Barrel gripping block

[MilGunsmith]

What is the opinion on barrel block design? Round or V-block? Aluminum block directly on steel barrel? Paper, plastic, or rubber between steel and aluminum? Bed with Marine-Tex or similar? This will have to work with miltiple barrels for ammo development.

[CubCouper]

My Powell has a V-block design. I cut three long, narrow strips of that 10-mil PVC tape to serve as a buffer between the barrel and the block at teh three points of contact. This has worked very well for several different barrels that varied from 1.450 down to 1.350 and even a bit smaller.

Rod

[MilGunsmith]

I have noticed in the pictures section, that some of the V-block designs are a V-block on bottom and a flat plate for a 3-point contact, and others are a double V-block for a four point contact. Any preferences? This will be for 1.500" dia. barrels in .338 Lapua Mag and .300 Win Mag.

[hepburn45110]

Wait a minute. We talking about putting a magnum round in a rail?

[MilGunsmith]

Yes. We are working on sniper ammo and need to have an accurate setup to test from. Probably going to have to use Thompson Bearings to keep it together.

[Bill Gruby]

WOW, now I have a question. That a powerful round, how will you keep the rail from flying off? I was under the impression that the weight held it down.

"Bill Gruby"

[MilGunsmith]

That is why we will use the Thompson Bearing Rails.

[Bill Gruby]

Linear Bearing Rails, that's cool.

"Bill Gruby"

[hepburn45110]

WOW, now I have a question. That a powerful round, how will you keep the rail from flying off? I was under the impression that the weight held it down.

"Bill Gruby"

That was my concern. If you put a magnum chambered barrel on my "Young" ,you're gonna have the cradle in your lap every time you set it off.

[Bill Gruby]

Another question. Windage is adjusted at the rear and pivots at the front. Elevation is adjusted at the front and pivots at the rear of the Rail Guns. Either the bearing or the rail must be locked. How are you going to incorporate this? Or did I miss something. Curiosity killed the cat but this really grabbed my attention.

"Bill Gruby"

[MilGunsmith]

We use a Frank Mann designed "Bond Mount" for testing. Windage and elevation are built into it. The different test mounts then attach to it. This is a setup we did to catch the bullet as it left the case on High Speed video. This is useing the old V-Block accuracy setup on the Bond mount. We will make a Thompson Rail fixture to attach to the mount.

[Bill Gruby]

Thank you for the pictures. It is easily seen now how you could incorporate the Linear Bearing Rail. That is quite a set up you gents have.

"Bill Gruby"

[MilGunsmith]

We have two 100 meter and one 300 meter tunnels. We are constantly trying to improve our test procedures.

[classcat]

Why don't you build an extended plate on the sides of the upper and sand bag them,or counter-weigh them ? Those MASSIVE springs may be effecting accuracy.
The Barrel blocks on our rails are about 6" long and most,,not all,, are torqued to specific settings. That short block may be Choking the barrel.
Are you taking the lash / harmonics into consideration ? a 1.500 will shoot differently than a .750

I M O which is reinforced by better rail shooters than I am,, 3 point is the way to go on Powell based design ( Aluminum to steel), however a mylar sleeve works well on a Young design ( Round) . NO BEDDING Compounds,,,, You're in UNCHARTED TERRITORY

Pretty rare that my rail will like the same load that my bag guns like. Just saying.

[Dusty Stevens]

First off whats the accuracy standards youre hoping for? If youre hoping for 3/4moa anything will work. If youre trying to prove better i dont think the linear bearings are gonna cut it. You could make an underslung rail and make the slides extremely long. You can have it hit a long spring plunger after 1/2-2" travel then slow down over a couple feet. Of course in a tunnel youll have time to let the wake turbulance settle and realign the scope each time