A few ramblings

[wonky donky]

I've just .been playing with my 2 TX 200 rifles. One running one of my pistons @ 188gms the other @ 190gms so little difference.

Both ports 3mm shorter than standard but standard diameter, one stroked to 78mm & the other @ 82mm.

Started with 34 coil 3mm wire spring in both. HW 25mm seal & both rifles chucking AA 4.51 field out roughly the same Vo...788fps & 795fps

Now I usually have the TX running at 780fps 82mm stroke, skimmed piston, head removed & HW/short stroke adapter fitted, Vortek seal port standard but 3mm shorter, well 2.4mm actually with lovely firing cycle.

My 2 the firing cycle is is terrible, very slammy, fast but slammy. So springs out, new 30 coil 3mm wire springs in, btw the springs all have the coil spacing the same so lth is pro rata. Brass top hats made to take both pistons to 206gms.

Rifles now shooting at around 720fps, out with the HW seals, in with a Walther seal in one rifle, Vo now mid 740fps, Vortek Vac25 seal in the other rifle Vo 790fps, Vortek Vac25 fitted to the other rifle Vo now mid 780's.

Both rifles firing cycles feel better, but they ain't good by any stretch.

My .20 HW77 is short stroked to 75mm, rotating piston weighing mid 170gms, this too imo has a poor firing cycle.

Now when I say poor firing cycle & slammy, the cycles over lightening quick, it,s mega fast but I just don't like that, it also gives me a headache if my face is against the stock, head off the stock it's alright & seems reasonable, so to me these rifle are not user friendly.


It's difficult to put in words as most of you know when your trying to describe a feeling, but certainly we are all different, we each may like something different.

Sometimes a compromise is needed, it's no good having a rifle with the cycle you want if you can't shoot it long term, can't follow through properly or most of all hit what your aiming at. If it works for you go with it!

[Shed tuner]

Make a new 3.5mm dia port

[bigtoe01]

Make a new 3.5mm dia port

Jon

yes that would help, but no it will not help Dave i feel, 82mm stroke, 235g piston and I feel a weaker spring will help him, im up at 34coils 237mm LGV spring with a stock hwseal and you kinda liked it just fine remember and it has not changed since I swapped springs to gain back the 5mm i took off to bring the power back to 780fps.

My 440 went thru a 75mm stroke 180g piston phase, it seemed awesome to shoot but was an utter biatch to cock and when i did field test it it was over harsh. Ultra light weight pistons take a lot of finer tuning imo, they can be awesome, but its seriously hard to get them real nice.

For you and Nik who will strip the TX or 97 many many times till you get the firing cycle just how you want it light weight pistons are fine, however im swaying now to 220 to 235g and pushing the stroke to around 80mm or so, HW had it right with the old 77 in .177 imo, you get the guides and the spring right they are easy to cock, east to shoot and follow thru superbly...even in .177. Plus how many people would buy a kit, fit it and mess around with piston weights and preload to get it seriously sweet...not many How many would fit an 82mm stroke piston and a spring with guides that is a drop in for around 11fpe and they just shoot it performing like a well tuned old 77....loads!

Dave...the ONLY thing I would check is no leaks, seal and breech seals and breach plug are ok?

[Two200's]

I have never done the TP/ Stroke / Weight mods, but have slicked up a couple of TX's with tuning kits.
I had them shooting without a hint of twang and very consistently.

One thing i did notice and do notice with every TX i shoot is the god awful metallic clank of the skirt of the piston hammering into the compression tube and driving the whole lot forward to muller the oring seals.

I notice it on every one i shoot and i hate it, its enough to give me a headache especially if the stock is walnut.

I know the TX's are great guns and of course revered.
But i have a number of bugs with these guns and the clank is one of them.

[bigtoe01]

I have never done the TP/ Stroke / Weight mods, but have slicked up a couple of TX's with tuning kits.
I had them shooting without a hint of twang and very consistently.

One thing i did notice and do notice with every TX i shoot is the god awful metallic clank of the skirt of the piston hammering into the compression tube and driving the whole lot forward to muller the oring seals.

