Runnout and Bullet sorting

[Don P]

Also is this deviation enough for me to even worry about?

Considering that the human hair is .003 thick I say you are over thinking it and worrying about nothing

[milboltnut]

Originally Posted by DonP

Considering that the human hair is .003 thick I say you are over thinking it and worrying about nothing

I used to think like that.

[HiBC]

It was actually two questions, you were the first one to notice, I was wondering if the ogive difference of +- .0004 makes a difference in runnout of the COAL.

You might get runout due to a bullet seated out of square,or a bullet that is not round,or a cartridge that is bent,etc.

To get zero runout,the cartidge case and the bullet must be coaxial,and they must be round.

When they are rotating with a dial indicator on them,the needle does not move.

If,from high to low,the total travel of the indicator is .003,then you have .003 Total Indicated Runout (T.I.R.)

Runout does not apply to CQAL,as it is a static length. Referencing "runout" to "the flat spot" or COAL just does not fit. A "flat spot" does not have runout.Neither does a length.

Diameters have runout based on axis of rotation.

Perhaps a better word for you is "variation"

I'm not trying to criticize. I spent over 30 years earning my pay machining,inspecting,and reading blueprints. When a word like "runout" is misused,it tells folks the person misusing the word may not know what he is talking about. Its kind of like misuse of the word "headspace".

Folks who take the effort to educate are trying to help you express your ideas accurately.

Its done with respect.

You may search "Geometric Dimensioning and Tolerancing" to hind references.

or try this

http://proofengineering.com/white_pa...olerancing.pdf

Update and correction, You can measure runout on a flat face,such as a flywheel,or exhaust valve,or cartridge case head.

If you accurately could chuck a sizing die co axial with a lathe spindle, you could use it for a pot chuck and insert a cartridge case till the case taper adequately held the case with friction. Then you could set up an indicator on the flat base of the case head,rotate the spindle,and check for runout.

This would indicate if the case head (and perhaps bolt face) were square.

If you measure 50 cartridge cases for trim length and find the range of length variation is .013, its not runout.

[milboltnut]

post members name in the quote, I'd like to know

Runout.... concentricity. "variations" in a circle in this case.

actually no I did not misapply runout.......

He asked also about OAL instead of COAL
bullet and case COAL not OAL in relation to just the case. Maybe you could have picked up on that, I did.

Originally Posted by akinswi

I was also wondering if there is any correlation to the ogive being different +- 4 thousandths and runnout on the OAL.

[Bart B.]

SAAMI's glossary says for Ammunition that OAL is the greatest dimension of a loaded cartridge, i.e., from face of the head to the tip of the bullet for centerfire or rimfire.

There's no abbreviation for case length from head to mouth.

[milboltnut]

It’s what I and millions of other handloaders call it

[akinswi]

Thanks for all the info guys, After several tests For My M1 measuring each ogive didnt change anything as far as group size.

This is the best I could get . see attached file below, It was a 5 shot group the first shot was low underneath the enbloc clip. Next 4 was the best I could get.