Home Forums Reloading Big Game Rifles Hornady OAL Gauge?

Note the posts and I'll tell you. If they are mine, you are missing something.

What has you most confused? Where to take a measurement or how a bullet is seated.

Then I'm lost/done.

You've not explained real well what posts are confusing to you. I asked if you understood what an ogive is because if you do - you'd never think that they'd vary so much bullet to bullet.

A bullet's over-all length, base to tip will vary considerably bullet to bullet in the same box of ammo because the tips aren't very consistent.

The base of the bullet to ogive is rather consistent. That's why you want to use a comparator to measure the length of your rounds as you set up your seating die.

For instance - my Ruger 243. Measurement from the base of the brass to the ogive on a 105 Amax is 2.248 - that's also distance to the lands in this particular rifle as it prefers to be right at the lands for accuracy. Measured to the tip on one is 2.772, the next one is 2.780, 2.771, 2.775 but if I measure all of them to the ogive - 2.248 I adjust my seating stem - which does not make contact with the tip till the final round comes out 2.248. Set the lock ring and rock forward. I know of no seating stem system that makes contact directly with just the tip of the bullet. It may look like it - it don't.

The ogive measurement is the most consistent and that's what I want to use to set up my dies. Tip don't mean a thing, it never contacts the barrel. Nothing on the bullet forward of the ogive does.

I think I got it now. Thanks.

The biggest thing for me was the variances just like the AB vs TTSX comparison above. It just really seemed to me that measuring from the tip or the ogive and vice versa. Seems like if the tips are off, the ogive should be off too. That's where I was getting screwed up.

Hard to put into words on the net I guess...

Not to steal from Stick, but "1,000 words"

Here are factory loaded Hornady Match 75 gr HPBT. Why the hell do I have factory ammo? 'Cause I just picked up a NIB Tikka 1:8 223. Rule #1 for any new rig for me is 1 box of factory JICIFU (Just In Case It F**ks Up) and to see some sort of "baseline" I'm dealing with. My gun, my rule. Anyhoo....

2 measurements here: Cartridge Over All Length (COAL) and Base To Ogive (BTO)

COAL measured this way:


BTO measured with 22 cal comparator insert:



Chart below tells the tale. You can see the variance measuring to the tip of the bullet vs. ogive with standard deviation shown below.



Stealing from the big man again, the $0.99 Sharpie is a reloaders best friend. The line on the top is where the seating stem hits the bullet when performing the seating operation, the line on the bottom is where the comparator insert hits the bullet when measuring.




You could take 10 sets of calipers and 10 sets of inserts and get 10 different results, but I doesn't mean jack schit. What matters is that if I want to reproduce that particular COAL, I'll spin out my seater stem (with the die itself at least 1 1/2 turns off the shell holder, yet another long story) and turn it in until my calipers (with comparator attached) reads 2.836. Why 2.836? Because 70% of the sample says so with MY calipers and MY comparator.

Now, if I'm sitting around bullschitting with the fellas and they wanna know my COAL I can say anything from 2.226 to 2.232 and be correct. I'd probably say "2.226" since that's the mode. It doesn't matter because when I make another lot, the BTO is the number I'm dialing the seater to and the number that matters. And to make life easy, micrometer stems (Reddings for me) are next in line to being buds with the Sharpie....

Your schit has to be relative to your schit. Not a book, bubba, or Campfire bonehead.....

I found Hornadys OAL gage with modified cases to be terribly inconsistent. I am a very analytical type. It gave me measurements probably good enough but not repeatable enough for my liking. I had also tried the cleaning rod with rod stops method with similar results. The Sinclair tool, otoh, gave dead nuts perfectly repeatable measurements every time.

And I find measuring anything referencing on the bullet tip very inconsistent use the ogive.

The part about "if tips are off, ogive should be too" just isn't the case. Think about a garden variety SP bullet. That last little few thousandths of lead can be misshapen quite easily. This is won't change where the ogive is, though.

Thank you!

Interesting.

