Recoil system for Hatsan 125/break barrel air rifle

[sandu_race]

Idea : adapting a recoil system on Hatsan 125 .
It wouldn't bother me to add 0,05-0,2 kg to the already heavy rifle , Diana side-lever recoil system looks pretty practical and I was thinking about 2 recoil rods installed laterally between the stock and that SAS ring , 2 recoil rods installed "Diana style" near the trigger .
Does anyone tried this ? advices/pro&cons/ideas/
As a project looks pretty fine for me but I'm not sure if the results will make me happy considering that it's a lot of work ( new redesigned stock/designing and create the rods and sliding pieces/ welding some holders on the rifle cylinder)
I'm waiting for any kind of ideas , even "forget about it" it's important for me . Thanks!

[lizzie]

Moving to the Turkish air gun forum section...

[MartyMcFly]

I have not tried the same idea but I whole heartedly encourage you to try it. Unless, this is your only rifle and you are already in love with it.

Expressing your creativity/ingenuity can be a rewarding experience even if it results in failure, because it is often the journey and not the final destination that provides the most enjoyment. You might find that you come up with a better system or not - but at least you won’t have the regret of not having tried.

Good luck!
-Marty

[mikeyb]

My opinion?

Lube-tune your Magnum springer to shoot as good as it can, then enjoy shooting it.

Bank the time and money you would have spent trying to make a recoil-less springer (an oxymoron IMO) and use it to buy a PCP rifle and a hand pump.

You will have the BEST OF BOTH DESIGNS... a (relatively) smooth shooting magnum springer, a wonderfully simple self-contained system for launching pellets, and a laser-like accurate PCP air rifle with no recoil that is super easy to shoot.

Do whatever makes you HAPPY

[Mossonarock]

I experimented with drawer slides: https://www.gatewaytoairguns.org/GTA/index.php?topic=164474.0

My efforts were crude and clunky but it definitely proved proof of concept.
I haven't taken time to try the cnc rails that the others suggested but I recommend going that route.

[Mole2017]

Neither of these guys share what they did, but the first video at least has the action out of the stock:





...Videos from 2010. I am surprised there aren't more.

[sandu_race]

Thanks for the advices so far .
Marty / you're right , considering I'm a diy guy I have nothing to loose by giving a try , I'm sure that smarter guys before me already tried the concept and I don't like pretend that I will invent hot water .
Mike/ you're also right. I owned a PCP , Hatsan BT65 , bought when they just released the gun , I'm still in love with that powerful PCP . The point if doing something about recoil on 125 is to try improving as much as possible "home made style" the gun . I'm not disappointed about the actual recoil , I just take it as a challenge and somehow I like it . I'm already in deep search of a Marauder gen 2 .
Mole / pretty easy to do something on side-lever air rifle , actually one of my air rifle is exactly like the one from 1st video , an old Sig Hammerli mod401 , that one is very very accurate even in the initial shape. The second video already checked few months ago ,  smart guy with a lot of skills and a lot of machines . Unfortunately for me  I have only basic home tools so I have to figure out the best way to use them . For break barrel air rifle is pretty difficult to do something under the rifle where that lever has to do his job.
Still winter , pretty cold here in Finland so let's see how my brain is affected by the different ideas on this post . Feel free to advice me !

[MartyMcFly]

Neither of these guys share what they did, but the first video at least has the action out of the stock:

...Videos from 2010. I am surprised there aren't more.

That HW97k demo was impressive. I can’t say that I like the overbuilt stock, but the recoilless action looked sweet!

I have always wondered whether it would be possible to build an after market stock that has a recoil dampening system built in. Imagine a sleeve on rails within the stock that is molded to the shape of the action. You simply pop out the action from the original rifle and pop it into the sleeve on the new stock. The only downside beside extra bulk is that the trigger would travel with the action.

-Marty

[Mole2017]

I too have actually thought about it. For example, on my CFX, what if I turned the stock screw holes up front into slots, somehow modified the rear stock screws connection and added a bearing surface so the action could recoil like that? It's been a while since I looked at the issues to do it, but it may be that "easy".

How much recoil (maximum) is just a function of the mass of the piston vs rest of the action and the piston travel for a shot, with a little fudging for the spring or nitro piston mass. Once you have that number you know the maximum movement you might see. However, thinking about it right now, I have to wonder if the rifle aim still benefits if the mechanism is allowing only part of the recoil movement, either due to a spring/bumper or a harder stop. The shot cycle is less than 10 ms and the longer the rifle can recoil freely during that cycle, the less time it has to swing off target...something would be better than nothing.

[mikeyb]

IMO there are 2 reasons to reduce recoils.

1) Reduce rifle movement to maximize accuracy.

2) Reduce rifle movement to prevent scope damage.

If you want #1, then a full floating action is the best approach. What seems to by misunderstood by many, including some air rifle manufacturers, is that when the rifle action is decoupled from the stock MASS & shooter MASS the double recoil accelerations of the action AND any attached scope actually becomes LARGER and potentially more damaging to the scope mounts and scope internals!

The rearward recoil is usually similar to a PB recoil, in most cases significantly less, and many scopes can handle this motion quite easily. The 2nd recoil motion (the rifles abrupt STOP and REVERSE to a forward motion as the piston decelerates, slams home, and likely rebounds) is MANY times greater and is the primary cause of scope damage.

The high speed video of the Diana ZR mount shows this quite well. The initial recoil looks positively glacial in slow-mo. Watch when the piston slams home and you can see EVERYTHING vibrating and flexing (watch the end cap). It "looks" like the rifle is going to shake itself apart. THAT is the scope killer impulse.

If you only want to protect the scope #2, increasing the rifle & shooter mass (tighter coupling to the stock and shooter) AND isolating JUST THE SCOPE from rifle motions is the correct approach.

[Mole2017]

Good reminders Michael. Reading that I realized I had recoil movement in mind, not recoil acceleration, when I wrote about calculating the recoil to expect. Related concepts, of course.

[Mossonarock]

IMO, y'all are making it overly complicated but do what you want.