Hornady oal gauge

[CovertGunny]

Trying to determine my bullet seating depth, im using the hornady gauage with comparator and i feel that im getting results all over the place. It is a freshly cleaned rifle, nosler ballistic bullets, it is a factory barrel from remington i dont know if that makes a difference, but my results vary from like 1.827 to 1.8470 i swear ive tried every bullet in the box trying to get any consistentcy at all and always coming up with different numbers.

 

[jcampbellsmith]

Trying to determine my bullet seating depth, im using the hornady gauage with comparator and i feel that im getting results all over the place. It is a freshly cleaned rifle, nosler ballistic bullets, it is a factory barrel from remington i dont know if that makes a difference, but my results vary from like 1.827 to 1.8470 i swear ive tried every bullet in the box trying to get any consistentcy at all and always coming up with different numbers.

It doesn't really matter, all you are achieving with this tool is a relative measurement. Take the average of the first six measurements you have made and use that as your reference.
Regards
JCS

 

[mikecr]

Trying to determine my bullet seating depth

You're not trying to determine seating depth, but cartridge base to ogive(CBTO) that represents 0" distance to lands(DTL) in your barrel, with your bullet, right? I call this MaxCBTO.
If you're just measuring seating depth, well you can do that with calipers.

The Hornady/StoneyPoint system plays hell with many folks because it takes datum off both a case shoulder and a bullet ogive.
There are better systems out there, and even soft seating is probably better for MaxCBTO.

 

[mikado463]

It doesn't really matter, all you are achieving with this tool is a relative measurement. Take the average of the first six measurements you have made and use that as your reference.
Regards
JCS

agreed, besides you're using a hunting bullet and while "I've gotten variations myself with Nosler B/Tips, albeit only .002-3, I've gotten better results with match bullets.

 

[watercam]

FWIW my experience with the OAL tool was improved when I inserted the case/bullet and held continual pressure on the body of the gauge while pushing the bullet in fairly firmly with the center rod. With your third hand then tighten the lock screw. My readings were all over the place as well when not holding constant pressure on every moving part of the darn thing.

 

[CovertGunny]

well using the coal gauge to determine my base to ogive measurement then using this measurement to determine the proper seating depth by knocking off .02 or so from the lands to have a starting point to work with for seating depth. What is a better system then, I've never gotten used to the whole sharpie and steel wool type tricks to determine coal that way probably just lack of experience on figuring it out.

 

[Old Navy]

It takes a little practice and you must start with a clean barrel. I can get very consistent results holding the case in and very softly pushing the bullet it. The case has to able to seat all the way against the shoulder. I have two 6BRX cases. One works better that the other. Later! Frank

 

[37Lincoln1]

http://forum.accurateshooter.com/index.php?topic=3851712.0

Try this: Push rod in as hard as you can and then lock it. Bullet will get stuck, so drop a smaller caliber bullet down the bore to dislodge it. Let us know how consistent your measurements are using this method.

 

[mikecr]

Pushing the bullet really hard ITL is taking you to MaxJam# rather than touching.
I don't see how this is useful.
The pressure spiking point(0-DTL), which is what you're trying to define, occurs way before this.

That you can seat bullets deeper ITL than 0, will play out during seating testing. But in itself, there is no upfront meaning.

 

['Freak]

Next time, I’ll try checking the measured dimension for its consistency when simulating an honest jam compared to the consistency when trying to feel out the point of first contact. Whichever method returns the most consistency will become my zero point. Afterwards it’ll depend, if jam is zero I back away from jam but if just touching is zero you can change in either direction. Your notes need to reflect methods used either way.

 

[Erik Cortina]

Pushing the bullet really hard ITL is taking you to MaxJam# rather than touching.
I don't see how this is useful.
The pressure spiking point(0-DTL), which is what you're trying to define, occurs way before this.

That you can seat bullets deeper ITL than 0, will play out during seating testing. But in itself, there is no upfront meaning.

It is useful because it is easier to get consistent measurements.

Back off .025" from jam and start testing. Once you find what shoots best, reference it as jam - x
0.xxx"

 

[mikecr]

Once you find what shoots best, reference it as jam - x
0.xxx"

No, you're missing the meaning in all of this.
You don't log 5thou off, or 30thou off from jam..
Once you find best seated depth you measure & log your CBTO, because this is all that matters.

The DTL attribute only matters to those approaching touching with a high pressure load. This is a reloading consideration only.
Tuning, with seating, purely comes down to CBTO as determined best.

