Hornday Comparative

[williaada]

New to reloading, and I have bought the hornday comparative kit. Does this kit really help with measuring the overall length? For some reason I am having a hard time understanding how this tool actually works to make sure I am not over sizing or unseeing sizing my cartridge? Any answers are appreciated.

 

[cjcavinaw]

The tool is extremely helpful for consistent reloading but it does not measure overall length at all. For the headspace comparator tool I like to bump my shoulders back 2 to 3 thousandths. As for the bullet comparator tool it measures base to ogive and not COAL. So essentially youre measuring cartridge base to where you are engaging your rifling which will give you a much more consistent reading than COAL, you just have to test and see how far off the lands your gun likes to shoot. Hope this helps a little.

Sent from my SM-G965U using Tapatalk

 

[eaglemountainman]

This^^^^^^^^^^
To measure COAL, from headstamp to bullet tip, just a set of calipers is needed. But as stated above, measuring from headstamp to bullet ogive is the more accurate method. This is due to the inconsistencies in bullet tips. I recommend having both, the headspace comparator and bullet comparator.

 

[sdupontjr]

And to add what is already mentioned, COAL will only come into play for Magazine length. Other than that, measure CBTO (cartridge base to ogive)

 

[ORhunter74]

New to reloading, and I have bought the hornday comparative kit. Does this kit really help with measuring the overall length? For some reason I am having a hard time understanding how this tool actually works to make sure I am not over sizing or unseeing sizing my cartridge? Any answers are appreciated.

As mentioned above, the headspace comparator is the one that would help you with your brass sizing.

You would measure your fired brass with the correct insert for that caliber. I usually measure a bunch of fired cases and you should start to see an really consistent average across them all provided they were all fired from the same gun. You can zero out your calipers on the case so you’ll be able to see what the results of the next step are.

Then, assuming you’ve already set up your sizing die per the manufacturer’s instructions, you would size a lubed case and re- measure. You want to see a difference of negative 2-3 thousandths. If you see something like negative 6-8 thousandths, then you’ve oversized your brass and need to back your sizing die out a little. If you see a positive difference, then you actually stretched the brass a bit and need to screw your sizing die in a little. It can be a bit fiddly but it’s definitely worth it to get consistent results when sizing. Sorry for the long winded response.

 

[Flea21]

New to reloading, and I have bought the hornday comparative kit. Does this kit really help with measuring the overall length? For some reason I am having a hard time understanding how this tool actually works to make sure I am not over sizing or unseeing sizing my cartridge? Any answers are appreciated.

Congrats, you've entered a world of fun! That tool is invaluable... The OAL guage is good to measure base to Ogive and the OAL that you can go before touching the lands. From there it allows you to play with your seating depth on your bullet choice to see what your rifle likes when you do load development.

When i first started reloading, i followed what I read in the loading books and my rifles shoot better because things were more consistent. However, when I started using that tool and really dove into more precise ammo, thats when things dramatically improved for me.

Best advice i have for you is read read read! And plug into others that can help, like youre doing now.

 

[Hurley88]

I’m not new to reloading, nor to the Hornady OAL gauge, but last night I did something that caused me to doubt its accuracy. I took multiple measurements.

I’m setting up a couple new rifles in 6.5 Creed, never had one before. So I’m setting the CBTO for two bullet styles and it was extremely strange that at 0.030 off the lands I wasn’t even grabbing the bearing surface of the bullet with the entire neck. So, I dug in & the first thing I noticed was just how long the “rub” on the bullet was from jamming it into the lands. I had gone way past touching the lands, as evidenced by a rub that was (I’m guessing, I can go measure) around 1/8 to 3/16”.

So, obviously I wasn’t supposed to push the bullet that hard. I re-did the rest to find out where the bullet first barely touches the lands. And my COAL went from 2.878 to 2.746”. Now I was concerned. That’s a lot of variance. So I re-did the test with the gauge ten times to get an average, trying to find where I just touched the lands. Across ten tries my extreme spread was 0.287”!

