Jim Tyler Thumbs Down August AGW

[TonyL]

Have many of you seen the August AGW yet?

The usual excellent Technical Airgun ones from Jim; this time three articles - one on crossover and a very, very interesting one on pellet release pressures, where Jim's going to be looking at different efficiency levels for the different calibres next.

Can't wait!



BUT......The article on the "thumb up" style of hold / trigger control. How many of us shoot a springer thumb up? I suspect many as, as Jim says, it's an excellent idea for less strain and more precise trigger control. But, this month Jim looks at how having the thumb in this position affects recoil / surge. The findings then showing that surge is actually increased, through the thumb being springy, absorbing recoil from the first cycle, but helping to fling the action forward on the surge. The difference is not as marked as, say, comparing recoil and surge with a tight and soft hold, but definitely there.

It's quite spooky how Jim sometimes seems to read our minds. I'm sure that a few springer peeps may have wondered about the effects of thumb up themselves. I know I have, but then do nothing with this germ of an idea. Whereas Jim fully embraces the thinking and does an in-depth study, backed up with scientific measurements and facts.

Probably why I LOVE that synthetic thumbhole stock on my 77 so much!

Nice one Jim!

And highly recommended reading for any springer enthusiast.

[Two200's]

I tested the grip vs velocity on a springer - quite crudely - about 5 years ago.

I held a hw97 in a number of different ways - while shooting through a chrono.

The tight holds had the velocity bouncing up and down like a brides nightdress.

The more passive holds had a much better result.

I know all thats not news, but it was clearly visible and proved that most springers - even the least hold sensitive - need a consistent shooting style.

PS - my 97 had a macarri (CS) stock on it - loaded with lead and in the butt had lead shot held loose, so as to kill recoil dead blow hammer style.

Also - I found an AWESOME way to bed a springer into a stock once.
Sheet lead cut into a semicircle and pressed home behind the trigger block and the stock.
This planished itself into an amazing bed for the back of the rifle.

We are not talking thick sheet, just 1.5mm thick.

Most model shops round here sell different small packs of sheet metals for the craftists, with a selection of guauges.

I bought some brass too, to shim a scope mount - as i am led to believe - brass has a low shift in temperatures.

[oldgeezer]

A word of warning.
If you are one of those shooters who shoots a shot gun and an air rifle then "thumbs up" is not a habit to get into.I got into the habit many years ago and on one occasion did a "thumbs up" with the 12 bore.
It took some time for the split thumb to heal. The top opening lever on a recoiling 12 bore can be very painful.

Pete.

[RobF]

Neither thumb up or down is ideal for the body. The thumbs natural position where it's not using muscle is in between. The only reason we don't have that it the majority is because rifles aren't designed 100% to fit people, they're designed to be made easily. In this day and age of rapid prototyping and advanced materials rifles should have better ergonomics. Rifle for is important, more so in a recoiling rifle. All the tuning in the world won't help you if you have a bad position trying to adapt to a stock design that hasn't moved on since the boar war.

[Josie & John]

That was a thought provoking article from Jim. I tend to prefer the thumb up hold and have found it works for me. One of my vintage rifles has an aperture sight where my thumb would usually go and it forces me to change my hold. After a little practice, I found that works too, so it just goes to prove we can usually adapt. I recently read an interesting article by a doctor, who was also a target shooter and he advocated using the middle finger to press the trigger rather than squeezing between thumb and forefinger. His view was muscles are not as bent when the middle finger is used and it was a more natural position.

John

[TonyL]

I recently read an interesting article by a doctor, who was also a target shooter and he advocated using the middle finger to press the trigger rather than squeezing between thumb and forefinger. His view was muscles are not as bent when the middle finger is used and it was a more natural position.

John

I have often thought of the very same thing but not, as yet, tried.

Will give it a go sometime and see how it feels.

[TonyL]

I tested the grip vs velocity on a springer - quite crudely - about 5 years ago.

I held a hw97 in a number of different ways - while shooting through a chrono.

The tight holds had the velocity bouncing up and down like a brides nightdress.

The more passive holds had a much better result.

I know all thats not news, but it was clearly visible and proved that most springers - even the least hold sensitive - need a consistent shooting style.


Also - I found an AWESOME way to bed a springer into a stock once.
Sheet lead cut into a semicircle and pressed home behind the trigger block and the stock.
This planished itself into an amazing bed for the back of the rifle.

