Another homemade OAL gauge

obiwannabe · February 14, 2014, 11:21 PM

Hey, folks. Long-time reader but first-poster here because I may finally have something worthy of sharing with the board.

I've seen several threads on OAL gauges but I don't recall seeing one done this way. I fly toy planes for fun and I have lots of bits and parts floating around for those things. I was cleaning my bench the other day when it occurred to me how these things could make themselves useful again.

The piece is patterned after the Hornady OAL gauge, of course. The parts are few and simple and can be had at virtually any hobby shop for about $5. I used:

1 - 12" length of 5/32" copper tube

1 - 12" length of 1/8" brass rod, and

1 - package of 5/32" wheel collars (These are for securing model airplane wheels to their axles. It's basically a brass bushing tapped for a small grub screw which is included in the package, as is a hex wrench.)

You also need a piece of fired brass from your rifle, solder and a decent soldering iron or gas torch. I used a propane torch since precision isn't key here and the case head has a fair bit of mass to it. I'll explain that black plastic cone thing in the pic in a bit.

Basically, you

-Solder one of the wheel collars onto the end of the copper tube and finish drilling the grub screw hole in the copper
-Ream the inside of the case neck so there's no tension on the bullet. I used a routing bit on a Dremel tool for this then neck sized the case. You could also cut slits in the neck as others have done.
-Drill a 5/32" hole through the primer pocket of your case, shorten the copper tube by about 2-3" and solder the case to the opposite end of the copper tube. I ran it into the case about an inch or so and locked it down with solder.

That's it. Takes about 10 minutes. It's important to make sure the brass rod goes straight up the center of the case when you solder the copper tube to it. I kept the brass rod inside the copper tube while soldering and used the little black plastic cone in the first pic to keep the rod centered in the case mouth.

Obviously, since the thing is soldered together you loss the flexibility of changing the cases like with the Hornady gauge, but at 10 minutes and $5 each it's not hard to make one for each rifle.

kendall

nemesiss45 · February 15, 2014, 12:07 AM

Nice, I think I will make one of those... you could probably make it interchangeable if you tapped the case and got an appropriately sized brass fitting

FiveInADime · February 15, 2014, 07:45 PM

I did this with the handle end of a 3-piece .30 brass cleaning rod. I use a Lee Collet die to make a tiny bit of neck tension (if I have one for the cartridge). I push the cartridge in with the bullet loosely seated and the bullet is pushed into the case by the lands. I then scuff the lands marks off carefully with a scotch bright pad and put it back in to make sure it's just barely touching. Then I measure the base to ogive length, record, set up my seater for the amount of jump I desire. I also check that the bolt closes with no effort with the firing pin assembly/plunger ejector removed.

nemesiss45 · February 16, 2014, 04:05 AM

ok, here's one I made today. I couldn't find the same parts you used, so I improvised. I got a 12"x 5/16" brake line from the auto parts store and the closest size steel bar stock I could find (a cleaning rod works great too, but I wanted something I could leave in it).

At home I chopped one flare from the brake line, drilled out the cartridge (I left a lip so the tube would fit a little more squarely) then soldered them together. On the back end, I drilled a hole for the lock bolt (a #8 bolt I had in my fastener drawer), then soldered the nut on (with bolt attached to keep it in place and to keep solder out of the threads). I did have to work the bolt loose a little, but now it works fine. I soldered a 5/16" nut to the head to turn it into a thumb screw.
At this point I tried to slide the bullet into the case neck and realized the fired round I had intended to used must have gotten swapped with a sized case because the bullet would not slip in, so I had to slice the case neck. I will probably prep a new case and swap it out tomorrow because I don't like how this one holds the bullet.

I tried it out and it gave me an OAL only .002 longer than the case I had prepped with me other method. close enough to make me happy until I get my bullet comparator and can actually measure accurately.

I also picked up a 1/4" brake line and associated components to setup a .223 gauge.

February 15, 2014, 07:45 PM	#3
FiveInADime Senior Member Join Date: January 25, 2012 Posts: 607	I did this with the handle end of a 3-piece .30 brass cleaning rod. I use a Lee Collet die to make a tiny bit of neck tension (if I have one for the cartridge). I push the cartridge in with the bullet loosely seated and the bullet is pushed into the case by the lands. I then scuff the lands marks off carefully with a scotch bright pad and put it back in to make sure it's just barely touching. Then I measure the base to ogive length, record, set up my seater for the amount of jump I desire. I also check that the bolt closes with no effort with the firing pin assembly/plunger ejector removed. Last edited by FiveInADime; February 16, 2014 at 11:50 AM.

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February 15, 2014, 12:07 AM	#2
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	Nice, I think I will make one of those... you could probably make it interchangeable if you tapped the case and got an appropriately sized brass fitting

February 16, 2014, 04:05 AM	#4
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	ok, here's one I made today. I couldn't find the same parts you used, so I improvised. I got a 12"x 5/16" brake line from the auto parts store and the closest size steel bar stock I could find (a cleaning rod works great too, but I wanted something I could leave in it). At home I chopped one flare from the brake line, drilled out the cartridge (I left a lip so the tube would fit a little more squarely) then soldered them together. On the back end, I drilled a hole for the lock bolt (a #8 bolt I had in my fastener drawer), then soldered the nut on (with bolt attached to keep it in place and to keep solder out of the threads). I did have to work the bolt loose a little, but now it works fine. I soldered a 5/16" nut to the head to turn it into a thumb screw. At this point I tried to slide the bullet into the case neck and realized the fired round I had intended to used must have gotten swapped with a sized case because the bullet would not slip in, so I had to slice the case neck. I will probably prep a new case and swap it out tomorrow because I don't like how this one holds the bullet. I tried it out and it gave me an OAL only .002 longer than the case I had prepped with me other method. close enough to make me happy until I get my bullet comparator and can actually measure accurately. I also picked up a 1/4" brake line and associated components to setup a .223 gauge.