I notice it on every one i shoot and i hate it, its enough to give me a headache especially if the stock is walnut.

I know the TX's are great guns and of course revered.
But i have a number of bugs with these guns and the clank is one of them.

Never experienced that, but will look for it. I am about to order a TX rifle so I can measure up and see what clearance is left before I swap pistons and set the rifle up how i want it.

Dave has used a 77 breech seal on a TX, im wondering if this would help maybe.

[audiguypaul]

No clank twang or anything else for that matter with my mk3 in .177. WD short stroked it and sprinkled some of his magic fairy dust over it and it shoots like a dream. Quite a quick lock time resulting in a slight shoulder nudge and averaging 777 fps with AA 4.52, it's so much more accurate than i am. I did manage to put 3 pellets through the same hole at 26yds the other week, and when i say one hole you couldn't tell the other 2 had gone through. I really don't know how it could be improved, i love it. Anyway Dave do to yours what you did to mine, don't think you'd be dissapointed

atb Paul

PS still loving the 99 too.

[TonyL]

HW had it right with the old 77 in .177 imo, you get the guides and the spring right they are easy to cock, east to shoot and follow thru superbly...even in .177.

Tony,

I think you've said before that a 26mm HW77/97 with lightened piston can be just about as sweet as a 25mm version?


But, I bet these days there will be more 26mm guns out there.......So, if one of you enterprising peeps were able to make and launch a complete drop-in internals kit, comprising new tube (maybe buttoned?) 25mm piston, spring, guide, top hat and sleeve, that could be truly awesome and a genuine fit and forget solution? The TP size and spring rate etc could be set at design stage, and there shouldn't be variations between different guns, as you've basically replaced the entire internals....Awesome!!

Now, I appreciate folk can get a V-Glide kit and I admit I've been a long term very satisfied user of Steve's awesomeness, but are the V-Glide kits 25 or 26mm?

If they're 25, then it's all ready done.

But if they're 26.....

[bigtoe01]

Tony

I learnt a while back you can make a 28mm piston gun shoot just as nice as a 25mm piston gun. The key is piston weight and stroke, for a .177 this is anywhere from 75 to 85mm stroke and around 220g ish, 230 works also. The issue witht he 28mm pistons is they need a lot of work to get the weight off, hence sleeving to 25mm gives an instant weight loss on the piston and so makes life much easier from the get go.

For the 26mm 77 you can get away with a 26mm piston and seal, yes i built a 23mm piston and tested it and yes at 83mm stroke it was superb, the added weight of the comp tube though kinda killed it for a sporting gun but for a target rifle it may be the way i would go.

I keep looking at this Diana 34 action I have here, the sooner i get the breech out the better and get the new one machined up, this one will have a 28mm comp tube with a 24mm ID so 24mm piston....weight will be less, so will be a no compromise 12fpe gun.

Drop in piston kits are tricky, has to be face to face from an RFD, modular piston kits, now thats something different and something I have been thinking about. I am thinking 26mm piston with 77mm stroke or so for .177, piston rotates, new trigger sear as part of the kit, fully lubed with new guides and spring. The only thing you have to do is build the piston before you put it in the gun....which this could be made easy for you.

Or the kits are shipped from outside the UK.

[wonky donky]

No clank twang or anything else for that matter with my mk3 in .177. WD short stroked it and sprinkled some of his magic fairy dust over it and it shoots like a dream. Quite a quick lock time resulting in a slight shoulder nudge and averaging 777 fps with AA 4.52, it's so much more accurate than i am. I did manage to put 3 pellets through the same hole at 26yds the other week, and when i say one hole you couldn't tell the other 2 had gone through. I really don't know how it could be improved, i love it. Anyway Dave do to yours what you did to mine, don't think you'd be dissapointed

atb Paul

PS still loving the 99 too.

Hi Paul I hope your alright mate.

I don't tune any rifle like the 2 TX 200s or the .20 HW77 I'm rambling on about above, I tune them mostly like yours although I will incorporate proven modifications.

The rifles are used to test theories like the zero transfer port mod I did to one some time back. If you remember I made about 10 compression tube nuts with ports of various dimensions & used different ways of sealing them too, but I digress.

