Springer anti bounce experiment

[Adam77K]

ah yes that is the thing, a penumatic shutter release. A worthy adaptation for those who have lost fingers to the frostbit or chainsawbit. Excellent! Is 'clinical' hunting done in abandoned hospitals? Big Sue the raggedy man from the drain end of the estate used to do that in the 70s with a Meteor and open sights, but no-one would risk eating one of those pidgins for their dinner.

It might be worth an experiment trying to make a springer with the MOST recoil and see if it is possible to tame it with technique. There are some natural contenders like the BSF B55 in a standard stock, but something with a super stiff spring, heavy, weighted piston and an oversize transfer port would be interesting. It would be naturally inefficient, so why not add a small nick in the piston seal - or an undersize seal could be used - to accentuate slam. I think using volatile lubricants might end one in trouble with the law, and combustion recoil is cheating really as it is drifting the airgun into the realm of the firegun.

Scrapyard challenge anyone?

That would be super harsh but not necessarily the most "recoil" movement. In fact I don't need that experiment, I've owned a Theoben Sirocco in .177! Best hung on the wall really; beautifully made but 'orrible thing to shoot.

To maximise surge, which is the movement which is most offputting and conducive to hold sensitivity, surely you'd want a really wide cylinder, heavy piston but undersize transfer port, and a soft spring with little preload.

[Hsing-ee]

That would be super harsh but not necessarily the most "recoil" movement. In fact I don't need that experiment, I've owned a Theoben Sirocco in .177! Best hung on the wall really; beautifully made but 'orrible thing to shoot.

To maximise surge, which is the movement which is most offputting and conducive to hold sensitivity, surely you'd want a really wide cylinder, heavy piston but undersize transfer port, and a soft spring with little preload.

Secret sauce! Sounds like a short stroked Mercury with a choked off TP.

[BTDT]

To maximise surge, which is the movement which is most offputting and conducive to hold sensitivity...

Let's just remind ourselves of some wise words I read somewhere or other, Adam.

“We are too much accustomed to attribute to a single cause that which is the product of several, and the majority of our controversies come from that.” - Marcus Aurelius

I would have agreed with your suggestion that surge contributed the most to hold sensitivity, but am now growingly convinced that the initial acceleration into recoil could be worse. Your Sirocco had a short stroke and, to compensate for the resultant short cylinder pulse (pellet and piston traveling in the same direction) necessitated higher peak cylinder pressure which, in turn, necessitated higher force acting on the piston, causing fierce initial recoil acceleration, giving the rifle a reputation of being 'snappy'. The snappy shot cycle has long been thought a consequence of the gas ram, when in fact it was a consequence of the short stroke, and gas ram rifles with longer strokes can function satisfactorily with lesser recoil acceleration.

Recoil acceleration is, of course, only one of several contributing factors to hold sensitivity; displacement plays a part, along with surge acceleration and displacement. To maximise hold sensitivity would entail increasing all of the factors, easily achieved by fitting a very stiff mainspring with little preload, lightening the piston, over-shortening the stroke, or all at once.

[Hsing-ee]

Recoil acceleration is, of course, only one of several contributing factors to hold sensitivity; displacement plays a part, along with surge acceleration and displacement. To maximise hold sensitivity would entail increasing all of the factors, easily achieved by fitting a very stiff mainspring with little preload, lightening the piston, over-shortening the stroke, or all at once. [/COLOR]

OK so a Haenal 303 with a stiff spring and a lightened piston.

[TonyL]

Let's just remind ourselves of some wise words I read somewhere or other, Adam.

“We are too much accustomed to attribute to a single cause that which is the product of several, and the majority of our controversies come from that.” - Marcus Aurelius

I would have agreed with your suggestion that surge contributed the most to hold sensitivity, but am now growingly convinced that the initial acceleration into recoil could be worse. Your Sirocco had a short stroke and, to compensate for the resultant short cylinder pulse (pellet and piston traveling in the same direction) necessitated higher peak cylinder pressure which, in turn, necessitated higher force acting on the piston, causing fierce initial recoil acceleration, giving the rifle a reputation of being 'snappy'. The snappy shot cycle has long been thought a consequence of the gas ram, when in fact it was a consequence of the short stroke, and gas ram rifles with longer strokes can function satisfactorily with lesser recoil acceleration.

Recoil acceleration is, of course, only one of several contributing factors to hold sensitivity; displacement plays a part, along with surge acceleration and displacement. To maximise hold sensitivity would entail increasing all of the factors, easily achieved by fitting a very stiff mainspring with little preload, lightening the piston, over-shortening the stroke, or all at once.

What a wonderful, concise and enlightening mini springer tutorial neatly packaged into a single, easily digested post.

