Today I was re-sighting my .25 Marauder and thought I would try something different. My chronograph is dead and I need to purchase a new one before too long.
So here is what I did:
First I sighted in my rifle at a known distance(55 yards) with the help of a laser rangefinder. Next I put zero data and an educated guess on pellet velocity into chairgun pro program to give estimated holdover for the next part. Then I Shot a group at a further known distance (112 yards) and compared impact to Chairgun table. Finally I adjusted the velocity in the program until it matched impact point of shot group.
I was wondering if anyone else has done this or how accurate it could be. I know this is not a replacement for Chronograph, but I was in a pinch. Lastly any advice on a good chronograph? something that can work well in most lighting conditions.
Thanks Dave
To follow up on this I just got my new Chronograph and light kit, thanks ajshoots on that suggestion. It works like a charm in my basement, Anyway from my above method I predicted a velocity of about 840fps(JSB Kings). Which I think is kind off disappointing from the manufacture tune. So with a fill from about 2750 my first 8 shots high 832 low 825 average 827. My next eight really started to drop off more, low of 796 on shot number 16. Anyway my prediction was only off by about 13fps.
So here is what I did:
First I sighted in my rifle at a known distance(55 yards) with the help of a laser rangefinder. Next I put zero data and an educated guess on pellet velocity into chairgun pro program to give estimated holdover for the next part. Then I Shot a group at a further known distance (112 yards) and compared impact to Chairgun table. Finally I adjusted the velocity in the program until it matched impact point of shot group.
I was wondering if anyone else has done this or how accurate it could be. I know this is not a replacement for Chronograph, but I was in a pinch. Lastly any advice on a good chronograph? something that can work well in most lighting conditions.
Thanks Dave
To follow up on this I just got my new Chronograph and light kit, thanks ajshoots on that suggestion. It works like a charm in my basement, Anyway from my above method I predicted a velocity of about 840fps(JSB Kings). Which I think is kind off disappointing from the manufacture tune. So with a fill from about 2750 my first 8 shots high 832 low 825 average 827. My next eight really started to drop off more, low of 796 on shot number 16. Anyway my prediction was only off by about 13fps.