Don't shoot me down is a 50/50 Spring and Gas Ram Possible?

[oldskoolzzz]

I've had a strange idea

Don't shoot me down in flames on this one

Do you think it's possible to modify a break barrel rifle and fit a very short spring and a cutdown or smaller length gas ram?

E.g. 50/50 split the small spring and guides top hat etc at the front and a gas ram at the rear.

Do you think this is possible or if it would even work?

I'm thinking in theory that if it would work that maybe it would be very nice to shoot and perhaps super smooth to cock.

Ok this idea is probably floored on every level and against physics but do you think that it would work?

Or has it been done or attempted before?

[TonyL]

It could potentially work, Nick.

And there are quite a few rifles in the past that used vaguely similar thinking by employing two springs.

But, with the accumulated springer knowledge that's now out there, and witnessing how lovely properly tuned apringers can be, you'd have to ask, "Why bother?".

[bighit]

there is a nitro piston air pistol. could use the ran from it and a cut down spring. the ram would I guess be fully extended by the time the spring started to move.

I'm led to believe gas rams have a quicker lock time than a spring.

[oldskoolzzz]

....you'd have to ask, "Why bother?".

Well...I guess to be different Tone

But I do understand where your coming from.

there is a nitro piston air pistol. could use the ran from it and a cut down spring. the ram would I guess be fully extended by the time the spring started to move.

I'm led to believe gas rams have a quicker lock time than a spring.

That's excellent food for thought thanks for the input

[tinbum]

Its easy enough to do. You could end up with a super gun having the advantages of both........

or not!

[Artfull-Bodger]

It's not really practical , springs and rams work in different ways.

If you have a 50lb per inch spring it requires 50lb to compress the first inch, then another 50lb to compress the second inch and so on as it's a linear rate, unless of course you have a variable wind, but lets not get overcomplicated.

A gas ram increases its pressure as the volume inside is reduced, so say you have a 50lb per inch ram it would take 50lbs for the first inch (huge ram I know ) the second inch would take 100lb and so on, so you would end up coil binding the spring trying to compress the ram.

not to mention the complication of trying to link both rigidly and then cram it all in the cylinder!

[TonyL]

Well...I guess to be different Tone

But I do understand where your coming from.


That's excellent food for thought thanks for the input

Can't fault you, Nick, and I'd hate to be the one to curtail any forward thinking.

Maybe one advantage of such a system might be that the equivalent of pre-load / spring rate might be easy to tweak with a separate little ram in there. Of course, not a sealed unit, but one with a valve so that the ram pressure could be adjusted accordingly to adjust the power and to set the shot cycle feel to the user's taste.

[TonyL]

It's not really practical , springs and rams work in different ways.

If you have a 50lb per inch spring it requires 50lb to compress the first inch, then another 50lb to compress the second inch and so on as it's a linear rate, unless of course you have a variable wind, but lets not get overcomplicated.

A gas ram increases its pressure as the volume inside is reduced, so say you have a 50lb per inch ram it would take 50lbs for the first inch (huge ram I know ) the second inch would take 100lb and so on, so you would end up coil binding the spring trying to compress the ram.

not to mention the complication of trying to link both rigidly and then cram it all in the cylinder!

Mmmm....makes me want to bin my previous post!

[tinbum]

Can't fault you, Nick, and I'd hate to be the one to curtail any forward thinking.

Maybe one advantage of such a system might be that the equivalent of pre-load / spring rate might be easy to tweak with a separate little ram in there. Of course, not a sealed unit, but one with a valve so that the ram pressure could be adjusted accordingly to adjust the power and to set the shot cycle feel to the user's taste.

No, a slim sealed unit with a wrap-around spring would be interesting to try. With the rams steady pressure at all times it could have a big effect on piston bounce

probably not, but I say go for it!

[Muskett]

The spring brings so many problems that why have one? The twist the biggest issue.
Gasram at least has no twist, why not a Park gasram system?

One spring thing never tried to my knowledge is to have the piston head on bearings so that the spring has nothing to twist on. I know the spring doesn't actually twist but it wants to. Someone who knows springs better than I might correct me, or add something here.

[oldskoolzzz]

No, a slim sealed unit with a wrap-around spring would be interesting to try. With the rams steady pressure at all times it could have a big effect on piston bounce

probably not, but I say go for it!

I like the sound of that idea hmmm me feels a bit of tinkering coming on

[tinbum]

The spring brings so many problems that why have one? The twist the biggest issue.
Gasram at least has no twist, why not a Park gasram system?

One spring thing never tried to my knowledge is to have the piston head on bearings so that the spring has nothing to twist on. I know the spring doesn't actually twist but it wants to. Someone who knows springs better than I might correct me, or add something here.

The spring does twist and a simple slip bearing is the best cure. Rotating pistons just mean you have more twisting mass and needle bearings don't work so well under extreme sudden pressure.
Opposing, counterwound springs are ok, but I'm interested to see Nicks finding on this idea.

[Rickenbacker]

If it goes badly wrong, it'll make you miss via hold sensitivity, then break your scope.

[Geezer]

If it goes badly wrong, it'll make you miss via hold sensitivity, then break your scope.

That genuinely made me laugh out loud.

And I fear it may be true. Tough cocking, snappy firing cycle, and some added twangy vibraty spring stuff. Not to mentionas a production item, complexity equaling cost.

[Artfull-Bodger]

The spring does twist and a simple slip bearing is the best cure. Rotating pistons just mean you have more twisting mass and needle bearings don't work so well under extreme sudden pressure.
Opposing, counterwound springs are ok, but I'm interested to see Nicks finding on this idea.

Don't wish to contradict Tin but I have been fitting needle roller thrust bearings for a while to counteract spring torque, if you have a rotating piston it makes little difference although it does help, I have tested this back to back, but on a non rotating piston like a HW77 it makes a big difference to the lateral movement of the rifle.

I test the bearings by firing the rifle at a 1cm square grid at 10yds, I aim at a highlighted point and freeze in place after the shot , then measure the distance the crosshair has come of target, do this ten times to get an average reading, fit the bearings and run the test again, in every case the bearings reduced lateral movement to practically nil, you can actually feel the difference.