I recently experimented with two rifles by full length bedding their barrels with clear construction silicon . Both barrels were in synthetic stocks and automotive car wax was used as a release agent on the barrels. The Remington 700 ADL in 223 gained a 25 percent decrease in group sizes. As the rifle was already pretty accurate and now shoots consistant groups in the .5 range, my regret is that this rifle is not mine. The other rifle is a mauser action 8x57 in a Ramline stock and the immediate c hange noted is that three different bullet weights now shoot to the same point of impact. As this rifle still is sighted with military open sights accuracy is as good as I can shoot them. Any comment on this form of bedding?

Silicone is for breast implants...

Full length bedding of barrels is done to (A) seal the barrel channel and (B) to provide firm support and reinforcement to the barrel and forend. Epoxy sets up hard and accomplishes both goals rather well. Silicone on the other hand, will probably work to seal the barrel channel, but because it remains pliable, does little to reinforce anything. Further more, if you are using silicone in a wood stock, the silicone may actually contaminate the wood to the point where epoxy won't stick. I think...

Malm

The silicon is dampening the barrel harmonics.

What happens when the barrel heats up???

I respectfully disagree with Malmborg and agree with Humbarger: it is conceivable and not at all unreasonable that a relatively hard bedding compound might amplify barrel vibration relative to something more pliable such as silicone, which perhaps tends to dampen. I have wanted for some time now to test this theory by bedding a barrel in rigid epoxy and then in something more forgiving, like urethane of the kind used for constructing molds. A relatively pliable substance such as silicone [or urethane mold making material] might serve to better dampen barrel vibrations so that the portion of the barrel extending past the fore end ultimately receives harmonic impulses of a lower magnitude, [translating into less oscillation or whip] as compared to a barrel in a more rigid, epoxy matrix. It is just a theory, but one which seems perfectly reasonable. The test indicated above, while anecdotal, suggests the theory has some validity.

My .02 worth!

Jordan

Jordan thats what I said. It dampens the harmonics.

Funny you bring this up, I had a 358 Norma I recently traded back to my dad, he originally bedded the full barrel in silicone just like you say.

It shot no better, no worse. But, the problem that is all to evident with doing anything other than fully floating the barrel is the inconsistant pressure applied to the barrel "through" the forend. The barrel heats up, you press harder on it, whatever, it's just asking for inconsistant results as these variables change.

Dampening vibration, maybe, but in a consistant way is really the most important question, IMHO. Anything concerning guns that's inconsistant, to me, is a detriment to accuracy and never aids in it. Just my 2 cents on silicone. I think the wax or SC Rust Prevent is a much better way to go. I'm just as much against solid bedding the full length as well, for the same reasons.

[ 02-20-2003, 06:48: Message edited by: Brent Moffitt ]

Is he talking about silicon or silicone. These are vastly different compounds.

I've tried it on sporters and a BR rifle. It makes them more consistant but the *very* best accuracy from the 40XBBR was bedded to wood 1.5 inches equal both sides the front screw and the rear tang with the rest of the barrel floated.

Emmons method I wrote up last week can't be called "bedding". It was a sealing film. All his rifles are bedded plumb tight.

I remember reading the Browning patent for the BOSS system that included the addition of a resiliant bedding material for the recoil lug. Harrold Vahuns book also talks about a movable recoil lug. One of these days I'm going to bed a rifle in silicone and see what happens.

Howdy,

Interesting theory and makes one think. My best GUESS is that this could turn into a real neat experiment at the very least.

I have bedded a very STIFF fiberglass stock with Accru-gel mixed with the atomized bronze at the front of the receiver and at the tang as per normal. Then, at the interior of the stock where the front sling swivel screw comes through the forend, I've construced a small pad ( about the size of a dime ) of silicon bath tub sealant. I wrapped the barrel with the wife's Saran wrap, put two neoprene "O" rings between the action and the stock so that the inletting screws could go through them but still give me a small rise, then waited three or four days for the silicon to "set."

