New TX200 mk3 help - mystery power washer?

[Mitigator]

Eyup,

Picked up my new lovely walnut leftie tx on Friday - tin of pellets thru it, trigger tuned and all good.

Decided to open it up for a nosey around having watched countless YouTube stripdown videos. As expected my gun has all the ( very simple) internals EXCEPT between the std metal spring guide and the spring is a metal washer - it’s about 2mm thick and very loose fitting.

Over the chrono after about 200 pellets it was very consistent 780fps with JSB exacts ( 11.3-4 ft lb )

I inderstand that the power of the gun may well go up as it beds in and 11.3 is a bit more than I’d want anyway.

So do I bin the washer?

Ta

Dan

[BTDT]

Losing 2mm of preload would deliver around 0.7 ft. lb. less to the piston, of which circa 40% would make it to the pellet, so that would be in the order of 0.28 ft. lb. less at the muzzle.

[Mitigator]

Do they all have one of these fitted - just seems loose / under engineered ?

If I’m right in thinking power will nudge up as beds in I think I’ll bin it?

Dan

[BTDT]

Do they all have one of these fitted - just seems loose / under engineered ?

If I’m right in thinking power will nudge up as beds in I think I’ll bin it?

Dan

According to Chamber's parts diagram, it's listed (as a 'thrust' washer) as standard only in the HC.

To check it's safely legal, I'd test the rifle with 7.87 grain JSB pellets, which seem to give the highest muzzle energy.

I wouldn't expect much increase through bedding-in.

[Mitigator]

Thanks for that - mines the std barrel and chronoed at 11.3.

I am surprise it’s an air arms bit - must have had a job lot in the bottom of the parts bin....

[svendogg]

Losing 2mm of preload would deliver around 0.7 ft. lb. less to the piston, of which circa 40% would make it to the pellet, so that would be in the order of 0.28 ft. lb. less at the muzzle.

How do you even go about working that out? I would imagine it's different variables for every model of rifle?

[BTDT]

How do you even go about working that out? I would imagine it's different variables for every model of rifle?

You start with the spring specifications, stoke length and preload, combine that with previously measured energy efficiency of the rifle and spring in question, and after that, it's maths.

[TonyL]

How do you even go about working that out? I would imagine it's different variables for every model of rifle?

You start with the spring specifications, stoke length and preload, combine that with previously measured energy efficiency of the rifle and spring in question, and after that, it's maths.

And never forget, he is Lord of The Springs for good reason.

[Amac]

Following a run in period of a couple of tins, my own brand new TX was stripped yesterday and had all of its internal component parts lovingly polished prior to an application of moly grease. My own .177 HC did not have any thrust washers fitted. On reassembly, the gun was down to 9.5.

I then decided to get it back up to elevenish this morning and have now dismantled it four times, having degreased all parts each time. Each time I have reduced the amount of moly grease I originally applied. This was present on both rear spring guide and piston seals. Dont get me wrong folks. I have not slopped in a load of grease, but carefully applied just a smidgeon to the areas under most load.
The final state of lubrication (which has now included the fitment of a couple of delrin thrust washers for preload) has got her back up to 11.5. To achieve this the gun is basically running dry apart from an application of SM 50 on seal, piston bearings and rear guide. I am now wondering if the gun was fitted originally with a thrust washer, which has now disappeared into the black hole of the workbench and oblivion.

I reckon I will have to keep a close eye on her, as I reckon once the seal has reformed following its extraction, it will be thrust washer removal time sooner rather than later.

I would have expected for the gun to sound like a bag of nails due to the lack of moly grease. However, she is relatively quiet, and presuming that the SM50 doesn't migrate too quickly, will hopefully continue to perform as well as the standard TX can. Which is pretty damned good in my opinion!

Andy