The handling is certainly different due to the shorter barrel and lever on the HC and as far as I know the stoke and pistons on the two rifles are identical so maybe my logic is flawed, but the HC is a fair bit harder to cock than the full rifle.
Not decided yet, I've only had them a week. The full rifle definitely more nose heavy and is much easier to cock and the HC feels chunky until you get it into the shoulder then the neutral balance make it very easy to handle. I'll be out on an FT course with them as soon as the weather allows..... 50 MPH winds down here at present.
Pretty special in Cornwall at the moment too. I thought things were improving but just looked at the forecast
The difference is tiny, and outweighed by the additional mass of the barrel and cocking lever damping muzzle movement.
The full barrel takes in the region of 0.3 milliseconds longer than the HC for 7.87gn pellets at circa 805fps.
Another 20-30mph might even persuade ol’ Jon to get out on a course with a rifle for some old Skool FT....
Having owned both the TX200 and HC, I much prefer the full rifle, and found it slightly easier to achieve any given standard of accuracy with, partly due to the extra mass of the longer barrel reducing muzzle lift, but mainly due to the higher energy efficiency of the longer barrel, which means that the HC has to be pushed that bit more to achieve equivalent muzzle velocity - the piston has to travel slightly faster and further, reflected in the recoil. Air Arms Express 7.87gn pellets, 808fps (HC) and 809fps (TX).
I'd agree with the mass and length helping to regulate muzzle flip. Along the lines of my thoughts Interesting graph. How was it generated/measured?
Linear generator and/or 400g accelerometer feeding a USB digital recording oscilloscope gives recoil velocity/acceleration respectively, integrated to find displacement.
It's easy to calculate to give you a good idea of what primary recoil will be, Phil. Available piston stroke minus a mm to guesstimate the compression stroke, multiplied by the weight of the piston plus a third the weight of the spring, divided by all up rifle/scope weight. For my 85mm TX, that's 84 (mm) divided by 0.251 (Kg) multiplied by 4.6 (Kg), or 4.58mm. In my test rig, I record around 4.5mm, the difference being the tiny amount of friction between the rifle and rig.
I don't quite follow you, Rob. Do you mean a piston with a hole in the face so it doesn't compress air? If so, the primary recoil displacement will be slightly greater as the piston travel would be greater. In all other respects, the recoil cycle would differ hugely.
That's what I'm getting at... surely the recoil distance cannot depend upon just the stroke divided by spring weight x the gun weight...?
It's a ball park figure, Rob, but yes, primary recoil displacement is dependent on the length of the compression stroke (itself affected by pellet start pressure and mass, spring and preload, transfer port length and diameter, and hence a guesstimate) multiplied by the mass of the piston plus a third the mass of the spring, divided by the combined rifle/scope mass.
I was wondering where spring rate was in the equation but I guess that primarily affects recoil acceleration rather than overall displacement. Hence how "soft" or "snappy" it feels?
Exactly, Adam. Spring rate and preload affect the nature of the recoil cycle, and any effect on primary recoil displacement can only come if they alter the piston displacement.
