Hornady OAL guage help

[Deleted member 107666]

Just picked up a new build. Measuring CBTO with hornady OAL guage, the hornady modified case and bullet comparator. 300wm w/berger 215s.

First 10 measurements were withing about .002

Broke it all down, put comparator back on, zero'd out and went back to measuring again. I'm still withing .002-.003 though for an average of 5 measurements, problem is, that 2nd group of measurements is averaging .005 longer than my initial group. Makes seating .020 off the lands a little difficult if my measurement to the lands varies by .005

Trying to use same method (gentle tapping till bullet barely hits the lands, then locking it down.

I've watched all the youtube vids and to me, I'm doing it correctly.

Any thoughts, tips, techniques? Considering driving 2 hours to my smith to have a pro give it a shot.

 

[YZ-80]

What you might be seeing is some variation of the contact point to the lands at the ogive profile. I've had it vary up to .007" with cheaper bullets and your Berger's might vary as much as .002-.003. I've also found that some projectiles don't necessarily come to a hard stop when they encounter the lands, giving you this
" mushy" resistance for as much as a few hundredths until they come to a hard stop. This can be frustrating but I don't think you need to go for a drive. .005 variance with an OAL gage is not unheard of and there could be other factors at play, perhaps your comparator case? IMHO if you can reliably seat at .005" off, I'd go with that. That's pretty close, relatively speaking and I've heard some fairly reliable reloading aficionados say .002 to .003" difference isn't make a heck of a lot of difference anyway. Good luck.

 

[Deleted member 107666]

That leads me to ask what's the right amount of pressure when pushing bullet in to hit the lands? Maybe slightly firmer and hope for a more consistent measurement, then back of .003-005 and load them em?

If anybody has a good video demonstrating that, I'd be happy to share an email to see it

I'm confident the case is fully seated, and from there I hold the gauge with some pressure to keep case seated as I very lightly tap the bullet in. At the first sign of resistance, I give it a few more very light taps and call it good.

I dont want to jam it into the lands, but dies it sounds like maybe just a little firmer pressure would give me more accurate results?

Pretty disappointing if the bergers are off up to .003, makes it pretty tough for me to seat them accurately to the .020 that folks seem to say they like.

 

[19 Badger]

I never could get a real consistant reading on mine until I started applying firmer pressure on the bullet. I used to try to just gently touch the lands but it never worked good for me.

 

[YZ-80]

Well Vandy, you might have a completely different result with a different bullet. If you took an Accubond for example, you might get a very defined "hard stop" at the lands and be within .001-.002 every time. When you talk about feeling resistance and giving it a few extra taps, that's what I was referring to (I.e., " mushy resistance"). I misunderstood in that I thought you were wanting to seat at .003" off the lands. Starting at .020 off is what I would advocate and I think that's what you're trying to do. I may be all wet, but I think with the Berger, If you can seat .015 to .020 consistently while watching concentricity and neck tension you will be fine. I think that Berger ogive profile is just too gradual in girdth increase to give you a defined stop at the lands and that's what's causing the problem getting a more exact measurement.

 

[Deleted member 107666]

That makes sense. Will give it just a little bit more of a love tap to be sure its touching and call that good.

Post was edited.... .020 jump was what I'm aiming to start with...I had .002 in there at first, typo. Seems a few folks with this specific chamber are anywhere from .020 to .040 with the 215s and solid results. Hoping to load as long as possible to help with velocity/keep pressure down, but still not put myself in a spot to potentially be jamming a bullet due to my novice errors in measuring/loading.

Thanks for the advice, as always fellas.

 

[YZ-80]

Hoping to load as long as possible to help with velocity/keep pressure down, but still not put myself in a spot to potentially be jamming a bullet .

Exactly. This is the compromise I always try to strike. If it makes you feel any better, load a dummy round to published COL and compare it visually to a loaded round @ .020" off the lands CBTO. The later will probably be a mile closer to the lands (but not too close) and you'll sleep like a baby.

 

[Deleted member 107666]

Someone posted this on snipershide...thinking I may give this a try as well...steve at hammer bullets suggested this method as well for finding the lands.

Any pitfalls or potential errors in this method? I do agree it seems less subjective than how hard an individuals 'tap'may vary on the OAL guage...

 

[YZ-80]

Hi. It seems a bit tedious but looks like a sound method to me. I wonder if that was a 6 Dasher or 6 BR maybe?

His point is well taken on the Hornady OAL gage probably giving you a measurement "jammed" into the lands .005". I back off .020" from that so I may actually be seating a bit longer than I thought!

 

[Buzzsaw]

stick a long wood dowel rod down the barrel till it touches the tip of the bullet. you can push against the bullet back and forth and get a MUCH BETTER feel where the bullet hits the lands.

also if you have any carbon ring, you can get false readings

 

[misterc01]

I finally decided to use both the Hornady and Sinclair comparators. I also "learned" tha t I need to use a fairly firm pressure to ensure I am on the lands. And at this point I have consistent readings to within .0005" measurements. I have done it for all different bullets I use. That is tedious as well, since I take 10 measurements with each (20 total), and then go with the average. Seating I am trying are .015 to .020.

 

[Mikecr]

Why all the concern for land relationship?
All that matters is best seated CBTO -as tested. It doesn't matter how far this is from YOUR land contact(which is different from that others might declare).

 

[skipglo]

That leads me to ask what's the right amount of pressure when pushing bullet in to hit the lands? Maybe slightly firmer and hope for a more consistent measurement, then back of .003-005 and load them em?
Absolutely try more pressure. These gauges require consistent pressure so practice with them is required just like everything in the game. You will get a FEEL for it quick enough..it's just new to you now. Kinda like just the right amount of pull on Every new trigger. Took me about 15 different trys....but I'm slow I guess!
If anybody has a good video demonstrating that, I'd be happy to share an email to see it

I'm confident the case is fully seated, and from there I hold the gauge with some pressure to keep case seated as I very lightly tap the bullet in. At the first sign of resistance, I give it a few more very light taps and call it good.

I dont want to jam it into the lands, but dies it sounds like maybe just a little firmer pressure would give me more accurate results?

Pretty disappointing if the bergers are off up to .003, makes it pretty tough for me to seat them accurately to the .020 that folks seem to say they like.

 

[Rhovee]

Alex's method is the most consistent I found. And best way to set up your die for correct shoulder bump. It matters a lot because I check lands every 50 rounds and stay on top of it. The Hornady tool puts your bullets in the lands for sure. That's why it gets stuck.