form trim dies

[tenx]

not sure if it's common knowledge but there is a difference in trim dies, rcbs trim dies have a f/l size die body and redding don't.
i make 222 brass from 223 in a 222 trim die and thats how i found out. if you periodically trim your brass in a rcbs trim die you are f/l sizing the brass. just wanted to pass that on.......thanks

[EDG]

Not quite.

The RCBS trim die does size the body and helps squeeze the case length back to normal for trimming.
When you use a trim die for trimming the case the length of the case will get longer after trimming if it is FL sized.
If Reddings don't size the body then your trimmed case will not be the same length after FL sizing. It will longer by .004 to .007. However the RCBS trim die for bottle neck cases does not size the neck. Those that I own are about .010 oversize compared to a FL size die made by RCBS.

I have a few trim dies made by Pacific and they are even larger in the neck.

The sole Redding trim die that I owned sized the neck and the case body - but it was for a 40-65 - which normally has the neck expanded with a 3rd die like a pistol cartridge.

[Char-Gar]

Yes, that is the different between the RCBS and the Redding. If a fellow is wanting to trim his neck sized cases and not size the body to change his carefully fire formed to his rifle case, then Redding is the way to go. You can use a Redding to case reforming, but the case will need to go through a FL sizing die as the last step.

The RCBS will FL resize as well as being use for a trim die.

As a general rule, I prefer the Redding for the above reason when used to trim cases, but the RCBS for other case forming and resizing operations. Not wanting to keep both in stock, I purchase the Redding and just use a FL sizing die when needed as I have them already.

I am glad that RCBS and Redding gives us a choice in these dies, but it behooves a fellow to know the difference when making a purchase for they are not the same.

[gunwonk]

So, for bottleneck cases:
The RCBS trim die fully resizes the body, and the Redding does not;
Neither one fully resizes the case neck?

[EDG]

Wonk
I have a dozen or more bottleneck trim dies by RCBS. They all size the body to some degree and none size the case neck to the final size. If your rifle has a huge over size chamber the trim die might size the neck some but no enough to hold a bullet.

However I have trim dies for the 6.5X53R Dutch Mannlicher and they vary in size. The older die barely sizes the body enough to chamber - but the formed cases do chamber. The new die is about .005 smaller in the body. I started out shooting the 6.5X53R with only the one trim die. After forming cases the necks were still too large so I neck sized the upper half of the neck with a 6.5X55 FL die and seated the bullets with a 6.5X55 seater.

I do not have any bottle neck Redding trim dies except for the 7.92X33 Kurz. I do not have a FL die to compare it too.
It is about .015 larger in the neck than a 8X57 FL die made by RCBS, Lee or Pacific. It is about .008 larger than the RCBS trim dies that I have so clearly the Kurz is a little different.
The 40-65 Redding trim die that I had seemed to be dimensioned exactly like a FL die. I measured the neck and it was the same as my Redding FL die. However it is a round that is loaded with 3 dies like a pistol cartridge so don't draw any conclusions from one die. If you are interested you can call Redding and ask the customer service guy there. You can find him in some of the youtube videos and he is pretty knowledgable. Back when Jay Postman (RIP) was still at RCBS he would tell you what the inside dimensions of the different dies were. I had a short chat with him about the 38-55 vs the .375 Win and he told me the inside diameters of both FL dies.



So, for bottleneck cases:
The RCBS trim die fully resizes the body, and the Redding does not;
Neither one fully resizes the case neck?