Gunsmithing Whidden V-Block instead of glass bedding?

[scotharr]

What do you think about using the V-block instead of glass bedding? This seems like a very attractive option versus re-bedding the stock every so often. I take my action in and out of the stock a lot to switch barrels and I'm concerned about wear and tear on the bedding job. This seems to be a great solution and also allows the stock to be swapped amongst different barreled actions. This would go in a McM stock.

http://www.whiddengunworks.net/beddingblock.html

John Whidden knows a thing or two about long-range shooting and is the inventor of a few innovative items like the bullet-pointing die....that Sierra has now been shamed into doing: http://accurateshooter.wordpress.com/200...repeat-victory/

I believe he was using the V-block during his 2008 NRA long-range victory. That would seem to be a good testament to its ability to function.

 

[Hateca]

Re: Whidden V-Block instead of glass bedding?

Problem is you still have to dissimilar parts and the Remington action is never perfectly round. HS stocks have the same principle with the V-Block. It still boils down to shot it un-bedded and if it does well leave it alone if not bed it and see what happens.

 

[Revenge Seeker]

Re: Whidden V-Block instead of glass bedding?

With a V-Block I would imagine a significant drop in contact surface, and contact points. changing contact points would lead to poor repeatability and less contact surface would lead to less strength, no?

 

[Clark]

Re: Whidden V-Block instead of glass bedding?


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Creeter2</div><div class="ubbcode-body">With a V-Block I would imagine a significant drop in contact surface, and contact points. changing contact points would lead to poor repeatability and less contact surface would lead to less strength, no? </div></div>
No.

If a round receiver is glass bedded, the glass is round.
If a screw has 1000 pounds of tension, the effort of prying the receiver side to side for small excursions is much less than 1000 pounds, because of leverage at the screw hole.

But if the round receiver is in a V block with 1000 pounds on the screw, then each side of the V block gets a radial force =[1/sin 45 degrees][500 pounds] = 707 pounds.
Taking this polar force to Cartesian coordinates, is 500 pounds to the side and 500 pounds down on each side of the V block.

This V block multiplier of forces makes the receiver have the same stability in the up / down direction, but much stiffer in the side to side direction than the round glass bedding.

Because the Aluminum is very strong like steel, but not stiff like steel, the Aluminum is likely to elastically deform to comply with the steel receiver's shape. This should give contact to the V block on a long line on each side of the receiver at the tangent. What makes this so likely is that receivers are round with good accuracy and V blocks have perpendicular and flat sides with good accuracy. This is independent of the receiver diameter, and so that manufacturing tolerance does not affect the fit.

The biggest failure of the round receiver is that it does not stand up to the torque created by the riflings accelerating the spin of the bullet. The glass bedding is then damaged with each firing:
Bart Bobbit 1994 post on the Rem700 glass bedding breaking down with recoil
The Aluminum V block solves some of these problems with higher force from the multiplication and Aluminum is more resilient than glass.

 

[scotharr]

Re: Whidden V-Block instead of glass bedding?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">

...
The Aluminum V block solves some of these problems with higher force from the multiplication and Aluminum is more resilient than glass. </div></div>

"solves some of the problems.." what problems does it not solve? Does the v-block weaken the stock, strengthen it?

Thanks

 

[Clark]

Re: Whidden V-Block instead of glass bedding?

Cut to the chase?

The V block is a much better way of gripping a round object than a round concave surface with a screw hole at the bottom. The added stiffness should provide better accuracy. The extra force and Aluminum resilience should provide longer life.

The down side is that the V block takes up weight, space, and money.

If you want a 5 pound rifle, a tiny rifle, or a cheap rifle the V block is not optimum.

But if you are building a 15 pound big expensive rifle, the V block looks good.

 

[9H_Cracka]

Re: Whidden V-Block instead of glass bedding?

Vee blocks are best used coupled with some sort of a recoil device so that not all the twisting force is absorbed by the tension between the block and action.

On the Barnard system, which BTW the actions are surface ground AFTER heat treating so they are in fact ROUND, Mac Tilton uses a hardened steel insert down in the vee block and a stud in the middle action screw which rides in the insert. This acts as your recoil lug while still maintaining the benefits of the vee block.

The bottom line is vee block works when you have a round thing being pulled down into it. M700 actions, which are heat treated after machining, most of the time are not round. You can have a 700 action's OD turned if you like and it will help the vee block work with one.

 

[Hateca]

Re: Whidden V-Block instead of glass bedding?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body"> The biggest failure of the round receiver is that it does not stand up to the torque created by the riflings accelerating the spin of the bullet. The glass bedding is then damaged with each firing:
Bart Bobbit 1994 post on the Rem700 glass bedding breaking down with recoil
The Aluminum V block solves some of these problems with higher force from the multiplication and Aluminum is more resilient than glass. </div></div>

Things have changed a whole lot since 1994. There are better products used for bedding. There are a whole lot of magnums that have been built since 1994 that are doing just fine in a conventional stock with better bedding materials, the bedding hasn't broken down, the lugs or barrels haven't shot loose.