I realized that the angle I held the OAL gauge body at & the amount of force applied greatly changed the results. I imagine the case isn’t properly headspaced because of this, and the bullet is allowed to touch on one side but not the other just because of the way I may/may not be tilting the gauge body. I’ve been using the OAL gauge for a few years now but doing repeated measurements to find an average has me very doubtful about the method of measurement overall. Made me worried that I may be a little too close on some of my other rifles.

Have any of you guys experienced this, or am I doing something wrong? Would be curious to see anyone’s results who tries it. I’m at a bit of a loss.

 

[Flea21]

I’m not new to reloading, nor to the Hornady OAL gauge, but last night I did something that caused me to doubt its accuracy. I took multiple measurements.

I’m setting up a couple new rifles in 6.5 Creed, never had one before. So I’m setting the CBTO for two bullet styles and it was extremely strange that at 0.030 off the lands I wasn’t even grabbing the bearing surface of the bullet with the entire neck. So, I dug in & the first thing I noticed was just how long the “rub” on the bullet was from jamming it into the lands. I had gone way past touching the lands, as evidenced by a rub that was (I’m guessing, I can go measure) around 1/8 to 3/16”.

So, obviously I wasn’t supposed to push the bullet that hard. I re-did the rest to find out where the bullet first barely touches the lands. And my COAL went from 2.878 to 2.746”. Now I was concerned. That’s a lot of variance. So I re-did the test with the gauge ten times to get an average, trying to find where I just touched the lands. Across ten tries my extreme spread was 0.287”!

I realized that the angle I held the OAL gauge body at & the amount of force applied greatly changed the results. I imagine the case isn’t properly headspaced because of this, and the bullet is allowed to touch on one side but not the other just because of the way I may/may not be tilting the gauge body. I’ve been using the OAL gauge for a few years now but doing repeated measurements to find an average has me very doubtful about the method of measurement overall. Made me worried that I may be a little too close on some of my other rifles.

Have any of you guys experienced this, or am I doing something wrong? Would be curious to see anyone’s results who tries it. I’m at a bit of a loss.

I’ve changed my lands measurement process recently from the Hornady tool to making dummy rounds (ie. Wheeler Method). In doing so I was off on all my rifles, some not by much a few thousandths but on my 308 it was dramatic. In that rifle I thought I was seating .020” off the lands when after making a dummy round d it was actually just .005” off the lands. The rifle shoots good but I think it can shoot better with some seating depth tuning now knowing that.

From now on I strip the bolt and make a long dummy round and seat the bullet a few thousandths deeper and chamber it and test and keep doing that until the bolt drops on its own weight. That I know definitively is where lands are at.

I think the Hornady tool works good but is clearly not perfectly accurate like a dummy round would be.

 

[Hurley88]

Thanks! Gonna try that. Just don’t have a warm fuzzy about the Hornady tool anymore, there’s too much variability it seems.

 

[Flea21]

Thanks! Gonna try that. Just don’t have a warm fuzzy about the Hornady tool anymore, there’s too much variability it seems.

I completely understand, neither do I. It’s not a bad tool but the best way to know exactly where the lands are is by stripping the bolt and making a dummy round carefully seating and then checking and seating and checking until the bolt drops and you’re right at the lands. I think that’s the most consistent way to find the lands.

He’s a video on how to do this.

 

[Hurley88]

Yeah I’ve been reading & watching videos since my last post, definitely doing this when I get time. Thanks a bunch!

 

[Flea21]

Yeah I’ve been reading & watching videos since my last post, definitely doing this when I get time. Thanks a bunch!

You’re welcome buddy. This is the answer, I was you not too long ago, lol

You’ll be fine, circle back with an update when you do… Good Luck!

