Hey guys,

I am trying to make the most accurate ammo that I can and I am haveing trouble seating bullets to the exact same depth every time. The OAL length of the cartridges vary +/- .010". I can't imagine that this is acceptable to everyone. I don't know if the problem lies within the bullets themselves or is this a tooling problem. What tollerances do you hold yourselves to? Is it possible to achieve 0.00 error?

Thanx,
Mark

Are you measuring from the base of the case to the tip of the bullet? If so, that is likely the problem. You should measure from the base to a reference line on the bullet's ogive using a comparator. You can get a comparator from many reloading supply houses.

yes I am measuring from the tip to the base. I thought this might be the case that it is bullet tolerance that is out of wack and not me. I will have to go get a comparator to measure from now on.

Thanx,
Mark

Hey Mark

You can get a bullet seater that allows you to seat bullet to the exact same measurement. That would be one of the competition seaters with the micrometer on top

The Forster


The Redding


Or the RCBS


What they will allow you to do is to back off on the micrometer at the top before you seat each bullet and seat the bullet and reset the micrometer and reseat until you get the bullet seated exactly where you want it.

Even the competition seaters will not seat the bullets to exactly the same place everytime unless you do the back it off and reset it routine, although they will come much closer than the regular seaters.

Then it will depend upon whether you are taking measurements to the ogive with a comparator or an OAL length to the tip of the bullet. Seating to a comparator measurement will be much closer to zero error in seating dimension from the ogive to the lands, but there will be a slight difference from one bullet to the other in the measurement from where the comparator hits the bullet and where the bullet reaches full diameter.

My recommendation is to get the RCBS and use a comparator. You can't get much closer than that and the RCBS has the side load window which helps start the bullet straight up and down in the case neck. It is very convenient and you will like it.

quote:

Originally posted by Markhpb:
Hey guys,

I am trying to make the most accurate ammo that I can and I am haveing trouble seating bullets to the exact same depth every time.

Yes well, I can't see why an ordinary die/bullet seater won't seat the bullets the same every time. The only difference is the length of the bullets point, which I've seen up to 16thou on target projectiles.

If seating depth is decided and measured on any one projectile which is then kept for a check, then the others will be as good as the meplat allows.

Sure the comparitor tools will aid checking, and the mic. bullet seaters handy for various adjustments. Hornady makes the cheapest by far I believe.

Hey Mark, If you try going from OCL to ODL you can get consistent Seating with your regular RCBS or Redding style Die and not need to waste any money on "Thingys" or on $100 Die Sets.
-----

I tried to order 1000 Thingys two days ago and the guy called me back yesterday with some kind of pitiful excuse. I suspect he was out planting Tomatoes or letting his dogs teach him how to play with a Frisby.

Best of luck to you.

quote:

Originally posted by Hot Core:
Hey Mark, If you try going from OCL to ODL you can get consistent Seating with your regular RCBS or Redding style Die

HC I`ve measured die lgt for some time and agree it is the easiest, fastest way to set up your seating die, especially if you use more then one bullet/wgt in a cartridge. However, you need to add the next box of bullets may have a slightly different ogive if the manufacture has new dies, or changed something for the "better". I still would recommend useing a comparator tool with a new box to insure the die setting is still valid. I do..

Hey Ol' Joe, You are absolutely correct, it should be in there to re-do it with every new box that is opened.

Best of luck to you.
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It is not nice to pull tricks on old folks.

Just looked at the link and found this near the bottom of the post:

quote:

I know that looks like a lot of stuff to do, and I guess it is. The Set-Up Bullet needs to be done each time you open a new box of bullets because of slight variances during manufacture. And occasionally the Manufacturers have to replace the Forming Dies which can change the Ogive shape and position.

Ol' Joe made me look

quote:

It is not nice to pull tricks on old folks.

Just looked at the link and found this near the bottom of the post:
quote:
I know that looks like a lot of stuff to do, and I guess it is. The Set-Up Bullet needs to be done each time you open a new box of bullets because of slight variances during manufacture. And occasionally the Manufacturers have to replace the Forming Dies which can change the Ogive shape and position.
Ol' Joe made me look

How the hell...........
Sorry HC I guess I gotta start reading what I thought I read, I totally missed that.

IF you were careful to ensure that the cases were all of identical length before the bullets were seated, what is the likely cause of your problem is bullets in which the ogives are not uniform from one bullet to the next, and your seating stem is resting in a slightley different location with reference to each bullet's tip. So the bullets are being pushed into the case to a slightly different depth because of this. Once you have all other variables under control to the extent that you are now able to fire 0.5 MOA groups with your ammo, eliminating this variable may let you get down to perhaps .3 MOA.... But you might have to change bullets to achieve this-you may even have to start swaging your own bullets so you can make sure they are all the exact same SHAPE AND SIZE.....

Hey Ol' Joe, No problem at all. It "did" need to be in there. And it is a lot to read, so I can understand how it can happen. (Happens to me a lot too. )