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Servo77
July 2, 2007, 08:13 PM
I recently took a rifle to a reputable gunsmith (he builds a lot of $3000 custom target rifles) to have it bedded. He said it needed to be bedded and have the barrel free-floated along with having what he referred to as a "dampening block" at the end of the stock to help with vibration control in the sporter weight barrel.....anyone hear of doing this? He basically seemed to be talking about bedding a very small portion of the barrel where the stock ends.

Not something I am familiar with, so I wasn't sure. The guy has a great rep, so I really didn't think anything of it. I haven't gotten the rifle back yet, so I don't know the results yet.

srtrax
July 3, 2007, 11:17 AM
Here is something i came across awhile back and kept. I also like a stock to be bedded somewhat thick with the pillars, because even fiberglass has some give to it, maybe more so than wood because most fiber stocks are not 100% fiber. You add the forces of recoil to any of them and there has to be some flex somewhere. The action and barrel should not rock out of the stock, but come out and back in /in a straight line. Damprning blocks are not uncommon, Remington does this to their rifles by leaving a small amount of wood up towards the forend. Only problem with this is mass produced stocks,and wam bam, stick a barreled action in and go. If more time was spent on the bedding, most people would'nt be taking out the pad! For the lighter weight barrels this works pretty well, not always, some like to be floated and well if the pad is there and its not shooting to what you think it should then its just a matter of releaving the pad.http://www.masterclassstocks.com/pillarbedding.html

Scorch
July 3, 2007, 01:09 PM
It is a standard practice to bed lightweight barrels by putting a pressure pad at the forend. This has the effect of controlling vibration and improving accuracy. In heavier barrels, it has little or no effect, and can actually make your rifle shoot worse.

sundog
July 3, 2007, 01:38 PM
I improved the performance of a heavy bbl Rem 700 in .223 in a factory laminate stock by removing the forward 'bump' in the bbl channel and bedding the action. Result is free floated bbl all the way back to the bedding. In fact, it looked like Remington relied on that 'dampening block' for everything as the lug well was way larger than need - not good. It's all fixed now. Just a few hours works on a cold day last winter.

tINY
July 3, 2007, 03:12 PM
There is some controversy over whether a pressure pad on the barrel hurts or helps. I think it's different for different rifles.

However, for a field rifle, that might be shot from a variety of rests or slung-up, having the barrel floated eliminates the change in POI. IF the barrel touches the fore-end, putting different forces on the stock can put different pressures on the barrel.....



-tINY

Dave Haven
July 3, 2007, 09:47 PM
However, for a field rifle, that might be shot from a variety of rests or slung-up, having the barrel floated eliminates the change in POI. IF the barrel touches the fore-end, putting different forces on the stock can put different pressures on the barrel.....That is an excellent point! Regardless of the stock material, outside forces WILL cause it to flex.

FirstFreedom
July 3, 2007, 11:20 PM
This is called pressure bedding. Or, I suppose, dampening. Some rifles will shoot better with pressure bedding vs. free-floated. Some will shoot worse or the same, vs. free-floated. If the alternative is touching the stock forend, rather than free-floated, then pressure bedding can only help, not hurt (or stay the same). Just never know til you shoot it; depends on the rifle. I'd try free-floating first, sporter weight or not, and then if accuracy is not acceptable for your use, then try pressure bedding. Free-floating will have a higher chance of shooting better than pressure bedding, I believe, even with light sporter barrels.

As for techniques, search around. Art Eatman here got me onto using wax paper folded over several times for pressure bedding. It melts and thus "sticks" in well.

Wait a sec....

have the barrel free-floated along with having what he referred to as a "dampening block" at the end of the stock

He must not be referring to pressure bedding, because you can't do both - it's either one or the other. So not sure what he means by "dampening block" - hmmmmm.

Art Eatman
July 4, 2007, 11:00 AM
A trick my uncle taught me, way, way back: I free-float the barrel, but with a minimum clearance at the forearm tip. I make a shim from a strip of kitchen wax paper, maybe 3/4" wide. I fold it back and forth until it's thick enough that it takes about a five-pound pull to spread the barrel and forearm to insert the shim. Just trim the ends with a razor blade. Quick firing of a few shots heats the barrel enough that the wax sticks.

This "damper" acts like the shock absorbers of a car on the car's springs. It apparently makes the barrel's vibrations uniform from shot to shot. It's certainly cheaper than a BOSS and does the same thing.

I've yet to do this where it did not make some amount of improvement in group size.

One thing I learned is to hold the forearm the same way, whether on the benchrest or in the field. In the field, my hand is behind the front sling swivel, so that's where I put the sandbag at the benchrest.

Art

fisherman66
July 4, 2007, 11:05 AM
Great trick. What else are you hiding in the recesses of Art's mind???

