Measuring correct Overall Length OAL or COAL??

[ALO]

I have seen many posts with people who provide the overall length of their bullets. I noticed that most measurements are just measured from the tip of the bullet to the end of the case?? Is this the correct measurement procedure?? Or the way I measure overall length is by using a Sinclair comparator - so when I insert the comparator over - say a 6mm bullet and measure the case from the ogive and the length of the comparator is significantly longer than one who just measures the case. Whenever we talk about about OAL I try to include the comparator length and denote it as COAL. Which method is preferred or best used here on this site??

Al O
aaostapowicz@roadrunner.com

 

[expiper]

What is right is what works for you....I prefer the overall length measurement,tip of bullet to base of ctg case) becuase it is the most universal measurement and can be easily duplicated or aproximated by anyone anywhere in the world...if you give a meausrement with a stoney point or sinclair or uncle ben's!! device that is used with your calipers and your set up and is not necessarily what my particular brand or homemade device will be able to interpelate,,,and the gun tells you what works ...so let your seater die measurement be the one that really counts to you...measure your seater stem length,and shim-pac,,etc.etc.)and record it for your own future comparison and duplication and to see how the gun is wearing as you chase the lands and keep an eye on round count.....Roger

 

[Preacher]

A bullets length to the tip varys way to much to be used with any authority anywhere on this earth... The correct OAL is to the ogive, thats the part that hits the rifling first and thats what needs to be known......
If your concerned about fitting in a mag box the measurement to the tip is important for only that reason...

 

[billmo]

Expiper and Preacher, Both of your measurements have merits.,Some bullets are longer and some ogives are placed with variations within a box or lot of bullets) I find it best to write down both measurements in my log book. That way when someone ask a question or maybe I simply want to double check in any given situation I have both numbers to compare to. So, I guess I agree with both of you. Bill

 

[expiper]

Good advice Bill...you are rite, both methods have their merit...I have found that the Stony Point/Sincalir etc tools vary as much or more than bullets from lot to lot...we all know that bullets vary by as much as .040 to 070' from lot to lot ..some of my best 105/107's do ...and guess what so do the various comparater tools...I am just saying that the measurements that we take with these various tools are more valuable to us,, in our gun,,with our bullets...I think the best info to share with the 'whole wide world' is the overall length with the obvious disclaimer for lot variations....and me giving you advice on seating depth is sorta like telling you what works with your wife/gf..!!! ....you just gotta work it out for yourself...they are all diferent,,grin....IMHO...Roger

 

[billmo]

Expiper, you completed my thoughts by applying,in our own guns with our own bullets and our own measuring devices)AND with our own wifes. They sure are different but I would not trade mine for the world. Been married to her for 36 years as of Monday March 16, 2009. IMHO. Bill

 

[jec]

I have been reloading and shooting my 6mmbr for a while. I have went through extensive case prep to achieve the utmost in accuracy. I have personally never measured my rounds from the case head to the bullet tip as it really doesn't seem to matter. In fact I know every meas. of my rounds except the OAL. The length to lands is the only one that matters to me, and only to me as my meas. wont even apply to another persons chamber since there length to lands will be different. If they don't have a system to measure to the bullet o-give then they will find it an indispensable tool.

 

[Ackman]

Overall length is meaningless except when there are magazine clearance issues. If the comparator you mention is that Sinclair six-sided thing, there's much better. A Davidson gauge,also from Sinclair) attaches to the caliper beam and is a lot more convenient to use. Get one for every bullet dia. you shoot. Casehead to ogive length when touching the lands is all that matters. Doesn't matter what the number actually is, it's just a reference point for seating depth. Using a split neck case is the quickest easiest cheapest way to find '0' or 'ogive length' or 'depth to lands' or whatever you want to call it, for each bullet. With a new chamber, get case-head to ogive distance when touching the lands and record it. Then put that very bullet in the die box and always use that EXACT same bullet when checking for throat wear. But when reloading get ogive length,distance to lands) with a bullet from the box you'll be using. Don't even worry about overall length.