Those rifles are test mules & the reply's above whilst intended to be helpful in the usual way Jon,Tony & many others on the forum often are are missing the point by many a mile.

My mind says read the post again guys!...

I have almost made my mind up long ago about piston weights & feel Tony is nearer the mark, but I will reserve my judgement untill I've had the opportunity to shoot one of Jon & Niks rifles..


It really is a statement of fact I'm making I suppose, Spring 4 coils shorter, a puny spring at that, now look at the seals, 60/70 fps more just by using a different piston seal, all new.

I spoke to Tony one day last week about this & he seemed surprised when I told him about the old HW 25mm seal needing more spring than the Vac25 to make the same power all things being equal.

With this in mind I revisited the experiment using 2 rifles last Sunday........for the record No Dieseling, leaking or anything else amiss.

One thing I will say is the Walther seal experiment will be done again as the seal I had to hand was for a LGV which had the pip removed.

The question I'm asking myself is is the result parculier to my 2 specific rifles for some reason or should I put the 25mm piston & tube out of my old .22 77 & put in a new .177 rifle & run the experiment again? I just can't help but feel there's something to be gained in a combination of ares we have yet to look at.

[bigtoe01]

Dave

The seal is seriously important, getting it sized right, sealing right is actually hard to do in many cases on a new build...Mattyboy could be fighting this right now with his 50s tuning experiment. The ONLY seal I ever used where i knew it would work, give the power and be consistent right off was you guessed it, an O ring. However i knew the comp tubes were dead true and I set the crush to a known value, at one stage i knew right off what the power would be with a given spring (as long as the springs were consistent also) give or take 10fps.

One of the big issues however is what I just touched on, the compression tubes being dead true...more often than not they are not and this causes massive issues. I have a Diana 52 here that would you believe has a comp tube that tightens as the piston gets closer to the breech, i sleeved it down to 25mm and had to machine the tube to slide down with a taper....right now though the 25mm bore is near dead true and the seal wear I was seeing at 28mm and power loss has completely vanished at 25mm and the gun is super consistent as you would hope.

Onto the Vortek seal you found just produced a ton of power...its sealing better with lower friction...its all it can be. The Vortek seals have to much lost volume imo but do deliver, however as you have found they are not always as consistently machined as you would hope. Matty has a 50s with a 24.8mm comp tube, if you happen to have a small vac25 thats under machined he may be interested

[Two200's]

Never experienced that, but will look for it. I am about to order a TX rifle so I can measure up and see what clearance is left before I swap pistons and set the rifle up how i want it.

Dave has used a 77 breech seal on a TX, im wondering if this would help maybe.

My ear picks it up every time.

I really wanted to like the guns, but am convinced the 77/97's are better guns.

Its just my opinion, but some things put me off the TX's now.

I think the Germans have it right with Springers.

To add balance to that comment, i have 3 pcp's - a Falcon, a Ripley and a Daystate - all british.

Nothing i buy is chosen by country of manufacture, its just how its panned out.

[prosport.177]

Have you tried the experiment using the pistons, springs, and seals in your test, put into a standard tx comp tube? Not shortened port ones?

[bigtoe01]

One of the big issues with the TX is the comp tube and seal, we have seen from Jon that he has had none true comp tubes, what happens is you get imperfections where the ABT grooves are machined in with tight and lose spots. Now couple in a hard seal which has a tendency to allow air leakage around the dovetail mount and passes air around the lip of the seal due to its hardness.

If you run a TX with a stock HW 25mm seal near every time with the same stroke you will see a substantial power increase, often 1fpe+

So onto the ringing compression tube, this may be a combination of slight slam due to a poor seal on the piston caused by out of round compression tube or leaking seal or both.

What should happen is the comp tube on the compression stroke physically sits against the breech face holding the O rings on the breech seal with just the right amount of crush to form the seal needed...so any ringing would probably be the piston slamming into the comp tube face.

[wonky donky]

Dave

The seal is seriously important, getting it sized right, sealing right is actually hard to do in many cases on a new build...Mattyboy could be fighting this right now with his 50s tuning experiment. .

