N/A Inertia Assisted, Lightweight Top Hat

[markhooper]

I was a little surprised that the Cardews did not try the mercury approach. The mercury capsules were quite common in various powder burners to spread the recoil impulse out over time.

I suppose if one could get mercury it could be used.. id want to use at least grade 8 steel and plenty of red locktite.. you just don't want to be exposed to it much.. and if it leaks.. the sudden recoil would probably atomize it in your face ..
I'd be interested in hollow and very light lubricant oil and small lead shot.. easy to get and work with.. and not the risk of mercury..
glad you have a lathe.. if you could up with something and need a fine polished finish or something please let me know..
also do you have any idea what the inside of the gamo varmint shotgun is like.. or the rws 34 and 48.. id be more interested in spring guns if they didn't make me hurt.. I have just never taken one apart, just shot them.. the nice thing about spring guns is that they have usually less issues than PCP over time.. I have a PCP that I need to reseal.. but my spring guns that I had 30; years ago I just put lots of tins of pellets through..
also I wonder about a few of the new cheap spring guns that pyramid sells with magazines.. I don't have any idea how they put the pellets in the barrel but repeating is a good aspect of PCP. vs the standard spring guns
I'm really interested to hear from others about these ideas..as for now I pretty much only shoot PCP guns. but I'd really like to be able to have fun with spring guns.. fond memories of long ago..
Mark

 

[beerthief]

I suppose if one could get mercury it could be used.. id want to use at least grade 8 steel and plenty of red locktite.. you just don't want to be exposed to it much.. and if it leaks.. the sudden recoil would probably atomize it in your face ..
I'd be interested in hollow and very light lubricant oil and small lead shot.. easy to get and work with.. and not the risk of mercury..
glad you have a lathe.. if you could up with something and need a fine polished finish or something please let me know..
also do you have any idea what the inside of the gamo varmint shotgun is like.. or the rws 34 and 48.. id be more interested in spring guns if they didn't make me hurt.. I have just never taken one apart, just shot them.. the nice thing about spring guns is that they have usually less issues than PCP over time.. I have a PCP that I need to reseal.. but my spring guns that I had 30; years ago I just put lots of tins of pellets through..
also I wonder about a few of the new cheap spring guns that pyramid sells with magazines.. I don't have any idea how they put the pellets in the barrel but repeating is a good aspect of PCP. vs the standard spring guns
I'm really interested to hear from others about these ideas..as for now I pretty much only shoot PCP guns. but I'd really like to be able to have fun with spring guns.. fond memories of long ago..
Mark

you could look for a Diana 75 , it is totally recoilless Giss system , seems to be a few for sale lately , and most need repair (David Slade is great )

 

[Airgunmann]

I suppose if one could get mercury it could be used.. id want to use at least grade 8 steel and plenty of red locktite.. you just don't want to be exposed to it much.. and if it leaks.. the sudden recoil would probably atomize it in your face ..
I'd be interested in hollow and very light lubricant oil and small lead shot.. easy to get and work with.. and not the risk of mercury..
glad you have a lathe.. if you could up with something and need a fine polished finish or something please let me know..
also do you have any idea what the inside of the gamo varmint shotgun is like.. or the rws 34 and 48.. id be more interested in spring guns if they didn't make me hurt.. I have just never taken one apart, just shot them.. the nice thing about spring guns is that they have usually less issues than PCP over time.. I have a PCP that I need to reseal.. but my spring guns that I had 30; years ago I just put lots of tins of pellets through..
also I wonder about a few of the new cheap spring guns that pyramid sells with magazines.. I don't have any idea how they put the pellets in the barrel but repeating is a good aspect of PCP. vs the standard spring guns
I'm really interested to hear from others about these ideas..as for now I pretty much only shoot PCP guns. but I'd really like to be able to have fun with spring guns.. fond memories of long ago..
Mark

Ive tried a light weight hammer with lead shot in a pcp rifle to see if it helps hammer bounce and it didn't help which I was surprised by as well

 

[markhooper]

you could look for a Diana 75 , it is totally recoilless Giss system , seems to be a few for sale lately , and most need repair (David Slade is great )

never heard of that model.. is it older?

