Free float vs. pressure points

[Dusty Stevens]

Did they include an explanation of their accuracy warranty?.. I have read many posts here of rifles being sent back to the factory for accuracy problems only to be told that it meets "their requirements"

Well if anybody knows accuracy its them

 

[rogina]

The only pressure points id use would be under the chamber only. If youve ever seen a high speed video of a gun barrel being fired you would cringe at the thought of a pressure point out at the end

I would never remove those forend pressure points on a flimsy stock, unless I was going to bed it.

 

[cdngary]

This may fall under a different application, but on some BSA rimfires the front stock fully contacts the barrel full length. What can one do to free float one of these? Or do a pressure point set up?

 

[std7mag]

Did they include an explanation of their accuracy warranty?.. I have read many posts here of rifles being sent back to the factory for accuracy problems only to be told that it meets "their requirements"

I bought mine 2nd hand. Maybe 3rd or 4th...
No paperwork included.
I downloaded the owners manual and found that statement from them. But not what the actual accuracy measurement would be.

 

[darkangel_r2]

The problem is that these pressure points can change their tensioning of the barrel with atmospheric changes if the stock warps with temp or humidity. Also what you have on the forend and what position you are shooting in will change the tension to a degree as well. Shoot standing with or without a bipod attached? That's going to change the tension on the barrel. The degree to which you load a bipod will change the tension as well.

The stiffer the forend and stock the less it changes. So if you have an incredibly stiff stock that doesn't change much dimensionally with temp and humidity then it can work consistently. There is a window of tension that will improve accuracy for most thin barrels. If your rifle system allows you to stay in this window in the different conditions and positions you will shoot in it will be a benefit. Having it be adjustable by torque screw driver so you can set it and check it in different orientations is probably a good idea and expands its usefulness.

This system is just reducing the preloaded moment in the receiver caused by gravity pulling on the barrel.

Higher quality barrels and trued actions now days combined with handloading generally makes this technology marginal in its practical effect.

I think adjustable horizontal dampening is a next gen idea that's going to come out in future chassis systems. Much more flexible in its applications.

 

[AckleymanII]

This is going to sound crazy, but I am going to throw it out there. IN my family's plastic stocks, we found a fix for model 7's to 700's. We free float the barrel, then use the glue on wheel weights in the forearm, as many as we can get in there, and brother do these wheel weights have some good glue on them.

Bed recoil lug, freefloat mag box, tune/replace trigger.

Then we add a Gentry muzzle break, amazing how many of these rifles shoot very tiny groups with tuned loads....Brother that owns a tire store found the fix, not me. I would have thrown every one of those plastic stocks in the trash.

Brother owns every model 7 caliber made in plastic stocks, and the fix above works on everyone of them. I suspect that the glue on the wheel weights makes the forearm more stiff, plus the added weight retards muzzle flip. Your guess is as good as mine, but they all shoot sub 1/2" groups and smaller.

If I had not seen it with my own eyes, I would not have believed how simple the fix is on such a flexible stock.

I always thought that a pressure point is covering up some major problems elsewhere, but if the bones of a dead black cat say to put in a pressure point, by all means do it.

 

[Old Navy]

Every rifle is different. Thin whippy barrels MAY benefit from a pressure point. I had a Ruger 77 ultralite that absolutely did NOT benefit from free floating. It was a quick project that went wrong & a longer project to put the pressure point back. YMMV.

A quick test could be to shim the barrelled action up a bit to see if groups improve or go down the crapper. Maybe pieces of an old credit card or something placed strategically under the action to lift everything enough to clear the lump in the forend when the action screws are tightened? Fire for effect & go from there.

I had the exact same thing with a Ruger 77 in .270 around 1975 version with the angled screw. Almost out of the box it was shooting my loads into .75 to 1.00". Wood stock touching the first inch or so. Floated it and ended up putting it back the way it was.

 

[Kittitas George]

I bought a Remington 700 22-250 when they were first offered. Following the wisdom of the day I removed the pressure points in the fore end. The gun quit shooting tight groups. Trying to figure how much pressure I needed I placed a folded match book between the stock and the barrel. The match book was still there when I sold the gun about 40 years later. I shot 3 crows with 1 shot, I lined up 2, didn't see the 3rd between them, a little lower between the corn rows. Two through the body, one in the head. I'd run a disc over that field, all the corn was down.

 

[Gargoyle]

Some pieces of credit card up front the forearm can do some wonders on a sporter.

 

[Tim Slater]

This may fall under a different application, but on some BSA rimfires the front stock fully contacts the barrel full length. What can one do to free float one of these? Or do a pressure point set up?

The two-piece stock makes free-floating hard. There have been a few attempts with the fore-end hung from a barrel band (if that counts as free floating). BSA themselves decided the Mk 3 needed a much longer receiver to support the aluminium cantilever fore-end strut. Later (reportedly after declining sales) BSA just bolted the strut directly to the barrel (Mk 4 and 5).

The truest free-float I know of involved bonding a Mk 2 International receiver into a rigid aluminium chassis.

 

[Bangs OH]

Those of us who’ve ever owned a Remington LVSF model rifle know not to mess with those little bumps in the barrel channel of the B&C stock. Unless you happen to enjoy three-inch groups, grind them at your peril.

 

[cdngary]

I know if the screw system is used that the amount of pressure can be varied. Does changing the position of the pressure point along the barrel length change the harmonics and poi? Has anyone tested for results?

 

[davidjoe]

I was born into the wrong generation but I believe it is entirely reasonable to use pressure between the stock and forearm to dampen vibrations.

This picture shows the relative size, weight and length of two Remington 700 barrels, and two F-Class barrels. The weights are written beside the tenons.

