.300WSM, Nosler M-48, 62.0 grain H4350, coal 2.865, 180 grain AB, Lupy 4.5X14LR with turretts, Site in at 1.7 high at 100 yds to be dead on at 200 yds. Made a mistake and sited in at 2.7 at 100 yds (no big deal two clickes down will take care of the mistake) Went to range today and shot a five shot group under 3/4 inch, hit target at 2.5 inches at 100yds (good enough for me) Went to 200 yds and shot a five shot group still very good group but hit target 4 inches high. That is about 1.5 inches higher than at 100yds. Why did the bullet rise that much in 100yds. Would the power of scope make a difference. 200 yds was at 14X and 100yds was around 8X. Should this be a concern for longer ranges. I would rather hit a little high than a little low.
Why?
- Thread starter chipper
- Start date
looks like you've got a gravity defying magical gun!!!!! :lol:
POI shouldnt ever change with power changes. you can stick a bore sight thingy in the barrel and watch the cross hairs to see if they move while you adjust the power ring, focus ring, etc.
Also, I hate turrets cuz I'm always bumping them.
POI shouldnt ever change with power changes. you can stick a bore sight thingy in the barrel and watch the cross hairs to see if they move while you adjust the power ring, focus ring, etc.
Also, I hate turrets cuz I'm always bumping them.
chipper":3ujrdt76 said:
I don't think you are far of looking at the ballistics table. I punched in the numbers you gave me, and assumed 2950 for velocity. If you are zeroed 2.7" high at 100, you would be about 2.4" high at 200, giving you a 255 yard zero. I ran this with the .507 BC of the 180gr AB. You would be 3.2" low at 300 yards. Granted, this is just a ballistic table, but it makes sense. I usually zero non BDC scopes at 3" high at 100. At 200 yards, I am about 3.5-4" high, and about dead on at 300. Seems you have an inch of unaccounted for height, but nothing to write home about. Could have just been you looking at a different aiming point on the target. Scotty
Are you taking into account the instrument height of that hubble telescope you've got mounted on there? Many ball. programs use a default 1". Most 50mm scopes must be mounted considerably higher. To get that trajectory to cross line of sight at zero range the bullet must rise considerably at midrange.
- Nov 4, 2004
- 25,179
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Polaris":6g4lmdc8 said:
Good point. Is the scope a 50mm?
JD338
- Thread starter
- #6
It is a 40mm bell, I used a 1.5 sight height from big game info, thye state 1.7 high at 100 for a 200yd zero, I am at 2817 fps, but it does not change at 2850fps. I not too concerned, just was wondering why it was high. If this holds true it should be high at longer ranges.
Antelope_Sniper
Handloader
- Jan 25, 2008
- 2,618
- 0
Chipper, changing powers can change point of impact.
As an example, the old Redfield scopes actually advertised the fact that they had a 2" higher impact on 7x then they did on 9x. So check your scope, see if the crosshairs wander up and down as you adjust the powers. Many of them do.
As an example, the old Redfield scopes actually advertised the fact that they had a 2" higher impact on 7x then they did on 9x. So check your scope, see if the crosshairs wander up and down as you adjust the powers. Many of them do.
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