 

[Erik Cortina]

Once you find what shoots best, reference it as jam - x
0.xxx"

No, you're missing the meaning in all of this.
You don't log 5thou off, or 30thou off from jam..
Once you find best seated depth you measure & log your CBTO, because this is all that matters.

The DTL attribute only matters to those approaching touching with a high pressure load. This is a reloading consideration only.
Tuning, with seating, purely comes down to CBTO as determined best.

CBTO is of course logged, my the reference point must be logged so that it can be checked every 100 rounds or so to be able to maintain the relationship between the reference point and CBTO in order to maintain accuracy. This is commonly referred to as "Chasing the lands"

 

[mikecr]

In our vast shooting world relatively few would benefit in chasing lands,, just as few would determine MaxJam,, and a portion of them (with larger cartridges) would soft seat so that land chasing isn't tail chasing.
After all, jam seating is most beneficial to reach a peak pressure tune(viable only in a few under-bores). Adjustment within jam is merely for minor group shaping, and not significant to the tune itself.
Maybe a 30br, a 6PPC, maybe even a 6.5x47L.
But I'll give it to you that in an example case where you NEED to maintain 10thou from MaxJam, then maybe it would benefit to continually determine where that is in CBTO.

I think this is more a special case than applicable in a broader sense. I think by far most reloaders would NOT benefit in determining MaxJam, and really, few even benefit in determining touching. They don't have to be running a max load while performing seating tests.
Their biggest gain is in determining BEST seating, as expressed in CBTO, regardless of land relationship.
That is, focusing on what matters.

You probably remember, I sure do, when so many implied that VLDs had to be seated ITL. Yet in the background, it was clear to some that nothing about this was true. It never was.
That was damaging to Berger I'm sure & they really took off with demonstration otherwise.
Today, a lot more shooters are actually testing to find best seating, and most are not finding touching through jammed as best, and most are not shooting 30BRs & 6PPCs.
Most will find that once they've determined best seating, they'll never have to adjust it with that barrel again.

Just my stubborn opinions..

 

[Erik Cortina]

I have to pre-load 550 rounds for the 2014 AZ regional and 2014 F-Class Nationals. I monitor throat erosion closely and account for it. I'm sure you know how big of a difference .003" makes, that's why I have to keep up with it.

 

[Erik Cortina]

Actually, I load a bullet long, apply die wax to ogive, and close bolt to allow lands to seat bullet. Snap bolt open and measure.
I end up with a bolt face to lands measurement.

 

[TZaun]

Up until now I would use a Sharpie, color the ogive, and seat .002" at a time until no marks would show on the ogive. When I did this for my deer rifle when I got it back from the gunsmith and worked up a load per Erik's advice, I found a real good one. What I used to think was a .013" jump turns out to be a .076" jump when I seated a bullet long, JBd the case neck, and left the bolt closed overnight. If I'm understanding this correctly, the .076" jump is the correct one of the two, right?

 

['Freak]

“Correct” I figger is whichever way you want to establish a reference measurement for use in seating bullets positioning its ogive somehow relative to contact with the lands, be it the point of first contact with the lands or a full boogie jammed into condition. Either way can work long as you can do it consistently, you fully understand what it is you were doing, and record the how you came about them as well as the findings so you will be able to repeat the how of it next go round so all comparisons of findings by that particular method will have real meaning. There’s nutin preventing you from doing it both ways for awhile then chose one or the other or continue both or add another or whatever, long as it works and you can get it to repeat consistently. I do find it easier to feel out what's going on with the projectile when using the Sinclair tool without having to deal with the dummy case all at once.

 

[mikecr]

“Correct” I figger is whichever way you want to establish a reference measurement for use in seating bullets

Just don't forget your reference is w/resp to tested for and validated accuracy.
The only factor is in repeating of it.

Unless a special circumstance, where you need pressure that can only be had in jammed condition, or you have a magazine muddling with CBTO potential, the reference point itself doesn't matter.
Too much focus on that..

 

[langenc]

Trying to determine my bullet seating depth

You're not trying to determine seating depth, but cartridge base to ogive(CBTO) that represents 0" distance to lands(DTL) in your barrel, with your bullet, right? I call this MaxCBTO.
If you're just measuring seating depth, well you can do that with calipers.

The Hornady/StoneyPoint system plays hell with many folks because it takes datum off both a case shoulder and a bullet ogive.
There are better systems out there, and even soft seating is probably better for MaxCBTO.

I believe I have a Stoney Point (now Hornady).

I only put a bullet into the chamber w/ the device and a dowel in the barrel. Push em back and forth until I get there and then lock it. Take it out and measure.
How is it "taking datun off the case shoulder?"
Maybe Im out in the bushes somewhere..