Winchester uses it in some of their M70's, and I've read that others have done so. There are comments about automotive grade (heat tolerant) silicon, but nothing specific. Has anyone tried it? What results? What product?

I thought it was some kind of hot-glue. I got the impression that it was a quick, cheap bedding solution for production rifles.

I know that it breaks down with age and some chemicals. I also see it shattered a lot of times. I can't prove it because I have never tested it, but I don't think it likes being pounded on at -20 or -30F. Just a guess.

I wouldn't even call it a bedding solution. I think it's a band-aid for sloppy/not even close factory inletting.

quote:

I wouldn't even call it a bedding solution. I think it's a band-aid for sloppy/not even close factory inletting.

+1

quote:

Originally posted by craigster:
I wouldn't even call it a bedding solution. I think it's a band-aid for sloppy/not even close factory inletting.

Wwweell, I did warranty for Remington, Winchester, Ruger, Savage, Kimber, Weatherby and many others over the years. You actually hit the nail right on the head.

The inside poop on the bedding systems they use really isn't directed towards accuracy at all. It's primary function is to take a loosely inletted stock that requires little or no hand fitting and mating it to the barreled receiver body in such a way that it can't shatter the stock from flopping back and forth under recoil. Of course marketing holds up their fingers just like Richard Nixon used to do, and claims that it's a high tech bedding system specially designed for accuracy. But we all know what became of Tricky Dick! I suppose that you can say it contributes to accuracy while doing that task, but the main function is to keep the thing from blowing the stock to pieces. And it does accomplish that rather nicely I suppose.

Enfield SMLE rifles used to be after factory bedded by A J Parker, G E Fulton, Alex Martin and the like using thin sheets of cork. The sort of cork once used, so I understand, for gaskets on car engines. So would that be 'soft' bedding?

quote:

Originally posted by enfieldspares:
Enfield SMLE rifles used to be after factory bedded by A J Parker, G E Fulton, Alex Martin and the like using thin sheets of cork. The sort of cork once used, so I understand, for gaskets on car engines. So would that be 'soft' bedding?

I am sure that was long before their accu glass available.

i doubt its silicon -- acts like clear caulk -

an easy solution, for quick bedding, is mega stick ...
https://www.partsmaster.us/Sit...s.aspx?Code=05351505

I have a 300 win on a springfield that is spot bedded fore and aft, and shoots very well..

shesh, i was young and dumb then, but it worked well, using floorwax as a release agent

You can buy thin silicone sheet like I have right here , 1/16".But I've never used it for bedding ! My ancient Acra-glass bedded rifles [CST] are still hard after 40+ years .A thin layer of Accra-glass or waterproof finish on the inside of the stock keeps moisture out of the stock. The school's advice was receiver + 2" of barrel. Works for me !

I raised the issue because:
-It looked like it might have some merit for damping vibration.
-I'm the curious sort.

Being retired my time is nearly worthless, unlike that of professional gunsmiths. So, I just might try a test. If I do I'll post results. But, y'all must promise not to laugh.

quote:

I am sure that was long before their accu glass available.

I think you might be right!

You can also use Adobe, it last for years! and its cheap!

quote:

The school's advice was receiver + 2" of barrel. Works for me

The action 2 or 3 inches of the barrel free float the rest has worked very well for me also

I should add here that "free float" for a light whippy barrel should have a wider space. That shows up especially for something like my 223 Kimber.

If you want to soft-bed your rifle just use a Miles-Gilbert kit from Midway. I've tried two different kits and can't get this crap to set up properly when mixed exactly as directed. When I pulled my M70 out of the safe a year after I bedded it, there were three little bubbles of bedding material that had squeezed out from under the floorplate. They weren't there two months after the bedding job. Sorry, rant off.

Sometimes a gun needs to be "Hard" bedded:

Bet that gets heavy in the mountains.

That "hot glue" bedding material that was used on M70 Featherweights was some aggravating stuff to remove. I tried a Dremel Tool with a HS carving bit. Bad idea. The bedding would liquefy at the bit and be spun into a bird's nest of threads which re-hardened. I think I finally chiseled/pried it out of the stock and bedded it with Acraglas.

I think I'll just stick with Marine Tex. It's nice and soft. About like a rock. It's also really chemical resistant, doesn't chip and it cuts as clean as steel and aluminum in the mill with carbide tooling without melting.

Plus, its a purdy dull grey/black color. That's my favoritestestest color in the whole-wide-wide-world-of-sports.

I've never had any formal in gunsmithing, but I've always understood that the purpose of free floating a barrel is because a barrel resonates at a given frequency when fired, and you're trying to have the muzzle in a consistent location as the bullet is leaving the muzzle. To do this, the pressure and/or velocity has to put the bullet at the right place at the right time each time. If one were to take resonance out of the equation (by dampening), it seems like variations in velocity wouldn't matter as much. One would think that dampening would make it easier to achieve accuracy.

