Piston head/weight on hatson striker 1000 - vmx edge?

[Bullpuppy]

Is the hatson striker Piston head removable? It looks like it maybe pressed on. Can it be removed from the piston?

[SteveP-52]

It may look like it, but the piston is all one piece. As far as weight, I don't have a scale to give you an answer to that one.

[mentolio]

My experience: they are not one piece, as demonstrated by my "refurbished" Edge .177, which the "head" of the piston assembly was loose enough to get plenty of "wobble," and 1/4 turn out of it before I welded that S-O-B on (another critical fail for Hatsan😶). I believe they are supposed to be friction or press fitted then crimped/peened. There should be NO movement/play/slop in the piston head. If there is, I suggest welding it (as I did).

[Bullpuppy]

Thanks for the info. Looking close it appears that the head is pressed on. 

How long is the piston supposed to be? How did they limit it to 12 lbs in the uk. The reason I am asking is the piston in miine is rather longer than it needs to be. There is about an inch of compression chamber that could be used by some minor modifications to the piston.

[Privateer]

Not following you here.
 
What do you mean by being longer then it needs to be and then saying there's an inch that could be used?

In The UK and such could have been a weaker spring.
Some companies drill a small hole in the piston head itself to bleed off pressure.
Don't know how Hatsan does it.

[Bullpuppy]

The reason I say it is longer is that it extend's about an inch and a half into the compress tube when cocked. Most guns I have worked on the piston seal and mayne a 1/4 inch of the piston sits in the compression chamber when cocked. In this gun  shorter piston would give a significant amount of swept volume. The cocking arm would support an inch of additional stroke without modification.

[Privateer]

I get what your saying now.
I'd look closer at IF the cocking arm would allow a shorter piston and also coil bind on cocking the extra distance.

[SteveP-52]

That piston, at least the one I have sitting in front of me from an Edge Vortex .177, is 5 and 15/16's long. No scale so I can't tell you the weight. If you're looking to shorten it, it would have to be done at the piston seal end. There's no room at the other end as that slot has to be there for the lower sear to drop into when you cock the rifle.
From there, you run into the things Jeff mentioned about coil bind and the cocking arm.

[unionrdr]

Hm...my curiosity is picked. I'll have to look into this one.

[SteveP-52]

Hm...my curiosity is picked. I'll have to look into this one.

Look into what exactly?? Here are the pistons from both my Edge .177 and the Edge .25 Vortex refurb I got from Hatsan USA not long ago. The silver one is because I polished it, from the .177 and has an ARH piston seal on it. The black one is straight from the .25 and untouched with the factory Hatsan seal on it. They are exactly the same size and I'm guessing the same pistons used in every Hatsan from the 95 on down, whether spring or gas ram, because all those rifles use the same piston seal and I know this because I've used that same ARH seal in both a 95 and several Edges.
My older VMX rifles have a slightly longer version of that piston. Why they changed the length I don't honestly know but it was something I found when I did the gas ram conversion on one of my VMX rifles and had to use the newer, shorter piston from the 1000X I got the ram out of to make it work.

The very rear slot on both is where the lower sear drops into when you cock the rifle to lock the piston back. The slot in front of it is what the end of the cocking arm presses against to slide the piston back. A lot comes into play when you want to try and alter any of that. Can it be done? Maybe, and someone with a lot more knowledge on the subject could tell you for sure, but you'd need quite a bit to pull it off.
Question now is would going through all that to find out be worth it on a $100 rifle other than just taking the time to see if you actually could.

[unionrdr]

Okay, looks nearly the same as the piston/seal I put in the NPXL1100 for my buddy. The way the op described it, I thought it might be a 2-piece piston assembly? I wish the cone-shaped piece unscrewed to make seal installation easier. Oh well.

[SteveP-52]

Dropping that piston seal in a glass of hot water for 10 minutes or so softens it up nicely to just press on. Once warmed up, set it on a clean towel grooved side down, set the back edge of the raised center it sits on, then just use both hands to roll the piston forward and on to the seal. It pops right on there without too much trouble or effort.

Whether ARH or the new Vortek seals, which I like better, the same seal fits at the very least, the 95, 87, 85, Edge, Striker, 1000x and a few others. Just order the one that fits the Model 95 and you're all set.