Point of impact

shooter mcreid · Post by **shooter mcreid** » Tue Jun 03, 2014 8:38 am

what are the major and minor contributing factors for slower shots impacting higher on a target. I had some interesting results when testing a load not too long ago. I remember reading something on a thread but couldn't find it. I can think of a few possibilities but I'm not sure how much effect each has.
Shooter technique
Barrel vibration
Amount of taper on the rear of the stock
Muzzle lift
Please feel free to add to my list, correct my list or give your opinion.

plumbs7 · Post by **plumbs7** » Tue Jun 03, 2014 9:24 am

Hi Josh,
Possibly barrel harmonics or barrel whip !
Cheers.

DenisA · Post by **DenisA** » Tue Jun 03, 2014 9:53 am

Positive compensation.

http://www.geoffrey-kolbe.com/articles/ ... barrel.htm

aaronraad · Post by **aaronraad** » Tue Jun 03, 2014 10:12 am

DenisA wrote:Positive compensation.

http://www.geoffrey-kolbe.com/articles/ ... barrel.htm

Nice one Denis :!:

shooter mcreid · Post by **shooter mcreid** » Tue Jun 03, 2014 10:29 am

Denis it's funny you bring that up. To give a little history the barrel is 400 rounds old. I wanted to put 100 to 200 down the barrel before any testing/load development, however the rifle shot so well with my standard load that I didn't feel the need. It has performed very well from 500 to 700m. The group size does grow a little either side of this bandwidth.

shooter mcreid · Post by **shooter mcreid** » Tue Jun 03, 2014 10:32 am

However that is the effect, I'm also interested in the cause.

aaronraad · Post by **aaronraad** » Tue Jun 03, 2014 10:39 am

I'm not sure where this might fit into the equation but I've just started looking at the Excel spreadsheet (I don't have QuickLoad) about 20 seconds ago :?:

http://www.the-long-family.com/optimal%20barrel%20time.htm

DenisA · Post by **DenisA** » Tue Jun 03, 2014 11:56 am

Positive compensation is the effect and the moment that the bullet leaves the barrel in reference to the muzzle angle during vertical vibration is the cause.

To my understanding..... The answer is to find the widest node for bullet exit where the muzzle angle is most consistent for a period of time. This can be done through further load development and/or barrel tuning via tuner or extending a node (if your on the edge of one) via a weight.