Hit the like button.

[Scott.]

Let's just remind ourselves of some wise words I read somewhere or other, Adam.

“We are too much accustomed to attribute to a single cause that which is the product of several, and the majority of our controversies come from that.” - Marcus Aurelius

I would have agreed with your suggestion that surge contributed the most to hold sensitivity, but am now growingly convinced that the initial acceleration into recoil could be worse. Your Sirocco had a short stroke and, to compensate for the resultant short cylinder pulse (pellet and piston traveling in the same direction) necessitated higher peak cylinder pressure which, in turn, necessitated higher force acting on the piston, causing fierce initial recoil acceleration, giving the rifle a reputation of being 'snappy'. The snappy shot cycle has long been thought a consequence of the gas ram, when in fact it was a consequence of the short stroke, and gas ram rifles with longer strokes can function satisfactorily with lesser recoil acceleration.

Recoil acceleration is, of course, only one of several contributing factors to hold sensitivity; displacement plays a part, along with surge acceleration and displacement. To maximise hold sensitivity would entail increasing all of the factors, easily achieved by fitting a very stiff mainspring with little preload, lightening the piston, over-shortening the stroke, or all at once.

What a wonderful, concise and enlightening mini springer tutorial neatly packaged into a single, easily digested post.

Hit the like button.

Absolutely agree with Tony, thanks Jim that was a brilliant post and you broke it down in such a way that even I understood the whole principle and problem easily

[cooper_dan]

OK so a Haenal 303 with a stiff spring and a lightened piston.

Years ago I had a haenal 303s for shooting bell target. That's one of those 'never should have sold it' guns. Especially as I sold it to an idiot who abused it

[Adam77K]

I would have agreed with your suggestion that surge contributed the most to hold sensitivity, but am now growingly convinced that the initial acceleration into recoil could be worse. Your Sirocco had a short stroke and, to compensate for the resultant short cylinder pulse (pellet and piston traveling in the same direction) necessitated higher peak cylinder pressure which, in turn, necessitated higher force acting on the piston, causing fierce initial recoil acceleration, giving the rifle a reputation of being 'snappy'. The snappy shot cycle has long been thought a consequence of the gas ram, when in fact it was a consequence of the short stroke, and gas ram rifles with longer strokes can function satisfactorily with lesser recoil acceleration.

Recoil acceleration is, of course, only one of several contributing factors to hold sensitivity; displacement plays a part, along with surge acceleration and displacement. To maximise hold sensitivity would entail increasing all of the factors, easily achieved by fitting a very stiff mainspring with little preload, lightening the piston, over-shortening the stroke, or all at once. [/COLOR]

Very interesting Jim. I had your earlier writings in mind, but I haven't bought a mag for several years now.

My thinking is that the surge is harder to consistently manage in your hold. The classic "artillery hold" is the most easily repeatable hold, but even if the butt pad instead has quite a firm contact with your shoulder there's still a good chance the recoil movement won't vary too much. The cushioning of clothing and flesh still allowing the rifle to move back the same amount. On the other hand a firm pull into your shoulder depends on muscle tension in your hands and arms. That can be more variable and, I would say, is more prone to a large surge movement amplifying those variations.

[BTDT]

What a wonderful, concise and enlightening mini springer tutorial neatly packaged into a single, easily digested post.

Hit the like button.

Absolutely agree with Tony, thanks Jim that was a brilliant post and you broke it down in such a way that even I understood the whole principle and problem easily

Thank you for the kind words, Tony and Scott.

Very interesting Jim. I had your earlier writings in mind, but I haven't bought a mag for several years now.

My thinking is that the surge is harder to consistently manage in your hold. The classic "artillery hold" is the most easily repeatable hold, but even if the butt pad instead has quite a firm contact with your shoulder there's still a good chance the recoil movement won't vary too much. The cushioning of clothing and flesh still allowing the rifle to move back the same amount. On the other hand a firm pull into your shoulder depends on muscle tension in your hands and arms. That can be more variable and, I would say, is more prone to a large surge movement amplifying those variations.

The first point perhaps should be that the pellet emerges from the muzzle very early in the surge, Adam, so that limits its effect on hold sensitivity to some degree, whereas the pellet is in the barrel for the entirety of the compression stroke.

I base my thoughts on hold sensitivity on HFT, specifically, HFT at Nomads ground, of which very little is level, and 80% of shots are taken prone, so the shooter's elbows are rarely level, which complicates trying to maintain a consistent hold, in addition to which, many shots are angled up or down. Springers that consistently do well at Nomads tend to be those with gentle recoil acceleration courtesy of soft mainsprings, the preload of which also helps soften piston bounce and hence surge.