30-06 point of impact change

R

roninflag

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for my .357 target revolver- if i go up from a 110 to 125 to 140 to 158 grain loads my point of impact at 25 yards goes up. for a 30-06 -going from a 150 to 165 to 180 grain bullet ( at 100 yards) which way would the point of impact go ?? thanks. roninflag
 
roninflag said:
for my .357 target revolver- if i go up from a 110 to 125 to 140 to 158 grain loads my point of impact at 25 yards goes up. for a 30-06 -going from a 150 to 165 to 180 grain bullet ( at 100 yards) which way would the point of impact go ?? thanks. roninflag
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Your revolver is shot at close range, so gravity has little effect, so the hevier bulet has a longer barrel transit time, and the revolver recoils more. Also, barrel whip does not enter the picture..

With a rifle, the larger bullet will cause the barrel to rise a bit more, but the lower velocity will cause the bullet to drop faster... it has been my experience that it is unpredictable with rifles.
 
aka Hunter said:
Lower velocity does not affect the speed of the drop. :)
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I think what was meant should have been obvious...

... but to clarify for any misunderstanding.

Lower velocity will cause lower impacts on the target, which will over ride the increase in launch angle caused by the increase in recoil before the bullet exits the barrel.
 
30-06

Rflshooter- thanks. i have 30-06 that when sighting it in, the scope was nearly maxed out on adjustment. i am shooting 165 grain bullets . i so not want to go to 180's in this rifle and i do not want to be at the ragged edge of the scope adjustment range; so i am going to have gunsmith shim the mounts. thanks. roninflag
 
Time of flight is the controlling factor.

Ironflag,

This advice is free so view it in that light.

Simple logic tells us that because a slower bullet will have a longer time of flight than a faster one it will take longer to reach the target. Most heaver bullets will have a lower velocity than lighter ones, therefore, a longer time of flight. We are only dealing with 100 yards. The drop due to gravity is dependent only on time of flight. Simple answer: The heaver bullet will drop more only because of the time of flight.

The difference with a 30/06 at 100 yards will be very little if you are shooting at deer at 100 yards. The deer will not know the difference.
 
XBBR Shooter said:
... Also, barrel whip does not enter the picture... it has been my experience that it is unpredictable with rifles.
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Agreed. How about a 2 MOA lower point of impact @ 100 yards when going from a 168 to a 155 grain projectile? (Same manufacturer, 155 grainer flying about 150 FPS faster.) Or a 3 MOA LATERAL shift (no change in elevation) when going between 2 different manufacturer's 155 grain bullets? Both obervations made using two different rifles. (Both chambered for .308 Winchester.)
 
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About 40 years ago I was helping at the range during "hunter sight in" and a father and son had two loads for the .30-06 they were shooting. One for sight in and one for hunting. They both shot groups that were about the same size, but one load shot about 3 or 4 inches higher than the other. Same bullet weight, but different brands of factory ammo. I tried to explain as best I could, and suggested that they sight in with what they planned to take hunting and use the other load for practice which was at about everyone's level of understanding.
 
30-06 point of impact

you would think loading almost 2500 rounds for my heavy krieger barrel, glass bedded garand one year, i could remember . loading 167 lapua , 168 horn and sierra and 175mk they all shot real close. with out a 36x leup on there i could not tell much difference. i have a 6 pound rem 700 mt rifle shoots .6 with 168 berger for hunting. no reason to mess with that. my sako 3 lug mannlicher 30-06 is a pain, heavy , pretty, fussy as far as accuracy, and now have a hard time getting it sighted. one click from max height adjustment with 168 balistic tips. thanks. roninflag
 
This thread just shows that you better sight you rifle in with the ammo that you intend to hunt with before you go hunting.
 
Nice and superb information all i really like and impressed with your knowledge...
 
30-06 point of impact

Bill Wynne said:
This thread just shows that you better sight you rifle in with the ammo that you intend to hunt with before you go hunting.
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i am sighted in .5 inches high at 100 yards and my adjustment in the scope is maxed out. the scope is a 3-9 diavari.
 
No disrespect to you or your gunsmith, but I have seen all sorts of improper gunsmithing when it comes to scope mounting. Your rings need to line up with each other so that they are not trying to bend the scope as the rings are tightened. I have no way of knowing if your rings are lined up now, or whether they will be if one of the bases is shimmed, but the likelihood is that they are not, and that they will not be. What you need to do before you put the scope back in the rings is to lap or bed the rings, or switch to the Burris Signature rings that have self aligning inserts. These inserts are available as offset pairs so that you will not have to shim your base, and because of their self aligning design, you would not have to lap or bed your rings.
 
30-06 point of impact

It is a sako (three lug )manlicher from 1968. the sako rings are original. they have windage but not height adjustment. have not lapped them yet or taken it to the gunsmith. my remingtons are easier just slap some burris zee rings with inserts and yer done.
 
up or down,,,

Hi Ron,,, I shoot a 6mm BR most of the time (Krieger 8 twist) and use bullets from 65 to 108gr,,,all at or near max loads/vel. for each bullet,,,at 100 yds the 65-68gr bulets will print aprox 1" higher than the 105-108gr bullets ,,,,and the 80-90-95-100gr bulets move up and down the target proportionally to their wt.....very predictably,,,,If I would shoot them using the same point of aim the group would look like a catapilar crawling up or down the paper depending on which bullet wt. I used first,,,,I have seen a 30-06 exibit the same characteristic,,,but most 30-06's wont shoot groups small enuff to see it at 100 yds,,,,,when you get down range the bigger more balistically efficient (higher BC) bullets start to hit higher when you dont change the scope setting...I hope this makes sense to U,,,Roger
 
30-06 point of impact

Roger - thanks , i may consider going down to 150's. do you use varget? or moly in the 6mmbr??
 
Hi Ron,,,,I use Rx-15 (and some blends of Rx-7--Rx-17) and WS-2 on the bullets to help with jacket wash and lengthen the shot string between cleanings.
 
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