Things come to he who waits.

[look no hands]

Cheers, Pete. I didn't know the piston size for sure, I was just guessing, but it surprises me that he guns you mention all share the same diameter piston. Every day's a school day!

Stripping down won't be an issue, Pete. As mentioned earlier, I stripped that one of mine many years ago and remember that it was very easy. I even still have the tube with the cut-out to compress the spring to clear the retaining pin - it came with a spring compressor many moons ago.

I just couldn't remember if you could remove said piston without removing the sear / trigger.

I also did the Challenger. Not as bad as one would think, but really can't see why they went to the trouble of going down the Maxigrip rail route.

It was all the rage a little while ago to fit the Diana 28mm piston seal to Airsporters to replace the O ring heads, if BSA had used the same sort of rail that was fitted to the early HW85 which just slotted in and was held on with a screw and was also the standard 11mm size width, then I can see why, now as we all know the BSA rail width is stupid but on the Challenger a rail that butts up against the rear trigger block (or deeper well cut grooves in the cylinder) was good as it allowed the scope mounts to come back that little bit further to give better eye relief, I actually used a set of two piece reach forward mounts turned around and filled a few thou off the bottom of the reach forward section to be able to mount on the rail and overhang the trigger block and give you even more eye relief.

You've just reminded me to find out my spring removal tool that's been hidden away in my parts tin waiting for the day that another BSA turns up.

Pete

[johnbaz]

I bought a .177 Airsporter mk1 that had a scope rail made, The fella that did it was a retired engineer who's garage put out fitting shop at work to shame!!

He drilled the cylinder (5 holes) and threaded them to a 4BA thread but had mislaid the screws as he'd removed the rail, I keep meaning to get some off fleabay but keep forgetting!

Here's another mk1 that a blacksmith must have scoped up!!

Sellers pics..






EDIT-It was only £65 posted so I can't complain!!



John