Springer anti bounce experiment

[BTDT]

Jim, did I conclude correctly that using a lighter lathe will reduce piston bounce ?

You had me scratching my head for a minute then, Jon. Did a word search on the text, and all became clear.

The caption said "To stop my HW95’s piston from bouncing would take a force equivalent to 1.6 times the weight of the lathe seen in the background". If the lathe weighted half as much, it would take 3.2 of them to resist piston bounce.

[Born Again]

If the lathe weighted half as much, it would take 3.2 of them to resist piston bounce.

I prefer to take an anvil on hunting trips, it doubles up as a chair.

[Shed tuner]

You had me scratching my head for a minute then, Jon. Did a word search on the text, and all became clear.

The caption said "To stop my HW95’s piston from bouncing would take a force equivalent to 1.6 times the weight of the lathe seen in the background". If the lathe weighted half as much, it would take 3.2 of them to resist piston bounce.

Damn, there goes that theory...

[TonyL]

Jim, did I conclude correctly that using a lighter lathe will reduce piston bounce ?

Damn, there goes that theory...

That may work if you used said lathe to open that TP out, Jon.

[TopDog]

A chartered engineer I work with says "If you can't put numbers on it you don't understand it". So well done, I wish I could.

Sounds like a paraphrased version of one of Lord Kelvins lectures which is one of my favourites too! It was a watchword for myself and my group of associates for many years - and remains so still! See:-

http://freepdfhosting.com/575f5449f7.pdf

Finding the things worthy of the detailed attention is where it's at!! That's where many of the observations, thoughts and ideas of AG enthusiasts come in!

Merry Xmas all and stay safe and well.

atvb
David

[Born Again]

Sounds like a paraphrased version of one of Lord Kelvins lectures which is one of my favourites too! It was a watchword for myself and my group of associates for many years - and remains so still!

I think my friend simplified it for me

I'm not an engineer, I'm a machinist / dabbler / enthusiast of mechanical mechanisms / Jack of all trades. Working with a genuinely excellent engineer is a pleasure, I learn so much every time.

[DJS]

How about adding a second smaller piston, in a cylinder underneath the barrel, with a spring holding the piston head flush with the front face of the main cylinder.
It may be possible to set this up so that at the point when the main piston would normally start its bounce backwards, the smaller piston would have moved down its cylinder. Both pistons then moving toward each until they meet.
If it could be made to work the small light piston would be the one bouncing rather than the main piston.
This would be very difficult to fit to an existing design but if making a rifle from scratch it would be fairly simple!
Daz

[TonyL]

Sounds like a paraphrased version of one of Lord Kelvins lectures which is one of my favourites too! It was a watchword for myself and my group of associates for many years - and remains so still! See:-

http://freepdfhosting.com/575f5449f7.pdf

Finding the things worthy of the detailed attention is where it's at!! That's where many of the observations, thoughts and ideas of AG enthusiasts come in!

Merry Xmas all and stay safe and well.

atvb
David

I think my friend simplified it for me

I'm not an engineer, I'm a machinist / dabbler / enthusiast of mechanical mechanisms / Jack of all trades. Working with a genuinely excellent engineer is a pleasure, I learn so much every time.

Excellent; nicely done, gentlemen.

[TopDog]

Excellent; nicely done, gentlemen.

Hi Tony

Yep; we used to simplify the Kelvin version a lot for the benefit of the suits and bean-counters!

"If you can measure something and express it in numbers, you know something about it; if you can't, you don't!"

My initial theoretical interest started trying to quantify the "gentle nudge in the shoulder" description of recoil since one man's "gentle nudge" is another's "kick like a mule"! Rather got out of hand ever since! Heck it keeps me off the streets when not out shooting!

