case length effecting accuracy

AKD

CGN frequent flyer
EE Expired
Rating - 100%
11   0   0
Anyone ever test how much accuracy is effected by case length if at all ?

With a difference of .005 between some rounds do u think it will have any effect ?

anyone ever test this ?
 
nw I do. I can be pretty pickey, the most ill let one slip is if it gets trimmed .001 smaller than the size im using. just curious.

what kinda danger do u think would happen if the neck was to small?

I just started reloading this year. I got a few hundred rounds down and fired off, none with any caution problems yet to "learn" from thank god.
 
A few 0.001's in length doesn't make any difference. What is more important is that the necks are square... or should I say that the chamfer you're adding afterwards is square. This affects concentricity, how straight your bullet gets seated. If your bullet isn't seated straight, it isn't going to go into the rifling straight and it'll be rotating off-axis when it leaves the barrel.

Its funny how many people nit-pick over trim length and then go and use a handheld deburr/chamfer tool that has no alignment features. The bottom edge of that chamfer (the first and last point in the neck to contact the bullet) will vary more than the cut length of most trimmers and it will be less square. If you aren't using something like a K&M deburr tool (thanks acrashb) or a trimmer mounted one, worrying about a few 0.001's of trim length is a moot point.
 
0.001's of variation have a much larger effect on accuracy when it comes to things like neck tension, neck runout and bullet runout. Yet, most people make no effort to measure and/or correct for any of these. Trim length is targeted mainly because everyone who reloads owns a caliper. It becomes important when you start doing things that rely on a very consistent length, like neck turning. Then it will affect how far you cut into the shoulder area. If you aren't addressing the three things above and you're chamfering the case mouth holding the tools and case in your hands, don't worry about that 0.005". Just keep them below max. OAL.
 
I took pictures of the K&M chamfering tool since the pics on the sites that sell it are worthless.

P1040809.jpg


P1040810.jpg
 
Back
Top Bottom