PCP accuracy variances?

[barbados]

I shoot air pistol silhouette, unlimited any sight with a Steyr LP50E.

We have a match every month and I am finding that the scope settings change a few clicks up or down each time. The scope is a Leupold 4X LER from their custom shop with parallax dialed down to 10 meters.

If I fail to dial-it in prior to a match, it shoots a 37-39 out of 40. Dialed-in prior to the match, it will shoot consistent 40s and generally 4-5 out of 5 of the 1/10 scale shoot-off targets.

What is causing it to change? I am unable to get an agreement from my fellow shooters.

Some say humidity. Some say temperature. Some say it’s the way I’m holding it against my leg damping or allowing resonance/vibrations.

It is always charged to it full 200 bar pressure. Pellets are Vogel with the same lot number. I’ve had it for close to a year and may have shot 500-1,000 pellets through it without cleaning. (is this a problem?)

Are your air guns consistent after they have been dialed-in, or do they change from month-to-month?

Any thoughts from you astute guys are greatly appreciated.

Thanks!

-dave-

[Finprof]

I shoot air rifle silhouette and need to change scope settings between matches the same day. We shoot two matches. One starts about 9:30 and the other about 12:30, after lunch. I think that the change is sunlight makes you see the targets differently. The afternoon settings are pretty consistent from day to day, but the morning settings are not. I keep the afternoon settings written on the scope and usually wind up returning to them for the PM match.
It took me a long time to figure out why I was consistently shooting better on the second match.

[barbados]

Interesting.

Thanks for the input!

We shoot in an indoor range, so the lighting doesn't change.

The other thing that I just thought of was that, in my case, sometimes the settings are flat. There isn't any change from chickens to rams. Other times, chickens and pigs have the same settings, then up two clicks for turkeys and up 8 clicks for rams (?)

Could it be an PCP air pressure problem? Guess I'd have to shoot into a chrono to see.

It could be just one of life's great mysteries....

Thanks again for sharing your experiences.

-dave-

[peterz]

Any chance that the real culprit is small changes in your eyes? Mine surely change over the course of a day, even the course of an hour's shooting in my basement.

[barbados]

Could be!

I don't have the best pair anymore, maybe it's time to get a check up!

Thanks!

-dave-