NEWS FROM THE TUNNEL, Barrel Indexing

alinwa said:
Jerry,

My contention is that all of the measuring in the world cannot accomplish this, I mean it's like setting a motor and "carb" to exactly where you think it needs to be........ until you fire that badboy up and tune it on the dyno all the pre-measuring is just ballpark. Sametime, screwing on another barrel and getting it to hit within an inch is by-golly luck for sure! But by the same token getting one to be more than 3-4" off no matter how you line it up to chamber is rare.

I've got no meaningful opinion as to whether your method of trying to measure the rifle up so that the muzzle hole is lined up exactly with the centerline of the bolt makes for more or less side forces BUT..... think about this. If you were to set up and chamber three barrels: one of them is "straight", one of them has .005 of curvature and one has .010 of curvature but in all cases the muzzle of the bore is exactly in front of the firing pin. Are they all going to recoil the same? Most rifle bores seem to describe a kind of helix, it'd be pretty hard to predict anything from them.


still fun to argue though ;)

Thanks Jerry,

al
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There is no argument that a rifle can not be built so the action centerline is in alignment with the surfaces of the stock that guides the recoil track. Not a lot of guns are set up this precise but the good ones are and an accomplished stocker like Terry Leonard or Tom Meredith certainly can.

That being said, just as the chamber must be in that alignment with the above assembly. Then too the EXIT POINT of the bullet must fit within this same centerline for the gun to track consistently.

Think about this, the indexing effort is to get barrel pointing UP so misalignment does not cause lateral recoil shift. Why? So DOWNWARD forces of recoil will force the gun into the bags and does not force the assembly sideways where stability of the setup can be effected.

All barrels have a wandering, or compound curve, in the bore cylinder. Nothing can be done about this problem, But if the entry point of the bullet fits precisely within the bore center at that entry point and the exit point of that bullet is also along that same centerline regardless how the bullet wanders from entry to exit then the barrel will perform much more accurately than if the bullet exits in another direction.

Gene has the perfect facility to determine th cause and solutions to the barrel curvature problem. Indexing is just a step along the way, but it is not the solution itself since indexing does not solve the problem, it just moves the problem to a location where it is less harmful to accuracy.
 
Jerry, your point about everything being lined up is good; I agree. This is yet another reason why the new "Ultralite" aluminum stock is way ahead of anything else in its class. The buttstock is adjustable so the buttplate can be placed precisely in line with the bore. The forend is also adjustable fore and aft as well as radially so no matter how long or how heavy the barrel, the rifle's center of gravity can be placed precisely where it should be. No more nose heavy rifles or actions that are glued in slightly crooked. :D

With a wood or fiberglass stock, you are stuck with what you've got; no adjustments are possible. With the 'Ultralite' the rifle can be set up so it rides the bags perfectly. No slip sheets, wax, powder or other 'slickem' products are necessary. The hardcoat anodize finish glides in the bags like silk.

Like I've said before, "Lots of exciting things are in store for '09! "

Later,

Gene Beggs

Later,

Gene Beggs
 
Gene

Gene Beggs said:
Jerry, your point about everything being lined up is good; I agree. This is yet another reason why the new "Ultralite" aluminum stock is way ahead of anything else in its class. The buttstock is adjustable so the buttplate can be placed precisely in line with the bore. The forend is also adjustable fore and aft as well as radially so no matter how long or how heavy the barrel, the rifle's center of gravity can be placed precisely where it should be. No more nose heavy rifles or actions that are glued in slightly crooked. :D

With a wood or fiberglass stock, you are stuck with what you've got; no adjustments are possible. With the 'Ultralite' the rifle can be set up so it rides the bags perfectly. No slip sheets, wax, powder or other 'slickem' products are necessary. The hardcoat anodize finish glides in the bags like silk.

Like I've said before, "Lots of exciting things are in store for '09! "

Later,

Gene Beggs

Later,

Gene Beggs
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Could you please post a pic of your Ultralite stock or tell me where I can find one.

Thanks
 
george in KY said:
i've aways thought what a wast of the BIG steel tube. gene i like the stock idea.
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Hi George

Sure,,, why support that heavy barrel with only the front receiver ring when we can put that sucker to work and make it support itself? :cool:

There is also no need to bed and glue the action. The barreled action is already one unit for all practical purposes; it does not need any support. All the shooter needs is a three inch wide forend, a buttplate in the correct position connected in some way to the action and a trigger gaurd. All that other stuff just adds unnecessary weight and gets in the way.

I know,,, I know,, the figerglass and laminated wood stocks are beautiful with their immaculate finishes and artwork but I prefer my firearms to be strictly functional. I think of the 'Ultralite' aluminum stock as the Glock of benchrest. :)

Later,

Gene Beggs
 
beggs01b.jpg
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Couldn't one also use the position of the "Mid-Barrel Bag-Rider Fore-Arm" as a Tuner of sorts?
 
A Quote - -

from an Email to me the other day from David Apple " The World has changed!" I say Indeed it has. :D
 
AVanGorder said:
Couldn't one also use the position of the "Mid-Barrel Bag-Rider Fore-Arm" as a Tuner of sorts?
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Adrian, this question has been asked many times before, but other than fine tuning the center of gravity, the forend position has no affect on how the rifle shoots.

