Walther Falcon Hunter ?

[StrawHat]

Okay, I was out back trying to figure out my hold over between different pellets/weights. While I was doing this I got my chrony out and got a few readings. I got the following averages with.
Predator              16g        770fps     21 fpe
Gamo Rocket       14.3g    792fps     20 fpe
Rabbit Mag          24.69g  493fps     13 fpe
What can I do to get the fps up. I have seen some other folks post up about 100fps faster for the same weight/pellets.
thanks for your help.
Carl

[pindog2000]

wow thats real low for that gun very low im sure the experts will chime in

[shadow]

Possible piston seal damage, losing compression. Ed

[StrawHat]

Well, that is what I was afraid of. Is there a good ref. for the breakdown and tune of one of these things. Also where can I get the parts needed to fix this?

[HNT5]

I home tuned mine not too long ago. Here is the seal. It is drop in, no sizing required. Trust JM on this or learn the hard way like I did($20 mistake, the cost of the new seal w/shipping). Do a search here as there was a post with some good pictures of the tear down. You NEED a spring compressor, no way around it. Also, be careful taking the trigger apart, it likes to come apart like a grenade. I have a PDF file for a Daisy Hatsan trigger tune I got from Paul Self (Rane Douglas)that helps alot. Probably wouldn't have got it(the trigger) back together without it. The trick is to make a dummy pin out of 1/8 stock(I used a wood dowel) to slide in the trigger as you take it out. That keeps all the parts intact, otherwise they go all over (been there done that twice).
Send me a PM with an e-mail addy and I'll send you the PDF if you'd like.
 
http://www.airrifleheadquarters.com/catalog/item/251485/6616786.htm

HTH

Nathan

[coochie]

how long have you had the gun and most important: how many shots have been through it? Is it a .22 or .25? Did you notice any other symptoms besides the chrony test???

[StrawHat]

Had it a little under a year and have put a few tins through it. She is a  .22 and never seems to hold zero. I have been blaming the scope but if I have a cut up seal then that could explain the wide open groups.

[StrawHat]

I checked the MALL and it seems like everyone is backed up. Can anyone give a recomendation for a tuner that works with the WFH?

[coochie]

I can feel you on that straw hat. I have a walther talon . 22 which is the  exact same gun. i have between 1000 and 1500 pellets through mine and it is dead accurate with most pellets except daisy pellets. seems the more i shoot it the more accurate it gets. cleaning the barrel and a lot of pellets was the key to my guns accuracy. it has never been chronyed though. please keep us posted on your progress with it.

[davee1]

First, I would rule out the breech seal, because it needs shimming, and its easy. If after shimming you still feel that the velocity is low, then get that piston seal replaced. It may even be a combination of the two, breech seal needing shimming and the piston seal needing replacement.

[StrawHat]

Okay, I tried the tissue test and it looks like the breach seal is okay. Well at least I didn't see the tissue puff.

[davee1]

None of my springers puffed when I did the tissue test...yet I gained velocity and consistency by shimming the beech seals in all of them. Shim and chrony, shim and chrony, until the gains stop or you have lockup issues.

If the piston seal is really bad to begin with, it may be hard to get a good stable reading on what your velocity gains are from shimming. Its easy to do though. It's worth it just to try.

[StrawHat]

What did you shim the seal with? O-ring kit or something harder?

[davee1]

You can try dental floss, vinyl tape, aluminum foil, soda can metal....you name it you can use it. Take the seal out, put the shim in, put the seal back in, and the seal sits a little higher than it used too and gives a better seal. You can use multiple shims if needed. Start out with something about 5~10 thousandths. One to three shims in that range usually does it...but due to machining tolerances/differences, every rifle is different so you have to experiment. Remember, patience is a virtue. You will need lots of patience to do it right. Shim and test, shim and test.