2 different readings with Hornaday OAL Gauge???

[Sullivan]

So last night I used my Hornaday OAL gauge to get a max length into the lands on my Tikka T3.. I put the bullet down into the case , pushed the shell into the chamber, pushing to seat the shoulder in the chamber , then I pushed the bullet out to the lands with the stick . the bullet was not stuck in there and came out in the shell. I got a measurement of 3.355" (I don't rezero my calipers when I put the different comparators on I just run the # it gives me)
I was looking for an average cause I know the test isn't perfect ... one time I thought I would leave the bullet hanging way out of the case and then slide it into the chamber and let the lands push the bullet back into the case . I pushed on the stick and locked it down , pulled the thing out , the bullet came out again. this time my measurement was considerably different . it was 3.415" so when I start with the bullet in the case I on average get the smaller # ,, and when I start with the bullet way out of the case I on average get the larger #..

My Question is which is the more accurate # from the shoulder of the case to the "lands" for the cartridge over all length on the "o" gauge
I was using a nosler partition 180 grain flat base spitzer. bullet

I tried a dummy round set at 3.400" and had a real hard time closing the bolt on the rifle. It wasn't until I got down to the 3.360" range where the bolt started to close more like normal..

can anyone tell me, definitively , which way is the right way and why?

 

[Patch700]

Get the actual tool that goes onto the blade of your calipers so you can measure from the base of the cartridge to the ogive of the bullet... Those numbers your getting won't amount to a hill of beans when it comes down to load development.

 

[Sullivan]

I do use the "o" gauge on my calipers as I stated above in parenthesis .. I just don't re-zero the calipers so the # is an inch longer than usual .
some guys run the neck tension a little tighter and use the bolt to seat the bullet on their dummy round.. I am using the "hornaday" cartridge OAL gauge. the red aluminum stick that the case threads onto , with the gray plastic stick you use to push the bullet into the lands.
The lengths listed above are the lengths taken with the o - jive gauge clamped on the move-able / dial side of my calipers.
it gave me a different # if I started with the bullet out , or if I started with the bullet in .
which is the right #????????

 

[Patch700]

So you did... Start short and feed bullet in , that way you have a "feel" for when the bullet is truely engaging

 

[searcher]

Using the Hornady tool with any real precision takes a bit of practice. My suggestion is to GENTLY push the bullet forward and STOP once a few ounces of contact is felt. Carefully hold the tool in position without any movement while turning the thumbscrew to tighten the push rod. You must do this, in my own experience, around ten times to get a good feel for what is "the" accurate reading. To get readings varying a few thousandths is common. It also varies a lot on the bullet you are using. Some brands give the same reading 3 out of four times. With some, it is hard to get the same reading more than a couple of times out of ten. I use the top three or four readings as my setting from which to work with when setting my bullets close to the lands. That way, a few thousandths difference in base to ogive won't put me into contact with the lands on any of the bullets - which aids the minor spikes and deviation we dread. You can sometimes also get more accurate readings by using a dummy case which has been fired in your chamber. They tend to sit more uniformly against the shoulder of the chamber in my experience - giving fewer odd-ball readings. Just purchase a tap and drill bit for about $12.00 total. I bought mine at drillbits.com. To expand the neck, place a wrap of aluminum tape around a neck expander (or sizing button in a pinch) to open the neck up so the bullet will slide freely. In short, you are most likely pushing with far more force than needed to set the bullet ajam.

 

[SS427]

I have the bullet barely sticking out of the case when I insert the tool. I hold the case firmly against the chamber, and then gently shove the bullet to the lands so it snuggly fits against them. While holding steady but light pressure on the case and the bullet, I lock the tool down and extract it. That is my "at the lands" measurement, although it could be .001 or even .002 into the lands.

I don't think it overly important which way it is done as long as you do it consistently.

 

[mudduck]

Try using a sized case and cut a slot in the neck so the bullet will slide and then chamber it and measure it
I have found this works good.

 

[Erik Cortina]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

 

[bdale]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

I would think this could put you several thousandths into in lands since copper is a gliding metal ???

