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

[vobster]

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!

[tinbum]

Delrin works better than the bearing washers I've tried. If used with a delrin tophat it creates a self lubricating join that's as slippy as a slippy thing.

[TORNADOS7]

2 PTFE/Delrin washers with a polished and lubed stainless shim washer in between works for me, stumbled across that little gem whilst tuning my 95k!

It gives the top hat something to slip against rather than just another PTFE/Delrin washer !.

[Shed tuner]

Why put them in the piston ? They work fine at the rear, where the std size (around 28mm) fits easy. Done it to my 77, TXs.

[Loki_79]

What size is the one you have that fits?

[TonyL]

Why put them in the piston ? They work fine at the rear, where the std size (around 28mm) fits easy. Done it to my 77, TXs.

Surely better to help impart spin at the front too, Jon?

Will look into the 28mm for the rear; cheers.

[vobster]

Thanks very much all! Lots to have a try with.

Jon...I'll see if I can find some 28mm's for the rear (url would be handy ), it would mean using a guide which would have to be on the loose side though, surely?

[TonyL]

2 PTFE/Delrin washers with a polished and lubed stainless shim washer in between works for me, stumbled across that little gem whilst tuning my 95k!

It gives the top hat something to slip against rather than just another PTFE/Delrin washer !.

Whereas what I'm thinking of next trying would be slightly different...two polished steel ones either side of a Delrin one..

[TORNADOS7]

Whereas what I'm thinking of next trying would be slightly different...two polished steel ones either side of a Delrin one..

I fitted a "Tinbum" kit and the stainless steel washer was already in the piston from factory so I just put the PTFE/Delrin washer that was supplied in the kit into the piston up against the piston liner and then slipped the moderately greased washer in between it and the top hat, bobs ur uncle an instant bearing !...

[slinger69]

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!

I'm most interested to learn about this please, so:

Does this twist come from the spring unwinding as it is released from compression?

Does this turning effort cause muzzle movement and/or anything else deteremental?

If these needle rollers are so economical as we see here and effective too, why don't the o/e engineers specify them, given the economy of scale firms like AA & Weirauch have?

Should every springer Have them?

Many thanks for your expertise...

[vobster]

Does this twist come from the spring unwinding as it is released from compression?..... Yes.

Does this turning effort cause muzzle movement and/or anything else deteremental?......I find rifles can pull right, but with a bearing they are straight, forward-back.

If these needle rollers are so economical as we see here and effective too, why don't the o/e engineers specify them, given the economy of scale firms like AA & Weirauch have?.......They are not really designed for high compression load, just light load and twisting.

Should every springer Have them?...ask me in ten or twenty years if one has come apart. It could be bad, small hardened bits of metal floating around inside your springer.

Buyer beware!

[bigtoe01]

Does this twist come from the spring unwinding as it is released from compression?..... Yes.

Does this turning effort cause muzzle movement and/or anything else deteremental?......I find rifles can pull right, but with a bearing they are straight, forward-back.

If these needle rollers are so economical as we see here and effective too, why don't the o/e engineers specify them, given the economy of scale firms like AA & Weirauch have?.......They are not really designed for high compression load, just light load and twisting.

Should every springer Have them?...ask me in ten or twenty years if one has come apart. It could be bad, small hardened bits of metal floating around inside your springer.

Buyer beware!

The idea is its not being smashed as such at the trigger end, just having differing loads applied to it, plus the spring only needs a bearing really at one end and either would do with the rear being the easy option.

For the front a tophat and slip washer is all thats needed really, i usually run the same on the rear (slip washer and bearing washer) but decided to give one of these a go on the TX....so we shall see.

[FPoole]

I have several I removed from a couple of guns. A tuner over here used to use them, but I really didn't notice an accuracy difference. The bearing is sandwiched between 2 thin hardened washers so the pieces would be captured if it failed. I have 1 for the piston as well and will try to find it. There really isn't much load on a TX because it takes years and years to wear the paint on the end plug with just a washer in place. I may drop some of the bearings back in 1 of my guns, but don't hold your breath. On a FAC TX there isn't room due to coil bind unless you use a shorter spring. One TX I own had an Ox spring with the bearings on both ends and it had survived for many 1,000's of shots with no wear. It was an ex U.S. and World champ FT gun and is still very accurate, even without the bearings.

[Jonas]

I used to own a Pro Sport with a thrust bearing between rear guide and trigger block. The guide was custom made to accept one half of the bearing, the other half was set in the trigger block. This was a roller bearing consisting of three parts if I remember correctly.
I too did not notice any difference in accuracy. It was still running the full 98mm stroke and was very hold sensitive.

[TonyL]

I'm most interested to learn about this please, so:

Does this twist come from the spring unwinding as it is released from compression?

Does this turning effort cause muzzle movement and/or anything else deteremental?

If these needle rollers are so economical as we see here and effective too, why don't the o/e engineers specify them, given the economy of scale firms like AA & Weirauch have?

Should every springer Have them?

Many thanks for your expertise...

Hi Gwyn,

Yes, the idea would be to negate the effect of twist from the spring unwinding.

I've mentioned this example on a couple of other threads.....

A few months ago I had the pleasure of shooting Kieran Turner's LGV Comp Ultra. As most will be aware, this rifle has a rotating piston. Kieran had not done anything other than strip, degrease and relube. And it shot beautifully.

Indoor range, high mag scope. Very, very accurate and easy to use. However, probably due to the fact that it was SO refined to shoot and, possibly, the high mag scope, a small twisting movement was evident. This is what keeps making me think that a bearing arrangement (however conceived - flat surfaces / thrust washers etc) would be preferable to a rotating piston, isolating any rotation WITHIN the piston body and not bring transferred to the cylinder walls via the rotating piston. Nothing new and many before have thought along these lines. Many also having put it into practice....Unlike me, where it's just in my head. Must play with this.