Determining OAL

[smirak]

One Armed Willie here (at least that what my wife likes to call me...I had my shoulder arthroscopically repaired two weeks ago). Anyway, what is the best way to determine OAL? I know I will get 150 different answers, but just trying to get some advice. I am loading 270 win for a Marlin XL7 with H4831 and 140 gr Nosler BT. Right now, I have only loaded 5 rds, and I just made sure they were within the limits set forth in my Lee book.

Thanks,
Kevin

 

[hubcap]

I like the stoney point O.A.L gauge from Sportsmans warehouse for 27 bucks. It is simple, quick and easy to use. cabellas sells a Hornady version for about the same price. The straight one is for bolt guns and curved model is for lever guns.

 

[DrMike]

+1 for the OAL gauge. Hornady is now marketing this, together with all the accessories you may require.

 

[JDMAG]

Just a quick question about this tool, Does any one know what size tap one would need to make their own OAL dummy cartridge for this?

 

[DrMike]

JD,

I've made my own cartridge for the 325 WSM and for the 358 (not available) by purchasing the 300 WSM and expanding the neck, and by purchasing the 308 and expanding the neck. I used an expander mandrel from Sinclair for these operations. It worked quite well. The tap would depend upon what you were using for a body to permit you to slide and lock the bullet when measuring.

 

[hardpan]

One Arm,
Have to check what the caliber and make is. On rifles with a lot of freebore, like weatherby's, you likely are limited by the magazine.

I take a spent cartridge, press in a side a bit, load a bullet, and then by trial and error get the OAL. In general, with WBYs it goes fast because I am checking the magizine. When I get the OAL, I bring it down 5 thousandths to allow for some movement in the mag.
Hardpan

 

[DrMike]

On page 43 of the Nosler Reloading Guide No. 6, is a great explanation of how to determine the proper bullet seating depth. It provides a step-by-step guide.

 

[JDMAG]

On page 43 of the Nosler Reloading Guide No. 6, is a great explanation of how to determine the proper bullet seating depth. It provides a step-by-step guide.

Thats what I do for the calibers I dont have a stoney point cartridge for .

 

[smirak]

On page 43 of the Nosler Reloading Guide No. 6, is a great explanation of how to determine the proper bullet seating depth. It provides a step-by-step guide.

By chance have a copy of page 43? Don't have a copy of the Nosler guide...

Kevin

 

[hubcap]

Just a quick question about this tool, Does any one know what size tap one would need to make their own OAL dummy cartridge for this?

I looked for a standard tap to make my own dummy cases. Had no luck. I think the stoney point tool has non standard threads for a reason. They knew if they made it easy for us we would simply make our own.

 

[JDMAG]

TRUE! :?

 

[257 Ackley]

The only variation I have to page 43, is to take a Dremel tool and cut three slots (equal spacing apart from each other) in the neck of the cartridge instead of making an indent on one side. The bullet slides in easy and gives me consistant readings on where the lands is at so I can have a starting point to back off from.

 

[Greg Nolan]

Very high tech. I just use a fired case and a new bullet and put a little grease on the bullet where it will touch the lans and give it about 4 repeats to make sure. I'd like to find out more about the Stoney point tool.
Good Hunting
Elkhunt :grin:

 

[hubcap]

Greg; The Stoney O.A.L is simple to use. Screw a dummy case onto the end of the gauge. Put your bullet in the case. Remove the rifle bolt and stick the assembly into the chamber until the dummy case seats. Then you push the bullet into the rifling lands with the gauge push rod and secure the thumbscrew. Then remove the gauge and the bullet from the rifle and measure from the back of the case to tip of the bullet with a dial caliper. This gives you the true cartridge overall length for the bullet you want to load. The dummy cases are 4.99 each. they come in a bunch of calibers. This method takes a whopping 30 seconds and is accurate to .001". This method is not difficult or cumbersom. It does not take practice . Its well worth 27 bucks. I consider this gauge my most valuble tool, besides my chrony of course. Good idea to check the O.A.L for each box of bullets. The Ogive is usually the same from the same box but can be different from a different box even if the bullet is the exact same type and brand.

 

[JDMAG]

Here's a couple of links to what they look like.

http://www.midwayusa.com/viewproduct/?p ... ber=479963

http://www.midwayusa.com/viewproduct/?p ... ber=570611

 

[Guest]

Just a quick question about this tool, Does any one know what size tap one would need to make their own OAL dummy cartridge for this?

The proper tap size is 5/16 x 36P. See one possibility here:

http://www.use-enco.com/CGI/INSRIT?PART ... NO=3904767

I'm no expert, but I think the P is referring to plug style tap. There are undoubtedly other sources, so search around if you'd like. I've never done business with Enco, and don't know if they're reputable or easy or what. I just googled for it and found that.

 

[JDMAG]

That would be the one to get if you have more than 3 calibers to load for.
I already have the 300 winny. and just need the 7MM, 243 and 30-06.
At about $4.50 plus tax, I could just about buy those 3, but then I would probably wind up with another caliber! guess it would still be cheaper in the long run.

 

[lrp3006]

If you need a dummy case for a caliber that Hornady doesn't normally sell (like the 7x30 Waters I needed) - you can send them two fired cartridges and they'll make one for you.

As I recall it was $11.00 - not a bad deal and they turned it around in a few days.

 

[DrMike]

smirak,

Measuring seating depth is as easy as lightly pressing the neck on a fired case so that it grips the bullet you wish to measure. Insert the bullet, base first, into the case and complete colour it with a felt-tipped marker. Place the case and bullet into the chamber and gently close the action. Do not pull the trigger. Then, carefully open the action and carefully remove the case. Retrieve the bullet. Where the bullet was pushed back into the case from contacting the lands, the ink will have been scraped off. Now, push the bullet back into the case to the point where the ink has been scraped off. Measure carefully the OAL. This is the seating depth to contact the lands. You will want to set your seating die to seat the bullet at some distance off the lands.

In short, this is the technique outlined in the Nosler guide.

You can measure the distance to the bolt face with a cleaning rod, marking where the end of the barrel is relative to the rod. Then measure the same rod when you have inserted a dummy round that engages the lands (making the case as per above).

Or, as you have been in the thread, secure a Hornady OAL gauge.

Good luck as you apply these concepts.