where do i measure?

[thechristianbear2001]

I found countless threads about what my measurement should be…words like ogive, oal, coal, etc…. I have digital calipers, hornady's bullet comparator, the lock n load gauge…. but I have no idea what I should be measuring to figure out everything I need to know. Seating depth, how much to trim my brass, etc…. sorry, this is all new to me and I am unfamiliar with the jargon to even know how to begin. I apologize for not being able to figure it out on my own….


ohh, I am trying to reload a accurate .308 load… lapua brass, fed 210 primers, smk 175's and a rcbs press and dies for my rem 700 aac-sd 20" 1:10"

 

[earthquake]

Your loading manual should give you specs on brass trim length as well as COAL. The Lock n Load gauge will then tell you your cartridge's seating depth to the riflings if you know how to use it...do you?

You only need to trim brass if it approaches max book length...that is if your rifle's chamber was cut like that. For example in my 6.5Creed, max is 1.920", trim-to length is 1.910" and so mine are about 1.913" so I have room to grow. Are you using brand new brass, or fired? Fired in your rifle, or someone elses? Get a bump gauge too, because eventually brass grows and you'll need to bump your shoulders back, and need a measurement to properly set your sizing die. What dies are you using?

Use your lock n load gauge as stated in the manual, put the comparator on your calipers and measure. The readout will give you the distance from the base of your cartridge to the ogive (the spot on the bullet where it first contacts the rifling). If you did it right, that's zero (0) jam, zero (0) jump. I don't know what caliber you're shooting or what bullet, but then you can research options and decide if you want/need to jam or jump your bullets. You'll have to play with it to see what your rifle likes.

Another example: My bullets are 2.230" to the ogive in my chamber, I'm jumping them 0.040" so I set my die to seat them at 2.190" (2.230 - 0.040 = 2.190) to the ogive. The COAL is 2.866" though, +/- 0.001". You also have to be careful of seating depth if you're feeding from a magazine or not.

I'm far from an expert so take this with a grain of salt. There are much more experienced guys on here, but this is what I've learned recently by reading books, reading these forums, asking on here and asking friends who do this. It's a pain at first and there have been a few times that I've questioned why I'm bothering with it. But, it is fun once you start to get the hang of it. Go slow, read and be safe!

 

[thechristianbear2001]

Thanks for the response

Your loading manual should give you specs on brass trim length as well as COAL. The Lock n Load gauge will then tell you your cartridge's seating depth to the riflings if you know how to use it...do you? I have watched a few youtube videos using the hornady lock and load gauge but haven't played with it yet

You only need to trim brass if it approaches max book length...that is if your rifle's chamber was cut like that. For example in my 6.5Creed, max is 1.920", trim-to length is 1.910" and so mine are about 1.913" so I have room to grow. Are you using brand new brass, or fired? Fired in your rifle, or someone elses? Get a bump gauge too, because eventually brass grows and you'll need to bump your shoulders back, and need a measurement to properly set your sizing die. What dies are you using? I bought the lapua brass new but I now have fired it at least twice. All of it has been in my rifle. We are using the standard rcbs dies. The way I tried to set the dies was more a trial and error where I loaded a shell and then measured it trying to get the overall length to 2.800 or close

Use your lock n load gauge as stated in the manual, put the comparator on your calipers and measure. The readout will give you the distance from the base of your cartridge to the ogive (the spot on the bullet where it first contacts the rifling). If you did it right, that's zero (0) jam, zero (0) jump. I don't know what caliber you're shooting or what bullet, but then you can research options and decide if you want/need to jam or jump your bullets. You'll have to play with it to see what your rifle likes.

Another example: My bullets are 2.230" to the ogive in my chamber, I'm jumping them 0.040" so I set my die to seat them at 2.190" (2.230 - 0.040 = 2.190) to the ogive. The COAL is 2.866" though, +/- 0.001". You also have to be careful of seating depth if you're feeding from a magazine or not.

I'm far from an expert so take this with a grain of salt. There are much more experienced guys on here, but this is what I've learned recently by reading books, reading these forums, asking on here and asking friends who do this. It's a pain at first and there have been a few times that I've questioned why I'm bothering with it. But, it is fun once you start to get the hang of it. Go slow, read and be safe!

I began reloading about two weeks ago so I don't know how much more green or wet behind the ears I could be….

 

[earthquake]

That's how I set my dies, trial and error, until I got the length I needed.

As far as the lock n load OAL gauge, I of course put my modified case on it, insert a bullet, then place it in my chamber. Slide the plastic rod into it until the bullet makes contact with the riflings, then I give it a light tap a few times so I know it's there, lock the nut and pull the gauge out. Most of the time the bullet is still in the chamber, which is no problem. Just tap it out with a cleaning rod, then place the bullet back in the lock n load gauge. You locked the plastic rod in the gauge so the bullet should sit back on top of it where it's supposed to be and then measure that length in your comparator. Do it several times to be consistent. I usually do a dozen or so measurements like this, then average them.

I did find out that if your chamber is dirty, the measurements will seem pretty far off and your bullets seated farther into the case than you may want. I cleaned mine and then I was getting measurements that matched (not exactly but close) the lengths my buddy had on his. No two chambers are alike.

I've been frustrated by loading because I thought every measurement had to be exactly the same. I was under the impression that a 0.001" difference was bad. Since then a friend has reassured me that I'll save time and stress by trusting the equipment and not worrying about errors that small. I have found it useful to have two sets of calipers though. One digital and one dial. Speeds things up and I can confirm one with the other as well.

 

[thechristianbear2001]

Will use the gauge tonight per you instructions and go from there....

 

[thechristianbear2001]

2.9576660 average out of 11 recorded gauge readings

 

[Wheres-Waldo]

Damn, down to the ten millionth!

 

[Rattler56]

My next step would be to load a dummy round ( no powder or primer ) at 2.957 or 2.958, coat the bullet with candle soot or use a felt marker and chamber the round to check for marks from the lands.

Then adjust accordingly.

 

[bruddah]

damn, down to the ten millionth!

lmao!