Measuring Tools, please help

[smitty81]

Hi, I have been reloading for a few years now. I have decided since I now have more money, I want to get more into it and do a better job. So I have been doing my homework and looking at different tools and misc. things.

I bought an OAL gauge, I understand how that works.

Last night I bought a bullet comparator. I have a general understanding of how that works but am still a little confused.

I understand why it says to measure it that way, Because each bullet can be slightely different. This will not be a true COL. length will it?
If you measure this way, You have to account for the thickness of the metal between the bullet and the caliper blade because your just measuring towards the base of the bullet and not the tip.

CORRECT?

So if I were to measure the COL without the comparator and the OAL gauge, the measurement would not be the same? This is just a more accurate way to measure and compare bullet lengths?

Am I right?

My next question is this. I understand that you want to be close to the lands which is obviously the reasoning for the OAL gauge, but on the instructions for the bullet comparator, it said that you want to be .020 from the lands for hunting cartriges.

Why is that? I dont understand why this is. I thought you wanted to be as close to the lands as possable.

Then I was looking at headspace gauges. I dont know if I understand the purpose of this. Is this the check and make sure your necks are being sized back down to the proper size?



thanks for any help.......

 

[C.Smith]

I'll try to answer as much as I can for you. I just got a comparator last November and love it. I also have th Stoney Point OAL gauge which helps but is not necessary.


First you need to know what the distance to your lands are with the paticular bullet you are using. You can do this with the OAL gauge if you have one or by taking a fired case, slightly bend the mouth so it will hold a bullet (making sure that it is long enough to contat the lands, and then blacken the bullet with a candle flame.

Next load it into your rifle and close the bolt. I use a dowel or you can use a cleaning rod but open your bolt slowly and remove the case and use the rod to push out the bullet. Due to the blackening you should see where the bullet stopped in the case.

Re-insert the bullet to the line and you and use your comparator to find your distance to the lands. With this distance you can now start playing around with different lenghts and as long as you load to the above measurement you should not touch the lands, with that bullet (each different syle bullet will be different).

As for the .20 off the lands for hunting I think it is more of a realiability caution then anything.


Corey

 

[smitty81]

I think I understand how to figure the distance from the lands to the bullet to get the seating depth. My question though is this........

I understand why it says to measure it that way, Because each bullet can be slightely different. This will not be a true COL. length will it?
If you measure this way, You have to account for the thickness of the metal between the bullet and the caliper blade because your just measuring towards the base of the bullet and not the tip.

CORRECT?

Why is it a caution to be .020 away from the lands? Is it dangerous to touch the lands?

If someone could please help i would appreciate it.

 

[C.Smith]

If your bullets touch the lands it can send your pressures through the roof. This could be with an ordinarily safe load.


Corey

 

[smitty81]

Ok, That makes sense to me. I can see the reasoning behind that.

Does anyone know the answer to this though

Last night I bought a bullet comparator. I have a general understanding of how that works but am still a little confused.

I understand why it says to measure it that way, Because each bullet can be slightely different. This will not be a true COL. length will it?
If you measure this way, You have to account for the thickness of the metal between the bullet and the caliper blade because your just measuring towards the base of the bullet and not the tip.

CORRECT?

Can anyone answer this for me too?

Then I was looking at headspace gauges. I dont know if I understand the purpose of this. Is this the check and make sure your necks are being sized back down to the proper size?

 

[C.Smith]

I can't answer the headspace gauge for you. But I only use the comparator measurement for my OAL. So I guess you can say that it is a true OAL for my gun. I don't worry about the OAL from tip of bullet to the other end anymore.

Corey

 

[smitty81]

I think that Stoney Point needs to put the info about the seating being .020 away from the lands on their instructions for the OAL gauges. I would have never had know about this info if I didnt buy the bullet comparator. That could have been dangerous!!!

Maby its just common sense but each person has to learn about it sometime and it would have been nice if it were on the instructions for the OAL gauge.

Feel free to add your two cents........

 

[C.Smith]

My instructions mentioned that under USE COMMON SENSE WHEN SELECTING A BULLET SEATING DEPTH. It's on the second page.

Corey

 

[smitty81]

My instructions mentioned that under USE COMMON SENSE WHEN SELECTING A BULLET SEATING DEPTH. It's on the second page.

Corey

A first timer would never had know that information..............
I understand not to seat too deep but I wouldnt have know about the land info.

Go ahead and criticize me if it makes you feel good about yourself

 

[C.Smith]

I'm not critiziny you. Why do you think that? If I sounded that way that was not my intention, I'm just trying to do my best in helping you out. Sorry if you took that the wrong way.

Corey

 

[smitty81]

ok, sorry man

 

[C.Smith]

No problem. I hope I was able to help you out.

Corey

 

[Guest]

I can tell you that even a novice handloader should be in possession of at least one good manual, which will clearly detail why you should keep bullets off the lands, or work up carefully with bullets touching the lands. I am assuming you have either a Speer, Hornady, Nosler, or Lyman manual, and have read the beginning sections thoroughly. I took it to mean that the information was in the section entitled 'Use Common Sense..." as a line item. I may be wrong. I have that same comparator set at home, so I will look over the instructions sometimes this weekend if I get time.

