A standard probe would obscure the rear bowled section of the pellet where the concentration of air needs to be,a retractable one leaves that area clear?
Guy, The picture shows the two types of pin more or less to scale. When the retractable pin is pushed right in it pushes the pellet the same distance into the barrel as the standard pin. I can use both types of pin in my pistol and they give exactly the same performance, provided you remember to push the plunger of the retractable pin in fully and release.
There's a clue in there somewhere.
A standard probe would obscure the rear bowled section of the pellet where the concentration of air needs to be,a retractable one leaves that area clear?
The retractable pin has a larger diameter thus allowing less pellet skirt distortion, but that may be a secondary effect. When pushed to full length it seats the pellet past the transfer port and retracts allowing better air flow than the standard pin which partially restricts air flow from the transfer port.
BSA Super10 addict, other BSA's inc GoldstarSE, Original (Diana) Mod75's, Diana Mod5, HW80's, SAM 11K... All sorted!
dart pusher?
When the standard pin is screwed in this can cause the pellet to turn and potentially 'ring' the pellet to the bore causing some damage to the soft lead and ruining the seal. Perhaps the spring loaded version is to ensure that the pellet is not rotated in any way. Maybe not such an issue with a smooth bore but could be problematic in a rifled bore?
Or maybe not.
Carl
So John--if you do not push the retractable pin in and try to fire the pistol, will it actually fire a pellet out or does the pellet obscure the transfer port and there is not enought kinetic energy to shift it? Is the engineering good enough so the seals seal and the barrel moves very slowly (A bit like checking the seal of a tap on a tap loader)???
Cooler than Mace Windu with a FRO, walking into Members Only and saying "Bitches, be cool"
Does it act as a safety catch, in that it wont fire the pellet unless its been pushed past the transfer port?
Load, then when your ready to fire press the insertor in before pulling the trigger?
Matt.
Brilliant, Matt, you have nailed it!
Yes, it is probably the most reliable safety device you could have on an air pistol.
Other safety systems on airguns mechanically intercept the trigger or the sear in some way, and if the sear were to slip or shear the gun would still fire the pellet whether the safety was on or not. In this case however the gun is incapable of discharging the pellet (or dart) under any circumstances until the plunger is pushed in.
When I realised that this was what Frank Clarke intended, I couldnt wait to check it out on my Briton. I cocked the gun, inserted the pellet with the pin and screwed it home. Sure enough, the gun would not fire the pellet. You could cock and fire it until you were blue in the face and the pellet would not budge. Not surprising really when you think about it! However, one push on the retractable knob and the gun fired the pellet with no problem.
As a safety it is great, as you can activate the gun at the last possible moment while it is on target, just with the thumb of your shooting hand. It also means that you could carry the pistol around ready cocked and with a pellet in the breech with perfect safety - very useful when hunting large game I should imagine.
Frank Clarke obviously had a thing about unusual safety devices as he invented a very simple safety system for his later Titan pistols. On these the safety is released just before firing by squeezing the grip.
I wonder why he never patented his retractable pin idea? It would have been universally applicable to any push barrel pistol, or any pistol loaded by a breech pin, such as the Anson Star. All it would have needed was minor modification of the plunger length and the thread. To put a traditional safety catch on an existing push barrel pistol would have required major reconstruction work and new tooling (as Harrington took on with his later Gats).
Does anyone have any thoughts as to why Frank Clarke never capitalised on his invention, given the great number of push barrel pistols around at the time that could have benefited from it?
[P.S. I liked Rich's suggestion that the pin could have been used to allow two pellets to be fired in succession. Unfortunately it didn't work when I tried it out. It seems that as the two pellets are pushed up tightly aganst each other in the breech, the air can't get between them to push the first pellet out.]
Pre load?
I was thinking safety catch, but there is no indication weather it is on or off! and one would know if the gun was ready to fire or loaded as the barrel would be extended [safe] or inserted [live]. I think it was used as a method of "pre loading" your pistol as they can be fiddly, unscrewing, small pellets , oop's have just dropped the screw in the grass & it's going dark ! etc.
I would not want to carry a loaded Gat in my pocket, just in case some thing faild & I ended up with that extended barrel in my nut's
regards al
try this, what I meant with pre loading was you might have the facility to have two pellets in the breech? [1] load 1st pellet & push forward, so it would be ready to fire [2]. load 2nd pellet but do not push forward [like it would be reserved] [3] after first shot re-cock & push forward, you would have the ability to do two consecutive shots without all the fiddly reloading?
does that make sense?
regards al
Last edited by cringe; 17-04-2019 at 03:40 PM. Reason: try this
Do I get a runner up prize for asking whether it would fire in my last post?
Cooler than Mace Windu with a FRO, walking into Members Only and saying "Bitches, be cool"
Thanks, obviously hadn't thought of that!
Not that I would want to carry a cocked and possibly "chambered" but maybe not? pistol around either in my hand or my pocket, but yes it is a safety mechanism. Obviously it's non-resettable, once the pellet is "chambered" it's live 'til you "fire" it.
BSA Super10 addict, other BSA's inc GoldstarSE, Original (Diana) Mod75's, Diana Mod5, HW80's, SAM 11K... All sorted!
Fiddly,a bit like working the lever-action on a Daisy 1894 then having to cock the hammer before it fires. But clever. The only recorded 'death' inflicted by a pop-out seems to be the killing in the TV thriller,'A clubbable Woman'.It was the pop-out barrel that did the killing! I think back to those halcyon days when I carried a 'concealed weapon'-a GAT in my pants.I think pocketing a gun with the barrel pushed in would have ultimately done me a damage.None the less,this wee gadget has a certain appeal.Any craftsman care to make some replicas?
Wouldnt have given it a second thought if it wasnt for this thread, as I said I have one of these on my Briton and just assumed it was an over elaborate pellet probe.
I might do a little YouTube vid demo of it in use.
Thanks John,
Matt.