Hunter sport, breach seal and barrel droop

[rkr]

G'day all,

Yesterday I finally received my Hunter Sport that I ordered almost a month ago. The price was reasonable so I think it was worth waiting. The gun looks good and is definately easier to handle than CFX was. However, it has barrel droop. After further inspection I noticed that the breech seal o-ring is nicked some and it protrudes quite a lot. I suppose this is the cause of the droop. Now how do I fix this? I remember seeing a reference to dental flos and breech seal o-rings somewhere, any links perhaps?

I think this is going to be a nice gun. Very light and easy to shoot when compared to my AR1000. I ordered Charlie's trigger and plan on doing a shrinktube tune + other small things once it gets here. The scope needs parallax adjustment and I think I'm going to fix a new trigger guard for the gun.

Cheers, Riku

[vinceb]

Sometimes the Gamo breach seal does stick out a bit more than it should, and it gets caught on the transfer port when closing the gun (hence the nick). But since the Gamo seal is relatively soft, it might still be sealing just fine.

Also, because the seal is soft it has nothing to do with the barrel lock-up position (unlike the B19/Quest series, which uses a harder seal). The Gamo locks up metal-on-metal, if the barrel droops it's because something isn't machined quite right. Unfortunately, if you want Gamo to fix it you'll have to pay to ship it to them... and then wait possibly 3 or 4 weeks.

You may be able to fix it yourself by hand filing back either the breach or transfer port mating face.Shouldn't take much. But I'd get some more advice before doing that...

[rkr]

Yep, I took off the seal and found out that it's not an o-ring, rather a rubber cylinder. Took off some 0.3mm from it but the transfer port is still nicking the seal. The droop was less without the seal but still there. I guess I'll have to shorten the seal a bit more to fix the nicking and see if there's a need to file the breach. Is there a rule of how much the seal should protrude from the breach?

Cheers, Riku

[rkr]

Well, Charlie's trigger arrived today so I went on and disassembled the rifle for a quick tune up. Shrink tube to the rear guide, filed smooth all those stamped slots, worked a bit with the tophat and polished the spring ends. The seal was nicked as usual so I used some 240 grit paper to make it better. Applied some lubes and put it back together. After parallaxing the scope I must say that the rifle is working quite well. The trigger is good as we know and shooting the rifle is a pleasure. Nice solid thud, no twangs or twists. The accuracy seems OK as well. I casually shot some 30 shots from sitting position and without any concentration it was making a big 10mm hole at 10 yards. With some effort the group shrinked to 6mm or so there is definately some potential in this gun. I think I'll concentrate on the looks next. Overall I'm so far very happy with this little gun.

Cheers, Riku

dont yell if im wrong but i heard that the seal is supposed to have a nick in it after use and it helps it seal better ... thats what i heard

[rkr]

The stock trigger guard was looking really bad after I installed the "golden trigger", so I made a new one to match. Looks quite pretty I'd say.

Riku, that really looks nice. A great accompaniment to the GRTIII. Well done!

Bryan