As for the reason you measure from the ogive of the bullet, it is really pretty simple. You want to consistently seat bullets the same distance from the lands of the bore, so you need to know that distance. Also, you will find that if you seat bullets to be consistent in length to the ogive, the length to the tip will be somewhat less consistent as bullets are known for being slightly different lengths (especially those with exposed lead tips). So if you measure from the ogive, you solve two problems at once. It also makes setting up your dies easy, as you have a consistent length (to the ogive) for all your rounds, so you don't have to convert based on the length of the different bullets. You still have to make sure they will feed at a given length, but once you establish a COL using the comparator, you can generally use that with every bullet, and then check for proper feeding.

Keep the questions coming. Everyone here likes to share their knowledge.

 

[C.Smith]

Smitty81,

I just realized why you thought what you did, after the last post. Sorry I did not explain that better. But the common sense thing was a heading in the instructions. Do you need a copy of them, I would be happy to scan them and e-mail you a copy if you did not get them with your OAL gauge.

Just let me know.

Corey

 

[smitty81]

I have the instructions, just a little confusing I guess. I have the answer to two of my questions now.

Yes pop, I do have a Nosler and a few Hornady manuals which I Inheriated from my grandfather. I guess I better go through them again.
Always want to be safe.

Can someone answer my last two questions now/

I understand why it says to measure it that way, Because each bullet can be slightely different. This will not be a true COL. length will it?
If you measure this way, You have to account for the thickness of the metal between the bullet and the caliper blade because your just measuring towards the base of the bullet and not the tip.

CORRECT?



So if I were to measure the COL without the comparator and the OAL gauge, the measurement would not be the same? This is just a more accurate way to measure and compare bullet lengths?

Am I right?

And this one too

I was looking at headspace gauges. I dont know if I understand the purpose of this. Is this the check and make sure your necks are being sized back down to the proper size?

This tool is what im talking about just in cas anyone is confused.

https://www.hornady.com/shop/?ps_se...&category_id=4ffc0a8772783e83440ac87ed0c3ee5b

thanks for all the help guys

 

[rick smith]

Smitty81, is your measuring gauge the Stoney Point? The number you get from measuring from the base of the case to the ogive of the bullet is unique to that bullet in your rifle. You don't need to take anything else into account. You have a case with bullet seated, base of case on one side of the caliper, bullet is inserted into the comparator, square the case/bullet in the caliper and read your number. Nothing to add or subtract. If you are measuring to the lands, several good methods, I quite with smoking the bullets with a candle, I use 4/0 steel. Twist the bullet/neck of case around in the 4/0 and you will have some very fine marks to read the lands. I make a magic marker line where the bullet meets the neck of the case, easier to tell if the lands moved the bulet back and forth.
Once I have a to the lands measurement I make a dummy round, steel wool it and close it in the action. Carefully remove it and look for land marks. Measure that with the comparator, record the number. Now you have a reference for seating of that bullet in your rifle. It is now much easier to set your seating die to give you 10-20-30 off the lands. You don't want to be so close to the lands that you may stick a bullet in the lands and dump a load of powder into the chamber, pressure will go up once you start getting into the lands. There is no rule that says you have to be close to the lands for good accuracy. Many short action magazine boxes won't accept the length of a bullet seated to the lands, WBY mags have so much freebore that the bullet is out of the case before it contacts the lands. I never seat any closer than 0.010" off the lands and most are farther than that.
The headspace gauges are to aid in setting your FL die. You can measure to the datum line on the shoulder so you will have a reference point for setting the shoulder back. Helps prevent over working the brass and decreases the chance od case head seperation.Rick.

 

[Guest]

Just so you know, Smitty, I wasn't trying to be a jerk, either, when I mentioned that about the manuals. I go back through my manuals every so often just to be sure I am not forgetting things, too. When I get a new manual, I always read the basic handloading stuff in the front of it, just in case there's something I forgot or some new way to 'look at' something that helps me load better. Or maybe it's just my OCD.

The gist of it is that I hope you weren't offended or felt as though I was being condescending, I surely didn't mean to d; so.

We all started out as novices, and we have all made mistakes, so please don't think any of use are above reproach.

I think that Rick answered the questions better than I did, but if you are still unclear, ask away, we will do our best. At least the advice is worth what we're all paying for it, huh?

 

[smitty81]

no offense taken, thanks for the help guys!!!!

But im still a little confused on the marking the bullet thing.

Would'nt I get the same affect if I used the OAL gauge and put it into the chamber with the bullet and pushed the bullet clear to the lands. Then tightened the set screw so the push rod wont move. After that put the bullet back into the cartrige and measure the length with the bullet comparator. Take that length and minus .020 to set it back from the lands.

Wouldnt that work?

 

[rick smith]

Smitty81, are you using a modified case that has the rod that screws into the bottom of the case? If so you don't have to mark the bullets. Marking is used when you use a resized case to hold the bullet as you try it in the rifle. I do use 4/0 steel wool to mark the bullet when I make a dummy round just to make sure of the land contact, just want a light touch and measure from there.Rick.

 

[smitty81]

YES!!! It is a modified case. That clears all the confusion. so my method will work right?