Quest. to the experts regarding COAL incosistency.

[Jimmy2Times]

OK, so let me preface this by saying my reloading press is a piece of shit. It's an old RCBS 4x4 auto that I've been using for 10 years. It's great for pistol rounds but sucks for rifle stuff. When I load rifle rounds, I do not load them progressively. I load them single stage, except I use the individual stations of the progressive press. It works out real well except for the bullet seating. My bullet seating depth varies from anywhere between .010 to .015 round to round. I can't figure out why. I have checked everything, die is tight, shellplate is tight, die guts are tight, I can't figure it out. I've even went so far as to use the same exact position on the shellplate each time I seat a bullet, but it still varies. Is this variation normal? Is it possibly causing inconsistency in my reload performance? I really need to try some FGGM or BHA.

Thanks, as always, for any insight.

 

[cinosbus]

Re: Quest. to the experts regarding COAL incosistency.

What you are finding is not uncommon. It could be from several things, but probably NOT the press.

It most likely could be:

A. Differences in bullet length/shape from wherever the seating stem contacts the bullet to the bullet tip - especially noticeable in lead tipped softpoints. This is 99% likely to be your problem. Get a comparator and use it to measure OAL instead of measuring to the tip, if you are concerned about this. "Match" bullets are more consistent for this - but still not perfect. The cure is a different seating stem, different bullet, or to ignore it because it's probably NOT a problem unless you are trying to win a benchrest match.

B. A poor interface between the bullet and the seating stem resulting in the bullet being seated "by the nose" or being deformed during seating.

It COULD have something to do with flex in the press, but probably isn't. Most seating dies also crimp - so you cannot have the shell holder touch the bottom of the die or you will crimp (probably way OVER crimp). Lee includes what they call a "dead length bullet seating die" in their collet die set - which just means it has no crimp ring - so you can bump the shell holder with it to account for any press flexing. Most "in-line" seaters also do not crimp, but I don't think you're supposed to bottom them out either. Try seating with a quick, smooth motion that goes all the way to the press's stop and see if it helps. If it doesn't, it's probably not the press.

 

[Creature]

Re: Quest. to the experts regarding COAL incosistency.

I'm having similar problems with my Rockchucker II and Redding micrometer die using 168gr bthp Nosler competition bullets. Everything is locked in tight but I'm still getting variations from 2.805 to 2.810(the desired OAL).

I'm thinking it might be the bullets.

 

[Queequeg]

Re: Quest. to the experts regarding COAL incosistency.

Jimmy2,

You're getting this spread with your match bullets too? All loaded in the same lots of brass trimmed to the same length?

Mine vary around 5 thousandths in .308 when loading hpbts like SMKs, Hornady or Nosler. The AMAX rounds vary less for me as the polymer tip is more uniform. So when I set up for 2.815, I might find some as short as 2.812 or as long as 2.818. Most are within 2 thousandths.

For hunting bullets like soft points, it's a whole nutha thang!

Seems like 10 - 15 thou is more than you should expect for match rounds. I'm going to check some random samples of my own to see if my head is just up my ass!

 

[Jimmy2Times]

Re: Quest. to the experts regarding COAL incosistency.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: queequeg</div><div class="ubbcode-body">Jimmy2,

You're getting this spread with your match bullets too? All loaded in the same lots of brass trimmed to the same length?

</div></div>

Yep, SMK HPBTs, 175 & 168s. All brass trimmed, deburred in and out, or factory new WCC brass.

 

[EddieNFL]

Re: Quest. to the experts regarding COAL incosistency.

I've had lots of .308 SMKs that varied as much as 0.010" measured with a comparator.

 

[Outsydlooknin75]

Re: Quest. to the experts regarding COAL incosistency.

Ever measured the length on your bullets?

I measured a box of 155smk's the other day and the length was all over the place. What is happening is tht the seater is seating off the ogive, and the tip varies, where the ogive srmains a constant.

I need to get a bullet comparator myself so that way it measures off the ogive when I measure a round and not from the tip.

 

[kwild]

Re: Quest. to the experts regarding COAL incosistency.

I had this issue too and screwed around with it by adjusting my dies each round so that I get it down to .001" but it is very time consuming. Lately I have just set my oal length on the first few rounds and go to town. Not sure how much it is affecting things at this point but I have been trying to find out which corners I can cut and which I cant.

 

[ewoaf]

Re: Quest. to the experts regarding COAL incosistency.

you dont have a problem

 

[ChadTRG42]

Re: Quest. to the experts regarding COAL incosistency.

