View Full Version : RCBS die types -- HELP

November 27, 2006, 22:24
I am new to reloading and wishing to load mostly for highpower and tactical matches.

I will be loading 5.56 and 30-06 Springfield at first. I am shooting service rifle, M1 Garand and AR15. I am looking at 168Gr .30 bullets and 75gr HPBT .223 bullets. For the tactical matches I will load mostly .223 using 55gr FMJ.

I need some dies. There are three specific types of dies listed on the website and I do not understand the differences.

They are:

Standard "full length"



"Small Base"

Can some one please explain the difference and/or steer me in the right direction?



Dakota FAL
November 27, 2006, 23:09
The full lenght dies resize the entire case. This is the "normal" standard for reloading dies.

Some dies just resize the neck and are oddly enough called "Neck Sizing" dies. neck sizing dies are sometimes preferable for shooters who will shoot the ammunition in the same gun it was originally fired in. This is sometimes more accurate as the case still conforms very closely to the rifle's chamber with only the neck being resized enough to hold the new bullet. The advantage, in addition to potentially better accuracy, is that there is virtually no stretch, the brass lasts longer and the necks do not grow and consequently do not need to be trimmed. On the downside, neck sizing is normally only used in bolt action rifles where the strong camming action of the bolt will allow the snug fitting round to be reliably chambered. They do not work well in semi-autos.

"Small Base" dies are designed to return the brass to it's original new dimensions. Some shooters prefer them as they feel the round lays in the bottom of the chamber consistently and some shooters feel this provides better accuracy. Small base dies also ensure the round will chamber well in a semi auto, or in many different rifles where chamber dimensions may vary. On the down side, they work the brass more, tend to cause more stretch in the case and cause more growth in the neck. This tends to reduce case life compared to standard and neck sizing dies.

RCBS X-dies are relatively new. They are designed to prevent excessive neck growth once you trim all your cases to a uniform size. However there have been reports of problems with them in ammunition used in semi-auto rifles.

I have reloaded 30-06 for M-1 Garands, 7.62mm NATO for M-1A's and .223 for AR-15's in national match competition and I have never had any failure to feed issues using standard full lenght resizing dies.

I'd recommend you go with a full lenght resizing die as small base dies are not needed in any of these rifles.