 

[Hurley88]

Yeah after researching I remembered having heard of the various methods from way back, but I had just never gone further with any of them. I’m going to do the lighter method first, then strip the bolt down for the Wheeler method…don’t think I’m going to go as far as doing the barrel removal method though. That one seemed a bit involved, I mean unless the gun is completely new & hasn’t been to the range with scope installed yet. Will report back for sure, may be a few days.

 

[Hurley88]

Tried it, love it, that’s the only way I’m doing that from now on. I didn’t try the lighter method, right off the bat it’s obviously inconsistent. But anyway, thanks for the help I’d have probably circled that for weeks. The Wheeler method is a snap, easy as pie.

 

[Flea21]

Tried it, love it, that’s the only way I’m doing that from now on. I didn’t try the lighter method, right off the bat it’s obviously inconsistent. But anyway, thanks for the help I’d have probably circled that for weeks. The Wheeler method is a snap, easy as pie.

Fantastic! I’m glad you got it figured out. Like I said in my previous post, I literally was in your shoes not too long ago and once I did the wheeler method, I’ll never go back to doing it any other way.

Welcome back from the rabbit hole.. LoL!

 

[EdP]

To expand a bit on what ORHunter74 said regarding sizing:

As you thread the die in to try for the desired shoulder setback you may initially see the case lengthen. This is because the die is not contacting the case shoulder yet but is squeezing the case inward causing it to lengthen. Keep threading in the die in small increments and eventually you will reach a point where the shoulder is making contact. Keep adjusting in to reach the desired setback.

 

[Flea21]

He was having issues finding the lands properly not resizing a case. However, the best way I’ve found to setup a sizing die is with Redding dies and Redding competition shell holder set.

Just screw the die down till contact and add a little more to slightly cam over using the +.010 shell plate. Then resize with that and change plates till you get the desired shoulder bump and you’re done. The plates come in .002” increments which make the process quick and easy.

 

[B23]

With using the Hornady tool for finding where the bullet touches the lands I've found using one of the generic store bought Hornady modified cases can give inconsistent readings because those modified cases tend to be fairly undersize to the chamber and kind of wobble around a bit. I always make my own modified case for the Hornady Overall Length Tool by taking a piece of brass that's been shot in my gun and having it drill & tapped.

By making a modified case from a piece of brass shot in my gun it perfectly fits the chamber and I get consistent measurements every time versus using one of the Hornady modified cases that's a bit undersized, probably done intentionally so they fit everyones chamber, and doesn't fit perfectly and sort of wobbles around a bit giving me inconsistent measurements.

 

[Harvey_NW]

Have any of you guys experienced this, or am I doing something wrong? Would be curious to see anyone’s results who tries it. I’m at a bit of a loss.

The throats on these new chambers are tight, typically .0005" over bullet diameter, which means pretty much any degree of tilt while going in with a bullet will cause resistance and could give you a false reading. Easy to do with a sloppy modified case with a loose neck and a plastic rod.

My personal preference is to use the Frankford Arsenal kit on a cleaning rod to take the OAL, or to the lands measurement. It takes the measurement from the bolt face so you don't have to strip a bolt and sit there seating .001" at a time, it's a true max measurement. You can seat a bullet long in a case and stick that in the chamber by hand and wiggle it with a little pressure, and feel when the bullet pops through the throat area and hits the lands. From there you can double check by pushing back and forth with the cleaning rod and your finger feeling the bullet make contact with the lands, and use however much pressure you feel necessary to take that measurement. It's been very repeatable for me with only a couple thousandths variance, depending on finger pressure against the lands.

 

[Hurley88]

Yeah the case sizing I’ve pretty well settled on .005” shoulder bump. More than most of my shooting buddies but I like the extra feed reliability. I went through full length then into neck sizing, and about five years back settled on full length but just enough shoulder bump.

@B23, yessir I think you’re onto something there. That makes sense, I could see you getting good results with a properly fitted case. That said, unless you have a particularly difficult bolt to strip down the Wheeler method took me all of ten minutes on my first try without the need to drill & tap or buy a gauge.

Thanks again guys!