Changing Pocket Uniformers On Lyman Prep Center

[Ranch Dog]

After yesterdays run of brass across the Lyman Prep Center, I decided to ordered new RCBS Large Pistol and Small Uniformers to replace the Lyman toolheads. Some time ago I had bought the RCBS Large Rifle Uniformer as the Lyman tool is not specific as to which primer pocket it is made for. From measurement, it is for a Large Pistol pocket; hence, the need for the Large Rifle.

What I've noticed is that the Lyman Cutters have dulled where the RCBS Large Rifle is still is as sharp as the day I bought it and it has prepped more Large Rifle brass than the Lyman Large Pistol and Small has combined. The problem with the Lyman cutters is that they have a flat surface with no way for the trimmed brass to exit the head after it has been removed. I have found myself with a toothbrush in one hand cleaning the cutter between every case.

The RCBS tools have a slot cut on each side of the head for the debris to exit.



If you have ever wondered what the dimensions of primer pockets are, here is the SAAMI drawings.



Hey, the forum has been slow.

[JohnnyEnfield]

Great info as always. Thank you sir.

[Ranch Dog]

Great info as always. Thank you sir.

You're welcome!

[GasGuzzler]

An obvious thanks.

[larryw]

Question RD, when you use the crimp remover to
bevel the primer pocket mouth, do you give it the
full, all the cutter has bevel, or just touch it &
just break the Edge?

[Ranch Dog]

The full depth.

[daboone]

I've used the assortments of RCBS, Lyman, Hornady on my RCBS case prep center. But for primer pockets I've been using Sinclair uniformers. They required DYI adapters (a pistol case drilled for 10/32 threaded rod, nuts and friction tape). These little sucker refuse to get dull.