Getting a true aol.

SO I HUNT

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Dec 28, 2014
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I have a 300 ultra mag. And not able to find a casing to put in my Horndy gage so what other choices can I use? Take a once shot case and put a small ding at the mouth to hold the bullet and use a black marker?

The gun is Remington 700 sps and it has the wyatts installed now. Just starting to make up a load to shoot 210 Vld bullets....

Any help would be great.....
 
SO I HUNT,
Best thing to do is contact Hornady ( 800-338-3220) and see what it takes to send them a once fired , un-sized case from your rifle that still chambers in your rifle so they can drill and tap the primer pocket for you to use on the OAL tool . Really improves the accuracy and function of the tool.
 
I take a wooden dowel with a plastic bushing on it (hardware store) and a set screw in the bushing. I put that down the barrel with a closed unloaded bolt and set the bushing against the muzzle face, then I pull the bolt and use another dowel to push a bullet up against the lands and measure the distance between my muzzle and the bushing. Repeat a couple times to make sure its consistent. Then I can measure that bullet with a comparator so I can repeat the ogive position since the tip lengths can vary in some bullets but ogive tends to be fairly consistent.
 
take a sized brass with no powder or primer lube the inside of the neck and seat a bullet in it just enough to hold it in place. It should be not able to feed in the mag, now chamber that and as the bullet contacts the rifleing it will seat as you close the bolt. Withdraw the dummy and measure it subtract 20thou and this is a good starting point for oal for that bullet in your rifle.
 
Tapping it yourself is pretty darn simple. Go to tour local hardware and by the tap ( 5/16x32 , take the case gauge with you to be sure) and tap one of your own cases. then split just the case neck with one cut using a hack saw. this will allow the bullet to slide in and out easily.
 
We had to order that tap from an industrial supply store on special order.

Before we used the OAL tool method, we would seat the bullet long and polish it up with fine steel wool. Insert the cartridge into chamber and close the bolt. The rifling will make small rectangular marks on the shiny jacket. Adjust the seating die to move the bullet deeper into the case and repeat. With some careful adjustments you will be able to tell when it just kisses the lands. Adjust seating depth from there.
 
We had to order that tap from an industrial supply store on special order.

Before we used the OAL tool method, we would seat the bullet long and polish it up with fine steel wool. Insert the cartridge into chamber and close the bolt. The rifling will make small rectangular marks on the shiny jacket. Adjust the seating die to move the bullet deeper into the case and repeat. With some careful adjustments you will be able to tell when it just kisses the lands. Adjust seating depth from there.

+1 on what AZShooter sez...

That tap is an odd-ball size. I looked at several standard hardware type stores and was unable to find one. I ordered mine from MSC. The threads are very thin with this tap and the drill bit you use to make the hole is very important (can't remember offhand what size I use).

I find I get better results from the polish and seat method outlined above. I do this to establish a 'zero' on my seating die and then keep this as a reference point, offsetting my seating depth from there (e.g. .020" in, .020" out). Note that this 'zero' point will change as you shoot the rifle and the throat erodes. You will have to periodically re-check this along the way ("chasing the lands").

Note also, that different bullets (even within the same lot#) will vary enough to affect this, sometimes dramatically. I am of the school that believes that if you're going to jump or jam, do so by a large enough distance to negate this variance. Trying to jump or jam .002" is a fools errand unless you first sort your bullets by the distance from where your seating die contacts the bullet to the point it contacts the lands (ogive). If you don't sort first, your .002" jam may end up being a .002" jump. +/- .005" is no mans land.

-nosualc
 
If you look up Gunwerks how to find OAL they show you how to do this with out the Hornady deal ,I use their method works great just need a carbon fiber cleaning rod ,and a bullet ,and something to mark your rod .
 
I made one of these last night and it works great. It cost me $5.29 from the local hardware store and about 30 min.
 
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To make your own modified case for either the Hornady or the Stoney point O.A.L. Gauge , use a 5/16-36 tap. NOT 5/16-32.
 
Just size a piece of brass and split the neck with a Dremel. Color the bullet with a Sharpie, insert and close the bolt. Measure off the ogive and you're done.
 
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