confused big time

brenak47

i have a mauser sr sniper i took out the fps reducer screw the other day while plinking in the garden to see the difference in power didn't notice much but i lost screw so when i chronoed it it was at 340 yesterday my brother machined me a new screw but it took it down to 220 so i messed with it a little and got 250.i then decided to check it again without the screw to get an average to see if my bit of messing going to do anything other the destroying the screw to my surprise it came in at an average 300 fps all this was on the same madbull chrono set for .20 why would this happen was it a faulty reading from chrono or is there something with the rifle

thermo

please define "i messed with it a little".................

brenak47

oh i bored out the inner hole of the new reducer a bit more thats all managed to find the original screw this morning so going to chrono it later but it still won't answer why it was only shooting 300 without it been told it might be the batterys in the chrono

thermo

madbull chronos do give bogey readings when the battery is low. did you drill the air nozzle screw while it was fitted to the gun? if so swarf from the drilling may have damaged the piston seals, explaining the lower fps when the screw was out.

brenak47

oh right and no took it out each time so i wouldn,t happen not an easy task held it in my hand so i wouldn't damage threads

thermo

try new batteries in the chrono or a different one.

and the hop was turned off for all chronoing?

brenak47

ye was thinking of taking a trip up to kev in hobby there ones a 100%

brenak47

didn't get to hobby but i charged the chrono for about 3 hours then tried it again without the reducer and still 300-310 but in original reducer and got 250-260 this gun was chronoed at the compound a month ago at 290 with reducer fitted i have put a new bucking in since would i have done something wrong here

thermo

when you had it apart did you add or remove any lubricant on the piston?

brenak47

i greased up spring and guide while i had it apart doing the bucking thats all i thought this would help if anything or am i wrong

thermo

what lube did you use? if its to heavy/thick it impeeds the pistons movement and reduces the fps.

brenak47

it was a silicone grease i got in b&g in the plumbing section just thought all silicone grease would be the same

thermo

nope some grease's are thick sticky and some are thin and not all that sticky, you are better off for cylinders using a thin grease. hobby sell specialist lubricants for cylinders, gears ect.

brenak47

oh right didn't know that thanks going up to hobby during the week all going well