BSA Scorpion Piston Head - Help & Advice

[wildy]

Hi All,

Fantastic pistol once mastered but after many years mine has suffered the common deterioration of the buffer washer and was getting harder to cock so I stripped it today.

I was surprised to find a brass "nut" inside the piston where usually its just a washer and cir-clip retaining the piston head.

The cir-clip is still there.

There is no visible way I can see to remove the brass top hat shaped nut!

I can't quite get my head round what it is as at first I thought it was a stroke adjustment, but with the cir-clip in situ it seems tight up to it so wont make any difference to the stroke, any undoing of the threads would be stopped by the cir-clip! just adding spring tension.

The outer part of the brass "top hat" nut has a thread on it but no visible locking screw or way of preventing it spinning to unscrew it. AHH!

Anyone know what it is or how to get the darn thing off!

I'm getting the hacksaw out at this rate!

Any help appreciated.

Also any help on how you attach pics to posts!...just not my day

[oneseven]

My scorpion has sat in bits for a while after the seal finally crumbled. Can anyone tell me how to remove the circlip? Is there a special tool?

[leroy02]

My scorpion has sat in bits for a while after the seal finally crumbled. Can anyone tell me how to remove the circlip? Is there a special tool?

yes found mine at car boot they are circlip piers bent over 45% at the end with small pins on that fit
in the circlip holes and open up when used.

[oliver13]

yes found mine at car boot they are circlip piers bent over 45% at the end with small pins on that fit
in the circlip holes and open up when used.

Mine have all had a type of split ring, its made of square section spring steel wire with a butt joint at the split.

I use an old electrical screwdriver ground down to give a thicker blade, & insert it through the cocking slot, work it into the split which spreads it & expands the ring - which I can then lift carefully off the spigot. No prizes for guessing it takes a certain knack.
To get it back on I just persuade it back over the spigot taper by pushing it down in stages.

If there is a special tool for this type of fastening - that would work in this rather constricted loctation, I would like to know what it is.

[oneseven]

Mine have all had a type of split ring, its made of square section spring steel wire with a butt joint at the split.

I use an old electrical screwdriver ground down to give a thicker blade, & insert it through the cocking slot, work it into the split which spreads it & expands the ring - which I can then lift carefully off the spigot. No prizes for guessing it takes a certain knack.
To get it back on I just persuade it back over the spigot taper by pushing it down in stages.

If there is a special tool for this type of fastening - that would work in this rather constricted loctation, I would like to know what it is.

That's the same as mine. Sorry, its not actually a proper circlip with little rings at the join, just a split ring. I will wedge a screwdriver bit in and see how i get on.

[oliver13]

That's the same as mine. Sorry, its not actually a proper circlip with little rings at the join, just a split ring. I will wedge a screwdriver bit in and see how i get on.

You'll probably have to take off about 3mm of the blade then regrind, it's a finely judged thing but persevere & you'll get it.
In the meantime a proper tool to do it would be nice - what would BSA do about it? A whole new piston probably...