My MEC 600 was bending rims on Cheddite hulls. Lot of pressure needed to size. Remington or Federal no problem. Little Imperial size wax cured it. Design of the sizing ring is not all that good either are the Cheddites. Reducing friction fixed it.

Longer term and for me a better solution is size and Prime on my Ponsness Warren 375. Knock the primed hull out with a fitted Delrin rod. Then finish the load on the MEC. Fact is for short 10 the MEC is a poor sizer good crimper PW good sizer poor crimper. Separate MEC sizer would do the same thing.

William

MEC sent me one of their first SuperSizers to fix a similar problem. I was using a mix of Winchester, Federal and Remington cases in my Mag10 auto. The rim thickness would grow along with head diameter. I adjusted the collet until I got a case that would chamber. When the Sizemaster presses came out I got one and have not had any more sizing problems.
C.G.B.

I bought my first short ten, Parker NH in 2009 and along with it a used but like new VersaMec 10ga loader in the box. I never had a problem with reloads with Federal, Remington and Winchester hulls.

Then I got my second short 10, a Remington 1894. I would have occasional problems with the gun almost closing but not quite with some reloads. I blamed it on tight chambers.

Then I got my third short 10, a Lefever, even tighter chambers, the gun could be hard to close on many reloaded shells.

Then I got a 10ga collet for my MEC Supersizer. When I adjusted it properly all guns would function as they should with all reloads.

This winter as part of a larger order I bought a new 10ga resizing ring for the Versamec. I noticed on the very first reload there was more resistance, and some new shiny brass on a Remington hull.

All reloads done on the Versamec with the new resizing ring will now chamber perfectly in all three guns.

I shoot and reload around 500+ or - short ten shells a year. I shoot hulls until they wear out, Federals often crack down the side, the rest are gone when a piece in the crimp area is missing.

Moral of the story, if having a problem chambering reloaded shells when using a MEC 600 or Versamec, start with changing the resizing ring, they are less than $6.

Good advice Pete

I had to go to the super sizer because of the English short short ten. That chamber is enough oversized that hulls fired in it are a hair too big to even start in the mec 600

So since I needed the super sizer any way. May as well use it on them all

I'm a little cheaper than Pete. When my 10's start being bad on the end I cut it down to 2 3/4 or even 2 5/8. They still shoot just fine. Only problem is sorting them so I still get a good crimp. I'm probably the luckiest guy in the world when it comes to 10ga hulls. A friend cleans up at a DNR range and gives me any 10ga hulls he picks up. It's around a 100 a year - Rem, Win, and Fed hulls. I buy him a water or pop over at the club. I almost feel guilty. I have the Super Sizer with 12 and 10ga collets but haven't had a problem resizing with my 10ga Jr yet.

[QUOTE=Paul Harm;212917]I'm a little cheaper than Pete.:biglaugh::biglaugh::biglaugh:

All sorts of cheddite problems crop up. I have a 16 G Remington M 31 that would drop the 2nd shell out of the bottom under the carrier instead of on top once or twice in a box of Herters Cheddite shells. Took it apart half a dozen times worked on the shell stop and carrier every possible way no cure. Then ran my Remington hull reloads through with no problems.

Measured a fresh box of Cheddite, Rims smaller than Remington's and not very consistent.

William

Would frugal have been a better word ? Let's just say I hate throwing away 10ga hulls. I get them down to 2 1/2" if necessary. Look kind of cool being so big around and short. One of my Parker lifters had 2 5/8" chambers. Still use those shells in my other guns.

Further analysis has found that some of the rim diameters are larger than others. Those that fit measure 9.025 those that do not are 9.03. Hope the Remingtons I have ordered are 9.025! Thanks to all for your input!

Bad decimal point..... .9025 closes.... .9030 will not.....super sizer does not seem to help but still adjusting....