I'm still frying my head with mine.
I changed the front pins again on mine to countersunk. This meant that the head of the pin lodged itself in the small thread hole in the stock and centralised itself.
I then zero'd in at 35 and put about 200 pellets through it. Zero never budged. I went back a couple of days later and another 150 pellets and still no budge. The 2 days were on warm days over a week ago ( probably 15 degrees ). I then went back last Saturday and the temp had dipped again ... not freezing ... but coldish ... about 5 degrees ... but with an icy wind ... it actually hailed a few times. POI had moved about 12mm high ( but I put that down to the cold taking the power up ... although I didn't chrono but I know it goes up when cold ).
So I left it at that as it was round 1 UKAHFT next day at Kibworth. I thought it had forecast for a tad warmer in the afternoon session the next day so leave alone and hope it sneaks back down. Lunch time on the Sunday at Kibby it was quite pleasant temp wise. On the zero range with wind coming from behind us, the gun was back to bang on. On the course I couldn't hit owt but I think that was just me mis judging a healthy wind and the toys came out after about 8 targets. I haven't re checked the zero yet ( cricket has kicked in now so no time for shooting ) so don't know if it has changed or not. Results looked good with those new pins before the comp though with best part of a tin going through it with no change.
The other thing that I'll mention in case you want to have a quick look at it ... and Herx put me onto this ... so many thanks ...
My buttpad isn't really a buttpad ... it's a home made snow plough. It's basically an experiment job which is just a longish alloy plate which is straight. This allows to me to get some shoulder contact when prone. I noticed that I only have to have the very top of that plate in a different place on my shoulder ... like just 10mm different ... and it moves the POI vertically. So during that tin of testing with the new front pins I made sure that I had the end of that buttplate in exactly the same spot on my shoulder ( tip of plate actually sat on a line of stitching on the jacket ). Problem with HFT is that's not always possible on a course as you find yourself lying in different positions at different angles.
That may explain why when I'm shooting sh1te on a course and I throw the toys out and shoot the rest of the targets kneeling I actually start hitting more targets. When kneeling I can pretty much get the gun, and the butt, in exactly the same place.
It has taught me that I'm going to have to completely change the stance I use for HFT comps. My present stance is great if I'm shooting at our range and on courses with pretty flat peg areas ... but once I have to change that stance my POI goes t1ts up.
So not sure yet if I've cured the 'Shift' ... but all good fun!
I mentioned earlier that this gun never lost zero in another more sporter style stock. The other thing that I thought was different from shooting it in that old stock is the mounts. In that old stock the cheekpiece was low so I used lowish mounts ( they were probably medium but the front bell basically sat half a mm above the action tube ). On this Paul Wilson FT stock the cheekpiece is very high so I have to use very high mounts ).
So I wondered if the change in POI due to temp is more with these mounts as there is a longer block of alloy to move in the cold. I can't remember this temp shift being so great with that old stock and the small mounts ? I know the power does go up but I'm wondering if the extra height in the mounts adds to the issue ?
Last edited by skires; 3rd May 2013 at 07:04 AM.