BSA Meteor mk 3 advice

[trajectory]

Had this mk 3 Meteor for a while & found it had 'seized' because of the buffer washer deteriorating so it needed that sorting at the very least. Getting the piston out was straightforward enough & it also gave me a chance to have a look at the rest of the internals. I've never had this appart before.

Generally everything looked ok, but in need of a clean & polish. I've made up a new buffer washer ready to go on when the times right, but....

Well, the spring was straight, 245mm long 34 coils 13mm internal diameter & 19.2mm od. But it was a little tight in the piston tights maybe not quite the right word but it was a sliding interference fit ( I assume the springs not 100% dead straight & that's maybe why it's not free running) so it didn't look like there was much room for spring expansion when it was compressed. The piston has a 20mm entry that is reduced to 19.3mm id after about 8mm. The piston is circular internally & isn't oval. It seems there is only about 0.1 mm difference between the od of the spring & the id of the piston once past the entry point with the 20mm opening. That dosent sound like much to me.

Does this sound typical of a mk3 or do you think the piston on this one is a bit tighter than some?

I have seen 19mm od springs for Meteors advertised with quite similar other dimensions. Would they be a good choice or would you suggest looking for a smaller od spring?

What would you suggest please?

[lightning22]

It does sound tight though I can’t say I’ve ever measured. A Meteor piston being round certainly doesn’t sound typical though, oval is far more normal..

[trajectory]

It does sound tight though I can’t say I’ve ever measured. A Meteor piston being round certainly doesn’t sound typical though, oval is far more normal..

Know what you mean about a Meteor piston being round as not being typical! Perhaps not the most robustly made things are they, but hey the kind of do the job ok I guess.