The Poppet Valve

[trevor1]

I wonder,did any British spring/piston gun-maker use such a valve in an air rifle? In an ordinary spring/piston gun a breeched pellet starts to move up the barrel once air pressure overcomes the pellet's inertia.That pressure ultimately is aided by a variable detonation of hot pressured oil. In some USA-made guns of a type(eg the Crosman V300 and M1 types),a poppet valve is fitted to the air transfer port and this valve only opens when under the influence of a critical and high air pressure. The idea being that a faster higher pressured air thrust motivates a breeched pellet or BB to accelarate up the barrel very rapidly. Rather like a "sprint start "vs a "long distance" runners start. On the face of it,this valve appears to be a rather overlooked but helpful gadget.....just a late evening thought

[flatrajectory]

I have never seen one in any British made airgun in over 50 plus years of servicing and repair. Unless someone else knows different.
I would think that its advantage is minimal over a standard setup and not worth the cost....!

Pete.

[I. J.]

Ive never heard about hot oil injection. The nearest system to this Ive read about, but never seen, is the ether injection system on the HW35 Barakuda and Original 35 (?). Even that wasn't very successful.

ATB
Ian

[ccdjg]

In effect an over-tight waisted pellet would have a similar effect to such a "poppet Valve" - the pellet would not start to move until the air pressure was high enough to deform the skirt of the pellet and then it would be free to move with little resistance while subjected to the higher than normal air pressure. From what is generally found, over-tight pellets never improve to performance of an airgun, which suggests that the poppet valve concept would have little advantage. Of course, in the case of the tight pellet some energy will be wasted in the deformation process which would not be in the case of the valve, but would this amount to much? An interesting problem.

[I. J.]

Im certainly no expert in this field but didn't some of the German artillery in WWII have constrictions built into their barrels which increased muzzle velocity?

ATB
Ian

[trevor1]

Ive never heard about hot oil injection. The nearest system to this Ive read about, but never seen, is the ether injection system on the HW35 Barakuda and Original 35 (?). Even that wasn't very successful.

ATB
Ian

Woops! The oil I refer to is on the piston head and chamber walls-ie not especially added.

[gedfinn 2]

Woops! The oil I refer to is on the piston head and chamber walls-ie not especially added.

I remember reading about an airgun with an encapsulated ball bearing in the breach, The idea in this instance was to raise the temperature of the pressurised air to ignite a gunpowder charge ?
If this was the case, It would certainly ignite any oil residue .

Ged.

[DT Fletcher]

I believe the idea behind the Crosman poppet valve was only intended for use in BB guns. When Crosman finally decided to take on Daisy and produce BB guns, they were determined to overwhelm Daisy with superior "Crosman" quality guns. The poppet valve was part of that effort. I think they succeeded rather well: Hahn 45, MI, 760, and the mighty Plink-O-Matic.