Setup sizing die on Hornady LNL Single Stage w/ RCBS dies??

quikcolin

Sergeant of the Hide
Full Member
Minuteman
Dec 16, 2018
157
69
London, Ontario
FYI I’m currently researching reloading, I’m new, “very new” and although I have all the gear, I’m trying to figure this all out. I have yet to throw a bullet through my press (reloading table is being built as we speak).

As per the title, I have a Hornady lock n load single stage press and RCBS dies as follows:

AR15 in .223 - RCBS Small Basie dies in .223
Stag10 in 6.5CM - RCBS Small Base dies in 6.5 Creedmoor
Tikka T3x in .223 - RCBS Full Length dies in .223

Hornady and RCBS say two different things when it comes to setting up the resizing die on a press. Hornady says raise the ram to the top of the stroke (with shell holder installed) thread die until it bottoms out on the shell holder and then tighten and done. RCBS says do the same, but once bottomed out, lower the ram and then turn IN another 1/8 of a turn and then lock down. Is this due to the differences in how the Hornady and RCBS presses function, ignoring the dies all together? I know that when a Hornady ram is at the top of its stroke, it actually isn’t. When you go to lower that ram it actually lifts again ever so slightly before lowering. Could this do the same as that 1/8th turn RCBS is requesting when seating their die? The RCBS presses do not do this - when the handle is in the full press position the ram is at the highest point, unlike the Hornady.

The second part to this question is “does any of this matter if I’m using a OAL gauge?”. As that measurement will dictate how low/high the resizing die is installed? I plan to buy the Hornady OAL gauge today along with a case trimmer.

I’m just trying to understand why the two manufacturers recommend different processes to the installation of the die.

THANKS!
 
Follow the RCBS instructions with the ram at its highest point. Like you mentioned, the ram on the LNL is not at its highest point when the handle is all the way down. When set properly, the ram will slightly cam over the highest point on the down stroke and again on the upstroke. This just ensures that the brass is resized the full length of the case.
 
Without a case headspace gauge you're just guessing setting up your dies. Regardless what those directions say. They will get you in the ballpark, that's about it.

Buy this


And while your at it buy these 2 as well:


Note you'll need to buy the modified case for each caliber you load to.use this tool:

 
  • Like
Reactions: SupressYourself
Either will work for initial resizing of new brass, but neither are really optimal for resizing brass that has been fired in your rifle. For that, you want the die to be set so that it just bumps the shoulder back a couple thousandths. For gas guns, you may want a bit more, but for a bolt, you only need to bump the shoulder enough so it reliably chambers. Resizing more than that only shortens the life of the brass.

For the second part, I'm not sure if you have the wrong idea, or are just using the wrong term. The Hornady OAL gauge is used to determine where the bullet meets the rifling so you can tell how far out to seat the bullet. It has nothing to do with resizing brass. However, Hornady also makes a headspace comparator kit. You can use that to determine where the case shoulder is at, and how far you are bumping it back when resizing.
 
These above 3 tools should be owned by all reloaders. To properly setup your sizing die you do the following:

1) Take a once fired piece of brass out of each rifle and measure it with the case headspace gauge in your calipers and write that number down (make sure primer is removed before measuring).

2) screw your sizing die into your press with the ram in the up position till the bottom of the die hits the shell holder then back it off 1/2 turn.

3) lube that same once fired piece of brass with imperial sizing wax and run it through the die. Wipe lube off and measure it again. You want to screw the die down in 1/4 turn increments till the case measures 0.0015-0.002 less than your fired case measurement you wrote down for bolt gun brass. When your brass measures that number minus 0.002 stop turning the sizing die and lock it up right there.

For semi auto AR brass you want to go .003 less than your fired case measurement.


Hope that helps you
 
Step one is oversimplified. You need to measure multiple pieces or you can end up with a short piece of brass, and end up bumping the shoulder of other brass more than you think.

If you find a piece of brass that resists the bolt closing on it, then you are better off.

I prefer to measure a bunch. i can usually find a couple .001 different in measurement. One that chambers easy and one that doesn't.