Die set for 223 and 300BO

[willie]

FWIW, because I'll soon be on the .300BLK train - I spent WAY too long watching Johnny's Reloading Bench Youtube vids comparing the performance of 300 blk dies. He compared the RCBS "AR" dies, the Lee dies, and the Forster dies for sizing and forming brass across 4-parts - And my take away was -

1) the Lee dies may have an expander that is too big resulting in insufficient neck tension when the brass if formed, RCBS and Forster are better.

2) A Lee factory crimp die is basically mandatory for reliable function in .300BLK in a semi-auto (not really mentioned in the video). I just came to that conclusion pretty quickly, proper sizing is important, BUT a crimp is basically going to be mandatory and the Lee factory crimp die appears to be the best out there for .300BLK (as opposed to the taper crimp offered by the RCBS set). I think a decent crimp is basically mandatory for all semi-auto cartridges and any lightweight or magnum weapons.

3) When I go to assemble my die set for .300BLK - I'm going to opt for Forster forming and seating dies, and a Lee factory crimp die, and seat and crimp in separate stages*.

*I might also just be biased, but now that I've done 500 rounds on the Lee APP with Lee Carbide dies about half seating and crimping simultaneously and half crimping separately. I much prefer the crimp separately approach. It takes an extra 10-minutes or so, but I can actually adjust my crimp tension as opposed to the the taper-crimp of the seating die. I also don't like trying to simultaneously adjust my seating depth to further account for crimping. I basically, just don't like the way it works. A decent crimp is necessary on loads for a snubby revolver (what I am loading). I've had many instances of of bullet pull in the past with lead bullets and mediocre or non-existent factory crimps.

Seating and crimping in two different steps is more precise because case length varies within a case batch. If all were the same length, it would not matter as much. I read your post several times but could not detect why you could not select any crimp force even when doing the two part operation in one step. In adjusting the seat/crimp die, you would raise the die to be above the case mouth to prevent crimp section from touching case. Then you seat the bullet to the desired depth. Next raise seating stem up to avoid touching seated bullet. The last step is screwing down the die to bring about desired crimp. Set lock ring. Finally screw seating stem down so that stem touches bullet. Tighten. You now have diet to do two things: seat bullet and crimp. Wrongly adjusted, the bullet is forced down through the die's crimping section. I learned this the hard way 50 years ago.

I like Lee dies but prefer using a lock ring with a set screw to fix the ring in a permanent place. Hornady lock rings are
are slender, an advantage on some presses. Lee will make custom expanders to any dimension. Custom expanders abound. Larhesmith on Cast Boolit forum makes them to order for a few bucks. He has an excellent rep. Some places sell them. Or up if you prefer RCBS, you can buy their expander die or just buy their expander.

[Mike C]

@RevolverRob this:

Seating and crimping in two different steps is more precise because case length varies within a case batch. If all were the same length, it would not matter as much.

I’ve loaded a shit ton of 300 B.O. in the past. I found that trimming was critical to achieve good crimping. But crimping in a separate process wasn’t necessarily critical to good function and accuracy. I would resized deprime then use a Giraud trimming tool to cut and chamfer. This made the case mouth expansion easier and I had fewer issues with neck tension when seating and crimping in the same process or (over/under expanding of the case mouth during that phase of loading/processing).

Yes it is best to crimp separately but I decided not to since that would cause me to have to complete another step on a companion press because to heck with swapping dies around on my tool head. 1050 tool heads are best left alone and checked frequently IME. Case mouth expansion was also critical but primarily on subs when loading coated cast projectiles so as not to damage the coating. As always depending on your equipment and how well you have everything dialed in YMMV.

[mmc45414]

I have more time to reply, so I will blather on a bit more.

First off, I consider Lee dies to just be square one. Unless you can figure out something they don't do I suggest just getting them, for whatever. Not saying that there are not better things out there, but I have just been using this approach and have not been jammed up by it so far.

3) When I go to assemble my die set for .300BLK - I'm going to opt for Forster forming and seating dies, and a Lee factory crimp die, and seat and crimp in separate stages*.

It sounds like you have done more research than I have, and I have only loaded about 5-600 300BO so far, but I formed my brass with the Lee sizer. I did do this on my 650, so this facilitated doing this progressively, and I think I ran a 223 size die, then an RCBS small base die, and THEN formed them (with the bottleneck still on, will expand later) and this seemed to work out fine. Not sure I needed to do all that, but I had empty holes in the tool head so WTH.

1) the Lee dies may have an expander that is too big resulting in insufficient neck tension

Squirrel Daddy has alternative expanders for Lee.

As has been mentioned, Lee and others will make a custom expander, but the SD is pretty nice and they are cheap. And the expander is not exactly rocket surgery, it is just a diameter that gets pulled back through the case. If the Lee is too big you could probably chuck it in a drill and take a couple thou off of it with some 400 grit.

I like Lee dies but prefer using a lock ring with a set screw to fix the ring in a permanent place. Hornady lock rings are
are slender, an advantage on some presses.

The Lee lock rings are probably fine but I think they are goofy, and hard to bring as tight as I like while not moving the die. Since I am using the Dillion I just buy the bags of their 1" nuts and switch everything to them. I also just bought a simple Open-End/Box wrench at Lowes, works great and it was less than $20. I thought I might cut it in half or grind it down but have never needed to bother.

I much prefer the crimp separately approach. … I basically, just don't like the way it works. A decent crimp is necessary on loads for a snubby revolver (what I am loading).

Part of this is that it is very uncommon to trim stuff like 38 brass so it can be a moving target, and hard to maintain that perfect position of depth and crimp.

[RevolverRob]

Thanks for the thoughts guys. I will definitely plan to invest in a trimming setup soon.

I figure I'm going to need it when I start forming .32 NAA brass out of .380 anyways.

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Regarding the adjustment of the die for seating and crimping simultaneously. Yes, I've worked with it, but frankly, I find it more irritating to adjust the die, as opposed to basically run the die down, lock it, and adjust the seating stem for my desired seat height. Similarly, I can do do the same with the factory crimp die and then dial my crimp tightness in and out to my preference.

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For those who are getting into 300BO loading - I noticed Redding has the 300BO National Match dies with micrometer adjusting seating die and taper die included. Not cheap at ~200 bucks a set, but might be worth it for anyone starting for scratch.

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Also, totally agree the Lee lock rings suck. I'm going to follow up on @willie's suggestion and look for lock rings with the set screw. That's what is on my powder measure (Lyman) and I like it much better.

[mmc45414]

Thanks for the thoughts guys. I will definitely plan to invest in a trimming setup soon.

Might check this out:
https://pistol-forum.com/showthread....l=1#post923992

[OlongJohnson]

For those who are getting into 300BO loading - I noticed Redding has the 300BO National Match dies with micrometer adjusting seating die and taper die included. Not cheap at ~200 bucks a set, but might be worth it for anyone starting for scratch.

This and the regular seating die will add up to ~1/3 less than the competition micrometer seating die, and AFAIK, you end up with an equivalent result.

https://www.brownells.com/reloading/...prod44705.aspx

749-012-722WB
#19 VLD Bullet Seating Micrometer
Mfr Part: 09179

Now you can easily covert your conventional seating die to a precision micrometer seating die for use with VLD bullets for precise, repeatable bullet seating depths to within 1/1000th of an inch and potential world-record accuracy. Designed for all seating dies that use a seat plug with ½-20 threads. Easily changes from one die to another, just match the number on your current seating plug to the corresponding bullet seating micrometer number.

View Redding Micrometer Reference Chart here.