Rail Gun Questions

C

C.L. Peterson

Active member
Action Questions--BAT Action RB LP RE are knowns

1.) A 3 lug vs. 2 lug--does this improve speed????
2.) Which action--the biggest and heaviest or do all actions function equally well or the same???

Thanks for your expertise/imput.

CLP
 
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It depends upon how the barreled action is mounted. If it's a barrel blocked rifle, IMO the action is along for the ride. Bigger and stouter probably won't hurt anything, but I doubt if it will help either. If the action is held and the complete barrel is freefloated then I'd want as large an action as you could use such as the old Stolle Polar or even a sleeved action. As to two or three lug, I doubt if you can tell the difference in speed. How well it ejects will make more difference in speed. You can getting going too fast if your barrel is still vibrating while you're shooting.

You'll probably get a lot of answers on this. It just depends upon how the top plate is configured on your rifle.
 
Mike Bryant said:
It depends upon how the barreled action is mounted. If it's a barrel blocked rifle, IMO the action is along for the ride. Bigger and stouter probably won't hurt anything, but I doubt if it will help either. If the action is held and the complete barrel is freefloated then I'd want as large an action as you could use such as the old Stolle Polar or even a sleeved action. As to two or three lug, I doubt if you can tell the difference in speed. How well it ejects will make more difference in speed. You can getting going too fast if your barrel is still vibrating while you're shooting.

You'll probably get a lot of answers on this. It just depends upon how the top plate is configured on your rifle.
Click to expand...

Barrel is held in V block and the action will be free floating behind the V block
Should of had that info for you.
CLP
 
Doc,

1. A 3 lug has NO speed difference over a 2 lug. The shorter throw angle of a 3 lug is far overcome by the greater lift force, even in a BAT w/ the cocking piece bearing. A 3 lug over a 2 lug bolt increases the lift force by 50%. A 4 lug over a 3 lug bolt increases the lift force by 50%. Only thing that the cocking piece bearing does is smooth out that force. Force is the same.

2. action. No matter which mounting manner you use, barrel block versus action block, there are many quirks in a rail. I would strongly suggest you consider a barrel bock rail system and an action you are familiar with and happy with, I.E. BAT. That way you are familiar with the quirks of the maker and know how to deal w/ them. then you will be able to eliminate the obvious problems as they occur and spend your time cogitating on the "what is that" ones. And before you buy a rail platform, talk to Tom Dixon about his design. It is the ONLY one out there I have been impressed by, and if I were to build a rail, the ONLY one I would consider.
 
Peterson, one thing you want to be cautious of when mounting in a barrel block, whether full circle, or V, is the torque on the bolts. You can distort the barrels ID with too much.

What I have stated doing is turning the OD of the barrel in way of the V-Block dead straight, (it only takes a few thousanths), then lapping it into the base of the V block. I then use only 70 inch pounds of torque to hold the barreled action in place. This seems to be the best I have come up with.

As for the action, as long as it is straight and true, I doubt the size matters on a barrel block gun.......jackie
 
This rail belongs to Gary Ocock and is one of the best shooting of its kind. It does not have an ejector. There is a Delrin sleeve between the barrel and the block. The one below it is owned by Tom Libby and was built by Skip Otto. You might want to look for Tom and Gary in the NBRSA record book. Of course there are others, but these are the only ones that I have pictures of.
Visalia10-18-09fiveshotunlim017.jpg


Allpicturesfromoldcomputer377-2.jpg
 
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Boyd Allen said:
This rail belongs to Gary Ocock and is one of the best shooting of its kind. It does not have an ejector. There is a Delrin sleeve between the barrel and the block. The one below it is owned by Tom Libby and was built by Skip Otto. You might want to look for Tom and Gary in the NBRSA record book. Of course there are others, but these are the only ones that I have pictures of.
Visalia10-18-09fiveshotunlim017.jpg
Click to expand...

Boyd on Gary Ocock's rail you say it has a Delrin sleeve between the barrel and block, I can see the black Delrin around the barrel but what is the white material between the two block halves?? Ian
 
Aging memory question: I thought Jackie at one time indicated that some were having a problem isolating the barrel from the block with Delrin. Is that correct, or should I go back to looking for my car keys?

The reason I ask is I have a rifle set up that uses a barrel block, where the block is bored to use 1.500 tubing. If I wanted to use that setup for an 1.250 or so barrel, I could just epoxy some Delrin to the barrel & turn to fit the block. I know people who have successfully used paper shims, but not to take up .25 inches.
 
