Hold sensitive PCP

[james79]

I'm sure I can't be the first person to experience this but out roost shooting tonight I missed three easy woodies in a row. All were from a seated position with me leaning back on a bale stack for support. I had previously checked my zero from a seated bench rested position but decided to stick a target to one of the trees 30 yards away and found my poi was 1.5 inches high and right (still doing 5p groupings) so tweaked the scope to sort it. Unfortunately I had no more chances at the pigeons so called it a day at about 7 o clock but decided to recheck my zero from a bench rested position (the sudden change was bugging me) and what do you know, the poi was now 1.5 inches low and to the left I've rezeroed from the bench rested position but was wondering if anyone could provide an insight for the zero shift, if it was a springer I would have said it was down to hold sensitivity but on a pcp its confused me a bit. The specifics are I was using a BSA r10 (sorry ) with an MTC viper connect and bisley lrg's and I'm pretty sure I wasn't canting the rifle

[eddie666]

make sure your scope mounts are tight,
if you have a moderator on your rifle make sure its lined up and the pellet is not fouling on it or its on tight,
sounds to me like a scope problem , do a 5 group then thump 3 or 4 times on your stock to make the scope vibrate , if all mounts are tight and your poi changes again some thing is loose in the scope , some eye relief adjusters have to be locked in to position by a lock ring , most are fixed that turn in or out,

if it was up or down , that could be your power
left to right is scope or barrel obstruction / moderator / or wind .

[james79]

Ive tried the knocking the scope/rifle trick to no avail, I'm pretty sure its me at fault rather than the rifle/scope combo (which makes it all the more frustrating ) as I said it seems like its something to do with shooting from the seated position that's putting me wrong

[eddie666]

some times its just you, last week my son was shooting 177 pellets off a 27yrd log , today he could not make a 50p group and he was down and left with all his shots,
i had a go on his lgu pellet on pellet , but it was cold today and we had been moving logs about on the range before,
so cold and tired can make you shoot all over the place .

so next time remember the basics : hold / level up / pull the trigger straight back / breathing / follow through ,
keep your hands warm , keep both eyes open or use a flip out scope cover to block your none targeting eye vision but not to block out the light from that eye.

[Andy-K2]

Hi James

I'm thinking your setting your zero from a rested position in a field/garden shooting horizontally? if so that could be the reason for the misses. Gravity has an effect on a projectile shot horizontally like a curve so your zero will reflect this. If shooting up gravity has an effect as in it pulls directly from behind so your zero will be different as there is no trajectory... Ok what I have typed may not be Newton's idea of an explanation but if you think about it you will know what I mean.

[Raj]

Shoot high, Aim low

[eddie666]

yes gravity can change things if you shoot up or down , http://www.pyramydair.com/blog/2005/06/ ... llet-drop/

[poguemahone]

aye up james,
sounds like a combination of things, with the main one being what andy k2 has suggested, gravity.
this will account for the/or most of the vertical error. without knowing calibre, range, and angle, its difficult to assess if 1.5" high is about right.
for the horizontal error, my money would be on canting or wind. when shooting up into trees, or on sloping ground your eyes are easily tricked into thinking you're shooting without canting, so much so that some shots look as though the scope is miles out when you're NOT canting it
not getting your eye behind the scope in exactly the same position as when shooting bench rested would/could account for a marginal amount of error.

[james79]

Thanks chaps. I feel like banging my head on the wall now, I can't believe I failed to take in to account the effect of shooting at an elevated target I'll blame it on a combination of getting used to a new scope, not having done any roost shooting for a while plus the new tablets the doc's just put me on Thanks again for the input, just goes to show its best to check the blindingly obvious before trying to blame more complicated factors I've just been out and checked my zero from a seated position on the level and out of the wind and its spot on I feel a right royal prat now

[wastrel]

Couldn't disagree more with the elevatated POI posts.
POI does/should NOT change with an elevated or downhill shot at UK airgun power levels, ever, factamondo!
I'd be checking for hold sensitivity points on my rifle for a 1.5 inch change at any distance or elevation.
FT/HTF shooters will back me here (help Ray!)