Gene Beggs
 
Gene,
It seems to me that the mid barrel "stock" would have an effect on the tune of the barrel. I spent about a year trying to make a NEF single shot in 223 shoot decently. It has the fore end attached to the barrel. The only way it would shoot reasonably good was to rest the frame/hinge on the bag. I even made up a special fore end that attached very close to the chamber and free floated the barrel,...no help there. I realize I didn't have much to work with on the NEF, throat is verrrry long. It just seems like the device attached to the barrel between the action and the tuner would cause the vibration pattern to change. Have you tried moving the aluminum fore end to see if it changes the tune? Also, how much for your alum stock and fore end? Thanks for your dedication.
Donald
 
Donald said:
Gene,
It seems to me that the mid barrel "stock" would have an effect on the tune of the barrel. I spent about a year trying to make a NEF single shot in 223 shoot decently. It has the fore end attached to the barrel. The only way it would shoot reasonably good was to rest the frame/hinge on the bag. I even made up a special fore end that attached very close to the chamber and free floated the barrel,...no help there. I realize I didn't have much to work with on the NEF, throat is verrrry long. It just seems like the device attached to the barrel between the action and the tuner would cause the vibration pattern to change. Have you tried moving the aluminum fore end to see if it changes the tune? Also, how much for your alum stock and fore end? Thanks for your dedication.
Donald
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Don, moving the forend of my 'Ultralite' stock fore and aft changes the point of impact, but I could not see any affect on the way the rifle tuned.

Price has not been determined because I have not received the bottom line cost of production but I assure you, it will be far less than one would pay for a conventional stock.

Later,

Gene Beggs
 
Gene

Since the bbl is tapered do you have some sort of mechanical locating device like a pin or a groove or is the clamp fit enough to keep it from coming loose?
 
crb said:
Since the bbl is tapered do you have some sort of mechanical locating device like a pin or a groove or is the clamp fit enough to keep it from coming loose?
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Once the location for the forend attachment is determined for the specific barrel, a flat section is turned on the OD to fit the hole in the forend using a .005 crush fit. The forend bolts up rock solid and does not move.

Some have said resting the barrel/forend solid in the front rest will, "Mess up the 'harmonics." :rolleyes: I think the results speak for themselves. :cool:

Gene Beggs
 
Pete Wass said:
Is there a savings in weight over a conventional stock? Thanks, Pete
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Pete, I have not weighed a production 'Ultralite' stock but my prototypes weigh 19 ounces. Every effort was made to keep the cnc machined parts as thin and light as possible.

The main tubes of my prototypes are 1.125 diameter with a .125 wall thickness which is what I had on hand and unnecessarily heavy. The production tubes are .058 wall thickness. I'm shooting for a total weight of one pound.

Later,

Gene Beggs
 
Hi Gene,
as you know we have been following barrel Indexing threads closely....

Thanks to you we have a better understanding and have tried to put our few brain cells to work. The problem with tenon diameter in the standard action seems to be the stumbling block.

Would not threading the tenon, making it a snug fit in the action with a flange on the barrel that a external nut fits over and screws onto the outside of the action work? Bit like what’s on a AR16 with very little added weight. Maybe the downside could be excess movement....

John
 
John M- -

The idea of threading the outside of the action and using a nut would sure make it moore dificult to mount a scope/ring base on the front of the receiver. I'm still thinking a "boss" on the front of the receiver like a Mauser large ring. Manufacturing [or sucking Jerry into it] may not be profitable, he would have to do it for love! I'm sure there is someone out there who would LOVE to trade him two blond ex-wives for just one of those actions.

It ain't over yet !!

Steve Moore
 
JohnM said:
Hi Gene,
as you know we have been following barrel Indexing threads closely....

Thanks to you we have a better understanding and have tried to put our few brain cells to work. The problem with tenon diameter in the standard action seems to be the stumbling block.

Would not threading the tenon, making it a snug fit in the action with a flange on the barrel that a external nut fits over and screws onto the outside of the action work? Bit like what’s on a AR16 with very little added weight. Maybe the downside could be excess movement....
Click to expand...

John,

I have always been intrigued with the Savage barrel nut system. I have no experience with the AR-15 M-16 type rifles. Maybe I should get someone to show me how one works.

This thread has got a lot of people thinking and surely there will be some new discoveries. In the meantime, my first prototype of the barrel-indexing bushing works great. It's a tight squeeze in a 1.062 receiver, but with the PPC size cartridges, it works well as long as the barrel tenon is not reduced below .900. Rimfires?? Now that's another story in itself. I'm looking forward to the next few months; it's going to be interesting. :D

Later,

Gene Beggs
 
Gene Beggs said:
John,

I have always been intrigued with the Savage barrel nut system. I have no experience with the AR-15 M-16 type rifles. Maybe I should get someone to show me how one works.

This thread has got a lot of people thinking and surely there will be some new discoveries. In the meantime, my first prototype of the barrel-indexing bushing works great. It's a tight squeeze in a 1.062 receiver, but with the PPC size cartridges, it works well as long as the barrel tenon is not reduced below .900. Rimfires?? Now that's another story in itself. I'm looking forward to the next few months; it's going to be interesting. :D

Later,

Gene Beggs
Click to expand...

To be honest Gene I don't know a lot about the Savage barrel nut system, better look it up :eek:

and I have little time for AR16s ect, but maybe some system could be used thats based on how they attach the barrel?

I also wouldn't think the nut used would be in the way of the scope or its mounting as crb has very nicely shown :cool:
 
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