RCBS dies in a Lyman 450

[pistolshooter]

I picked up a "used" (it never had lube in it or any other signs of use) Lyman 450 sizer off Craigslist very cheap. Mounted it to the bench and put some lube in it, and tried to install a RCBS 452 die in it, but it wouldn't go in far enough to engage the die nut. That die works fine in my RCBS LAM2. Tried a couple of other caliber dies, both RCBS and Lyman, and they all seem to install just fine. Why the issue just with the 452 die? Anyone else have issues with the 450/RCBS combo?

[C.F.Plinker]

I e-mailed RCBS about the fit of their dies in Lyman sizers a while back. Their response was that about 90% of their dies would fit into Lyman sizers -- the rest were too big. They didn't say whether the dies were too large in diameter or too long.

How long is the longest die that will fit and how long is the die that doesn't fit. This may give the rest of us a way too tell if our RCBS dies should or should not fit the Lyman sizers? Can you tell what part of the sizer is stopping the die?

[pistolshooter]

as far as I can see, it doesn't seem to be a length issue. The 452 die is about the same length as all of the others. The die will go in as far as the bottom of the lube area, but won't go into the frame below (does that make any sense?). It seems to me that the die is just a bit too big around. I wish I had a Lyman 452 die to try. I have always been told that RCBS and Lyman dies were interchangeable, but I can see that they are not. Have others had the same issue?

[462]

Though I've not had an interchangeability problem, many members have posted that they've experienced it. Perhaps manufacturing tolerances are to blame -- a die body that's on the plus side trying to fit in a hole that's on the minus side. (Ever see a woman lay on the bed while trying to fit into a pair of jeans? Same-same.)

I know some RCBS dies are machined with two different outside diameters. Is yours like that?

I spent some formative and wasted-youth years in Auburn, and had many relatives who lived in Algona and Sumner.

[pistolshooter]

the .452 die measured ~.706, and the .358 die (one of the dies that fit in both sizers) measured ~.700. Not much if a difference, but enough to keep it from being used in the Lyman. I have to assume that the Lyman .452 die would measure closer to .700. I am going to use the RCBS sizer for 45 caliber, and the Lyman for the other calibers. Learn something new everyday.


462, I'm just spending my wasted retirement years here in Auburn!

[40Super]

I have an RCBS .452 die also that was to big to fit. I took it to work and turned .003" off the od, my Lyman 450 opening is .703" , and now it works. Maybe it's certain size dies that are bigger.

[pistolshooter]

Some of my dies work, so I guess I get the offending dies turned down to fit, or get the sizer bored out to fit all of the dies.

[Marvin S]

I have had the same problem, can't remember if it was the dia or not enough chamfer on the bottom. Think it was chamfer. It was a .458 dia IIRC.

[farmbif]

having the same problem, received two new rcbs sizing dies today from midway. one of them has an outside diameter of .700, it fits in the lyman 4500 perfectly. the other die has an outside diameter of .704 and it has visible tool, lathe marks along the entire length of the outside and is not quite finished. I guess i will have to either return it which is a PITA or take some emory cloth to it and finish the outside bottom 1/2" so it will fit in the sizer casting. The bevel at the bottom outside edge looks to be the same angle as the seating area inside the sizer and since the othe one fits perfect the problem has to be the outside diameter. This seems to be a quality control issue that rcbs has and makes me wonder about how exacting these dies will size boolits. I guess its time to clean out the garage so I can get to my 80 year old american tool works lathe and start making sizing dies and the like myself.
PS if anyone is interested I have a couple south bend 9 inch lathes and a craftsman/atlas 6 inch with complete tooling available