Tuning Barrel holding device for Daystate Aplha & Delta Wolf PICS

[spinj]

A method I employ when trying to determine if barrel position/movement might be the physical cause of a POI shift is mounting a laser on the barrel then adjusting the laser dot so that it superimposes the crosshairs of the scope, then I torque, twist, bump, carress (), or even stare hard at the barrel and see if the position of the dot changes.

The BRK Ghost and Daystate Alpha and Delta Wolves do not need the barrel clamp. If there is any POI shift from any of these rifles, if all else have been ruled out, change the front-end barrel-retaining O-ring for a tighter one.

I need to be clear here about the method I use—to perform a fair assessment the laser MUST be mounted on the barrel and not the shroud. Owners of Ghosts and Wolves should know that the shrouds over the guns’ barrels are retained by two O-rings and that the purpose of the two set screws on the barrel collar (inside the shroud) is to keep the shroud in place only, NOT TIGHTEN it as there are no threads on the shroud’s screw holes. That said, to test for any movement you’d be applying lateral force to the exposed parts of the barrel from the openings of the chassis. Also, make sure that there is some clearance between the base of the collar and frame. If the laser is mounted on the shroud and you see movement—meaning, the dot does not return to its original position or zero—which is not apparent when the laser is mounted on the barrel itself, obviously the problem of POI shift would therefore be coming from the shroud or any of the components it encases. Keep in mind that any angular or lateral deviation from concentricity of the shroud with the barrel can cause pellets to clip, thus leading to POI shifts. This problem would be magnified if there is a moderator mounted.

If no change in the laser dot’s position is detected when administering the procedure above on the barrel (not shroud), the above, good folks, is why there is no need for a barrel clamp, even when there is a change in the dot when the laser is mounted on the shroud. And if it’s not directly the shroud, it could be the threading on the muzzle that causes the shroud or moderator to be misaligned (To test for this tape the exit hole of the shroud/moderator and fire a round. If the hole is off center, then it’s likely clipping.)

 

[Scotchmo]

That’s pretty cool. I wonder if it makes any difference?

In some situations, a significant difference. If shooting benchrest, where the rifle stays on the bench for the entire session, and you get sighter shots, maybe not needed. For PRS or FT events, with moving, bumping, position changes, it keeps the poi more consistent.

I used a prototype version and it was an improvement.

 

[cavedweller]

Ghost has the same system of a single set screw. The set screw isn't what's maintaining (or not) the point of impact though, but rather the three frame orings. The set screw is just keeping the barrel from sliding out of the frame (and to a lesser extent, keeping the barrel from rotating). And on that thought, those orings hold it securely enough that the barrel has to be pulled out of the frame, ie even gravity isn't strong enough to dislodge it if tipped muzzle-downward with set screw removed.

A little story here from my Ghost experience.....
I collected dope for the 19.9fpe .20 Ghost in the week leading up to April 26th and then printed that dope sheet and taped it to the bottle on the 26th. Since then I've used that dope to shoot a 49/52 @ the Duncan AZ FT match in May, a 50/52 at the FT match near Luna, NM in June, a 45/48 at a FT match near Flagstaff, AZ also in June, and just yesterday, a 58/60 back over in NM at another field target match. I've used the dope data from April 26th in all of those mathes. And I've not changed my scope zero since April 26th.

In fact, last week I pulled the barrel from the gun and removed the shroud so that I could give the barrel a thorough cleaning after all the .20 slug testing. Put it back together and scope zero was right where it has been prior.

So, I've seen a couple guys comment about wandering poi with the Alpha/Delta/Ghost barrel fixing method, and I can believe that theyve experienced that with their guns, BUT, the Ghost that I've taken nearly 10,000 shots from at this point, has not demonstrated any issues of a wandering poi, and that's across three different barrels (.177, .20, and .22).

I was told that the Ghost has a high durometer specification for those three barrel locating orings. A # wasn't given but I'd guess it's 90d. Perhaps the review Ghost I've been working with has the harder D orings than the guns being reported as problematic.

I'm also not seeing the recommended gap (in OPs photos) between end of shroud and frame of gun that was recommended to me. And so maybe there's some temp shift issues he's seeing that I'm not.

Any further guesses as to what's causing the shifting issues for the OP would just be additional conjecture. However, it is a cold hard fact that the review Ghost I've been shooting for nearly a year now does not suffer from that problem.

it would be more likely that the shroud / moderator interface is likely to blame for any POI changes IMO of course...

 

[cavedweller]

I need to be clear here about the method I use—to perform a fair assessment the laser MUST be mounted on the barrel and not the shroud. Owners of Ghosts and Wolves should know that the shrouds over the guns’ barrels are retained by two O-rings and that the purpose of the two set screws on the barrel collar (inside the shroud) is to keep the shroud in place only, NOT TIGHTEN it as there are no threads on the shroud’s screw holes. That said, to test for any movement you’d be applying lateral force to the exposed parts of the barrel from the openings of the chassis. Also, make sure that there is some clearance between the base of the collar and frame. If the laser is mounted on the shroud and you see movement—meaning, the dot does not return to its original position or zero—which is not apparent when the laser is mounted on the barrel itself, obviously the problem of POI shift would therefore be coming from the shroud or any of the components it encases. Keep in mind that any angular or lateral deviation from concentricity of the shroud with the barrel can cause pellets to clip, thus leading to POI shifts. This problem would be magnified if there is a moderator mounted.

If no change in the laser dot’s position is detected when administering the procedure above on the barrel (not shroud), the above, good folks, is why there is no need for a barrel clamp, even when there is a change in the dot when the laser is mounted on the shroud. And if it’s not directly the shroud, it could be the threading on the muzzle that causes the shroud or moderator to be misaligned (To test for this tape the exit hole of the shroud/moderator and fire a round. If the hole is off center, then it’s likely clipping.)

exactly what i have experienced on my Wolverine

 

[Scotchmo]

It might be more of a benefit on the Delta and Alpha Wolfs. The Ghost does not have the spring loaded pins interfacing with the shroud, so spacing is less of an issue.