I wonder how it would work on a full stocked rifle. Would you put the wax paper below the sling attachment or at the tip under the muzzle?

Art Eatman
July 4, 2007, 11:19 AM
I've not had occasion to try it with a full-length Mannlicher stock. The problem there, seems like to me, is the front barrel band. If it's tight, the expansion of the steel makes for a change in stress on the barrel. The wood won't change dimension with temperature.

Off the cuff, just guessing, if I wasn't happy with the way a full stock critter shoots, I'd loosen the barrel bands as much as is feasible and see if that makes a difference.

I bought my .243 Sako Forester carbine, full stock, back around 1970. It grouped vertical strings, each shot one inch higher than the one before. I went to messing with it and found that the stock was actually two-piece, joined at the middle barrel band.

Modification time: I cut the stock back and removed the front sight. Shimmed the forearm. Result: 5/8 to 3/4 MOA, year after year after year.

Anyhow, if a Mannlicher-stocked rifle already shoots "pretty good", I don't think I'd mess with it.

Art

srtrax
July 4, 2007, 11:23 AM
Every shot you take puts viberations and barrel movement (whip) through out the barrel. The end result is to have the barrel stop at the same place, move in the same way at each shot as the bullet exits the barrel. The more everything acts the same at each shot is where most of the accuracy comes in. The stiffer the action (no movement) and the control over the barrel is the key to bedding a rifle. It usally requires a good bedding job of the action first and then a little playing with the barrel channel. I find with a good bedding job of the action and floating of the barrel, light or heavy seems to work more often than not. But with all the variables there are in a rifle, other things come into play other than just bedding, (crown, lug contact, and so on).

fisherman66
July 4, 2007, 11:27 AM
I have yet to get my RSI to the range. I think it's probably underwater (the range, not the RSI), but I have not traveled in that direction in some time. I will eventually ditch the muzzle band and have a schnable tip for the full stock similar to the stock below.

http://www.cabelas.com/cabelas/en/content/community/gun_inventory/images/dundee/fine_rifle/655267_rugr1375_02l.jpg

srtrax
July 4, 2007, 11:31 AM
Thanks Art, i'll have to give that one a try, I've also heard of people using rubber electrical tape!

srtrax
July 4, 2007, 11:35 AM
Off subject: My range is under water to, half the town is here. Two lakes at 30' above flood stage, come on sunshine! I like my 338/06, o.k. back on subject.

Art Eatman
July 4, 2007, 11:49 AM
To me, an important factor is that the shim be just barely thick enough that only a slight pull is needed to separate barrel and stock for insertion. The wax paper is thin enough to make this buildup controllable. I just want a slight dampening, not any real upward push.

These NyLok inserts do pretty much the same thing, and they're adjustable without disassembly.

Art

srtrax
July 4, 2007, 11:58 AM
Got ya, the rubber tape was used in place of the remington wood pad and also did not give the barrel any or very little, lift.

Picher
July 5, 2007, 07:27 AM
In my long shooting/accurizing experience, I prefer to have barrels free-floating, but some rifles just shoot better with some uniform upward pressure. My pressure pads are normally located at 4 and 8 o'clock, about 1/8" wide and located about an inch back of the forend tip.

I sometimes try making temporary pads with card stock or electrical tape, just to see how it may affect groups, but have never found them very successful. I prefer to make hard pressure pads with bedding epoxy, pre-setting uplift from 3 to 8 lbs, depending on barrel stiffness.

The big problem with pressure pads is that point of bullet impact tends to change with varied rests, stock warpage, and sling pressure. It doesn't take much pressure variation at the end of some stocks to throw a shot 6" off at 100 yards. Only the stiffest stocks and barrels are not severely affected.

Free floated barrels are not as affected by such variations. The problem is that most people don't practice from varied positions and field rests, so they don't understand why they could possibly have missed easy shots in the field. The reasons for misses are many, but I prefer to not have the rifle's POI change due to forend pressure variations be a factor in my shots.


Picher

Martyn4802
July 5, 2007, 07:34 AM
My rifles all shoot good with barrels free floated. So, I've never experimented with putting a pressure pad at the tip of the stock. That forend pressure creates variables that free floating eliminates.

Martyn

Art Eatman
July 5, 2007, 08:42 AM
Martyn, just remember that we're talking about just barely touching as a dampener, not any real upward force. No doubt some rifles are "happier" with a free-floated barrel, and I'd leave such alone. But my deal has worked on well over a dozen rifles, these last forty years or so, including two of my most favorite pets.

Seems to me it's nothing more than the usual deal: Ya keep messing around until you find the best combination that works on a particular rifle. There are no real absolute rules about what works or doesn't work.

Art