Crosman 140 and the 12 ft/lb limit

[Phil B]

Just bought one and really love it. An interesting and accurate rifle.

However....

I know you can pump these and fill the "tank" and on trigger release, ALL of this stored air is sent down the barrel.

Questions.

Before I design/make a new piston with a blow off valve to set at the pressure that produces say, 11 ft/lbs, has anyone done this before?

Any designs out there?

Is there another piston out there that fits/can be modded to fit, that has a blow off valve built in?

Long shot I know.
Thanks for reading.

[crowbar]

Shorten the piston stroke so it will only pump to required pressure and any extra pumps will not open the fill valve .

[crowbar]

As less air is required a sleeve can be made to reduce the volume of the firing pot which will reduce
the amount of pumps .

[cringe]

As less air is required a sleeve can be made to reduce the volume of the firing pot which will reduce
the amount of pumps .

if you disassemble the air reservoir you can insert a small cylindrical piece of aluminium I guess about 8 millimetres diameter x 6 to 8 mm long?, this will limit the amount of air you can compress. hope this helps.

[Phil B]

Great ideas chaps and all easier than making a valved piston. I wanted to avoid mumping say 10 times to get maybe 10ft/lbs. Rather five and get to max and the valve blows off telling you it's maxed out.

Please keep the ideas coming. I'm new to Crosmans, all my other pumpers are Sheridans (1963, '68, '73 and '85). Totally different system, easy to pull back to the UK limit.

[averageplinker]

Whatever solution you find, take care not to make the pumping action to hard/stiff for fear of bending or straining the pump links.

[T 20]

Great ideas chaps and all easier than making a valved piston. I wanted to avoid mumping say 10 times to get maybe 10ft/lbs. Rather five and get to max and the valve blows off telling you it's maxed out.

Please keep the ideas coming. I'm new to Crosmans, all my other pumpers are Sheridans (1963, '68, '73 and '85). Totally different system, easy to pull back to the UK limit.

The later Crosmans had a sprung piston head, when the pressure in the system reached a certain point the spring pressure was overcome and the piston head moved forwards so limiting pressure and velocity.



All the best Mick