Keep safe and well ALL and have a great happy shooting Christmas and an even better New Year!

atvb
David

[Hsing-ee]

Hi Tony

My initial theoretical interest started trying to quantify the "gentle nudge in the shoulder" description of recoil since one man's "gentle nudge" is another's "kick like a mule"! Rather got out of hand ever since! Heck it keeps me off the streets when not out shooting!

atvb
David

PCPs will nudge if you use an 'artillery hold' and are sensitive enough. So even a non-springer has an issue. Does madness lie in the direction of eliminating recoil? Lets find out. Once that is done, get rid of the rearward motion of the trigger by using a mouth operated cable-release.

The Park RH91/93 opposing piston rifles were supposed to have the pellet weight accounted for when their recoilless-ness was designed or 'tuned in'. I cannot see how, but they are extremely dead when fired. I mean dead. They just don't do anything in terms of recoil. Maybe because of the simple but ingenious design but also because they weigh a ton.

[TopDog]

PCPs will nudge if you use an 'artillery hold' and are sensitive enough. So even a non-springer has an issue. Does madness lie in the direction of eliminating recoil? Lets find out. Once that is done, get rid of the rearward motion of the trigger by using a mouth operated cable-release.

The Park RH91/93 opposing piston rifles were supposed to have the pellet weight accounted for when their recoilless-ness was designed or 'tuned in'. I cannot see how, but they are extremely dead when fired. I mean dead. They just don't do anything in terms of recoil. Maybe because of the simple but ingenious design but also because they weigh a ton.

PCPs definitely exhibit recoil characteristics and in fact, my Daystate Huntsman has just the same shape acceleration profile as a springer, just scaled down in amplitude and timescale (hammers are lighter than pistons!). Others show different characteristics, such as my Logun Solo but is still dynamic. All my exacting tests were done using my "frictionless" sledge and remote trigger release (either pneumatic shutter release derivative or a model servo) to eliminate any external influences.

As a parting shot; I do not find recoil per se as a problem and rather like some in fact, it's just a matter of being consistent in hold and trig release! Large field or naval guns recoil like crazy but are still capable of staggering accuracy (of course they are not hand-held!). I tend to use PCPs as clinical devices for hunting (they are lighter to carry and do not involve huge movements on the part of the shooter to fire the next shot if magazine fed, but they do not provide the pleasure gained by shooting a springer well!

Variety is the spice of life!!!

Stay safe and well and have great festive season, even if a bit more curtailed than usual!

atvb
David

[TonyL]

Absolutely 100%, David.

Even going back many years upon first firing multi-pumps like the Innova, I found them "dead and soulless". I love a little movement. Makes it feel like a living, breathing entity, at one with its keeper. As you say, no less accurate. And I've often said that, once a shooter has become seasoned to springer characteristics, many hold sensitivity issues indeed become non- issues or, at least, much reduced issues.

Have a most splendid festive period yourselves and it will be lovely to be able to see you once again at a Bash one day.

[Hsing-ee]

All my exacting tests were done using my "frictionless" sledge and remote trigger release (either pneumatic shutter release derivative or a model servo) to eliminate any external influences.

As a parting shot; I do not find recoil per se as a problem and rather like some in fact, it's just a matter of being consistent in hold and trig release! Large field or naval guns recoil like crazy but are still capable of staggering accuracy (of course they are not hand-held!). I tend to use PCPs as clinical devices for hunting!

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?

[TonyL]

The B2 might provide the ideal, modern test bed, Alistair?

Cheap, plentiful, disposable and, from reports on the forum, with a TP that's far too big.. Easy to weight that piston and re-spring and the indifferent trigger will also add a further challenge.

[Hsing-ee]

The B2 might provide the ideal, modern test bed, Alistair?

Cheap, plentiful, disposable and, from reports on the forum, with a TP that's far too big.. Easy to weight that piston and re-spring and the indifferent trigger will also add a further challenge.

I know the B2 was built to be sacrificed, but it has a shocking trigger so is exempt from this particular 'evil scheme'. Maybe one of the other PRC offerings?