Airsporter S barrel question?

[DEAN C.]

You are very welcome mate!
It was a nice excuse to drag them out and measure them!
Did you see the dims for the BSA Mercury .25 barrel? - when you deduct the unusually long counter bore - that's a very short effective bore length and that (I believe) was a production BSA barrel!

I too have a rounded forend stock - do you know if the push button concealed type underlever will fit other Mks?

ASM

Hi, Yes I saw the dimensions and never thought to check my Mercury S either, good point.

I dont see why the later concealed button underlever shouldnt fit most other later marks. The genuine pin for the catch is again available at the moment from Knibbs.Thats the bit I was stuck for and was about to make one. I have a spare push button new old stock underlever if you need one as well. I think the only limiting factor is where the catch pin fits, so maybe Mk5 onwards should fit without mods........ I hope! I'll let you know how I get on.

[duomatic410]

Dean.
On another note, have just acquired a mk2, but the scope clamps are different to any I have seen in the past.

The usual short one at the back, then a gap then one about 3 inches long?.
Stripped it down and would say it's all original inside, spring still quite good, piston head like new.
Reg. John

[DEAN C.]

Dean.
On another note, have just acquired a mk2, but the scope clamps are different to any I have seen in the past.

The usual short one at the back, then a gap then one about 3 inches long?.
Stripped it down and would say it's all original inside, spring still quite good, piston head like new.
Reg. John

I've not seen one of those John. I have a couple of late Mk2's with full length scope rails, seen a few modified ones as well.
Wonder if it is a late crossover model, unless someone at BSA fell asleep when machining the cylinder!!
Keep well John,
Dean.

[duomatic410]

Just checked it again Dean.
They are machined into the metal at 15mm, not the clamp style and very deep at that, much more so than the later scope rails.
The scope mounts would certainly benefit from profiling to cylinder shape to make most of ithem.John

[greenwayjames]

That's very interesting James,
Do you know what John used to do to the piston by way of a seal & piston head?
Are the modern Titan springs the same as those that John used?

Regards,

Pete.

He used a polyurathane? head combined with an 0 ring in the Airsporter/Mercury but there was a lot more to the conversion than just fitting another head. He said the piston weight was not reduced.
No. John used to get the springs coated for Knibbs who bought them from a company in Redditch. The springs JB used were specially made for him by Mike Wade who "hired" machinery on a weekend to make batches for himself as well. They were not the same as Titan springs he said.