As an aircraft mechanic, I often work with a sealant that Boeing (and most other large aircraft manufactures) uses, called "B1-2", or "B1-6" (which is the faster setting version). B1-2 sets in about 24 hours at 70F, and B1-6 in about half that. It's used as a fuel tank sealant, to seal cockpit windows, and just about anywhere two or more layers of sheet metal overlap. It's a two part compound that sets up to be very similar to inner tube rubber, is gray/black in color, and is tough as all get-out. It's impervious to jet fuel, hydraulic fluid that removes polyurethane paint, and regularly goes from 120F to -40F and back, several times a day for 20 years or more without changing it's elasticity. I've always thought it would make an excellent bedding material... but have never gotten around to trying it.

Porosonik.

The whole idea of "soft" bedding is ridiculous!

A bedding should be as tight as possible.

On all our rifles here, we used Titanium bedding if possible, especially hard kicking rifles.

Never had any problems.

quote:

Originally posted by Porosonik:

As an aircraft mechanic, I often work with a sealant that Boeing (and most other large aircraft manufactures) uses, called "B1-2", or "B1-6" (which is the faster setting version). B1-2 sets in about 24 hours at 70F, and B1-6 in about half that. It's used as a fuel tank sealant, to seal cockpit windows, and just about anywhere two or more layers of sheet metal overlap. It's a two part compound that sets up to be very similar to inner tube rubber, is gray/black in color, and is tough as all get-out. It's impervious to jet fuel, hydraulic fluid that removes polyurethane paint, and regularly goes from 120F to -40F and back, several times a day for 20 years or more without changing it's elasticity. I've always thought it would make an excellent bedding material... but have never gotten around to trying it.

Porosonik.

Instead of b1, I'm sealing some fuel tanks with a2:





Never thought about using it for bedding though. I'm more of a marinetex guy.

Saeed is right . The vibrations are caused by the bullet going down the barrel.So the barrel should be free floating so as not to interfere. everything else should be rigid , acting as one piece.

If it'soft.

I's a poor excuse for bedding. Kenny

quote:

Originally posted by mete:
Saeed is right . The vibrations are caused by the bullet going down the barrel.So the barrel should be free floating so as not to interfere. everything else should be rigid , acting as one piece.

The way I've always pictured it, an unsupported barrel attached at the breech would sag slightly at the muzzle. Pressure applied to the inside of the barrel would cause the barrel to straighten, much the same as pressure applied to a Bourdon tube in a pressure gauge causes it to straighten, moving the needle. Momentum would cause the muzzle to pass through level, then return to where it was when at rest before beginning another cycle. I guess if a rifle was fired in zero gravity, there would be no vibration.

Porosonik.

quote:

Originally posted by Porosonik:
I guess if a rifle was fired in zero gravity, there would be no vibration.

Porosonik.

I think some guy once proposed a theory that: "for every action, there is an equal and opposite reaction." I somehow think it would maybe move/vibrate.

Another bunch of smart asses used it to go to the moon and back. Unless of course you're a conspiracy theorist, in which case I am sorry and regret having offended and butt-hurt you by discounting your religion!

I'm very polite! Dontchaknows.

quote:

Originally posted by speerchucker30x378:

quote:

Originally posted by Porosonik:
I guess if a rifle was fired in zero gravity, there would be no vibration.

Porosonik.

I think some guy once proposed a theory that: "for every action, there is an equal and opposite reaction." I somehow think it would maybe move/vibrate.

Another bunch of smart asses used it to go to the moon and back. Unless of course you're a conspiracy theorist, in which case I am sorry and regret having offended and butt-hurt you by discounting your religion!

I'm very polite! Dontchaknows.

I'd always figgered that recoil effected the longitudinal axis, and not the up/down axis so much. There could be a Nobel Prize for Physics here!

Porosonik.

quote:

Originally posted by Mark:

quote:

Originally posted by Porosonik:

As an aircraft mechanic, I often work with a sealant that Boeing (and most other large aircraft manufactures) uses, called "B1-2", or "B1-6" (which is the faster setting version). B1-2 sets in about 24 hours at 70F, and B1-6 in about half that. It's used as a fuel tank sealant, to seal cockpit windows, and just about anywhere two or more layers of sheet metal overlap. It's a two part compound that sets up to be very similar to inner tube rubber, is gray/black in color, and is tough as all get-out. It's impervious to jet fuel, hydraulic fluid that removes polyurethane paint, and regularly goes from 120F to -40F and back, several times a day for 20 years or more without changing it's elasticity. I've always thought it would make an excellent bedding material... but have never gotten around to trying it.

Porosonik.

Instead of b1, I'm sealing some fuel tanks with a2:





Never thought about using it for bedding though. I'm more of a marinetex guy.

