Strange groups

powdergun

powdergun

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I was at the range today trying a new load. I wanted to see if some hornady BTSP would shoot as well as my nosler ballistic tips. ( Both 150 gr in a .308 )

The 100 M groups were no big deal. 2" with a vertical string. However, at 300M the gun gave 2.5" groups consistently with both types. Just to end the day I lined up the pigs at 300M and dropped 3 in a row with both types of bullets with exactly the same point of aim.

Question is: can a gun/load group better at 300 than at 100 ?
 
powdergun said:
Question is: can a gun/load group better at 300 than at 100 ?
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Yes......... sort of.............. ;)

It takes some bullets a fair bit of flight to straighten out and "go to sleep". The groups don't magically tighten up at the longer ranges but they sometimes don't open up any wider than the shorter range groups.

BTW, This type of performance is why actually shooting at all your expected distances means so much more than relying on some silly trajectory table in a book or on a cartridge box. :)
 
Agreed. I seen many a fellow go to the range and set there gun a bit high at 100M and then go hunting and wonder why they miss deer at 200M or further.


Also, those trajectory tables very often aren't even close to what the gun is doing.
Worst one I ever ran into was a fellow with a .308 Norma mag from the east who told me all he did was use a bore sighter at the begining of the season to set his scope then went hunting. His reason were that the shells were too expensive to waste at the range.
 
I saw a guy miss the target entirely at 100 yds on his first shot and the second one was one inch high. When I suggested he should try it at 200 I learned one of the most valuable lessons ever!!! "The 300 Win Mag is the flatest shooting rifles ever. It is one inch high at 100, 1" high at 200, and dead on at 300".

Going to sleep is the best way to put it.
 
stubblejumper said:
:onCrack:
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He is not too far out of whack .........

My 300 wizzum launches a 165 Accubond @ ~3020 fps. It is 1 3/4" high at both 100 and 200 yards when zeroed for 260 yards and is only 2 1/2" low at 300. The additional 100 fps from a 300 Win. should reduce that 300 yard drop to less than 2 inches. The apogee of the trajectory is +2 1/2" at ~ 175 yards.
 
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My 300 wizzum launches a 165 Accubond @ ~3020 fps. It is 1 3/4" high at both 100 and 200 yards when zeroed for 260 yards and is only 2 1/2" low at 300. The additional 100 fps from a 300 Win. should reduce that 300 yard drop to less than 2 inches.
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But you are not taking into account that the 3/4" difference between your 100 yard point of impact of +1-3/4" and the quoted +1" at 100 yards will work out to 2-1/4" at 300 yards.In other words if you set your rifle up to be 1" high at 100 yards,it would be about 4-3/4" low at 300 yards.Another 100fps is not going to make up that 4-3/4".
Even my 300 ultramag driving a 180gr bullet at 3380fps needs to 2-3/4" high at 100 yards to be dead on at 300 yards.
 
Don't get me wrong.

I was not saying the trajectory he quoted was 100% correct, only that it was not as "wrong" as most of the stories we see on most hunting/shooting bulletin boards. :rolleyes:

You know the "I saw a friend's cousin's uncle shoot a moose at 600 yards using a worn out old Cooey .22" stories we have all come to love............... ;)
 
I was not saying the trajectory he quoted was 100% correct, only that it was not as "wrong" as most of the stories we see on most hunting/shooting bulletin boards.
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Wrong is still wrong,and a little wrong can actually have worse results.A bullet that misses the vitals by an inch or two usually results in a wounded animal,while those that miss by a few feet usually don't harm the animal.
 
Back to the original story though. The fellows first shot wasn't even on the paper. I hope he at least fire a few more rounds to find out if the gun or he could actually shoot.
 
There is another varible, but I would not expect to see it at 100 to 300.

If the barrel harmonics launch bullets while the muzzle is rising, fast bullets are aimed lower than than slower bullets. At long range the sloer bullets, aimed higher,will converge. Thus a 900 yard group might be 1 minute but a 600 yard group might be 2 min vertically.

The Lee Enfield #4 has this "compensation" and I used one at long range for years in preference to a front locker.
 
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