Measure it from the ogive and see if you get the same variation. The tips will vary quite a bit. I use the ogive for the actual measurement, since that's the most important in relation the the rifling.

 

[Brent Thornton]

Re: Quest. to the experts regarding COAL incosistency.

Just look at your the meplat on bergers for instance and notice the difference...remember that a sheet of paper is 3 thousandths in thickness. I'm not an expert but asked one the same question and rec'd the same answer...you don't have a problem.

 

[Jimmy2Times]

Re: Quest. to the experts regarding COAL incosistency.

Awesome. Thanks very much for all the helpful responses.

 

[Fuzzball]

Re: Quest. to the experts regarding COAL incosistency.

Chaseing OALs to .001", or .005" is not only an exercise in frustration, it rarely means anything on targets. Not unless you are really on the ragged edge of what shoots well.

Question on the 4x4 press, do you have the turret head locked down tight? If it can turn at all it has too much "spring" right there.

 

[former naval person]

Re: Quest. to the experts regarding COAL incosistency.

When you are seating with a die, you are using a "datum line" on the bullet that doesn't compare with anything except your die. You can seat to an OAL or to a comparator. When you do that it refers only to that datum. Pick what you want, and adjust to that. The OAL will vary depending on what the factory variences accepts as jacket varience. The datum line as determined by the comparator will only vary as it differs from your rifle throat, but will be consistant. Sooo...get a comprator of any make that you are comfortable using, and establish what you wish to be your throat length using the comparator...no matter what the make or length. Then load from that datum line. JMHO

 

[Tactical30]

Re: Quest. to the experts regarding COAL incosistency.

I had the same problem when I started out and realized its no big deal cuz thats such a small of a difference. I noticed in alot of the Nosler bullets I load for .223 they vary sometimes from 2.255 to 2.235! I checked and 99% of the time its the shape of the bullet (77HPBT) you will see on the bullets that seat at the right size have a very small hole at the tip (HP) and the bullets that seat smaller like 2.235 ex. have a larger hole at the tip (the bullets weigh less if you measure them). Its usually the make of the bullet. Measure from the ogive. I noticed that with Noslers the most. Out of a batch of 50 ill get 40-43 that are 2.250 and up.

 

[LA_Lawman]

Re: Quest. to the experts regarding COAL incosistency.

use a comparator.... dont use meplat to base measurements....

 

[Tomekeuro85]

Re: Quest. to the experts regarding COAL incosistency.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadTRG42</div><div class="ubbcode-body">Measure it from the ogive and see if you get the same variation. The tips will vary quite a bit. I use the ogive for the actual measurement, since that's the most important in relation the the rifling. </div></div>

Thats what I agree with. the tips of SMK's for example are quite inconsistent. however the important measurement is that of the ogive. thats the part that touches the rifling. The bullet tip just floats in the barrel so its not as important.

 

[81sfo]

Re: Quest. to the experts regarding COAL incosistency.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChadTRG42</div><div class="ubbcode-body">Measure it from the ogive and see if you get the same variation. The tips will vary quite a bit. I use the ogive for the actual measurement, since that's the most important in relation the the rifling. </div></div>
Im using ojive measurement too but im getting inconsitancy there too.i use an Rcbs Comp Seater and Redding Comp seater too,both with micrometer dial on top.For some reason my 175smks wont seat all at the same ojive?sorry to hijack this mans thread.thanks in advance if someone can help.

 

[Killswitch Engage]

Re: Quest. to the experts regarding COAL incosistency.

measure a box of FGMM and you will find there shit is all over the place also if you measure at the meplat. ogive is usually good though. fwiw

 

[The Mechanic]

Re: Quest. to the experts regarding COAL incosistency.

One additional check. Just like putting a round into a chamber the same way, put a line on your brass with a felt marker and insert into the die with the marker in the same direction each time and see if the runout is at the same timing based on the marker line. That will tell you if it is bullet, die, or press based on some easy adjustments

 

[HillbillyfromAL]

Re: Quest. to the experts regarding COAL incosistency.

I had the same issue with the SMK's being different lengths from ogive to the tip.I was surprised to see that they were a whole hundredth of an inch different from where the stem contacted the ogive to the tip. I'm reloading for an M1A so length can't be more than mag length. I'll just check all of them to make sure they'll fit when I'm done. I took the Hornady OAL gauge and the bullet I used in it was the bullet I used to set up the first round. Now if My primers get here I'll be able to see how well it'll shoot.