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Author Topic: Reloading Difficulties - Inconsistent COL from a locked seating die  (Read 95 times)

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I'm new to reloading and I just made my first three batches of 5 rounds of 308win with three different powders.  All charge loads were in the lower 25% of suggested powder weights.  It's 10yo powder that's never been opened but it was kept in a garage (in air tight containers) along with primers so I just want to see if powder and primers still work well before I load 100 bullets of different powders and charge weights to find best loads.  These batch are for a bolt gun and I have no crimp on the rounds.
Here's what I loaded with:

*Brand new Hornady, NOT Trimmed, MATCH brass.  The new brass varies in length about .004", maybe I should have trimmed them before, but they're all well within SAMMI specs for min/max brass length for 308.
*Primers are fully seated and nothing protruding beyond base.
*Sierra Match King 175gr BTHP bullets
*RCBS single stage press and RCBS standard seating die NOT a competition die.  Seating die is locked in press with allen screw and nut is tightened.
*Mitutoyo dial caliper which is checked for ZERO frequently and seems to hold zero well.

PROBLEM - When I establish the correct COL (ON THE FIRST ROUND) of what I need at 2.800" I lock down nut on top of the die and try to press the rest of the rounds for this patch and sure enough some either are .002" too long or .001" too short and I have to re-adjust seating die for EACH round.  Sometimes I have to use a bullet puller to stretch the COL to re-press.  This is proving to be quite time consuming for 15 rounds of ammo with all these corrections.
I'm using 3 rounds of Federal Gold Metal Match 175gr SMK ammo as my control and they are dead on at 2.800" COL.
What am I doing wrong?
I'm slow and deliberate with each press.  I'm just adjusting the top seating screw just a fraction of a millimeter at a time which seems to do barely anything and then it's deep and creating ammo with short COLs (.001" to .0015" short).

All ammo is now at 2.800" to 2.8005" but it seems like way too much work to make them exact.
Cheap, inaccurate dies?  I should have gotten more expensive competition seating dies, like Redding?

Nuts in red are locked down.  Green circle is where I adjust seating pin with very tiny COL adjustments (1mm at a time or less) with with a slotted screwdriver.  Dark red area on the flats of the caliper is where I'm making COL measurements.  All seated bullets are left with scratch rings in the yellow circle, is this typical when reloading to have scratch rings on the bullets?

At some point I might worry about bullet runouts, concentricity and seating bullets close to the lands but right now I need make consistent COLs.   




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Re: Reloading Difficulties - Inconsistent COL from a locked seating die
« Reply #1 on: December 14, 2017, 05:58:58 AM »

Check your shell holder and where it snaps onto the press ram. Also take apart your seating die and make sure there's no junk in there.
Dan Webb
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Re: Reloading Difficulties - Inconsistent COL from a locked seating die
« Reply #2 on: December 14, 2017, 06:15:09 PM »

It is the hollowpoint, take measurements off the ojive of the bullet.  Take out five random bullets and measure the length and see what you get.  Measuring from the ojive is more consistant
You may find me shot in a ditch... but I will do everything in my power to be found laying in a pile of empty brass...