 

[Patch700]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

I would think this could put you several thousandths into in lands since copper is a gliding metal ???

That may be the lesser of two evils....As Erik mentioned , If you get too passive I've found the numbers to be quite short , in the vicinity of .040-.060"

 

[Erik Cortina]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

I would think this could put you several thousandths into in lands since copper is a gliding metal ???

It doesn't matter. You are looking for a repeatable reference point that you can work from. I always start at .020" short or that point which I call "jam".

 

[Sray53TXTN]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

I would think this could put you several thousandths into in lands since copper is a gliding metal ???

It doesn't matter. You are looking for a repeatable reference point that you can work from. I always start at .020" short or that point which I call "jam".

+1
Consistency is the key - practice will get you there.

 

[lurcher]

Call me OCD but always try and measure OAL at least two different ways. I know that confuscius say man with two watches... but they should be reasonably close and it avoids a brain fart issue with one tool. Try a neck-sized case fired in your rifle cut 3 slits in the side of the neck with a dremmel and push a projectile in by hand. stick it in the rifle and close the bolt. measure with an OAL guage. I prefer this method and the rp tool to the hornady. here is a rundown on the r-p tool

I found the measuremewnts with the OAL gauge that fits the caliper became more consistent once I started using a davidson base that fits on the other caliper spike and the base of the case sits in it

The plastic rod that comes with the hornady gets divits in it with use and hornady cases are unfired and hence a poor fit to your chamber so will give a slighly longer oal than actual, not that this matters too much but I wish they made that rod out of brass or steel.

 

[Barlow]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

10-4 that's what I do. The soft touch might contact the lead or a burr sometimes and give a false measurement, at least it has happened to me. I push them hard and call it a .010 jam, and it's seems to work well. Barlow

 

[Joe Maisto]

Push the bullet in as hard as you can and lock thumb screw. This will give you the most consistent results.

+1
My device has a plastic thumb screw which I think is superior to a metel one. It doesn't scarf up the channel it slides in.
I have never been able to get two readings the same anyway using the original tool designed for this. Now I smoke a bullet long, push the case in close the bolt. Open the bolt and look at the rifling marks. Adjust from there.
If you are able to seat the bullet so the marks are only as long as they are wide, you can work back from there in increments of .003-.005.

 

[Old Navy]

It wasn't until I got down to the 3.360" range where the bolt started to close more like normal..

This is the part of your post that caught my eye. If you have fired very many rounds through your rifle you might have a carbon ring. I had the ring in my BR rifle awhile back and absolutely nothing was measuring as it did previously. Something to look at. Later! Frank

 

[SS427]

Interesting to see most people jam the bullet hard into the lands with the Hornady tool. I will have to revisit my technique. When I experimented with it before, I noticed the plastic rod of the tool would start to flex which is why I went with the snug pressure rather than aggressive pressure.

Be interesting to see if I get more consistent results with more pressure.

 

[Old Navy]

I have the bullet barely sticking out of the case when I insert the tool. I hold the case firmly against the chamber, and then gently shove the bullet to the lands so it snuggly fits against them. While holding steady but light pressure on the case and the bullet, I lock the tool down and extract it. That is my "at the lands" measurement, although it could be .001 or even .002 into the lands.

I don't think it overly important which way it is done as long as you do it consistently.

+1 I have no problem at all getting consistent reading with quality bullets. More than a very lite pressure pushing the bullet in will stick it every time in my BR rifle. I use a wood dowel to ensure it comes out with the case. Later! Frank

 

[Barlow]

Otter, My Hornady tool has a metal rod, how long have you had yours? Brlow

 

[Joe Maisto]

Interesting to see most people jam the bullet hard into the lands with the Hornady tool. I will have to revisit my technique. When I experimented with it before, I noticed the plastic rod of the tool would start to flex which is why I went with the snug pressure rather than aggressive pressure.

Be interesting to see if I get more consistent results with more pressure.

Otter;
It is also interesting that you have a plastic rod . The original ( which I have) has an aluminum rod that does not flex. It no longer gets used and is available. It is the Stoney Point.