Concentricity

[Ferrum]

Does anyone check concentricity when loading? If so do you check everything or just precision loads? Your opinion on the necessity of checking it? What do you use (brand)?

[JagerDog]

Usually only done by hardcore benchrest guys.

[huckberry668]

I do it... but only on ultra accurate loads on unprepped brass or developing loads. Some of my rifles capable of .5MOA or less concentricity matters something like .01" accuracy gain. I feel the real benefit seems to be less fliers.

I think using fire-formed & prepped brass, floating dies set up is more fruitful and less effort. some simple brass prep and bullet sorting works wonders for accuracy more so than concentricity. My prepp'ed brass loads shoot so accurately concentricity is not a concern for me.

I once measured the concentricity of a box of Fed GM and they're all over the place. I remember a few were .005" or more. still shot close to half MOA groups.

[Ferrum]

^^^^^ That's what got me thinking about this today. I opened a box of Win .308 today and accidentally dumped a couple rounds on my work bench. While they were rolling around I noticed some wobble. So then I put the rest of them on the bench top and was surprised by the amount of wobble in the group of 20.

I may be wrong, but really expected more out of factory ammo?

[mark501w]

forester co-ax I believe my 4x4 runout was less than .003.

[huckberry668]

^^^^^ That's what got me thinking about this today. I opened a box of Win .308 today and accidentally dumped a couple rounds on my work bench. While they were rolling around I noticed some wobble. So then I put the rest of them on the bench top and was surprised by the amount of wobble in the group of 20.

I may be wrong, but really expected more out of factory ammo?

not really, factory ammo is made with virgin components on machines. There are a lot of variants in the components. handload on the other hand reduces a lot of them if done carefully.

but if they're that visibly wobbly there maybe something else wrong with them. a few thousandths of wobble is hard to tell by the naked eye. if they shoot good, don't worry about it.