friend of mine took his cz 458 lott to the shooting range and the result was like this at 100 meters shoot from a rest 3 shots group

300gr bullet with norma 203b 90gr was 25cm below point of aim

500gr bullet with vihtavuori N-140 80gr was 15cm above the point of aim


should it not been the other way around ??

regards Magnús

As for the lighter bullet hitting low that may well be just where the rifle was sighted in, not sure about that. However, since the heavy bullet would most likely be moving at a slower rate of speed, more recoil, or what I call "dwell time" in the bore and the additional recoil, muzzle raised prior to bullet exiting the barrel and hence placed higher on the target. Calibers such as the 45-70 with heavy bullets, 400-500gr and moving at some 13-1600fps will exhibit such results. I shoot a Ruger NO.1 458Lott and it is quite heavy and does similar performance using wide range of bullet weights. If you crank up the 300-350gr. bullets in velocity they leave the bore quickly and pretty much spot on. I may be way off base here, but sure others can give you more exact answers. Great caliber and very accurate with whatever you shoot in it.

quote:

Originally posted by Maggi:


should it not been the other way around ??

regards Magnús

Nope, That's the my rifles shoot. 100 yds - Heavier bullets shoots higher.

There is no telling how one particular bullet will shoot out of a rifle. But generally, the faster the bullet the lower the POI. And generally, the heavier the bullet the higher the POI.

JPK

my 45-70 does this also. like someone else said, The only reason I can think of is with heavier, slower bullets. the muzzle has more time to rise from recoil before the bullet actually exits the barrel

The very opposite for me...

I've loaded for eight 45-70s. All of 'em shot the heavier bullets MUCH LOWER than the lighter, faster bullets. The same with my .458 WMs. The difference is one foot higher for the lighter - faster slugs.

But then, on these heavy kickers, I don't allow the muzzle to rise off the rest when bench shooting. They come straight back. I hold down on the forearm.

That's a technique I learned a long, long time ago after reading an article on managing recoil of the Big Bores. It works!

Bob

www.bigbores.ca

I'm going to guess it this way, the lighter bullet traveling faster is going to have a different arc. My understanding of it being thus:

a bullet leaving a barrel does not travel in a straight line then begin dropping, as man suppose (again, I might be all wet here). It leaves and moves in an arc, rising higher in the middle of it's flight, then dropping again.

i.e. a bullet at 25yds may hit same spot on a target at 100yds, but the 50yd target would show it hitting high.

the 500gr bullet is probably higher in it's arc, and therefore further into it's effective range, than the 300. that's why if he sighted it in to be spot on at that distance the overall distance he'll still be able to hit them at without a lot of hold over is going to be short.

whereas the 300 probably has more "up" left, and isn't as far into it's arc. does any of this make sense?

Now hopefully somebody that shoots A LOT and is analytical about it (RIP?) will come along and tell me if my theory holds water (or ballistic gelatin as the case may be).

Red

thanks for all the info

we will test it again soon and post the result

regards Magnús

In every rifle I have shot the faster bullets hit higher than the lighter, and that is a lot of rifles gentlemen. The ONLY exceptions were a couple of doubles where the faster bullet hit a couple inches lower (action hinging as the pressures were higher).

The phenomena described by the original poster on this thread is most likely due to barrel vibrational nodes. Nothing more, and in my experience is strange, but well within the realms of plausible.

Threads like this are highly enlightening though.

No, this is correct ..
Quickload projects that your
300 gr load is going faster than 2650fps
and your 500gr is going about 2200fps

with the target velocity of the lott being 2300 fps

300gr bullet is both FASTER (means it will hit lower than target load) and lighter (means it will hit lower than target load) and spends less time in the barrel than your 500gr bullet, therefore less muzzle rise when it exits the barrel

the 500gr bullet is slower (means it will hit HIGHER than target load) and spends MORE time in the barrel than the target load (2300) means the muzzle is point slightly HIGHER when the bullet exits, as compared to 500gr at 2300 ..

as for arc, which is what we mean when we say "flat shooting" (its a flatter arc)..

assume a 6" max PBR (3" above, LOS, 3" below), then the max PBR range of his 500gr bullet is
about 204 yards

his 300gr bullet is about 228 yards ...

The way I see it,you have the same downward acceleration(gravity) acting on a bullet regardless of its weight.If we neglect air friction,the velocity of a bullet should be the only factor deciding where a bullet will strike a target.The faster the bullet,the higher it will strike because gravity has less time to act on it.So to answer the question,the faster bullet will strike higher.