 

[beerthief]

never heard of that model.. is it older?

yes older and has a few names too , not only Diana . i just bought one in great shape and shot it a few times before the piston seal blew , probably rotten. NO RECOIL.
But what a pleasure to shoot , If you cant take any recoil there is always the CMP Daisy SSP 853 @ $139 to your door completely rebuilt . I just got one and what a dream to use it is a 10 meter gun but good out to 20 yards easy . scroll to the bottom of th page for the 853

Sporter Air Rifles - Civilian Marksmanship Program

Sporter air rifles are characterized by their light weight, low cost and basic target features. We offer several varieties for purchase.

thecmp.org

 

[Sqwirl57]

yes older and has a few names too , not only Diana . i just bought one in great shape and shot it a few times before the piston seal blew , probably rotten. NO RECOIL.
But what a pleasure to shoot , If you cant take any recoil there is always the CMP Daisy SSP 853 @ $139 to your door completely rebuilt . I just got one and what a dream to use it is a 10 meter gun but good out to 20 yards easy . scroll to the bottom of th page for the 853

Sporter Air Rifles - Civilian Marksmanship Program

Sporter air rifles are characterized by their light weight, low cost and basic target features. We offer several varieties for purchase.

thecmp.org

Yeah buddy. The 75 is definitely one of the cooler guns to own. Ive had mine for a few months now and it still makes me smile every time I shoot it

 

[beerthief]

Yeah buddy. The 75 is definitely one of the cooler guns to own. Ive had mine for a few months now and it still makes me smile every time I shoot it

do you have a Daisy 853 ? if not you should . Accurate too . they have the 753 =daisy barrel or the 853 LW barrel . YES the 75 is wonderful , expensive to have worked on but still i think worth the $$

 

[cjtamu]

The Diana 75 is a tremendous gun but it’s heavy. Feinwerkbau 300 is a little lighter but still heavy. Sled system so you feel no recoil at the shoulder. Both extremely easy to cock. Both are 10M guns. Can be shot farther but they’re very low powered. You mentioned having owned a Diana 48. With whatever physical ailment you have can you still cock one? Diana Airking Pro would give you no recoil at the shoulder and 20+ FPE if you need it. And about 12+ lb by the time you mount a scope. All of these guns are going to cost 4 or 5 times the Daisy 853 mentioned above. Hate to say it, but with physical ailments PCP might be worth considering.

 

[markhooper]

The Diana 75 is a tremendous gun but it’s heavy. Feinwerkbau 300 is a little lighter but still heavy. Sled system so you feel no recoil at the shoulder. Both extremely easy to cock. Both are 10M guns. Can be shot farther but they’re very low powered. You mentioned having owned a Diana 48. With whatever physical ailment you have can you still cock one? Diana Airking Pro would give you no recoil at the shoulder and 20+ FPE if you need it. And about 12+ lb by the time you mount a scope. All of these guns are going to cost 4 or 5 times the Daisy 853 mentioned above. Hate to say it, but with physical ailments PCP might be worth considering.

