First time use of Hornady O.A.L. Gauge Questions??

[svxwilson]

Hello I have recently purchased a hornady oal gauge. I was using it tonight for the first time. I was getting slightly different readings depending on how hard I pushed on the rod. For my BRO 308 I got
First try: 2.250"
Second try pushed harder just slightly: 2.311"

I repeated this procedure, first try had slightly less pressure than second:

2.241"
2.304"

2.276"
2.306"

Final try I got 2.308" the first try.

My current hand loads measure 2.206-2.208"

The bullet was not getting stuck in the lands every try. I had a small long and skinny wood dowel to punch the bullet out when it did.

Am I doing someone wrong, or just not using enough pressure on the first try? Looking for tips and hints.

 

[elfster1234]

I push the rod hard enough so the bullet gets stuck on the lands every single time and needs to be knocked back off. If you are getting gouges on the bullet then you are pushing too hard.. You will get more consistent readings this way. I use the string end of my bore snake to knock the bullet back off

Hello I have recently purchased a hornady oal gauge. I was using it tonight for the first time. I was getting slightly different readings depending on how hard I pushed on the rod. For my BRO 308 I got
First try: 2.250"
Second try pushed harder just slightly: 2.311"

I repeated this procedure, first try had slightly less pressure than second:

2.241"
2.304"

2.276"
2.306"

Final try I got 2.308" the first try.

My current hand loads measure 2.206-2.208"

The bullet was not getting stuck in the lands every try. I had a small long and skinny wood dowel to punch the bullet out when it did.

Am I doing someone wrong, or just not using enough pressure on the first try? Looking for tips and hints.

 

[OldmaninNeb]

I also use it too, and I can tell you if you're trying to get the oal for Hornady's 178 A max, forget it. These bullets seat into the lands very inconsistently. I have found however, that their 178 gr.BTHP is very consistent. Just touching the lands is best, because when you're seating bullets it's dealing with 1000/th of an inch. pretty hard to tell how many of those you're pressing into the lands without a gauge.

 

[cacoltguy]

I use the Hornady tool as well and there is a slight learning curve at first in regards to consistency. After I fully slide the modified case into the chamber, I very gently push the rod in with the tip of my finger until I feel the bullet touch the lands, Then I ever so slightly tap the rod with my finger to make sure the bullet is making full contact against the lands but not so much that I'm jamming it in there with force. The key is to make the process as consistent as possible. I always extend the bullet out of the case very slowly and gently and then give it the slightest of taps with my finger tip to ensure contact. I also use one hand to put some pressure on the body of the case length gauge to make sure the brass case remains fully chambered and doesn't slide backwards as I am sliding the bullet forward.

 

[Bob 964]

I use the Hornady tool as well and there is a slight learning curve at first in regards to consistency. After I fully slide the modified case into the chamber, I very gently push the rod in with the tip of my finger until I feel the bullet touch the lands, Then I ever so slightly tap the rod with my finger to make sure the bullet is making full contact against the lands but not so much that I'm jamming it in there with force. The key is to make the process as consistent as possible. I always extend the bullet out of the case very slowly and gently and then give it the slightest of taps with my finger tip to ensure contact. I also use one hand to put some pressure on the body of the case length gauge to make sure the brass case remains fully chambered and doesn't slide backwards as I am sliding the bullet forward.

The key, as pointed out above, is developing a consistent "feel" for the bullet touching the lands. I took 20 separate measurements and looked for the length that appeared most frequently. It took me a while, but I did develop a sense of feel for using the gauge and now get consistent measurements.

