Seating depth??

[kleven626]

I started to use a caliper with my stoney oal gauge. I was using it to measure from tip to base. I was informed that this is ok for hunting rnds but not f/tr and up. I got a hornady comparator attachment and have gotten a lot better results. One thing I have noticed is that not all bullets are the same even with the comp. I am using scenar 155's and they will vary .003 +-. Does a guy measure every rnd in the oal gauge and than set the bullet to that measurement?

I shoot a Remington SPS .308. oal with the comp. is 3.349. The problem is when I go to seat the bullet in my seating die I get variations. For the most part the I get the bullets to seat where I want them but about every 5-6th rnd the oal will be .010 off. I've been setting those off to the side and seating them down after I have my lot done. I think I'm on the right track because I have eliminated most of my fliers. Am I correct in saying that if a guy measured every bullet for it's particular length and seat it, he would have better results? Or is the seating die wrong? I notices that the cone that seats the bullet doesn't push on the same spot that my comp. measures from. It pushes further up, more on the nose of the bullet. Is there a better seating die out there?

I shot two lots of ten. One with brass ran through RSBS FL dies. They were 2.5'' @ 300yds. And one lot through a Lee collet die. Unless I did something wrong with the Lee's, but I was getting 5'' grps with those.

My load is:
OAL w/comp 3.351 .002 into the lands
46.7 var
Lapua brass
155 scenars
CCI-LR

 

[whiskey08]

the oal isnt so important, all rounds have some variation some worse than others. sierra's are in my opinion pretty sloppy but thats what i shoot because they shoot great. a better place to measure is from the base of the bullet to ogive, id sort bullets that way if your worried about it. JLK's and Lapuas are pretty consistent the only ones id sort would be sierras.

to set my die i use bullets with a predetermined exact oal length every time i load, and thats what i set my dies with. The rest of the rounds will be plus or minus a few thousandths but i know the ogive is fairly consistent.

 

[fdshuster]

kleven626: As whiskey08 said, the oal is not important. It would only matter if you were loading for magazine length, like the 223 for an AR-15 magazine, ( 2.260" maximum). When using my Stoney Point/Hornady tool the only dimension I care about is from the base of the bullet to the point on the bullet ogive that makes contact with the lead in the throat. That dimension never varies by more than .001" or .002", and that's when I get sloppy with how much pressure I'm putting on the adjustment wheel of my dial calipers, or if I don't have the cartridge sitting square between the jaws. Over-all-lengths will vary, especially with hollow point bullets that have a ragged tip. And where the seating stem contacts the bullet has no bearing on the ogive point of contact with the leade, as long as the seater is adjusted using the dimension you arrived at with the Hornady gauge.