Neck Tension and Accuracy

[.223Savage]

My last trip to the range was ruined by some poor shooting that I am hoping to blame on my reloads.

My standard load for Hornady 55g SP is 25.5g of Varget. This combo has averaged under an inch over 20 five shot groups.

Last week one group of 50 loads did not perform well, 9 groups averaged 1.400 in. and 3 shots KEYHOLED at 100 yards. I have never had that happen. To add more confusion I took the last 5 shots at 5 one inch dots and hit 4 of them.

The poor results did not please me.The rifle is a Savage 12VLP.

In looking for what went wrong, two things came to mind:

1- I may have forgotten to clean the rifle the last time I shot. I suspect this is not the problem, but may be wrong.

2- I checked back into my reloading log and found a note for this batch of reloads. I scribbled that many of the bullets seated easier than normal.

The question is, could poor neck sizing cause the lack of accuracy and the keyholing with an otherwise great load?

Your thoughts please.

 

[ben hunchak]

If your loaded round allows the bullet to slip deeper into the case before firing, alot of potential problems come up, but I haven't heard of keyholing bullets being the result. You should be able to put your weight on a loaded round being pushed into wood, bullet tip first, the bullet should not slip, if it does, fall back and regroup. If your neck sizing isn't enough, you have a couple of options,a) try diff. brand of brass(thicker at the neck) b) purchase Redding sizing die with diff. bushings to match.c) use bullets with cannelure so you can crimp them.

 

[shootist22-250]

You should be able to put your weight on a loaded round being pushed into wood, bullet tip first, the bullet should not slip, if it does, fall back and regroup.

Yikesssssss.....
I'm in trouble Ben.
When you can only seat 0.050" of the bullet into the case (some serious barrel erosion) does that mean I cannot have accuracy?
I think not as both my T-3 223Rem and Sako 22-250 have no argument with shooting less than 0.5 seated in this manner.

 

[Dmay]

Can't see neck tension being your trouble...unless, like Ben says, your bullets are being set back into the case.....but none of this should cause keyholing.
I don't quite agree that neck tension needs to be super tight, should just be consistant.
However, I suspect something must be seriously wrong.....how did you meter your powder.....could your charges have been inconsistant?

 

[crout]

neck tension is not as important as neck concentricity. you want your necks tight enough so the bullet will not be pushed into the case due to recoil(tube fed, mag fed)but neither of which will cause bullets to keyhole.
my understanding is that a bullet will keyhole if the twist rate is too slow for the bullet weight as well as bullet velocity in some cases. so if you have a slow twist rate and a reduced load the combination could cause the bullet to keyhole, even though at an increase velocity the bullet/twist rate will stabalize.

 

[Baribal]

..... and bad or damaged crowning can also make a bullet keyholing.

 

[shootist22-250]

so if you have a slow twist rate and a reduced load the combination could cause the bullet to keyhole, even though at an increase velocity the bullet/twist rate will stabalize.

This I can personally vouch for. It has happened to me with light loads in a 22-250.

 

[ben hunchak]

The instability mentioned above does happen and I have to push bullets faster then I like in some cases because of it. For hunting loads, esp. in hard kicking cals., you need alot of hold on bullets or they will slip the crimp, in tubular mags. it can force the bullet back into the case. Extracting a loaded round from the chamber can leave the bullet in the bore and powder in your action/magazine. Smaller calibers, loaded singly, at the bench are a diff. story.....