Point of impact

Get or give advice on equipment, reloading and other technical issues.

Moderator: Mod

Message
Author
shooter mcreid
Posts: 322
Joined: Sat Mar 01, 2014 5:26 pm
Location: Ipswich

Point of impact

#1 Postby 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
Posts: 1124
Joined: Wed Feb 12, 2014 7:32 am
Location: Dalby/ Tara Rifle Club

#2 Postby plumbs7 » Tue Jun 03, 2014 9:24 am

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

DenisA
Posts: 1526
Joined: Wed Nov 09, 2011 7:00 pm
Location: Sunshine Coast, QLD

#3 Postby DenisA » Tue Jun 03, 2014 9:53 am


aaronraad
Posts: 573
Joined: Wed Aug 08, 2012 3:43 pm
Location: Brisbane, Australia
Contact:

#4 Postby aaronraad » Tue Jun 03, 2014 10:12 am



Nice one Denis :!:
Be careful what you aim for, you might hit it! Antipodean Industrial - Home of the G7L projectiles

shooter mcreid
Posts: 322
Joined: Sat Mar 01, 2014 5:26 pm
Location: Ipswich

#5 Postby 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
Posts: 322
Joined: Sat Mar 01, 2014 5:26 pm
Location: Ipswich

#6 Postby shooter mcreid » Tue Jun 03, 2014 10:32 am

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

aaronraad
Posts: 573
Joined: Wed Aug 08, 2012 3:43 pm
Location: Brisbane, Australia
Contact:

#7 Postby 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
Be careful what you aim for, you might hit it! Antipodean Industrial - Home of the G7L projectiles

DenisA
Posts: 1526
Joined: Wed Nov 09, 2011 7:00 pm
Location: Sunshine Coast, QLD

#8 Postby 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.


Return to “Equipment & Technical”

Who is online

Users browsing this forum: No registered users and 48 guests