We are not talking thick sheet, just 1.5mm thick.
.

Jim's article was studying the effects on recoil and surge of the thumb up position, and found that, with the thumb being muscly and quite "springy" it reduced the first recoil stage slightly, but increased the surge. And, where the pellet exits, the graph showing surge acceleration was much steeper with the thumb up, meaning that the pellet could exit at different angles of inclination of the muzzle, leading to inconsistency.

I've never tested for muzzle velocity variation whilst employing different holds, but have seen it quoted sometimes....another minefield!

Myself, and many others, have often extolled the virtues of a stock design which encourages more straight line recoil in a springer. Obviously other factors are also important, like weight and its distribution. And this latest experiment makes me apprecaite why I really like my two Thumbhole stocks. But then, I suppose, we'd also have to study the design there as, if the fit to the "web" of the hand twixt thumb and index finger wasn't correct, this could also create an area of resistance to rearwards travel.

As we all know, correct springer technique is all about relaxed hold and letting the rifle do its thang!


For the bedding disc at the rear of the action, I wonder if leather would also be quite useful?


He's good is that Jim! Really gets your mind mulling over different ideas!

[Two200's]

Jim's article was studying the effects on recoil and surge of the thumb up position, and found that, with the thumb being muscly and quite "springy" it reduced the first recoil stage slightly, but increased the surge. And, where the pellet exits, the graph showing surge acceleration was much steeper with the thumb up, meaning that the pellet could exit at different angles of inclination of the muzzle, leading to inconsistency.

I've never tested for muzzle velocity variation whilst employing different holds, but have seen it quoted sometimes....another minefield!

Myself, and many others, have often extolled the virtues of a stock design which encourages more straight line recoil in a springer. Obviously other factors are also important, like weight and its distribution. And this latest experiment makes me apprecaite why I really like my two Thumbhole stocks. But then, I suppose, we'd also have to study the design there as, if the fit to the "web" of the hand twixt thumb and index finger wasn't correct, this could also create an area of resistance to rearwards travel.

As we all know, correct springer technique is all about relaxed hold and letting the rifle do its thang!


For the bedding disc at the rear of the action, I wonder if leather would also be quite useful?


He's good is that Jim! Really gets your mind mulling over different ideas!

I bet Leather would work, I didn't think of it as a material if I am honest.

But thinking about it now, i would be concerned at it's ability to absorb some degree of moisture and so cause rust.
I don't do rust.

Has anyone got a Beeman C1?

Webley rifle, but a straight sporting grip.

[TonyL]

Yep, agreed on leather's ability to absorb and pass on moisture.

Maybe what we need are more pistol grips where the hand is in a much more relaxed state, with a palm shelf taking the weight of the hand and a grip arrangement (thumbhole or otherwise) that, through design, places no pressure on the web between thumb and index finger.

Some of the PCP FT rifles spring to mind, design wise, and rifles like the Pulsar and some of the "tactical" stocked Airguns with their pistol grip arrangements?

In fact, and I can't remember the model name off hand right now, there's that tactical stocked Crosman springer with pistol grip and a stock that you'd have to guess would allow for more straight line recoil.

[thisisdonald]

Vale boy has a rather nice beeman c1 that he recently and very kindly showed me. I have hankered after one of these for many years, but on holding it, my last vanished.
I found the grip to immediately be very uncomfortable fir my wrist, and to hold it anywhere near comfortable - my elbow had to be sticking up in the air. It's still a cracking looking gun, but I think I'll stick with its English brother, the Victor.

[RobF]

For the bedding disc at the rear of the action, I wonder if leather would also be quite useful?

Pillar bedding completely transforms the feel of the rifle. On my 97 there's no wood touching the action. The pillars are set up to fractions of a mm so there's no compression of the wood either. It's bolt to metal to metal. All the wood does is hold the fore-end to the back.

Pistol grips even on thumbholes are wanting. The volume of people's hands is very different. Top pistols and 10m guns have variable sized grips, and pistols are made to fit much better with fettling. I've packed mine out with self adhesive rubber layers, cut to fit... it's taken up a lot of the slack, but not quite right. The main issue for the thumb though is the spar passes over the wrong side of the thumb, it should be either lower, or over to the right. But that's stock buyers and sellers revert to type, and there's not many/any who make a stock to fit.