MAR177 chrony result

[PatrickB]

So my MAR177 has been kicking around for a while but I never really bothered to chrony it because I'm lazy.LOL but today I had some time and broke my chrony out to see what is going on with it and I have to say I am a bit disappointed with the results. This air rifle is lacking any type of consistency from shot to shot. I started at 2900 psi and ended up around 1900 psi. Some of it was my fault as I am not quite familiar with using a chrony and I did delete two strings (20 shots) and had a few errors until I got on track and I never bothered to zero out and start from scratch. I do have some extra ports on the way from Crosman so I can eventually play with the velocity, I would like to get it to 800fps and try it out on a field target set up after a few mods to it to see how it does. I am fairly certain I can easily get a 60 shot string out of this air rifle and I do have a Robert Lane regulator kicking around (set at 1400 psi but is adjustable) with a complete set of spacers for setting up the "mini" reservoir  after the reg. I was using RWS Superdome .177 Cal, 8.3 Grains pellets. Here's the results.

              60 Shot string, start 2800 psi end 1900 psi Pellet= RWS 8.4g Match               
string 1   string 2   string 3   string 4   string 5   string 6
581.4   567.0        597.8        612.2        604.4        605.8
589.6   597.0        598           579.5        575.9        604.7
581.0        588.5        592.9        603.7        603.4        596.6
586.3   573.1   602.5   577.0        598.6        604.2
569.3   564.9   567.7   582.8   598.5   581.7
556.5   589.6   555.1   579.7   580.3   578.2
582.6   588.0        589.6        577.1        574.2        599.2
580.5   555.2   588.9   596.5   574.1   578.1
583.5   568.7   561.0        578.3   579.4   605.9
556.5   565.9   570.9   577.2   572.2   592.3

So as you see I have a bit of work to do as far as getting this rifle to shoot consistently.
Thanks
Pat