well I have a american tactical liberty nova 22 PCP, a hatsan blitz 22 and it shoots well and a umarex notos pistol that I'm getting ready to hopefully soon machine down and put a air stripper in the shroud so it will hopefully be more like a pistol.. I never put the stock on the notos, just bought the factory grips and open sights for using it as a pistol but at 22" long I can't shoot it freehand and it's impossible to get a holster.. so it's going to be shortened to 16 inches but I am also going to open the air tube and see about shortening it too .. hopefully end of with a 12" pistol but if not then 16 plus I am going to do some relief and texture on it and try to get it weight down.. then hopefully this winter rebuild the American tactical.. it's got a very slow leak.. it similar to the avenger but no regulator pressure gauge..
I'm thinking that the leak has to be from the atmosphere vent because it only leaks down 1000 psi every week until regulator pressure of 2000 psi and it has has held there for a month now.. and I have the Omega trail charger for filling..got the gamo varmint shotgun 22 and it shoots shot shell and a pellet adapter but as mentioned it's uncomfortable to shoot very much but it will serve well for it's intended use.. rattlesnake around the house.. works great so far, no snakes have been around since I got it
not sure if I would like a low powered gun.. but not sure what power I would need.. pistol I normally shoot 30 yards and rifle at least 50 yards and I mostly shoot reactive targets such as tin food cans if I am energetic and if not I shoot my 3" spinners, since they are set up.. they don't move much with pellets since they are also ones that I used to shoot 9mm and 38 and 22lr at.. but they have only seen a few 22 LR since 2020 and mostly pellets.. I just found my 12" bullseye that I need to make a hanger for out farther.. hopefully around 100 yards..
I have thought about the 54 air king in 22.. I have stayed away from 177 because they are hard to handle with carpal tunnel.. but I did really consider getting the Colt SAA CO2 in BB since you can just dump some BB in a tray and push the cartridges over them.. but it's been so long since I shot anything CO2 that I don't even know if I could shoot tin food cans at 10-30 yards and put holes in them and knock them over.. or if the BB is going to bounce back off.. the other thing is that I really like cowboy guns and well my favorite powder guns are 22 Henry golden boy and Ruger 22 bearcat single six..
I think I can still cock a 48-52-54.. I think same action.. but I like the fact that you pretty much just need pellets and the gun..
but first on my list is to get the thread protectors and barrel extension for longgundallis made.. and, well I'm just flat out deleting all the pyramid air emails since I had a end of the year bill that I was expecting but it was a bit more than expected so I kept figuring out what to do.. paid the rent yesterday.. tomorrow is another bill and I got good news.. the $100 I was short on can wait until I get my next disability check I like either a balanced budget or a surplus.. and it's really stressful if you find yourself trying to figure out how to make it happen and are feeling totally miserable.. I wouldn't wish cancer on the worst person.. and much less the medicine.. I flat out quit one because the side effects are horrible.. arthritis flare up and painful joints.. when you can barely get sock on and can't touch your toes sitting down.. it's too much.. but I quit two days ago and I am feeling better.. tomorrow I should feel 5 years younger
oh on the air king it's also a bonus that it comes with open sights, since I don't use any scopes.. I am going to have to borrow a scoped rifle from someone and see if I can see through them now that I have glasses .. it's made finding PCP guns that I would like hard since nowadays most don't have any way to put open sights on..
Mark

 

[SpiralGroove]

Hey Sqwirl,
What are you hoping to get or what is your intended goal with the testing?

- In my tuning experiments, I have spent countless hours fiddling with things that never seem to make a difference. However, when you find one that does, you use it on everything forever. Where would we be without our curiosity .............

 

[Sqwirl57]

Hey Sqwirl,
What are you hoping to get or what is your intended goal with the testing?

- In my tuning experiments, I have spent countless hours fiddling with things that never seem to make a difference. However, when you find one that does, you use it on everything forever. Where would we be without our curiosity .............

It shoots better than the standard 6g top hat did but thats as far as I've made it so far. Ive had classes after work all week and just haven't had the energy or time for tinkering afterwards. What I can say is that at the power I'm going for, the ideal overall piston weight is somewhere around 30g less than where it was from the factory. On this type of powerplant, adding weights inside the top hat seems like a great way to go about it vs adding extra preload with weights.

 

[beerthief]

Sorry i just wanted to suggest a gun with no recoil to someone that needed it . Truly Sorry for Hijacking this very interesting thread .

 

[Sqwirl57]

Sorry i just wanted to suggest a gun with no recoil to someone that needed it . Truly Sorry for Hijacking this very interesting thread .

The D75 can show up on any thread it likes in my books. She's earned that

 

[SpiralGroove]

Yeah, I can't imagine having a 55 gram top-hat in the first place ..... requires substantial spring power to get the piston moving.

It's a fine balance between top-hat weight and spring power to get optimum results at whatever FPE your goal is.
Fortunately, it's all about shot cycle feel ......... interestingly enough some folks like it rough, like other activities.