I can't tell that it has a positive effect, I guess I should work up my very best loads for this, then remove the pad, and compare records then. Four different weight bullets shoot within about an inch and a quarter. Pretty consistent point of impact if you ask me.

Anyone care to comment on THIS method?!?!?!?!?

Coach

The silicone used is what comes in tubes like caulk. I used a caulk gun to apply it and made no effort to cause it to give any pressure to the barrel. The material dries to semi hard and is rated to 300 degrees. I expect it does absorb some vibration along with filling the gap between the stock and barrel. I showed these posts to my friend who owns the rifle and he said leave it like it is! I expect between us we'll put 500 rounds thru it this summer and shoot a few coyotes with it too. I don't think there will ever be a time when we get the barrel to 300 degrees. I ordered a 700 ADL in 223 today and you can bet I will make sure it is free floated and give it the silicone treatment also.

By my login name you can guess I have a tendency to be preoccupied with older rifles.
I bought a gunsmith special yugo m24/47 and put it in one of those ATI scout stock clones. I ended up tossing the top section in the trash, for posterity's sake. This left the barrel channel open on top. In a fit a buba genious(oxymoron) I put release agent over 3 layers of tape on the barrel. The idea being to fill the forend with the canned foam insulation, let it dry, remove the barreled action, trim the excess and seal with acraglass resin. I did the project and put it away for a month. when I took the rifle out to test, the foam had expanded enough to deflect the stock.

To make a long story short, it shoots better than ever! I had originaly thought I would have to at least true the action and rebarrel to get any use from it. Not now,shoots better than any modern rifle I own.



[ 02-20-2003, 09:13: Message edited by: TERRY8mm ]

I tried the silicone bedding on a Browning B78 in about 1978. The rifle sucked before bedding and the bedding didn't hurt it any!
Seriously, in some circumstances it seems like it could be a viable system.
A Light Varmint rifle I built on a 788 action always tended to shoot a little bit vertical giving groups that were in the .350 range at 100 yds. Interestingly enough it managed about the same vertical dispersion at 200 and I was able to win with it at that range. After trying to tune the 100yd vertical out and failing I gushed a bunch of silicone into the gap at the forend tip (I used Permatex orange) and it worked. The rifle became a pretty consistent .2 performer.
Some friends tried a rubber epoxy compound as action bedding and said it worked alright as long as you were the only one shooting. In a match situation though the concussion from the other rifles made the gun jiggle uncontrollably.
On one hunting rifle I had that was glued into the stock, I ran a bead of silicone along the barrel gap. This was another case where it appeared to do no harm and the rifle shot extremely well. Regards, Bill.

Silicone caulk may change the harmonics as doug said but it does not provide bedding. There are a lot of things you can do to change harmonics, none of them are substitutes for good bedding.

[ 02-20-2003, 23:53: Message edited by: Customstox ]

Very interesting. I wonder though if anyone has noticed an increase in rusting of the barrel. It seems that some years ago I applied silicone to an auto windshield that I thought was loose and within a very short period the rusting process appeared at an accelerated rate. Anyone notice this happening? Silicone would certainly hold the moisture against a barrel that became wet.
Frank

[ 02-21-2003, 14:29: Message edited by: Frank Martinez ]

Most RTV caulks of the older variety give off acetic acid as they cure. I don't know about the newer latex ones, but being water based they seem to rust stuff up as they cure too. Enough wax on the barrel would probably protect it against water, but acetic acid vapors could get places you couldn't wax.

I've use the clear latex caulks on raw steel before and you can see the rust they leave underneath - this helps with adhesion, though. As far as that goes, any coating will create the potential for rust at the air/coating boundary unless it's a sacrifical anode like zinc.

I have had excellent results keeping firearms from rusting using Turtle wax and Armaloy on metal parts. On both these rifles I think that the silicon makes a pretty good moisture seal. certainly less moisture will make it under the barrel than the way they were before. At any rate dissasembling a rifle after it has spent some time in the rain is normal maintenance.