 

[insight3b]

I use one as well and what I do is point the muzzle straight up I usually prop the rifle in a corner and insert the tool and slide until the bullets gets stuck in the lands. Not stuck hard enough that I need to knock it out through the barrel though. Stuck enough that a tap on the stock with my palm sets it free. Fresh batteries in a digital caliper help when results are inconsistent without explanation

 

[svxwilson]

I push the rod hard enough so the bullet gets stuck on the lands every single time and needs to be knocked back off. If you are getting gouges on the bullet then you are pushing too hard.. You will get more consistent readings this way. I use the string end of my bore snake to knock the bullet back off

I am using the bent version that they offer for lever and semi-auto rifles. It doesn't have a rod, it has a bendable braided metal rope. I think the straight version would be easier to use with a solid metal rod.

No gouges, but I did see some slight marks on it. I would push till it stopped, remove and measure, reinsert it with first possition locked in and give a second push. I tried to keep the amount of pressure even from the first to second try. It would slip forward just a little bit more the second try. That is how I got the above second readings.

Am I squishing the bullet just ever so barely into the rifling on my second reading? My measurements seem very deep as compared to elfster's in your epic AR journey posts. I also used the same bullet for about 20 measurements. Did I over use the one bullet at hand?

The bullets were SMK 168bthp. I have some other bullet choices I am going to play with it some more tonight and see what kind of results I get.

 

[femadog]

One issue I identified with the Hornady tool is that the internal rod can move when you tighten the brass knob (lightly.) I was getting a small indentation in the middle of the groove that affected measurements. I have to buff it smooth once in a while. I also do the measure like someone else mentioned, with the barrel pointed up. I get more consistent readings that way. The Amax bullets do seem a little harder to get measures on than SMKs. Same issue with JLK 90 grain bullets (.223), I assume because of the long, thin profile.

YMMV

 

[svxwilson]

I went home at lunch and did a few more tests. I used 2 brand new bullets in the new tests. I did these with the rifle upright. The first try with both new bullets provided similar results. The following tries after the initial try also provided similar results that were significantly different than the first try with the respective bullet.

First new bullet
First try: 2.223
Second: 2.310
Third: 2.310
Fourth: 2.313

Second new bullet
First: 2.242
Second: 2.313

The first try with a new bullet keeps giving me a result that is~ .05 shorter than the subsequent following tries with the same bullet....

 

[cacoltguy]

I use the straight rod style hornady tool so I cant comment on the "feel" of the bent one but I have a hunch that the braided rope may take away some of the sensitive feel of when the bullet hits the lands. I recently used mine to develop some OAL's for 80 grain SMK for my AR. I used 10 different bullets. My OAL for 8 of them was within .002. The other two were within .004. You seem to be getting very erratic readings from what I see. I would not reuse the same bullet more than one reading for a couple of reasons: 1) if you did jam it in too hard the first time the gouges will affect subsequent readings (.001 is about 1/3 the thickness of a human hair so even a slight burr or gouge from the bullet touching the lands makes a difference. Since it looks like you are getting longer readings on your second, third and fourth tries this might be the culprit 2) The point is to measure a group of bullets and get an average reading. Even match grade bullets will have slight variances in bullet base to ogive distance so remeasuring the same bullet doesnt help you much.

 

[.308mk4]

My measurements are always the same each time. I put the tool in with the case on and hold it , at the same time gently push the rod until it stops , hold it and tighten the knob. It takes a little coordination and a little practice. You cannot let off the tool itself to push the rod in. You have to keep the shoulder of the case pushed up against the shoulder of the chamber while you gently push the rod and tighten the knob. Sorry if my explanation sound confusing.

 

[OldmaninNeb]

Do you use Hornady's ogive gauge that fits on your calipers to make sure your bullets are the same? (I now sort)
Have you tried using a rod and two locks as TresMon mentions in his hand loading series?
Do you think drilling and threading a 2-3 times fired brass would give you a better reading?
I have started using fired brass, seat a bullet, then pull it and start it, finishing by pushing the bolt but not camming it. seems to work for me, if I doubt it, I'll use fresh bullets and check. I'm following this hoping for a fool proof way myself tho.

 

[.308mk4]

I use the nut from Sinclair.

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