I'm looking for an alternative to needle roller bearings (springers)

[vobster]

I'll stick one in my lgv and see what happens. I suspect you are correct though.

[slugger]

i would think even rotating piston guns would still benefit..afterall, a piston is a big heavy object thats flying forward pretty fast !... lets say [for example] that a spring when compressed is 180 degrees out of orientation compared to free-length [might be more, might be less] ....... point is a big heavy piston isnt going to spin 180 degrees during the short firing cycle to "correct" itself , i have no proof of this, just using common sense.... so i think its likely that a baering fitted at one or both ends IS going to help

[Artfull-Bodger]

The rotation is quite small, an example would be from 12 to 2 o clock, rather than half a turn per shot, so if you have a bearing in a rifle that already has a rotating piston then the effects are negligible, or so I have found comparing a TX to my HW77!

[ART1969]

I'll stick one in my lgv and see what happens. I suspect you are correct though.

The Walther LGV and LGU have a rotating spring guide as well as a rotating piston. I wouldn't expect any additional benefit.

[vobster]

The Walther LGV and LGU have a rotating spring guide as well as a rotating piston. I wouldn't expect any additional benefit.

As I've just discovered

[Shed tuner]

Hhaha. I caved in too lol. Always assumed it was a bit of a gimmick or if it would survive for long. But winter is here, need a few projects.

Mine have lasted over quite a few tins with zero degradation. I think at the rear guide end, where there are no impact type forces, they should last forever. Piston end will be a harsher environment, but so long is preload is high (i.e. no slack), no reason they shouldn't last.

I find it makes cocking smoother on a TX, where the piston can;t really rotate when being rammed against the end of the comp tube. Firing - on a TX - no real difference. However, firing on a '77 (std(ish)) the reduction in twist is noticeable.

[Hsing-ee]

Once you have the spring and piston isolated with bearings, you need to look at isolating the barrel. The inertia of the pellet causes the barrel to twist in the opposite direction to the 'handedness' of the rifling, the only solution is to allow the barrel to rotate relative to the cylinder. I think it was Diana that used to sell one of its match rifles with a barrel set at both ends with bearings inside an outer shroud, the barrel would rotate slightly on firing to compensate for the pellet's twisting force.

[bigtoe01]

Once you have the spring and piston isolated with bearings, you need to look at isolating the barrel. The inertia of the pellet causes the barrel to twist in the opposite direction to the 'handedness' of the rifling, the only solution is to allow the barrel to rotate relative to the cylinder. I think it was Diana that used to sell one of its match rifles with a barrel set at both ends with bearings inside an outer shroud, the barrel would rotate slightly on firing to compensate for the pellet's twisting force.

M8 thats going a little too far..LOL,

I think a bearing on the rear spring guide, really is as far as we need to go...

[vobster]

M8 thats going a little too far..LOL,

I think a bearing on the rear spring guide, really is as far as we need to go...

I thinka he taka de pees!

[greenwayjames]

Once you have the spring and piston isolated with bearings, you need to look at isolating the barrel. The inertia of the pellet causes the barrel to twist in the opposite direction to the 'handedness' of the rifling, the only solution is to allow the barrel to rotate relative to the cylinder. I think it was Diana that used to sell one of its match rifles with a barrel set at both ends with bearings inside an outer shroud, the barrel would rotate slightly on firing to compensate for the pellet's twisting force.

Have you been taking that falling down medecine again

[greenwayjames]

I have only one needle roller bearing that will fit the piston of a hw97, they seem to be as rare as a very rare thing as no one seems to sell them in the correct size.

Alternatives? Needle rollers really kill the twist on firing, standard greased washers arent even close.

Has anyone found something else that works? PTFE washers etc?

Thanks!

If you had a time machine you could go back to about 1980 and buy a set of "Power Boosters" for £2 inc post and packing from Bowket. Thats wot they were

[Snooper601]

Once you have the spring and piston isolated with bearings, you need to look at isolating the barrel. The inertia of the pellet causes the barrel to twist in the opposite direction to the 'handedness' of the rifling, the only solution is to allow the barrel to rotate relative to the cylinder. I think it was Diana that used to sell one of its match rifles with a barrel set at both ends with bearings inside an outer shroud, the barrel would rotate slightly on firing to compensate for the pellet's twisting force.

4 months early.

Cheers

John

[vobster]

If you had a time machine you could go back to about 1980 and buy a set of "Power Boosters" for £2 inc post and packing from Bowket. Thats wot they were

Boring!

[greenwayjames]

Boring!

Both of my children used to get bored easily but they grew out of it when they matured a little.

[vobster]

Both of my children used to get bored easily but they grew out of it when they matured a little.

pm sent