Reading OAL measurements

[richardca99]

Thank you. I'm going to have to see about getting one of those. Is there any difference between his dial indicator and any of the others that I have laying around my bench?

 

[Martin52]

Thank you. I'm going to have to see about getting one of those. Is there any difference between his dial indicator and any of the others that I have laying around my bench?

Bob's indicator measures to a tenth (0.0001), if the dial indicators on your bench are like my others, these only measure to 0.001.

 

[Shynloco]

You cannot regulate what a manufacturers of bullets produces hence you are relying on the accurate measurement of each bullet produced. That won't happened in a million years so you could measure every bullet's length and separate them which I believe is a total waste of time as there is an alternative...forget OAL measurement period because it'll drive you nuts. I measure each completed cartridge (using the comparator attached to my caliper) at the ojive and don't even waste my time with AOL. My casings are also carefully and closely trimmed to the same length so any slight variation in my measurement are negligable and have no affect on the consistency, repeatability and accuracy of my loads.

I am measuring to ogive. I mentioned that, and I stated that I was using a comparator.

Then why even worry about OAL measurement as you stated when you know you will have a more accurate measurement via the ojive, plus you already know that bullets may vary in length for to a number of reasons that will render an OAL measurement completely useless?????

 

[Strongman]

Ther are a lot of veriences from one bullet to another. Exspecialy if your measuring from the base to the tip. One thing you might consider after measuring each bullet and placing them into separate lots is to use a meplate trimmer to take a thousand or more off the tip. If the bullet lenghts are not the same neither will the BC of the bullets. Those that are to short just use for fouling or plinking.

 

[Martin52]

As I commented above, the Green tool measures the distance between the point on the bullet nose where the seater stem makes contact, to the point on the bullet that contacts the leade/lands of the barrel.

This allows bullets with similar measurements to be batched together and this reduces/eliminates one variable in reloading and I think has helped me to shrink my groups.

I have found this step also reduces (but has not yet eliminated) the variation that I find when seating bullets. To further reduce seating depth variance, other factors need to be considered, particularly neck tension. I find greater variance when using very light tension, around 0.0005 so now tend not to go much under 0.001 for this reason.

Meplat trimming is a further refinement for accuracy, as has been suggested, something to consider along with the above. The OAL is not the issue.

Martin