A Note for John Kepler - Slower Bullets Hit High

John,

My response to your post recently might need revising.

I went out to my range this morning while waiting for my partner. We had to trim some horse hooves, including an unbroken stallion with a mare on location in heat.:banghead: For those who have never tried this endeavor, it is akin to spitting in Dick Butkas' face.:yikes:

I had two groups of 22 K-Hornet rounds to test. 1st group was a 40 gr V-Max in front of 12 grs IMR 4227 (fire forming load). The second group was the same 40 gr V-Max in front of 13.5 grs IMR 4227.:madsmile: Velocity of the first group averaged 2840 fps, the second group averaged 3140 fps. :bow:

I fired the first group first, totaling 13 shots, all right around the Bull. I then fired the second group, 5 shots, and much to my surprise, they grouped several inches below the slower velocity first group. :confused:

On this day, with my rifle, the slower bullet impacted higher on target than the faster bullet, all other variables equal.:dunno:

I am just calling them as I see them, but I was wrong about this one, and I am man enough to admit it.:slap:

I tried to load a composite target showing the results, but the file was too large. I intend to repeat the test. I find it confusing to say the least.:surrender:

The game is still afoot!:cheers:

Jim:cool:

But this slower/higher effect only occurs at close ranges, Jim. So your glass
is as half full as it is half empty.

:-)

Quote:

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Originally Posted by MEHavey

But this slower/higher effect only occurs at close ranges, Jim. So your glass
is as half full as it is half empty.

:-)

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MEHarvey,

I must admit I don't quite understand the situation. The K-Hornet has so little recoil, it is difficult for me to believe that the added milliseconds in the barrel will raise POI that much; but right now, evidence (my own) indicates it does.:confused:

I am going to repeat the test this weekend. I have some 55 gr bullets that I might add to the pot. I want to understand the physics of the situation in my own mind.:surrender:

It is interesting to say the least, but probably boring to most folks.:super:

Is 100 yards considered close range for a K-Hornet?:madsmile:

Jim:cool:

Sorry about misspelling your name. I know better.

Jim

It's not boring to me I'm interested in your findings.

Hang in there, Hank. There is more to come. I just ordered several hundred more bullets. The little K-Hornet is cheap to reload, comparatively.

Jim

The lower impact of faster bullets is well known and can be shown in handguns, but I am surprised at it in such a low recoiling weapon as a hornet.

The cause may simply be different vibration pattern with different loads.

I have a mauser sporter still in 8mm which shows as much as a 24 inch change in elevation at 100 yds simply by changing bullet weight. I don't remember if fast is low or the reverse. I find this very odd, however. It cannot be simply the recoil factor.

I have to agree with you. I may dampen the barrel to see if things change.

Jim

Velocity and barrel harmonics go hand and hand here as well as the recoil.

Quote:

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Originally Posted by Bruce McAskill

Velocity and barrel harmonics go hand and hand here as well as the recoil.

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The barrel on my K-Hornet is a slim SS Hart barrel (all Hart barrels are SS). Due to its light weight and small crosssection, I expected heat to be a factor after a number of shots. It is not unusual for me to put 30-50 rounds through it in an afternoon. :madsmile: For that reason, I free-floated the barrel. I may put some upward pressure (5-8 lbs) on the barrel at the tip of the stock, but that is for a later day - maybe.:thup:

Jim:cool: