HW77 .177 transfer port size

[brucegill]

Trying to get another set to play with.

These grub screw.... Do you need to do anything else to the grub screw, other than drill them?

Cheers
B

[Snooper601]

Just make sure the gurb screw length is the same as the port length to save making any extra lost volume.

Cheers

John

[brucegill]

Just make sure the gurb screw length is the same as the port length to save making any extra lost volume.

Cheers

John

Thanks John

I was worried about the actual Allen key hole, would this not cause problems?

Cheers
B

[Snooper601]

As Tony says above, make them flush at both ends.
The slight lost volume due to the Allen recess is only slight and is like putting a pellet with a deeper skirt in the barrel, probably less than the 0.1mm size difference in the drilled holes, though it may be a bigger difference on a short transfer port.

Cheers

John

[greenwayjames]

There was a very early 20th century, pre first world war, trade magazine called Arms and Explosives? I read an article in an edition which detailed in several pages experiments carried out by BSA using the Lincoln Jeffries patent underlever rifles they were making at the time. They experimented with light and heavy pistons eventually settling on the heavy for best overall performance in their production air rifles.

"an early 1900s rifle (can't remember the make/model right now), where the maker fitted an aluminium piston in the target version to reduce recoil."

[bigtoe01]

the difference now is in an age of sharing, before 99% was all kept secret, so even though 99% has been done before it really is all new as before most was never released.

Ask Jb if he will share all his secrets....report back to us what he says

the gun trade is very secretive.....

[greenwayjames]

"the gun trade is very secretive...."

Read my previous post again.



There was a very early 20th century, pre first world war, trade magazine called Arms and Explosives? I read an article in an edition which detailed in several pages experiments carried out by BSA using the Lincoln Jeffries patent underlever rifles they were making at the time. They experimented with light and heavy pistons eventually settling on the heavy for best overall performance in their production air rifles

That doesn't sound very secretive to me
As well as I can remember JB gave details in Airgun World of what he did in his air rifle conversions including information about piston heads, weights transfer port sizes, barrel locks, adjustable hinge bolts etc. Is there anything specific you want me to ask him tomorrow? Why don't you ring him and seek his advice yourself? It would save me the cost of a phone call

[bigtoe01]

drill them from the back so the Allen key still works to get them in and out and make sure each one is sized to exact length to finish flush with each face both inner and outer.

[brucegill]

drill them from the back so the Allen key still works to get them in and out and make sure each one is sized to exact length to finish flush with each face both inner and outer.

Thanks Tony. I didn't see your post yesterday for some reason.

ATB
Bruce