That looks too big to be an Ercoupe... DeHavilland Chipmunk perhaps?

I'd always figgered that recoil effected the longitudinal axis, and not the up/down axis so much. There could be a Nobel Prize for Physics here! Big Grin



I think the upy, downy, side by sidey rotational motion of the barrel may have something to do with the roundy round, back to front scratches in the inside of the barrel what tend to go roundy round.

Just a guess. LOL

quote:

Originally posted by speerchucker30x378:
I'd always figgered that recoil effected the longitudinal axis, and not the up/down axis so much. There could be a Nobel Prize for Physics here! Big Grin



I think the upy, downy, side by sidey rotational motion of the barrel may have something to do with the roundy round, back to front scratches in the inside of the barrel what tend to go roundy round.

Just a guess. LOL

Interesting theory. The same guy that proposed that "for every action there's an equal and opposite reaction", also proposed that "a body at rest tends to remain at rest". Just wondering where this force comes from that causes all the "downy and side-by-sidey actions. The uppy force I have figured out.

Even if the inside of the barrel had these "roundy-round, front to back scratches" in it, given that the scratches were dispersed at equal intervals around the bore, I'd think that the sum of the vector forces would equal zero- hence no downy or side to sidey effect on the barrel... only the uppy force due to the side of the bore away from the bend having a tich more surface area for the pressure to act upon.

But, I never went to college .

Porosonik.

quote:

Originally posted by Porosonik:

That looks too big to be an Ercoupe... DeHavilland Chipmunk perhaps?

Anyway, back to the bangy stuff, if it had been figured out then everyone would be doing it that way or at least they would if the bean counters would let them. I do have to admit the field of barrel harmonics overwhelms me but I've never been a benchrest shooter anyway. And then the talk and videos on how bullets travel in a spiral. It's all pretty amazing. One thing I have wondered about on occasion is if barrels have ever been damped in a water or gel type bath, possibly resembling a vickers machine gun water jacket or something.

quote:

Originally posted by Porosonik:

Interesting theory. The same guy that proposed that "for every action there's an equal and opposite reaction", also proposed that "a body at rest tends to remain at rest".

Porosonik.

Well, I think when you ignite the powder and the bullet engages the rifling the forces of acceleration and forward push against the edges of the lands tend to try to "UNTWIST," the twist in the rifling, so to speak. That rotational torque is "magically" transmitted to the barrel and causes it to whip around like a pigs tail at feeding time.

I never went to college either. Trade school, but college was to spooky for me.

I'm sure one of the engineers that frequent this forum could probably toss up a bunch of numbers that neither of us would understand.

quote:

Originally posted by speerchucker30x378:

quote:

Originally posted by Porosonik:

Interesting theory. The same guy that proposed that "for every action there's an equal and opposite reaction", also proposed that "a body at rest tends to remain at rest".

Porosonik.

Well, I think when you ignite the powder and the bullet engages the rifling the forces of acceleration and forward push against the edges of the lands tend to try to "UNTWIST," the twist in the rifling, so to speak. That rotational torque is "magically" transmitted to the barrel and causes it to whip around like a pigs tail at feeding time.

I never went to college either. Trade school, but college was to spooky for me.

I'm sure one of the engineers that frequent this forum could probably toss up a bunch of numbers that neither of us would understand.

I was thinking about that. When the twisty scratches accelerate the bullet around it's fore/aft axis, the "equal and opposite reaction" would be to apply torque to the barrel around it's axis.

The amount of distortion could be calculated based on the mass of the bullet, rate of acceleration, and elasticity of the barrel material. Can't be much, or it would twist the gun out of your hands while firing.

It's hard to believe this thread started off as a discussion about bedding!

College is for those folks who can't use their hands.

Porosonik.

quote:

Originally posted by Mark:

quote:

Originally posted by Porosonik:

That looks too big to be an Ercoupe... DeHavilland Chipmunk perhaps?

Anyway, back to the bangy stuff, if it had been figured out then everyone would be doing it that way or at least they would if the bean counters would let them. I do have to admit the field of barrel harmonics overwhelms me but I've never been a benchrest shooter anyway. And then the talk and videos on how bullets travel in a spiral. It's all pretty amazing. One thing I have wondered about on occasion is if barrels have ever been damped in a water or gel type bath, possibly resembling a vickers machine gun water jacket or something.

OK- I'm running out of conventional geared, low wing, metal skinned monoplanes. Vultee Vibrator?

Porosonik.

Original subject -- as the bullet goes down the barrel that bullet expands the barrel at that point -- thus barrel vibrations.

Aircraft subject -- aircraft vibrations --watch out , Mohawk Airlines in NY State had a plane that vibrations would sometimes break off the prop blade which would go into the passenger compartment .Designers had said chances of breakage were too small to consider .It happened more than a couple of times !!