The pin at this point was loose and I slid it out of the way. If the coil spring had been fitted I would have had to make a pusher that slipped around the pin and pushed against the spring guide to relieve the tension.
The end of the gas ram. The setscrew in the cap apparently is used to set preload on the ram. I'm not sure I'm happy about that setup as the force of the ram is against the two screws that hold the end cap on, rather than the pin.
The gas ram slid out.
Don't worry, I won't open it. Likewise I couldn't find any place for the pump fitting to screw onto, so it must be a later ram that does not have adjustability? Or the pump port is hidden?
There was a steel washer at the piston end.
I had to hammer with a drift against the "Maxi Grip" rail, to get it to slide backwards and off the action. I don't like this system...
The long wire spring that retains the cocking lever in the slot was removed.
The sear is the last thing blocking the piston.
The pin that it pivots (and slides...) on was pushed out and it was removed.
The sear and pin.
The piston looked pretty good, if gunky.
I don't think I'll need to replace the piston seal.
I pried the rotary breech handle out.
And pushed the rotary breech out using a wood dowel through the barrel.
The rotary breech. I always assumed it was steel, but it's a plated alloy casting.
This might be the source of my power loss. Lots of gunk.
And the seal seems to be on its last legs. Both of the o-rings will be replaced.
Your images showing the layout of the trigger assembly saved my sanity.
ReplyDeleteEven so this trigger system is extraordinarily complicated and altogether the most awkward and fiddly thing to assemble. Fitting the sear was the worst part as it requires you to offer up the sear blindly into the mount against the pressure of the sear spring. A final note to say that one of the pivot pins is longer than the other 2 and must not be fitted as the trigger pivot because like me you will find that you can't refit the stock which of course means disassembling the trigger mechanism because sure as eggs when you try to swap pins over the others will fall out. I have never cursed so much before.
However, thanks for your blog it saved my marrage.
Best Regards
Glad I saved your marriage! It's definitely one of the oddest guns to work on.
ReplyDeleteHi Nick like the other chap this blog has been really helpful to me thank you. I have been rebuilding/restoring a super star I have nearly replaced all the internal parts except for the piston body and the rotary breach but I still have a intermittent power difference between 6ftlbs and 10.5 2 shots at 10.5 out of 10 the rest at 6ish. The only thing I think it might be is the rotary breach which looks fine except for the ball bearing it looks like it is pushed in and not protruding. Please could you tell me if yours was like this. By the way all seals are new.
ReplyDeleteThanks in advance Dave davekb123@gmail.com
Which ball bearing? I don't recall any being there and don't see mention in my posts?
ReplyDeleteNick
Hi thanks for replying
ReplyDeleteYou didn't mention a ball betting on your rotary breach and I can't see it on your photos of it but there is one on mine. It's reassessed on the underside of the rotary breach in a hole but it is not sprung which I thought it would be. I thought it might be out of sight on your photos as where it is on mine is not shown on your photos
Regards Dave
Just read your blog, so it will seem a little tardy. BSA piston seals are prone to burning at higher power levels, and generally power loss experienced is not due to spring or strut but the poor grade piston seals.[ may look good to the eye,don't be fooled] I have three superstars and three supersport/lightings [yes very greedy I know] In all three calibres. All have suffered with power loss in each gun and eventually replaced piston seals with Terry Robs excellent ptfe seals. Highly recommended have not found any better in forty years.
ReplyDeleteTerry Rob is based in Essex England a quick search will bring up his web site, if you are worried about postage from UK etc I would be happy to contact Terry on your behalf and post them to you myself, I can be contacted at manninmann001@yahoo.com
Kind Regards Dave.
Thanks, I bear that in mind if I need to open it up again!
ReplyDeleteNick