HW77K Rebuild

[E]

In the beginning I had a .22 HW77K and it was good.  I am more of a .177 person so I looked for a HW77K action in .177 to convert it but they were all out of stock so I got a HW97K one instead. It came from Germany so the muzzle brake has the stuffing in it!  Eventually I bought the blue stock for it and I realized I was more than halfway to putting my HW77K back together.  I bought the needed spares and the 77 was back in action.  My wife said what a deal, 2 guns for the price of 3... lol.  It wasn't quite that bad if you factor the blue stock in.

I put a FAC Vortek spring in the 77 and shot a couple hundred rounds.  At 15.7fpe it was a lot rougher shooting than my other guns which are all under 12fpe. It had some flyers and POI shifts which I attributed to the new spring.  I like the additional power a lot especially in .22 but was feeling the urge to experiment again and I didn't want to downsize the spring. But it needed to be smoother.  What to do? I read about making the piston lighter which I was OK with doing.  So I got a spare to experiment on (I seem to like experimenting as much as shooting). After reading the results of some knowledgeable people I took it from 260g down to 240g by drilling holes symmetrically around it to keep it balanced. Sanded the heck out of it to remove burrs inside and out and when I put it back together wow what a difference.  It went from 15.7fpe to 14.7 but feels like 11.  But there were still too many  flyers and POI issues. So I shot the crony (again, literately, I really need to stop doing that) to check the power and it looked better than it ever had...

601.3
603.8
605.8
604
606.1
600.7
603.3
606.3
601.9
603
600.7
606.3

ES 5.6
Ave. 603.6
SD 2.0

JSB Exact Heavy 18.13
FPE  14.7

So the power wasn't the issue.  I tried some different pellets but the JSBs were still the best.  But the POI shifts and flyers continued.  The scope? The barrel? So in frustration I put a peep sight on it and lo and behold it started drilling the same hole at 22 yards. No flyers and the POI was rock solid.  I may  need to send my scope (Burris Timberline) back.  It may not have survived the more powerful rifle.  I will test it with another rifle when I am done playing with the 77 but it is just way too much fun to put down right now.  Plus I rediscovered how much I like peep sights.

[cliffspot]

I have used the Bushnell Trophy with the adjustable objective in 4-12X40mm on an R1 and an HW77 both with Maccari kits installed. No problems. Used BKL rings. Dead on for years. Your scope or mounts are suspect.

[E]

I have used the Bushnell Trophy with the adjustable objective in 4-12X40mm on an R1 and an HW77 both with Maccari kits installed. No problems. Used BKL rings. Dead on for years. Your scope or mounts are suspect.

I agree so I finally took the scope and mount and put it on my TX200 and no problems.  Accurate and consistent at 30yds so the scope is fine.   The HW77 is still shooting well with the peep sight.  I know everything was tightened down on the 77.   It went from noticeable barrel flip to virtually none after I lightened the piston so I can see and feel how much it has calmed down.   Guess I will find another scope and see how that behaves.

thanks