HW45 Spring/Piston Seal change

[Rumplestiltskin]

Although my .177 HW45 was recording high velocities (600fps/5.6ft/lbs) it was Dieseling on every shot, I know this is normally the case with the PTFE Piston Head on the HW45 but it was quite inconsistent.
I purchased a new Spring and Piston Seal, now fitted the Pistol is smoother and a lot more consistent but the power is down to 4ft/lbs, is this usual?

[munchman]

Let it run in for say 500 shots.If you put too much gun grease on the spring etc that will impair the perfromance.I just use my finger and smear LT2 along the spring.Do not put any lube in front of the piston seal.If you are not careful when inserting the piston into the tube you take a chunk out of the piston seal on the cocking guide 'cut out'.This will impair the performance also.
CDB

[Riva]

To get an effective sealing in the HW45 you will have to fire it without a pellet in it for a couple of times, after seal change.
This is what Beeman in US recommended some years ago. I have done this with both my HW45s both .177 and .22. My .22 is dong about 6.5 fltlbs with RWS Hobby, and the .177 is doing appr. 5.5 ftlbs. with JSBs.
It will crack like h... but may be worth it in the enrgy field.

Cheers,
Per - Norway

[Rumplestiltskin]

Thanks for the reply's, I'll give it a try.

[Riva]

When dieseling, use the heaviest pellet you have for some shots. This will usually stop the diesleing after 10-20 shots. Been there done that, about 12 was enough I remember.

Cheers