I always choose the most power for my ideal shot cycle ..... feel - a cushion-y, balanced pop with no twang.

 

[Sqwirl57]

Yeah, I can't imagine having a 55 gram top-hat in the first place ..... requires substantial spring power to get the piston moving.

It's a fine balance between top-hat weight and spring power to get optimum results at whatever FPE your goal is.
Fortunately, it's all about shot cycle feel ......... interestingly enough some folks like it rough, like other activities.

I always choose the most power for my ideal shot cycle ..... feel - a cushion-y, balanced pop with no twang.

I'm a fan of the quick and snappy myself but my main goal here is basically to build a springer class field target ready rifle that is sub $300. I'm more or less there I think but I need to get a little free time so that I can verify that. These darn 4:30pm night times aren't helping.

 

[beerthief]

im old ,Retired , the sun is my time keeper , and yes these short days are frustrating . even for me .

 

[Berserkeley Mike]

Go ahead and steal the idea and build on it with me. Forums used to be about doing stuff like this together.

I woke up this morning wondering now how well a sealed steel top hat semi-filled with mercury would work. Anyone have thoughts? Can a regular Joe buy mercury? Time to find out.

I wouldn't play with mercury for this application. Shaken by the firing cycle, a failure outcome is it gets everwhere and contaminates you and your work area. Plus I'd imagine you want something that holds shape and retains its position in the piston when you are aiming, so the gun's center of mass doesn't shift when tilted. There are a lot of other safer ideas to play with before resorting to mercury.
I like the light spring or air cushion ideas to give you a sprung piston and semi-independent sprung top hat weight.
And how about a copper tube in the piston and a magnet as the weight?

 

[Sqwirl57]

I wouldn't play with mercury for this application. Shaken by the firing cycle, a failure outcome is it gets everwhere and contaminates you and your work area. Plus I'd imagine you want something that holds shape and retains its position in the piston when you are aiming, so the gun's center of mass doesn't shift when tilted. There are a lot of other safer ideas to play with before resorting to mercury.
I like the light spring or air cushion ideas to give you a sprung piston and semi-independent sprung top hat weight.
And how about a copper tube in the piston and a magnet as the weight?

Yeah that was basically my hold up with using mercury. Suitable containment is definitely a concern. I was wondering if maybe removing the front breather hole would work to slow the brass insert. Would that air cushion transfer energy through to the piston? I feel like it would

 

[Star7]

The Cardews concluded that significant velocity gains (through improved efficiency) would be had by eliminating piston bounce. They built a piston with a rod that would be trapped by hardened balls against a hardened ramp. This would restrict the piston to compression only. They had calculated that at the point the pellet released and started travel, pressures were such that the first rebound would be an impulse well over 1000# force. The mechanism got mangled. They did refer to the Theoban inertial piston but did not publish anything that I can find as to research in that direction.

People occasionally, have responded that when they stripped their Theoban, the inertial piston was stuck and not working. Upon removal, they largely note no difference. Well duh! If it wasn't working removing it would make no difference and if it wasn't working, everything else was probably gummed up and the comparison invalid.

I look forward to your work....looks cool to me.

 

[markhooper]

I'm a fan of the quick and snappy myself but my main goal here is basically to build a springer class field target ready rifle that is sub $300. I'm more or less there I think but I need to get a little free time so that I can verify that. These darn 4:30pm night times aren't helping.

yes these short days are hard to get anything done outside.. so I like being around 950 fps since, I don't often, but my favorite is long range shooting.. and 22 caliber because 177 is just too hard to handle with carpal tunnel.. I'm probably stuck with PCP or possibly someday a rws 54.. but it would be nice to be able to get a smooth shot cycle like you are trying with the simplicity of a spring gun..
do any of you know how these new guns that pyramid air is offering.. I think called swarm with magazines work? they are break barrel and I don't have a clue how the pellet gets in.. wondering if I could convert one or even my gamo varmint shotgun to the top hat. like you are doing?
it's been 25 years since I had my rws 48.. I just remember that it was a good one and made in Germany..
Mark