Pressure points on lighter barrels

[johnstonblake]

Weatherby recommends an upward pressure point on their lighter (#2 and smaller) barrels, and chooses not to free float them at the factory. I've read that this is just a way to get around not properly bedding the action to the stock.

What's the truth in this? I've always known to be true that a properly bedded action with a free floated barrel better, no matter the barrel diameter.

I'm thinking about putting a new stock on a weatherby vanguard series 2 that I own, and just wondering what the general consensus is on free floating it to try to gain a little more accuracy.

 

[I Am Hero]

Honestly I have seen accuracy gains and diminishings from putting an aftermarket stock ona light barrel that makes it free float. Although vibration on a barrel is a good thing, that is only to a certain extent and too much flex can cause accuracy problems. I don't know if this has to do with the cartridge size/velocity/weight or what, but like I said I have seen it go both ways.

 

[Elite_KG]

Best I heard from reading its a trial and error process. Normally I wouldn't respond without first hand information, but you didn't have many replies. I believe Frank from Bartlein barrels posted somewhere that some lighter barrels can benefit from a pressure pad and some do not (I'm sure if he didn't I will soon be corrected - I'm speaking from memory). The pad reduces the harmonics when properly positioned and with proper load. The position and load (upward force) is where the trial and error comes in. Heavier weight barrels (stiffer) generally vibrate at a higher frequency with less amplitude. Lighter barrels conversely have more "whip"'as it has been described.
I have heard of people using playing cards, match books, coke can slivers etc. to wedge under the barrel in various postion to trial various loads in various locations. I'm sure a little searching may reveal more detailed and clearer explanation of the process.

Good luck.

 

[Frank Green]

Best I heard from reading its a trial and error process. Normally I wouldn't respond without first hand information, but you didn't have many replies. I believe Frank from Bartlein barrels posted somewhere that some lighter barrels can benefit from a pressure pad and some do not (I'm sure if he didn't I will soon be corrected - I'm speaking from memory). The pad reduces the harmonics when properly positioned and with proper load. The position and load (upward force) is where the trial and error comes in. Heavier weight barrels (stiffer) generally vibrate at a higher frequency with less amplitude. Lighter barrels conversely have more "whip"'as it has been described.
I have heard of people using playing cards, match books, coke can slivers etc. to wedge under the barrel in various postion to trial various loads in various locations. I'm sure a little searching may reveal more detailed and clearer explanation of the process.

Good luck.

Elite_KG is pretty much on spot! Building a lighter weight gun/contour barrel I full float my first and see how they shoot. The rebuilt Browning Sako Safari below has a muzzle diameter of .600" and is in .260 Rem. It will shoot 1/2 moa or better and the gun only weighs 7# or so with out the scope. If it shoots I don't mess with it. If your groups seem large but consistent then try a pressure point on the barrel. If it tightens up then I would put a pad with some bedding compound on the forend tip but this can be tricky as to how much pressure do you have to put on it to get shoot. To me this is a trial and error method. The rebuilt Browning's barrel is full floated.



Other guns like some factory rifles and the 1903 Springfield etc...have pressure points on the stocks against the barrel and can shoot well. The idea is that the pressure point will dampen the harmonics and keep the gun more consistent. If I remember correctly the 1903 Springfields were suppose to have like a 30lb. pressure force against the barrel. This rebuilt '03 shoots great. What I don't like about this and it's worse with a cheap stock or a wood stock is if the wood in the barrel channel isn't sealed properly as the temperature, humidity changes or if the stock gets really wet it will want to warp/bend change and will cause the barrel to change it's point of impact.



To me the contour isn't as critical (heavy vs. light) as some think it does. To me the straighter the barrel blank, the more uniform the bore and groove dimensions and the more uniform the twist and this is the key also the more stress free the blank the more forgiving the barrel is going to be.

Later, Frank
Bartlein Barrels

 

[johnstonblake]

Thanks for the help!

 

[Huskerhunter]

I greatly improved the accuracy on a CZ in 17 HMR with a pressure pad/bedding at the tip of the forend. Used a little cardboard as mentioned to experiment before mixing the JB weld.