MFR barrel and shroud schematics/photos

[Trooper]

You should end up with something similar to this, bush, muzzle support, end cap & tube which is threaded both ends.

Thanks Mate, greatly appreciated.  That does make it clearer as 'a picture says a thousand words'.

[Trooper]

Would any of you learned Gurus on here know what the male thread is that screws into the rifle, out of the the standard 280cc bottle on the MFR?  I don't seem to be able to include the photo. 

It measures up as 13.15mm O/D with verniers but seems to have a pitch of 19TPI. 

I'm thinking the 55 degree, 1/4" BSPF. 

The valve seems to be crooked in the bottle.  Because of that, when screwing the bottle in, the flat base (nearest the muzzle) wobbles all over the place like a drunken goat, and when it locks up, fully screwed in, the bottle presses against the barrel shroud. 

So one solution I'm thinking of, and I'm definitely not that keen on it, is to to turn up a female bush out of normal bright, then while still mounted in the chuck, screw the bottle valve into it.  Then with the lathe on 30-40 RPM it should confirm if it is in fact crooked.  I could then put paper masking tape around the flat base of the bottle, then using the tail stock, gently slide a lead pencil towards the bottle until a mark appears on the paper tape, which will the direction of error. 

Now here's the part where one would have to hold their breath and cross all fingers and toes.........when 'gently' nudging the bottle over with the hand until at least until it enough of the error has been removed that the bottle no longer touches the shroud when screwed fully in.  But of course I'd then be concerned about damage to the valve or bottle itself.  But on the reverse side of that coin, it can't be left to press against the shroud either.

[angrybear]

it's 1/4" BSP, in downloads is thread size list.
TBH I'd think it more likely the shroud is out of line, a straight edge along the top of the block should pick that up,
but if you just roll the bottle on a flat surface your eye will spot if the valve is out of true.

[Trooper]

it's 1/4" BSP, in downloads is thread size list.
TBH I'd think it more likely the shroud is out of line, a straight edge along the top of the block should pick that up,
but if you just roll the bottle on a flat surface your eye will spot if the valve is out of true.

Thanks Mate.  I actually did do both of those checks before posting and it is definitely the valve in the bottle.  The shroud alignment on the barrel is perfect, and so is the barrel.  I placed a 600mm Stabila level along the top of the block to confirm that with verniers. 

I have two bottles and the second one doesn't wobble around when screwing in, and when it is fully screwed in, it doesn't touch the shroud at all. 

[Trooper]

Being a newbie, I am still trying to find my way around this forum and haven't stumbled across the download section until now.  That's pure GOLD!  Sincerely, THANK-YOU to everyone who has contributed to that resource.