Ian,
Short answer...I don't know. Speculation...I went back to the original file and magnified the image, and saw that there seem to be two layers that are acting as a spacer between the faces of the block. It could be that if a standard thickness of some sort of plastic, in combination with a thinner shim, of anything that was the right thickness would limit crush, and distortion, at a given fastener torque. and possibly act to further unify and damp the assembly, or I could have an overactive imagination.
Boyd
 
Answer's about my Rail

I’ve been asked about my rail over the last few years and just recently in regards to this thread. One thing I’ve learned about rail’s in general. Not all of them shoot the way they should. I firmly believe that when they don’t perform it’s a vibration problem within the rail construction. I’m assuming that we are using quality components to make up the rail. My solution to a rail that didn’t shoot (previous to the Jay Young I have now) was to make a new block with a round hole through it and then make a delrin sleeve, placed between the barrel and the block. Snug up the whole assembly and start shooting. Simple, and it worked dramatically. I have found that a .004 oversize fit between the sleeve, barrel and block works fine. I don’t want the top of the block to touch the bottom of the block. At this point I recommend an 8” block, shorter one’s may work but I don’t have any experience with them. Thickness of the sleeve is anywhere from .150 to .250 they all seem to work. I split the sleeve to allow for an expansion fit. If I error on the torque of the block bolts I error on the side of loose rather than tight. I’ve used 1.350 and 1.450 barrels and prefer the 1.350’s as they are lighter and easier to carry around (think of Raton at the NBRSA Nationals). At some point I will try a 1.250 barrel.

In regards to my rail pictured above. The white appearance on the block is nothing more then a beveled edge I put on the top block and the bottom block to cover up a dent it put on the top block when I dropped it. I beveled top and bottom edges to match, a cosmetic thing only; although I do like Boyd’s way of thinking.
If anyone has any additional questions you can call me at 623-398-8337, 9-4 AZ time. I’m a 2 finger typist, lousy speller and would prefer to answer questions via phone.

Gary Ocock
 
Inquiring Minds Wondered

Gary, like many, I have looked at that picture many times and wondered about that "white" strip between the splits on the block. I even went so far as to think that you machined Delrin strips a few thousanths thinner than the actual compression of the sleeve so as to avoid overtigtning, vibration, or what ever.

And low and behold, it is simply a bevel that covers up a boo-boo. That is priceless:cool: .............jackie
 
When working with a barrel block that offers some flexibility, don't quit until you have tried several positions (fore and aft) of the barrel. Generally, this movement is limited by the action in one direction and the trigger in the other. A minute movement can make a big difference. No way of knowing whether it's the position or the way the screws were tightened but when you get it right you'll know it. Then....wait on the wind to let up and shoot ten times.

Try not to get hung up on some rule of thumb in inch pounds. If it ain't moving that's good enough. Amazing the force you can apply with four to six allen bolts and a comon 90 degree allen wrench.

As far as speed goes, Keith Gantt could shoot a sleved XP, RB, RP as fast as I've seen. It's all what you get used to.
 
I have to say that my rail gun the is posted here has the secret factor that no one else can have or duplicate. I have the ghost of Skip Otto with me and as long as I give my rail a bath with soap once a month Skip lets me shoot it very well.

Ps some of you will not get this but many will and its all in fun.
 
Tom, sometimes a little levity is needed. Not long after Skip died, I was at Rachels Glenn, we started talking about Skip. I mentioned how he must have died instantly from the heart attack, and that darned Bart Sauter said, "heck, it was the shower that killed him". I could not help but laugh so hard my sides hurt.......jackie
 
Mikey
I was always poking at Skip about taking a shower. I would get on the mike at Visalia and let him know I had a bar of soap etc all on fun, buy he really needed some good deordant. When he lifted his arms and put his hands behind his head with the wind coming from behind WOW.
I got a call from Lou one morning with him telling me I killed Skip. I said what do you mean? Lou said he died taking a shower so I killed him with all the nagging I did at him.
I remember when I asked him to make me a rail gun. He went up to Lou's Bus and told Lou what I said and asked Lou if he thought I was serious. Then two years later I had Carolyn ask him to make her a top, I didn't have the balls to ask him but I knew he would do it for Carolyn.
Having him make me a copy of his rail was one of best things I have done.
 
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