Onto the Vortek seal you found just produced a ton of power...its sealing better with lower friction...its all it can be. The Vortek seals have to much lost volume imo but do deliver, however as you have found they are not always as consistently machined as you would hope. Matty has a 50s with a 24.8mm comp tube, if you happen to have a small vac25 thats under machined he may be interested

The one thing I won't do & I've said it before is size a seal, you take the "skin" for want of a better word off the seal, that's just plain asking for trouble imo. I've known power fall off very rapidly using sized seals so to me it's just not worth it. One other thing that can create problems is absorbtion..remember the BSA nylon/poly heads?
Put it in prospective we are talking running in seals not adding 20 more spring coils because the seals tighter than a nuns nudger!

Now the Vac25, yes it's quite a hard seal, about 95 shore A, it's dished but that is not lost volume, actually there's no such thing imo but know what you mean

Right consider this: walther with the LGU have put a small dia. indent in the center of the piston seal, they also did it in reverse with the LGV seal, now why....to create what is commonly refered to as lost volume. I did a similar thing when I double "O" ringed my HW77, why, because it became more efficient. Oh BTW the Walther LGV seal I had tested was 95 shoreA too.

The Vac25 has more of a dish (parachute) it's quite stiff & the lip is a little thick but not overly. Now consider the forces inside the rifle, when firing the rifle, I don't think for one minuet that seal is dished any longer when it come to the end of the stroke. It may relax when everything is over but I suggest it starts to flatten from the outside inwards continually expelling air

Have you tried the experiment using the pistons, springs, and seals in your test, put into a standard tx comp tube? Not shortened port ones?

Yes charlie some time ago now, I've made quite a few TX breech plugs & transfer ports of various dimensions, dead simple to produce if you have the correct tools & can screw cut. I quite like the standard port as is at 86mm stroke, bit long really, much better in .177 at 78/83 imo depending on other factors.

One of the big issues with the TX is the comp tube and seal, we have seen from Jon that he has had none true comp tubes, what happens is you get imperfections where the ABT grooves are machined in with tight and lose spots. Now couple in a hard seal which has a tendency to allow air leakage around the dovetail mount and passes air around the lip of the seal due to its hardness.

Almost every TX I have seen exhibits this

If you run a TX with a stock HW 25mm seal near every time with the same stroke you will see a substantial power increase, often 1fpe+

This year I have tuned 12 TX & not once have I found this, in fact I have found quite the opposite.

So onto the ringing compression tube, this may be a combination of slight slam due to a poor seal on the piston caused by out of round compression tube or leaking seal or both.

What should happen is the comp tube on the compression stroke physically sits against the breech face holding the O rings on the breech seal with just the right amount of crush to form the seal needed...so any ringing would probably be the piston slamming into the comp tube face.

I haven't experienced ringing either, interesting!

Tony those pistons are going to be too light mate, mark my words! Mine are all steel with a cocking ring, bearings, steel noses as well. I want to see 220gms. I don't think brass or phophor bronze top hats will cut it.

[bigtoe01]

Tony those pistons are going to be too light mate, mark my words! Mine are all steel with a cocking ring, bearings, steel noses as well. I want to see 220gms. I don't think brass or phosphor bronze top hats will cut it.

The TX here has 235g piston, 82mm stroke, HW30 seal and LGV spring and rear guide, a mate cocked it last week and thought it was a .22 running 8fpe and yet its a .177 running 11.3fpe....transfer port is 3mm shorter than oem, same dia.

Not everyone likes a 235g piston, some like 190g pistons and much stiffer springs, NikG's 97 was much harder to cock but had an awesome firing cycle...a modular piston would give that capability, steel head, alu head, steel rod, steel skirt, alu skirt, all bases covered, just imagine the weights that could be hit with minimal machining. Also consider a rod 40mm longer such as what i put in my Diana's, i don't want a steel nose as that will push the piston weight to high, I want an alu nose to drop the weight I added with the longer rod.

Much bigger picture here Dave....stop thinking 97/77 and TX, add in all the Diana under lever and side lever range too along with LGV LGU range also