300BlkTalk

I'll sum up what I have learned in reloading 300 BLK, there is a lot of variability in brass dimensions, variance in die specifications and variance in chambers that can cause issues. Lee dies work for some, not for others.

I use Forster dies with 300 BLK, they work great as long as you don't use brass with too thick of necks. My AAC barrel chamber is tight, it must be close to minimum chamber size as you have to have properly sized brass with proper brass (i.e., not too thick).

YMMV

YAY! mine are hornady

I haven't even gotten started on reloading supplies yet, but I'm definitely leaning towards the RCBS small base .223 dies for depriming/reforming cases first. I will be reloading both .223/300 blk, so think this is best route to start with. Will definitely get the Lee Factory Crimp Die though. Have used some Lee dies in the past for pistol, but so long ago I don't remember how good they were, and RCBS was "it" for reloading back then. Trying to learn from all of you guys!!

I had a Lee mold that was dropping at .304" and .307". It was both undersized and oblong so I sent it back. I got it returned with a letter saying I needed to lube the handle hinge and it would cast in spec. I called them and they were adamant about the fact it would cast perfect bullets if I made sure the handle hinge was lubed. I asked them if they cast any with it and they said they had. I asked what they sized at because my lead dropped undersize. They said they do not test using lead because it is against company policy. Luckily Midway USA took care of the problem.

I had trouble with my Lee BLK dies, same problem others had. I had to pull a bunch of rounds.

For those who say it's my rifle that is not in spec, why do rounds formed with Hornady and RCBS work then?

I chalked it up to you get what you pay for. As far as Lee not standing behind them, that is fine I will never buy anything from them again. I have been converting a ton of in-spec brass since I bought different dies.

Maybe the quote from Lee regarding their 300 Blackout dies came from the same dolt who designed the Loadmaster! Lee also says that you can't use two of their adjustable charge bars in their double-disk kit, but, with a minor modification, I did just that.

My current plan is to go ahead and decap, size, and swage 5.56 brass, then cut it and run it through a Lee 300 Blackout sizing die, using that die only for neck-forming. I'm loading on a Dillon 650 press. Maybe the superiority of the Dillon press accounts for my excellent experience with Lee dies??

When I was loading with a Toadmaster, I found that, due to crappy press/shellplate design, I couldn't adequately bump bottleneck shoulders. I didn't find that out until I bought the Wilson .223 case gage.

I've had good luck with Lee dies for other calibers, so I didn't hesitate to get Lee 300 BLK dies. Mine work just fine, no complaints.

mrgein wrote:YAY! mine are hornady

+1

I'm a new 300 BLK loader but I'm not new to Lee dies. When purchasing new dies my first choice is Lee and the Lee 300 BLK dies I have work just fine as all of the other Lee dies I have do. They reform 556 brass where it chambers easily in my rifle without over working the brass.

Ken

OP, just buy the RCBS small base die. You only need the one die and not the set. That will get the case down to the smaller dimension your chamber obviously requires. If you got some Cerrosafe and a good micrometer that measures to the .0001", you could make a chamber cast and then measure it and find out how close to the blueprint it is. And measure the formed brass and see what you got.

Lee stated why they don't make a small base die; they feel it works the brass too much. Plus their dies seem to work for most users. Like others have said, 300 isn't the easiest round to produce. Especially if you're using different headstamps. You'll notice a lot of the vendors make a point of using only one headstamp, they've already found out about variances.