Recently bought a Hornady bullet comparator for my 6.5x284 Norma and find that after I set up my RCBS seating die to the predetermined length that there are varying readings of as much as 5or6 thou on some rounds.Any one else experience this? Any solutions?
cartridge length to ogive
- Thread starter hogger1
- Start date
I will take a stab at this, but please realize that I am quite new to this hand loading stuff, so I may be blowin' hot air! 
First of all, if you are using a VLD type bullet, the tip might be bottoming out on the inside of your seating die and therefor not actually being pushed into the case by the ogive. If this is happening it means that your bullet is being pushed in from the tip rather from the ogive, and bullets very often are different OAL.... you would have to drill out the cone of the seating die so the bullet tip does not contact it.
From what I understand, the RCBS presses have a "cam over" design at the bottom of the stroke. If I was getting weird measurements I would screw the die in far enough so that there is no cam over so that you would push down until the shell holder contacts the die firmly. That way there would be no extra play, possibly skewing your measurements.
Other than that, just make sure your die is good and tight in the top hole and nothing is wobbly.
I have never had a variance of more than 1 thou. either way, but like I said, I am quite new at this (and perhaps very lucky that things have gone smoothly for me). I sure hope this helps you out. It's a nice feeling when the finished product pops out the way it's supposed to. Good luck... C.
First of all, if you are using a VLD type bullet, the tip might be bottoming out on the inside of your seating die and therefor not actually being pushed into the case by the ogive. If this is happening it means that your bullet is being pushed in from the tip rather from the ogive, and bullets very often are different OAL.... you would have to drill out the cone of the seating die so the bullet tip does not contact it.
From what I understand, the RCBS presses have a "cam over" design at the bottom of the stroke. If I was getting weird measurements I would screw the die in far enough so that there is no cam over so that you would push down until the shell holder contacts the die firmly. That way there would be no extra play, possibly skewing your measurements.
Other than that, just make sure your die is good and tight in the top hole and nothing is wobbly.
I have never had a variance of more than 1 thou. either way, but like I said, I am quite new at this (and perhaps very lucky that things have gone smoothly for me). I sure hope this helps you out. It's a nice feeling when the finished product pops out the way it's supposed to.
Good luck... C.It can be the bullets. Your average bullet comes off a press and into a bin with bullets from other machines, not all the dies are the same. Try measuring just the bullet from the base to the ogive and see what differences you get. Measuring from the tip is not a good way to compare them. Lots of guys sort this way to get consistent jam into the lands.
257Roberts
CGN frequent flyer
- Location
- Peterborough ON
I measure bullets with an old Sinclair nut comparator and have found that the bullet base to ogive will vary up to .005".
So far it has not made a lot of difference for what I have been doing.
It am using Hornady seating dies and I really don't think, because of the way most dies work, that seating depth would be more accurate but I could be wrong. In most situations seating length to the ogive will vary a small amount.
I have measured Factory loads and have found that they can be as much as .010" difference in length to the ogive.
David
So far it has not made a lot of difference for what I have been doing.
It am using Hornady seating dies and I really don't think, because of the way most dies work, that seating depth would be more accurate but I could be wrong. In most situations seating length to the ogive will vary a small amount.
I have measured Factory loads and have found that they can be as much as .010" difference in length to the ogive.
David
You're right skeeter, my apologies.I too am new to reloading and guess I was not wanting to show how green I am.
Here's where I 'm at:measured my bullets and there sure are variations in length! Took my rcbs die apart and see that the seating stem contacts well anead of the ogive.Don't know if this is common to all dies but if not I will get a Forster or Redding.Read some other sites on the net and see that a lot of reloaders don'tstress over a few thou here or there as long as there is no lands contact.Maybe I'm being too fussy! Going to shoot the loads I have this weekend and will update the results.
Here's where I 'm at:measured my bullets and there sure are variations in length! Took my rcbs die apart and see that the seating stem contacts well anead of the ogive.Don't know if this is common to all dies but if not I will get a Forster or Redding.Read some other sites on the net and see that a lot of reloaders don'tstress over a few thou here or there as long as there is no lands contact.Maybe I'm being too fussy! Going to shoot the loads I have this weekend and will update the results.
Hogger, no need for apologies, I'm just curious! I'm still tryin' to wash the green off me, too!
As long as the tip of your bullet doesn't contact the cone of your seater you're fine. I can't help thinking that you have some slop somewhere in your press.
I wouldn't "worry" about a few thou., but at the same time consistency is the name of this game, so less variance is good.
I use Lee dies and press. Not greatly liked by many serious hand loaders, but has been very good for me. As long as your die is clean I don't think a more expensive die would get you better results. Try screwing that die in to the point where your press doesn't cam over and try a few to see if the OAL is more consistent, and be sure to measure the finished product to the ogive, not the tip. Also, be sure to use the same amount of muscle on each pull of the lever... we are dealing in thous... doesn't take much to get different readings.
I have found happiness at 20 thou. of my lands, but your gun may like something different. Oh, and I use Horn. AMAX and VMAX bullets (.308 & .223), and have found they are very good as far as length and weight. (ya, I weigh every one when I buy 'em.)
That's all I got, so good luck... C.
I'm still tryin' to wash the green off me, too!As long as the tip of your bullet doesn't contact the cone of your seater you're fine. I can't help thinking that you have some slop somewhere in your press.
I wouldn't "worry" about a few thou., but at the same time consistency is the name of this game, so less variance is good.
I use Lee dies and press. Not greatly liked by many serious hand loaders, but has been very good for me. As long as your die is clean I don't think a more expensive die would get you better results. Try screwing that die in to the point where your press doesn't cam over and try a few to see if the OAL is more consistent, and be sure to measure the finished product to the ogive, not the tip. Also, be sure to use the same amount of muscle on each pull of the lever... we are dealing in thous... doesn't take much to get different readings.
I have found happiness at 20 thou. of my lands, but your gun may like something different. Oh, and I use Horn. AMAX and VMAX bullets (.308 & .223), and have found they are very good as far as length and weight. (ya, I weigh every one when I buy 'em.)
That's all I got, so good luck... C.
- Location
- Western Manitoba
Regarding RCBS dies - the sizing die is designed to use the "cam over" feature. (Although, some of us only "partial size") The bullet seating die instructions ask for clearance between the shell holder and the bottom of the sizer, if you want to just seat and not also crimp at the same time. Just guessing that there is not a great need for crimping, if you are really concerned about exact gap between ogive and lands. Try setting up your seating die with a nickel on top of the shell holder to set some space, then see if your seating length variation decreases. I load only rifle cartridges - I do not crimp any jacketed bullets except full power 458 Win Mag for my bolt action repeater, and I do crimp all my cast loads, but always as a separate step from seating the bullet.
