Which Chrono for a HW45

[tinbum]

I have been holding mind with my hand round the muzzle. Seems to work fine now

That should be ok, it was when I was testing power at 10m that I tended to clip the edge occasionally.

[Airways]

That should be ok, it was when I was testing power at 10m that I tended to clip the edge occasionally.

I tried that and never clipped it once. Then again never got a reading

[Airways]

I tried that and never clipped it once. Then again never got a reading

Well I’ve stripped and polished the internals. Got some Delrin coming as want to play around with guides and top hats.
Question for the experts out there the piston seal was a very tight fit and took a lot of effort to move the piston in the compression chamber. How much restistance should I be looking to move the piston in the working area?

[clarky]

Back it off....machine a 7 degree angle on the compound slide from the front face to the piston interface.
leaving a fine edge which seals...go sliding fit....it will soon seal up as the angle will bed in and self adjust for wear ...upto a point.
Just dont expect too much from the top heavy bugger....it is what it is...
5 ftlbs fairly accurate with no piston weight....
Any top hat weighting will add power ...gram per gram....but jump will be added gram by gram too.
Dont introduce lube ....run it dry until it wears out....it diesels on anything more than pure air....and im talking not the air in London....

[Airways]

Back it off....machine a 7 degree angle on the compound slide from the front face to the piston interface.
leaving a fine edge which seals...go sliding fit....it will soon seal up as the angle will bed in and self adjust for wear ...upto a point.
Just dont expect too much from the top heavy bugger....it is what it is...
5 ftlbs fairly accurate with no piston weight....
Any top hat weighting will add power ...gram per gram....but jump will be added gram by gram too.
Dont introduce lube ....run it dry until it wears out....it diesels on anything more than pure air....and im talking not the air in London....

Thanks Clarky. Not sure who has been inside before but the piston has 6 holes machined in it so significantly lightened. Will be lining the piston with PTFE so probably won’t need a to put anything in the piston other than a PTFE washer
Thanks for the info on the seal