The 1.25” F-Class barrel has a Panda tenon and the 1.45” tapered to 1.0” barrel has a Surgeon XL tenon. While the Surgeon tenon is largest in length and diameter, the barrel is over 12 pounds. Yes, the action is 4.5 pounds, but the stock dimensions in the stressed area are not particularly different from what would be sent for a 700, in fact the contacted supportive area is likely thinner because the action is thicker, the mold isn’t changing, and the trigger must correctly protrude. The action screws have a few more threads but are the same size.



To my thinking, my composite stocks benefit from supporting the barrel. I use something semi-compressible which I calculate by feel and appearance to begin compression as the screws are torqued. I seek to have some upward pressure on the barrel, but I do not try to turn the stock into an archer’s bow. I make absolutely certain the amount of material does not prevent the action from making full, flat contact with the stock. This is verifiable both by feel when tightening, and visually if one can discern very small angles, or if not, by witness marks on tape that would need to be equal front to rear.




I also do feel that my barrel’s propensity for harmonic resonance is diminished, though I don’t know how much these very heavy profile barrels want to resonate. I do this primarily because I feel that a 12 pound barrel exacerbated by 35 inches of length on those screws, the stock and action is a bit like picking up a toddler by the wrist.

I have shot and purchased completed F-Class guns that are free floated and shoot very well, but I can feel the post-shot vibrations that I believe are caused by whip and it’s distracting to me. I would agree that this type of rebounding could either be post exit, not material to accuracy, or in any event, tunable by load or by tuner, but to me, I’m inclined to minimize it if possible, meaning without sacrificing accuracy. To me, those vibrations would seem to be working against the action screws to loosen things up.

 

[darkangel_r2]

I was born into the wrong generation but I believe it is entirely reasonable to use pressure between the stock and forearm to dampen vibrations.

This picture shows the relative size, weight and length of two Remington 700 barrels, and two F-Class barrels. The weights are written beside the tenons.

The 1.25” F-Class barrel has a Panda tenon and the 1.45” tapered to 1.0” barrel has a Surgeon XL tenon. While the Surgeon tenon is largest in length and diameter, the barrel is over 12 pounds. Yes, the action is 4.5 pounds, but the stock dimensions in the stressed area are not particularly different from what would be sent for a 700, in fact the contacted supportive area is likely thinner because the action is thicker, the mold isn’t changing, and the trigger must correctly protrude. The action screws have a few more threads but are the same size.

View attachment 1318932

To my thinking, my composite stocks benefit from supporting the barrel. I use something semi-compressible which I calculate by feel and appearance to begin compression as the screws are torqued. I seek to have some upward pressure on the barrel, but I do not try to turn the stock into an archer’s bow. I make absolutely certain the amount of material does not prevent the action from making full, flat contact with the stock. This is verifiable both by feel when tightening, and visually if one can discern very small angles, or if not, by witness marks on tape that would need to be equal front to rear.


View attachment 1318933

I also do feel that my barrel’s propensity for harmonic resonance is diminished, though I don’t know how much these very heavy profile barrels want to resonate. I do this primarily because I feel that a 12 pound barrel exacerbated by 35 inches of length on those screws, the stock and action is a bit like picking up a toddler by the wrist.

I have shot and purchased completed F-Class guns that are free floated and shoot very well, but I can feel the post-shot vibrations that I believe are caused by whip and It’s distracting to me. I would agree that this type of rebounding could either be post exit, not material to accuracy, or in any event, tunable by load or by tuner, but to me, I’m inclined to minimize it if possible, meaning without sacrificing accuracy. To me, those vibrations would seem to be working against the action screws to loosen things up.

Did you start with that setup or add it later? Any with and without experiences on that setup?

 

[bsekf]

The only pressure points id use would be under the chamber only. If youve ever seen a high speed video of a gun barrel being fired you would cringe at the thought of a pressure point out at the end

Dusty, how about a link to a video of rifle firing. Would really like to see one of a Contender or Encore being fired.
Bill

 

[bsekf]

The only pressure points id use would be under the chamber only. If youve ever seen a high speed video of a gun barrel being fired you would cringe at the thought of a pressure point out at the end

 

[Dusty Stevens]

Dusty, how about a link to a video of rifle firing. Would really like to see one of a Contender or Encore being fired.
Bill

Never seen one

 

[Dusty Stevens]

Heres a start on youtube

 

[SeabeeKen]

The wood stocked Ruger 77, 77MKII, Hawkeyes have a pressure point.
Ruger flat out says in their paperwork that removing the pressure point will remove any accuracy warranty.

Hence i've not free floated my Rugers.
My Savages, and Mausers i own have been free floated and Devcon bedded at the action.

My Savage 243 had to have the last inch of the stock bedded to the barrel. It shot single hole that way

 

[davidjoe]

Did you start with that setup or add it later? Any with and without experiences on that setup?

I have tried both ways. I have five of those long forearm Manners F-Class stocks, and they benefit from it, I feel, as do my shorter stocks. Others might prefer to tune with more flex.

I do leave all my factory rifles as they came, (including old 40X’s and 52’s with pressure adjustments, free floated “sniper” type rifles, etc.) but for separate stock and barreled action combinations, the stock maker hasn’t tested every combination of channel width or barreled action size or weight, they just cut it to your specification, so you aren’t setting aside their own calculated determinations. They likely did not anticipate a scoped, barreled action weighing more than 18 pounds with a big 1.45” square action cut out.

In any event dampening material makes my barrels “thud” instead of ring if tapped, like clasping a ringing cymbal or guitar string would do. It does not hurt groups. I think it helps my 100/200 group size that I occasionally confirm, but I don’t try to prove that.

(My barrels are physically prevented from that kind of downward whip and rebound bouncing that Dusty’s video shows so well. I can feel that on the line and I really do not like it.)