COAL because of Seating depth difference?

[Cinchy]

I have only used Hornady dies,nothing else, & I have noticed my COAL- seating depth always varies slightly? Just by a few thousands but I don`t understand why? I set seating die to desired & then lock down per instructions.With everything locked down I don`t understand why the variance in lengths on a given case & bullet? What seating dies hold there depth most consistently? Would I be better served to get a micro adjustable precision seating die? I have read good reviews on Redding? I use a COAL gauge to determine seating depth, & figure what I want, but then my seated bullets are varying so much, its irritating! Any suggestions will be appreciated

 

[jimbires]

do you measure of the tip of the bullet ? are you using a compressed powder charge ?

 

[Cinchy]

do you measure of the tip of the bullet ? are you using a compressed powder charge ?

Maybe a few are, but most are not? Yes I have been measuring to tip but just got new comparator so see if that helps measuring to ogive?

 

[ShtrRdy]

The length to the tip will generall vary. If you measure from the cartridge base to the ogive using the comparitor that length should be more consistant.

 

[cjuve]

Sometimes there is spring back in the brass that causes inconsistant length. In order to avoid this run the cartridge up into the seat die again. As stated above there is almost always a difference in total length of each bullet.

 

[375fan]

To the OP, what bullet are you using? Bullet with plastic tip? If so, your coal issue is not uncommon. As others have stated, measure off the ogive with a comparator.

 

[jimbires]

it's best to measure to the ogive of the bullet , tip lengths will vary .

if you are using a compressed load , or close to being compressed , use a drop tube funnel . this will help settle the powder so the bullet is not pushing into the powder . I use the forester blue ribbon funnel all the time .

make sure the seating stem in the die is pushing on the ogive , not the tip . some of these new long slender bullets the tip hits before the ogive . when this happens the bullet gets seated by pushing on the tip .

 

[L.Sherm]

You will find also measuring off the ogive they will vary some. Not as much as measuring from the tip. Some manufactures or lots are worse than others that's why BR shooters sort or are after a particular lot #

 

[vitaminado]

How much difference of measure is acceptable for each bullet?

 

[cjuve]

How much difference of measure is acceptable for each bullet?

I try to maintain a + or - .001 or .002 as measured by my comparator. I usually test seating depths at ranges up to 1000 yds. at that range you can see difference in group sizes and consistency with depth changes of .003. If you don't expect to shoot greater than 500 yds then you don't need to take it to that level. IME every rifle bullet/powder combo reacts differently. My best advice is to test seating depths with the loads and determine the level of variability that is acceptable to your application.

 

[LoneTraveler]

I have ran into the changing OACL with plastic tipped bullets too. Hornady V-Max, GMX, Nosler E-Tip and Barnes TSX But using my comparator they measure within +0r- of .002.

 

[bob4]

Using Forster ultra seating in mine with Bergers when I seat
for my 300 WM it's dead on every time. When I seat for a 243 1 or 2 out of five have a .002 .003 difference. I've learned to live with it and just adjust for the 243. Point being: I have also learned that some times pushing a bit harder on the handle may give me the .001 or .002 I am looking for. When it goes the other way have to pull and try again. So I always start with a lighter touch on the handle.

 

[Cinchy]

It finally warmed enough to go out to my reloading room. I measured 5 each of 300 win mag with 180 gr nosler accubond, & 5- 264 win mag with 140gr berger vld bullets. All bullets for both calibers fell within .002 to .003 when measured off ogive. When measuring off the tips there was as much as .005 to .006 variation? The berger bullets had a slight edge on their averages of variations on both measurements. So I guess my Hornady dies are preforming satisfactorily for hunting rounds! I had not mentioned it before but the bullet run out - concentricity has been super with these dies.