Jumpman2334
Jumpman2334
19 posts
Joined January 2019

I'm either loading sub moa ammo/or unshootable 223 ammo

As the title states. It's one or the other and incredibly frustrating (for 223 rem).

I have a 550c. Dillon 223 caliber conversion kit with rcbs x series sizing/seating dies (non small base), and a Lee factory crimp die.

Brass is once fired LC brass. Trimmed to 0.020 under max (per the instructions), hornady 62gr bthp w/ cann, win sr primer, and cfe 223. Yes swaging the primer pockets with the dillon tool.

All of my issues are the seating die. I called rcbs and they wanted me to get a "custom plug" made. That takes 4 to 6 weeks, and if I switch projectiles I have to wait again to get another plug made. That doesn't work for me (I shoot every weekend). So I'm trying my luck here.

The projectile will not seat perfectly concentric into the brass. If you roll the loaded ammo on the table, you can see the projectile wobble. I have to check every piece of ammo by hand and it's incredibly time consuming. Something is also happening with the seating die that is causing the projectile to seat super deep into the case:
http://tinypic.com/r/517dkm/9

My test gun is a very expensive Christensen vtac. I shoot the "wobbly" rounds out of a crappy radical upper. I'd like to not have to do this anymore.

I know for a fact the seating die is setup correctly because the ammo that does come out good shoots sub moa. I've only loaded two batches and the first batch was 0.90moa and the second batch was 0.70 moa on a semi auto(100 yds, 5 shot group, laying down on ground, rifle supported via bag). Im just not sure what's happening at station 3 and I need help. Rcbs wouldn't help me other than requesting I order a "custom plug" and they also sent me a vld debur tool. I already trimming via a three way cutter. I'm not trimming one piece of brass twice.

Any help? I'm going to assume dillon would like me to buy their rifle seating dies. I dont want to buy another seating die and have it do the same thing and then have to turn around and buy "custom plugs". I'm really trying to understand how this happens. I've asked 4 to 5 people and I havent gotten one straight answer.

Thanks in advance.
dillon
Administrator
dillon
3,222 posts
Joined July 2007

RE: I'm either loading sub moa ammo/or unshootable 223 ammo

Hornady uses a slightly different radius than other brands of bullets, but this should not affect concentricity. If you are not chamfering case mouths, I suggest you do so. The two other actions you can try are first, loosen all of the die lock rings, and with a fired case in station 1, sized, primed case in station 2, etc, pull the machine handle down so the cases/cartridges are up in all the dies. Now, with the cases up in the dies, tighten the die lock rings. This ensures that the dies are centered in the threaded holes.
Finally, readjust your seat die as follows. Back the seat die out several turns. Put a sized, empty case into station 3 and pull the handle down. With your fingers, thread the seat die down until it stops on the case, then back it up 1/8 turn. Finger-tighten the die body lock ring. Now, back up the seat plug several turns. Put a loaded cartridge of the desired OAL into station 3 , and a fired case into station 1. Pull the handle down. Screw the seat stem down until it stops, then tighten the die body and seat stem lock rings.
Jumpman2334
Jumpman2334
19 posts
Joined January 2019

RE: I'm either loading sub moa ammo/or unshootable 223 ammo

Thank you. I dont feel comfortable messing with the plug adjustment so I just bought some hornady match dies. I shoot hornady projectiles so I'm hoping pairing the two will help me. The dies also state that it aligns the projectile prior to actually seating in the case. Hopefully this will help me.