Issue with forming 300 BLK from 223

[madmosche]

Hi everyone,
I've been reloading 9mm for a little bit, and now I'm expanding into 300 BLK. I have read a lot of posts on this forum and other guides for forming 300 BLK brass from 223/5.56 brass. Here is the issue I'm having: I am forming FC and WCC headstamps 223 brass using the 300 BLK RCBS Small Base AR-series dies on a Lee APP single stage press. I annealed them and chopped them down on the Harbor Freight saw with a jig. Then when I process them through the RCBS dies, they do not pass my Wilson Headspace/Case Length Gauge. They are sticking up slightly above the top shelf on the headspace gauge. I've tried different headstamps of 223/5.56 brass and have the same results every time. However, when I run a once-fired factory 300 BLK case through the same die without changing anything, then it passes the Wilson gauge no problem (might even be sitting below the bottom step, pushing the shoulder down too far). Why would this die not be forming the cut-down 223 the same was as a fired factory 300 blk case? I can't figure out the issue. Thank you in advance for any guidance you may be able to provide.

[Snozzelquaf]

I too am very much interested in this topic should some one with some insight have a suggestion..

I'm currently waiting for my L.E. head space gauge I was afraid to order lyman like the rest of my tooling..

[cwlongshot]

I would not be doing this on the APP press

Its NOT DESIGNED FOR THAT! Very possible its not doing you justice and causing the problems.

I have been critical of LEE but THIS IS NOT A SLIGHT. Its simply not what the press was designed for.

Use a good single stage press.

CW

[madmosche]

I would not be doing this on the APP press

Its NOT DESIGNED FOR THAT! Very possible its not doing you justice and causing the problems.

I have been critical of LEE but THIS IS NOT A SLIGHT. Its simply not what the press was designed for.

Use a good single stage press.

I appreciate the input and I will try this on my friend's Lee Loadmaster to see if that changes anything. But I can resize 223 no problem, and factory 300 BLK no problem on this APP press, so why would this press be the cause of issues forming 223 to 300? I'm curious because it's advertised as a single stage press by Lee.

[cwlongshot]

Simply said, because FORMING is not re sizing.

Not being a smart azz here. The APP is a wonderful lil thing. ITS NOT FOR FORMING. Just ASK LEE!!

Also not for nothing, but you want a "O" press or in the very least a strong beefy "C". Turrets and progressives always tend to have flex in them. NOT something desirable with forming a case.

I use my Ammo Master or Summit presses. (Prefer the ammo Master) Lee classic Cast is a beast and well suited. (Just to show I'm not a lee basher)

CW

[dellet]

I would not be doing this on the APP press

Its NOT DESIGNED FOR THAT! Very possible its not doing you justice and causing the problems.

I have been critical of LEE but THIS IS NOT A SLIGHT. Its simply not what the press was designed for.

Use a good single stage press.

I appreciate the input and I will try this on my friend's Lee Loadmaster to see if that changes anything. But I can resize 223 no problem, and factory 300 BLK no problem on this APP press, so why would this press be the cause of issues forming 223 to 300? I'm curious because it's advertised as a single stage press by Lee.

First problem is highlighted, There is a huge difference in the force needed to form a case than the re-size a case. That press just won't cut it. You will wear it out very quickly forming cases.

You might have a lube problem contributing also. if it's hard to pull the formed case out, that should be a clue.

Most likely your fired cases will fit your Wilson gauge before sizing, so that's not a good indicator of the job the press is doing. Sizing some that don't fit is the test.

If you still have problems with the loadmaster, lube or something else in your process is off.

Or basically what CW said

[madmosche]

You might have a lube problem contributing also. if it's hard to pull the formed case out, that should be a clue.

Most likely your fired cases will fit your Wilson gauge before sizing, so that's not a good indicator of the job the press is doing. Sizing some that don't fit is the test.

The cases are actually pretty easy to run through the RCBS sizing die using the APP. They come out easily.

My fired 300 BLK cases do NOT fit in the Wilson gauge. After I run them through the RCBS sizing die on the APP press, they fit nicely into the gauge.

I might just pick up a Lee Challenger press for $75, since cwlongshot mentioned that progressive presses can have flex in them.

Thank you for the input everyone.

[hunton35]

i had this issue with some lc brass now i cut,anneal,resize ,trim.in that order and no more problems. i use lee dies

[madmosche]

i had this issue with some lc brass now i cut,anneal,resize ,trim.in that order and no more problems. i use lee dies

That is the same order of operations I was following, just with the RCBS dies. But I know the die isn't the issue. I have a brand new Lee Challenger single-stage press on the way, and I'll report back if that fixes the problem.

[Omega]

As long as the die goes all the way down, then the press should not be an issue. When I formed cases with my Lee dies and Lee Turret press, I had to take a bit off the shell holder and size-turn-size in order to get them to get a pass on the Sheridan slotted gauge. Once I got some Hornady dies and an RCBS shell holder I could usually form/size just once and it would pass the gauge.

Edit:
These are .277WLV, but the 300BLK are formed the same way. The sheridan gauge makes it much easier to see where the issue is, neck, length, or base.