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O. A. L.

Brian in Montana

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Jan 20, 2017
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Ramsay, MT
I have a Hornady OAL gauge, the one that uses the modified casing to determine at what length you projectile will touch the lands, but I haven't been able to find a modified case for .280AI. Any tricks to finding this measurement some other way, without having to try and make my own modified case?
 
You can make one from a spent case.

I don’t remember the drill bit size and tap size but they are on internet.
I purchased both and have them in my tool drawer if needed.
 
Cut a couple slits in the neck of a sized case, deburr. Put the bullet in so the case barely holds it, chamber it, gently tap it out with the cleaning rod.
 
Hornady you can mail a fired case from your rifle to hornady and they will tap it for $15. Info is on their website under the OAL gauges
 
I have a Hornady OAL gauge, the one that uses the modified casing to determine at what length you projectile will touch the lands, but I haven't been able to find a modified case for .280AI. Any tricks to finding this measurement some other way, without having to try and make my own modified case?
Sharpie, one bullet, and an empty case.
 
I bought a tap and probably have a drill bit. The tap was $10 or so on Amazon. Worth it to just buy the tap and do it yourself for all the rounds you need it for. Saves lots of money in the long run.
 
I've watched a lot of Erik Cortina's videos. They are informative, but regardless of how many matches he wins, etc., I still like to know where the lands is in my rifles. It's not the end-all of handloading that some people make it out to be, but knowing closes one more gap when trying to fine tune and can be beneficial. I actually don't use that OAL gauge much, but I have found it helpful in my 7mm-08 which is a fairly long-throated Remington 700 action like my .280AI.
 
Ive heard of this method, but not really clear on how to do it. Want to elaborate a little?
Take an empty case, press one edge of the mouth into the bench so it forms a flat surface that will grip the bullet. Color the bullet with the sharpie, just set it into the case, and chamber it. The lands will grip the bullet so you might have to tap it out with a cleaning rod, but you’ll see where the scratch on the colored bullet stops. Repeat 3 or 4 times. You can get a very consistent measurement done right.
 
Close the empty chamber, insert the cleaning rod in the muzzle until it touches the bolt face, mark it. Remove cleaning rod, remove bolt, drop in a bullet, hold in place with a cleaning rod, insert cleaning rod in muzzle until it touches, mark it. Measure between the two marks. Not very scientific but gives you a pretty good idea of where the lands are.
 
$32. It does all calibers and all cartridges. Very accurate. Use with your dial or electronic calipers for OAL.

I have never understood why someone would want an OAL tool that requires a different adapter for every cartridge.

 
Close the empty chamber, insert the cleaning rod in the muzzle until it touches the bolt face, mark it. Remove cleaning rod, remove bolt, drop in a bullet, hold in place with a cleaning rod, insert cleaning rod in muzzle until it touches, mark it. Measure between the two marks. Not very scientific but gives you a pretty good idea of where the lands are.

This is the method I use except I took a old brass jag and sanded the end flat to use at the end of the cleaning rod so it will be flat against the bullet tip same as you would measure. Also it’s important to make sure the rod is actually on the bolt face and not the ejector pin, this is done by inserting the rod with the bolt half open then keeping tension while closing it. I use masking tape on the cleaning rod and use a razor blade flat on the muzzle and spin the rod cutting the tape to the rod. Then remove one side of the tape. Next insert the bullet and use another rod to push it till it touches lands. Put the other cleaning rod in the muzzle and get a idea of where to put the other piece of tape. Mark that one with the razor and remove the tape, now you can measure the distance between the tape to a fine line of a couple thou.

I’ve used the marker trick (less accurate), cut case (semi accurate or pretty good as long as the bullet doesn’t engage the lands hard enough to pull the bullet back out some when ejected), and the hornady oal gauge. The rod trick done right will get you the same results as the oal gauge at no cost assuming you have gun cleaning equipment.
 
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