FWB 700 POI change w/ pressure

[Adams]

I've been shooting a Feinwerkbau 700 for about 4 months now and have over 3500 rounds thru it mainily in the standing position. Last night I was testing pellets from the bench rest at 10 meters. The accuracy with all the pellets tested was exceptional all going into the same hole however I discovered a disturbing occurance. The first several groups were shot with the cylinder pressure at 100 bar, still well into the green zone. I filled the cylinder to 200 bar and found the next group was 5mm higher. I confirmed this point of impact change by shooting several more groups. I'm surprised and somewhat disapointed. I thought that the regulator would have compensated for the pressure variation. Any comments (other than keeping the tank full) are requested. Also does anyone understand the purpose and how to adjust the dampener to optimize it's effect? The German translated instructions are very vage.
Thanks John Adams

[Guest]

I've been shooting a Feinwerkbau 700 for about 4 months now and have over 3500 rounds thru it mainily in the standing position. Last night I was testing pellets from the bench rest at 10 meters. The accuracy with all the pellets tested was exceptional all going into the same hole however I discovered a disturbing occurance. The first several groups were shot with the cylinder pressure at 100 bar, still well into the green zone. I filled the cylinder to 200 bar and found the next group was 5mm higher. I confirmed this point of impact change by shooting several more groups. I'm surprised and somewhat disapointed. I thought that the regulator would have compensated for the pressure variation. Any comments (other than keeping the tank full) are requested. Also does anyone understand the purpose and how to adjust the dampener to optimize it's effect? The German translated instructions are very vage.
Thanks John Adams

Try using a chronograph and verifying that the velocity is constant at the different fill pressures to confirm it is not a regulator problem.

Charles

[Adams]

I don't have access to a chronograph but I'm confident that the issue is reduced velocity as the pressure decays. The audible "pop" during firing when the pressure is low is less that when the cylinder is full. Is it normal for this velocity decline or is something wrong with my regulator? Also where can I take it for service?

[Tom Monto]

My 700 does not change point of impact.