I can get very repeatable results with mine in all my rifles. Guess it's just a matter of technique.

Perhaps the OP was thinking that the measurement starts from the tip and this caused the confusion?

Thanks to CLB for pointing out the mistake that I made. The measurements were actually from the base to the ogive - not to the tip.

turkish: how does the Sinclair device differ from the Hornady/Stone Point device? Is it primarily in materials or construction of the comparator inserts? I've generally had repeatable readings from my Stoney Point comparator with the stainless steel inserts. However, recently I have been challenged to get repeatable results when working with the 165 gr. TTSXs. That's why I did the checking that I referenced before.

I knew not to start at the tip.

I can't explain it really. I just figured that after I got the measurement with the gauge, the base to ogive measurement per bullet would deviate just as much as ojive to tip, therefore it wouldn't matter if you just set your dies with the dummy you create. I was trying to figure out how you guys were setting your seater dies to make sure the ogive contacted the lands exactly with each round without taking each and every round out of your seater die, measuring base to ogive, all without saying "that one needs .002 taken out, because the ogive to tip is shorter than the last bullet", then adjusting your die again and reseating the bullet depth a touch. I guess I assumed you were being much more precise.

That's the best way I can explain it.

I do now understand that the base to ogive measurement usually doesn't deviate much at all...assuming we're talking premium jacketed bullets.

Your best readings will come from a case that was once fired in YOUR chamber and sized. I've found that using a split neck offers the least amount of resistance when closing the bolt and most consistent at determining where the lands hit the bullet. Once I get the measurement, I call it "0" or "kiss". Anything longer is "into the lands" and shorter is a "jump". I've tried the partially necked case, but it doesn't tell me what I want to know, which is "exactly how far is this bullet into the lands?"

I've done the rod stop method and it does give you the distance between the bolt face and lands, but found more variance in each individual measurement over the split neck. And it's a pain in the ass.

That's what's worked for me and where I hang my hat.

Try it with SMK's. Holy crap I was about to lose my mind. They have the worst tips out there. A fella would be hating life if he adjusted the seater for every round. I actually emailed Sierra with a picture of about 5 bullets and they said "that's normal, don't worry" I thought "BS". BobNH rode my ass about them and well......he was right.

Here's another visual on whats hitting where. 160 NPT/270WSM. Not that it matters, but hitting the lands at 2.859 in a 3.03 magbox is good juju....

The Hornady tool I had problems with was this http://m.hornady.com/store/Lock-N-Load-OAL-Gauge-Straight-1Each/ , which uses their modified cases. The Sinclair uses fired cases, a slightly different method, and stiffer, higher quality componentry.

I use the Hornady bullet comparator and headspace gages (with the inserts) with good results. If that's what you're referring to, I don't disagree -- it's the OAL gage that gave me problems.

The Hornady tool I had problems with was this http://m.hornady.com/store/Lock-N-Load-OAL-Gauge-Straight-1Each/ , which uses their modified cases. The Sinclair uses fired cases, a slightly different method, and stiffer, higher quality componentry.

Then make your own modified case
19/64 drill bit, 5/16 X 36 tap, and 5 mins of your time.

I don't know that the modified cases were causing problems, although a fired case is inherently better. I kinda suspected the plastic rod was causing the issues.

Sinclair tool is a just better. I read it over and over, ignored it, then found out for myself.

Basically you can make a modified case from once fired in your chamber. But after 10 years of using a Stoney point, I found it was better to tap the plastic rod until the bullet is grabbed by the lands enough to where you have to give the rifle a hand slap to get it to fall out. This tells you where the lands are for sure. After that I back off 10 thou and make a dummy round to see if it chambers, if not then back off another 5 thou at a time. When it chambers with just slight resistance I load up a few and go shoot, but I also take a portable arbor press and Wilson hand seater to the range to play with seating depth there.

The force with which I was jamming the bullet with the plastic rod very well could have been the source of the inconsistency I was getting.

Very we'll could be. YMMV but it has worked for me.

16bore, check your PM's.