Caliper Reading and Seating Depth- Confused???

[smoky]

I am about to ask a really stupid question, but here goes.

In reading some bullet seating depth topics here, it has been stated that most handloaders of rifle bullets try to seat their bullets .01 to .02 off the lands.  Now if I remember my math lessons correctly, that is one to two hundreths off the lands.  I thought that I should be seating one to two thousanths off the lands and shouldn't that be correctly represented by .001 to .002.

More importantly in regards to my dial caliber, is the distance between the smallest "hash" marks on the dial face .01 or .001?  I have always thought them to be .001.

For example if the measured ogive length of my 7 mag cartridge is 3.750 on the caliper (that is 3.7 on the bar and then 5 on the dial), and I wanted to seat the bullet 2 thousanths off the lands, I would seat to 3.748, which would be two "hash" marks off the initial reading of 3.750.  Am I correct in this?  

Any comments or clarifications are most welcomed.

Smoky

[bgjohn]

You can't tell where the lands begin that way. Seat a bullet in an unloaded case with the bullet a long way out. Mark the bullet with a magic marker. Chamber the dummy round. Extract it and observe the marks made by the rifling. Keep in mind that the shape of the bullet will change how deep to seat the bullet to be off the lands a given amount.

If you don't want to do all this then just follow the seating depth listed in your loading manual.
JM

[Flash]

You are correct in reading your caliper. the smallest increments are thousands of an inch, aka .001. Be careful in setting the seating depth because you can sometimes extract the case with the bolt and leave the bullet stuck in your chamber. What I do is load an empty round about .020 over maxium overall length and chamber it. If it doesn't touch the lands, I pull the bullet out about .050 with neddlenose pliers and reset my seating die for .005 less depth. It takes just as long as seating the bullet real shallow and camming the bolt over to get stuck in the lands, as it does my way but the bullet won't get stuck this way.

[longwinters]

I would just buy a Stoney Point bullet comparitor and the appropriate caliber dummy brass that they sell.  It is the easiest way to go as well as accurate.

Long

[Javelina]

Hello Smoky,

Longwinters has it exactly right, use a Stoney Point Comparator and you can't go wrong.  There are other non-commercial methods of doing the same thing.  One of them is here:  http://www.varmintal.com/arelo.htm#Chamber_Length

Go to the section on chamber length at the URL agove and review it.  Varmint Al has a lot of good info for reloaders/shooters/hunters, you might want to read what he has to say on various aspects of guns and shooting.  Good site and he's a heck of a nice guy.

Safe and good shooting to you!  

Javelina

[savageT]

I am about to ask a really stupid question, but here goes.

In reading some bullet seating depth topics here, it has been stated that most handloaders of rifle bullets try to seat their bullets .01 to .02 off the lands.  Now if I remember my math lessons correctly, that is one to two hundreths off the lands.  I thought that I should be seating one to two thousanths off the lands and shouldn't that be correctly represented by .001 to .002.

More importantly in regards to my dial caliber, is the distance between the smallest "hash" marks on the dial face .01 or .001?  I have always thought them to be .001.

For example if the measured ogive length of my 7 mag cartridge is 3.750 on the caliper (that is 3.7 on the bar and then 5 on the dial), and I wanted to seat the bullet 2 thousanths off the lands, I would seat to 3.748, which would be two "hash" marks off the initial reading of 3.750.  Am I correct in this?  

Any comments or clarifications are most welcomed.

Smoky

HOLD UP!
I believe you want to go back and read your reloading manual again........
The caliper, if it is a dial caliper, reads in 100ths and 1000ths of an inch on the dial.  The slide is laid out in inches and 10ths of an inch.  Now, the recommended back-off for bullet seating is 10 to 20 thousandths of an inch from the rifling, not 1 or 2 thousandths!!!!!!  
Jim