Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 5:44 am
by zzr1100
I'm having to re zero between solids and hollow points ... The solids hit about an inch high and and inch right at 50m ... Now I fully understand the vertical adjustment but why the horizontal ?
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 6:31 am
by dodgyrog
Different centre of gravity and different reaction to bullet spin?
Different ballistic coefficient?
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 6:33 am
by Dangermouse
Bullets do not just fly straight up and down they also spiral as they fly. What you are seeing may be the bullet at at different point in that spiral hitting the target a fraction of a second quicker or later.
Maybe!
DM
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 6:46 am
by the running man
Hollow points are traditionally sub sonic, it's therefore going slower, you work it out, its not rocket science me son....
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 8:52 am
by zzr1100
I can fully understand the vertical adjustment .. The spin thing makes the horizontal more understandable
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 9:23 am
by Maggot
Just a thought (I have pretty well always seen a small change in lateral accross load changes)
But if a gust causes slight elevation changes (precession etc etc...whetever does it....witchcraft etc), then should not a change in velocity/trajectory and presumeably stability cause a change of sorts?
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 10:01 am
by Dangermouse
If you search 1015fps on you tube there is a good video that demonstrates the spiraling bullet in flight. Sorry can't attach as on phone.
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 12:18 pm
by Maggot
Almost a bit cloverleaf in flight.
Re: Different POI on impact between hollows and solids
Posted: Thu Jul 03, 2014 12:21 pm
by 20series
Dangermouse wrote:If you search 1015fps on you tube there is a good video that demonstrates the spiraling bullet in flight. Sorry can't attach as on phone.
this be the one ???
Re: Different POI on impact between hollows and solids
Posted: Fri Jul 04, 2014 4:38 pm
by Mattnall
Dangermouse wrote:If you search 1015fps on you tube there is a good video that demonstrates the spiraling bullet in flight. Sorry can't attach as on phone.
Shoot RG tracer out of a 1:12" twist 5.56 barrel and you won't need high speed camera and tricky set up to watch the spiral.
You usual solid bullet is about 4gr (almost 10%) heavier than the average HP. This will also have an effect on their respective flight paths.
