The Remington Airmaster is rated at 725 FPS (Feet Per Second). The Crosman 760 Powermaster is rated at 595 FPS and the 760P is rated at 600 FPS. 10 pumps each.
Remington 870 pumps max out at $250
No more that 10 pumps! Per the Instructions.
Someone at the Remington Society of America should be able to help.
The Crosman Owners Manual states to NEVER pump the pistol more than 10 time and at least 2 times to fire a BB out of the barrel.
3 to 10 pumps. More than 10 pumps will damage the seals.
10 pumps = 580 FPS. made in 3 variations between 1968-1978
velocity diagram indicate the effect of vane angle, effect of jet angle on impeller speed
Benjamin ( who is owned by Crosman air gun) recommends 10 pumps. Over pumping may damage the rifle. You can still get the owners manual for this rifle for free. Go to the Crosman link below and click on "Download a manual" at the bottom of the web page, then click on Benjamin and locate your rifle.
To answer this question you would have to go back to Crosman and ask them directly. See the link below.
CROSMAN 1400: 10 pumps = 580 FPS. made in 3 variations between 1968-1978
Eventually everything wears out. But if you maintain it, it will last you for years. I own both a newer 1377c and a very old (and I do mean old) 1377. Yes I can tell the difference in how they pump, but the old 1377 (American Classic) still hits the target. If I had it rebuilt it would be like new. But why, it still performs well.
You have to swing the forearm to pump up an air cylinder in the rifle. Usually it take about 8 pumps. When you pull the trigger it releases the air an propels the BB or Pellet.