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S510 breech seal

Posted: Mon Feb 03, 2020 4:53 pm
by tonyc
I've just lost the breech seal in my S510. While I'm waiting for delivery of some uprated seals I thought I might try a BS008 o-ring as I already have some. Followed the standard AA procedure with an allen key... do you think I can get it in?! :x
Should it be any more difficult than the standard o-ring? Can anyone give me any tips or suggest alternative tool?

Re: S510 breech seal

Posted: Mon Feb 03, 2020 8:59 pm
by Archer50
I usually use a BS008 in my S400 as it makes a better seal. Won't fit my HFT500 though. Just try it and see :D

I put a 4mm wooden dowel down the barrel to form a backstop, then trap the bottom of the o ring in the groove with an Allen key and use the end of a broken wooden cocktail stick to push the ring into place. The broken cocktail stick makes a rough surface that lefts you manoeuvre the o ring better. Like a lot of these things, much easier to do than to explain.

Good luck.

Alan

Re: S510 breech seal

Posted: Mon Feb 03, 2020 9:09 pm
by tonyc
Sorted... I think!

I followed your suggestion for the BS008 from an earlier thread, Alan. Thanks. It does seem to offer more resistance to the probe than previously.

I made a tool from a brass 2BA 1/2" cheese-head screw and nut (or M3 would do it). Turned the head down to 4.3mm to fit inside the bore. Reduced the shank to 2.5mm over half the screw's length (next to head) leaving the rest of the thread for the nut so the nut stops the bolt from falling down the barrel. Slipped the o-ring over the screw head and inserted the screw, head first, into the barrel. Teased the o-ring into place using the screw head to stop it going down the barrel.

I say, "I think," because I just smoothed the sharp edges off the cheese head, with hardly any rounding, so I had difficulty removing it once the o-ring was in place. I hope it hasn't nicked the o-ring. In hindsight, I could have put a generous bevel on the head so it would self-centre on the o-ring and come out with minimal force.

I'll put a few pellets through the chrono tomorrow and check the accuracy. If I've knackered the ring I'll put one of the uprated ones in when they arrive.

Re: S510 breech seal

Posted: Mon Feb 03, 2020 9:50 pm
by Roger5
Pretty much the same as Alan, cleaning rod down the barrel and a VFG in at the breech, bit of lube, and gently ease it into place, works for me. Rog

Re: S510 breech seal

Posted: Tue Feb 04, 2020 8:19 am
by Blackbaronfish
I love a good wrestle with the ring. They can be very difficult. Like most a cleaning rod at the back helps a lot.


BBF

Re: S510 breech seal

Posted: Tue Feb 04, 2020 5:17 pm
by tonyc
Thanks guys, a rod would have been easier but I didn't have anything suitable to hand. Anyway, it's in now and giving a nice consistent 775 +/-1 fps this morning. :)