Bullet Tumbling

humptyjumped

humptyjumped

CGN Regular
Rating - 100%
7   0   0
Location
Vancouver
Ok.... so here is the scenerio.

I took my rifle to the range. It is a single shot build based on a Savage 110 action. 1-13 twist.

I noticed something bizarre. It liked the 155gr bullets, but i did not get under MOA. What was disturbing, is when I tried 168gr, the bullets seemed to be tumbling.... The hole at 100m was pronounced.

What could be causing this? Its an older target rifle, and I have a replacement barrel ready to go......but.....I am shocked!

Your thoughts? :confused::confused::confused:
 
I know with some bullets they do not fully stabilize until they reach a certain range, this may be the case here. I've experienced this with Berger VLD's.
 
That is funny, because most 155's are about the same length as 168's, and the stability vs. twist rate is dependant on bullet length not weight.
 
Maybe it's your rate of twist? I've got a 1:11 twist, I use 168's exclusively and have never observed any tumbling or strange holes on paper, be it at 100m or 200yds.
 
have you confirmed the twist w/ a snug patch on a cleaning rod? I'm almost betting that the twist is a good bit slower than 1-13... Which 155 bullet were you using? the lapua and 155.5 berger are quite a bit longer than the old style sierra.
 
mpwolf said:
have you confirmed the twist w/ a snug patch on a cleaning rod? I'm almost betting that the twist is a good bit slower than 1-13... Which 155 bullet were you using? the lapua and 155.5 berger are quite a bit longer than the old style sierra.
Click to expand...

the 155's are berger vld's.... the 168s were hornady amax. I will check the twist... thats a good point.
 
A true 13" twist will have no trouble with anything under 180-200 grains. I would suspect RPM. How fast were your loads? have you confirmed twist rate?
 
You must log in or register to reply here.
Back
Top Bottom