired from the shoulder” definition of a rifle that I looked up has concerned me somewhat. I thought it was belt and suspenders prudent to ask, even though as a lawyer I do read statutes daily.

In the post-research call back I got, the question to me was, would I be starting from component parts or a rifle taken out of a stock.

He ultimately said with something like a 30 inch barrel, there wouldn’t be a problem, but he knew that length was an assumption before the call back, when he still posed the original use of the parts, question.

When he asked that question, I asked him which way he considered the right way to do it. The answer was the separate components route, as I wouldn’t be changing a shoulder fired rifle to a different use. So, I got two conclusions from one person, to the question, which means there’s really no telling what mutiple, other people would say.

I don’t think I want to buy another action just for this. I have no actions that have never been put to a different type use.

It made sense when I had extra components on hand, but that would generate even more surplus.