The Vee block is another tool but it's not a fix all, it has, can, and does create other issues.

 

[scotharr]

Re: Whidden V-Block instead of glass bedding?

Thanks for all the comments....and thanks for not calling each other names!

It's nice to get respectfully dialogue.

HateCA, do you mind illuminating the "issues" you are aware of?

So far I've heard, extra weight, cost, and the receiver needs to actually be round for best function.

 

[USMCj]

Re: Whidden V-Block instead of glass bedding?

The v block is a waste of money IMHO. Nothing beats a good Stress free bedding job.

 

[Hateca]

Re: Whidden V-Block instead of glass bedding?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">Thanks for all the comments....and thanks for not calling each other names!

It's nice to get respectfully dialogue.

HateCA, do you mind illuminating the "issues" you are aware of?

So far I've heard, extra weight, cost, and the receiver needs to actually be round for best function. </div></div>

If I can find the pic I can show you.

Remington actions are not perfectly round. You can induce stress to the action by it not having full contact with the Vee block, or any stock for that matter. I would also say the Vee block isn’t perfect either.

It would be like putting tile down on a slab that isn't perfectly flat. Sure it will go down but step on a tile that doesn’t have full contact with the slab and it will break.

A real bad spot is the tang area of the Remington. Part of it is floating in space and with the Vee block it doesn’t have full support no matter if the action was perfectly round or not.

Most of the time you will see no real big difference between bedded and un-bedded Vee blocks in a tactical or field rifle, the rifles will shoot the same. I've tested this several times in the AICS and found no measurable difference. However some will bed the AICS stock and claim they had a measurable difference. I don't doubt that since the Vee block is not a fix all, and Remington actions are not perfectly round, and no two rifles are the same. Like I said shoot it first if it does well don't bother, but don't count on any one thing to be the fix all because it isn't.

 

[scotharr]

Re: Whidden V-Block instead of glass bedding?

Thanks Hate! What if I used a BAT Varmint Repeater which is a SA clone? That is the one I am thinking of...will talk to BAT about that obviously. How hard is it for a gunsmith to clean up the outside of the action? I just really like the idea of never having to bed a stock that will last lifetime. As my tastes have evolved, it seems the only thing I end up keeping are the stock trigger and scope.

Either way, this is exactly the info I was hoping to get before deciding: thanks!

 

[scotharr]

Re: Whidden V-Block instead of glass bedding?

I sent John Whidden some email questions and thought it might be helpful to post his reply (hope he doesn't mind! )

1. How much weight does it add to the stock?
JOHN> Weight is near 1/4 lb, but I'll have to weigh one tomorrow. Can I assume you're interested in a 700 Short action repeater? The solid bottom blocks are somewhat heavier.

2. Is it compatible with a lightweight McMillan Edge-fill stock? I believe it is a graphite/Kevlar material.
JOHN>Having worked with the Benchrest Edge stocks, I am a little hesitant to say yes. I know the BR stocks are hollow front and rear but I can't remember if the center is molded hollow or filled. If the center under the action is filled (even if it's light weight) there should be no problem with installing a V Block. If it's hollow we probably aren't a good fit for this stock.

3. Does McMillan have an inlet for your V-block and allows it to be dropped in?
JOHN> Not currently, but we can provide the CAD file for them to work from. I'll give them a call tomorrow and see what it takes to get that done on their end.

4. Will the V-block work with a BAT Machine Varmint Repeater Stock (supposed to be a Rem700 SA clone… I heard a rumor their front recoil lug is a little different and that they might have a rear recoil lug.
JOHN> We can work well with all of the Rem clones I have built myself, but I haven't used that particular BAT. Oversized recoil lugs generally pose no problem (we designed for that) unless they're exceptionally large. You might ask BAT if their action will drop in an HS precision stock and if the answer is yes then we're good to go.

5. Do you install these yourself?
JOHN> We do install these. Price varies depending on stock shape and how much or little inlet is done already.

6. Can a gunsmith modify the bedding block if needed and has this been done in the past?
JOHN> The block can be easily modified and we have had the rare occasion that we needed to do it ourselves.

7. Does John Whidden use this block in his competition guns?
JOHN> My rifles are built on Gilkes Ross, Stolle Panda, and Winchester 70 actions, all of which were already built before we built the first V block. I have guys that I shoot with weekly who have rifles built with our V blocks that shoot 1/2 MOA at 1000. We have had V Blocked rifles at the F class National Championships on the 3rd place F-T/R team and set range records at long range regionals at Butner, NC. I have every confidence in the system.

 

[Clark]

Re: Whidden V-Block instead of glass bedding?

Gilkes Ross have round bottoms and would be helped with a V block for secure clamping, but Stolle Panda and Winchester 70 actions have flat bottoms and get secured with just the action screws.

When a V block is used, it converts a round bottom to a flat bottom for interfacing with the stock. The bottom of the V block is flat.

When a Rem700 benchrest shroud is used, it converts a round bottom to a flat bottom for interfacing with the stock. The bottom of the shroud is flat.