keyholes

[trb0]

I have a savage model 10 that has been shooting about 1/2 in. at 100 with 168 gr. hornady match bullets at 2700 f.p.s. using blc2 powder.I tried shooting at 850 yards for the 1st time and the bullets are keyholing,so I went back to 300 yards and they are keyholing bad there also. At 100 the holes are o.k. The barrel is 24 inches and has a 1 in 10 twist?any ideas? thanks trb0

 

[trb0]

I keep logging in but when I go to a forum to post it then tells me that I'm not logged in .help please trbo

 

[zingdingo]

timbo,

Can't help you with your login problem, but what caliber is your savage?

Carl

 

[youarenotcrazy]

What size group were you getting @ 850?

 

[trb0]

The caliber is .308 and there was no group size because you couldn't keep them on a 4'x4' target.My 6.5x.284 is shooting about 8 1/2" 10 shot groups at 900 yards,this is off of sandbags over a truck hood.The gun is a Model 70 that weighs 13#s.Is this close to acceptable?Thanks trb0

 

[Bart B]

Try Sierra match bullets and see what they do. If they keyhole too, then the barrel or your handloading processes probably have a problem. If they don't, then don't shoot any more of the ones that die.

 

[CPorter]

Do you know what velocity your bullets are leaving the barrel? Keyholing generally means the spin isn't enough to keep the bullets stable. You can overcome this by speeding the bullets up a bit, getting a faster twist barrel, or going to shorter (lighter) bullets. You can check this using some of the ballistic calulators on the net. Most use the old Greenhill formula which isn't real accurate for spitzer type bullets but it does get you in the ballpark.

Less commonly a batch of bullets with bad cores can cause the bullets to deform in flight. These tend to blow up before reaching 850 yards though. If your targets show the bullets in one piece this probably isn't the case.

 

[älg]

timbo, are these match bullets the a-max? they are usually pretty long and maybe they are not stabilizing well... as someone has said, try some sierras if they are shorter. Or see if you can push the hornadys a little faster. Just ideas.