Oal gauge issues

[270ruger]

I am having problems with my oal gauge. I keep getting differnt meserments with the same projectile. I even have the bullit compareter and both are from hornady. What am I doing wrong. Please help

 

[kcofohio]

<deleted>

 

[spitballer]

I sometimes use one of those comparators, too, looks like a large hex nut with holes in it. For me it's kind of awkward to hold and sometimes I get different readings. I seem to get the most consistent readings when I'm able to hold everything in a straight line, but sometimes the bullet wants to settle into the hole at an angle and I have to start over. These days I don't use it as much because I'm able to fit a bullet loosely into a case and get a measurement to the rifling, but it still comes in handy when I'm diagnosing OAL problems.

 

[gamestalker]

As convenient as using one seems, nothing is more accurate than just working off the lands, IMO.

GS

 

[fguffey]

Please help

Spitballer, I started to respond then, I notice you were post number 3.

F. Guffey

 

[30Cal]

You're going to see variations from one round to the next; moreso if you measure OAL. The tips can vary quite a bit, even with match ammo. The comparator should give more consistency since the seating dies should be pushing from the curve of the bullet.

Either way, I wouldn't sweat it. If you can get the bullets within 0.020" of the lands, then great, but that's frequently not achievable unless you have a match chamber with a short throat.


If you want to find out where the lands are, seat a bullet very long and stuff it into the chamber with your thumb. If it doesn't come back out when you tip the muzzle up, the bullet is in the lands. Seat it a tiny bit deeper and repeat. Once it falls down on your own, measure the ogive or OAL; write it down--you are right at or just barely behind the lands. I would put that one in a drawer for future reference. Seat another one, measure then seat the bullet deeper by 0.020" or whatever you want the jump to be.

The dummy round you can use later to reset the die for zero jump (for that model of bullet). Back the seating plug out, run the case up, then thread the plug down till it contacts.

Make sure you keep roughly one bullet diameter below the case mouth.

 

[taliv]

that's been my experience with every OAL gauge i've tried. i think they are extremely sensitive to how the bullet goes into the lands and how much force you use. since it's difficult to do that the same way each time, you get different measurements.

i don't know what to tell you other than it's pretty annoying. you might think of it as a range instead of a precise measurement

 

[fguffey]

i don't know what to tell you other than it's pretty annoying

If the gage worked and the reloader got a measurement I ask" What would the reloader do with the measurement? I know, more tools, more measuring and checking and more measuring.

I do not insist the OP use the tools he has listed, I do not believe the tools are absolutely necessary, nice? Yes, but not necessary.

F. Guffey

 

[Otto]

The OAL gauge works but it requires a bit of technique. It's important to gently tap the bullet adjustment rod to ensure the bullet is in light contact with the lands. It's also important to a have a spotlessly clean chamber and throat. And don't forget to chamfer/deburr both the inside and outside of the Modified case to insure that the bullet slips freely.
Re-reading the instructions that came with the tool might solve your variance issue.

 

[270ruger]

Thanks for all the ideas. I'm going to do some reloading this weekend. I will post the resolute I get. Does any one what a good powder is for a 270 sst hornady bullit. I have the book but good advice is always great.

 

[higgite]

Re-reading the instructions that came with the tool might solve your variance issue.

It didn't for me. I could never get consistent readings that I trusted, no matter how many times I read the instructions. I do what 30Cal describes in post #6 above. No mysterious technique involved. It either sticks or it doesn't. ymmv

 

[RAT807]

A few things to consider.. The length of the bullets will be different, the bearing surface lengths will be different. Most times a more consistent measurement will be from the base of the bullet to the ogive. When I measure bullet ogive lengths, I spin the bullet in the digital caliper mounted comparator from Hornady. I take 2-3 measurements as I spin the bullet, to make sure the bullet is centered or straight. If you sort your bullets by ogive lengths, when you load your rounds, you will have a lot more consistency in the COAL measurements. I usually measure from the case head to the ogive. Using this measurement, I know how far the jump will be to the lands.

The lands on my .280 are right at 2.710 and my rifle groups best around 2.700-2.705 so I use the measurement to the ogive and not to the tip of the bullet. I also spin the loaded round when measuring from case head to ogive. Spin it about 1/3 a turn then measure, spin again and measure. If you get different measurements, I spin again. If the first two measure the same, I go with that.

 

[spitballer]

I used my hex comparator again last night just to check on a bullet that seemed long and wouldn't respond to a second pressing. With the comparator it measured the same as the shorter bullets, and confirmed my suspicion that the edge around the hollow point was to blame. Still glad I have the comparator. Very useful.

 

[2 Wild Dueces]

The OAL gauge works but it requires a bit of technique. It's important to gently tap the bullet adjustment rod to ensure the bullet is in light contact with the lands. It's also important to a have a spotlessly clean chamber and throat. And don't forget to chamfer/deburr both the inside and outside of the Modified case to insure that the bullet slips freely.
Re-reading the instructions that came with the tool might solve your variance issue.

BINGO! Spend some time to clean the gun....then develop a light, yet positive touch of the bullet ogive to the lands......via using a dowel thru the muzzle to "jockey" the bullet back and forth. You WILL find a repeatably, tho light, "sticking point" of the bullet to the origins of the rifling (the lands). Then, when you feel this same stick point.....lock the push-rod and carefully measure the results.

Done correctly, you should be within .0005" or so when measuring OAL. Takes a bit of practice....and you cannot be "heavy handed".....but such measurements are key to making precise hand loads.

 

[dirtman]

agree with Rat and wild... that exactly how it works for me....

 

[Bart B.]

Read the last paragraph in:

https://www.thehighroad.org/index.php?threads/cartrige-oal-and-why.813769/

Or the whole post, if you want.

Hopefully you'll understand that the case head to bullet tip doesn't define how far the bullet jumps to the rifling every time a round's loaded.

 

[murf]

two year old thread!

murf

 

[Doublehelix]

You're going to see variations from one round to the next; moreso if you measure OAL. The tips can vary quite a bit, even with match ammo. The comparator should give more consistency since the seating dies should be pushing from the curve of the bullet.

<snip>

Make sure you keep roughly one bullet diameter below the case mouth.

I love this post, and it makes perfect sense, except... the very last sentence: "Make sure you keep roughly one bullet diameter below the case mouth."

What do you mean by this?

Thanks!

 

[Bart B.]

I'm convinced it's a decades old myth contrived by an ignorant hand loader. Too many matches are won and records set violating that old moniker. Military ammo has never used it.