Having an issue with loading for 3 different 20 gauge guns. I have to resize because one of the guns is finicky (Rem 1187 auto loader) and probably being caused by my old SxS could care less!
I have been using the ring resizer that came with the old MEC 650 press - but what a PIA to set up each time! So, I end up resizing 600-800 shells on a few nights and then use them to reload. The problem I'm having is if they have sat for couple weeks, I have trouble getting the primers to seat properly on some shells - very tough! I've already increased the pressure on the re-prime tube about as much as it will allow. If I load them plain (no resize) and let it de-prime in the normal progression, I don't have this problem. I'm thinking maybe the resized shells are "growing" into the empty primer pocket sitting in the box. ?! Any thoughts on that?
Other thing I would like some opinions on. I've been looking for a resizer, found several of the old style MEC resizers available that use the rings. But I'm wondering if it wouldn't be better to get a Supersizer collet machine since it doesn't deprime the hull and maybe get away from this issue.
Any thoughts would be appreciated much!

The supersizer or Sizemaster gives you some adjustability. I have seen some cases that were sized down so much that the base actually cupped in a bit. I never have had any problems seating primers with any of the MEC tools though. I have used my MEC loaders to seat Winchester primers in Rem. cases without much difficulty. As a note I have seen Sizemasters sell for little more than the Supersizer, and you get the whole tool.
C.G.B.

Just a suggestion...keep fired cases separated per gun...size only enought to work throught the action...that would probably eliminate the primer pocket issue AND what sounds like a problem with oversize/undersize chambers.

Take ALL the shotguns to a shotgun man and have him mic the chambers then polish out to the same ID and match the sizer ring to that size.

Simple, cheap and easy to do and will solve your problem...except for having to size real heavy loads.

Mec Supersizer works great.

My cheap RCBS shotgun press digests all cases for my 4 12 ga guns and a several friends Mec 600 Jr's do the same...if there is an "oversize case" problem just polish out the sizer ring a little bit or have a machine shop do it.

I've done the same thing to levergun/pistols having the same caliber(357, 44 and 45LC) to "match" the ammo...makes things a lot easier and they end up more accurate.

Basically...try to match the chambers to sizers.

Luck

I would recomend a MEC Supersizer or you may well find it cheaper to sell the old 650 and pick up a used Grabber, that has the collet sizer already in it.

You do not say what hulls and primers you are using. Most of today's promo hulls have steel heads which take more force to resize. The other issue you might have is the size of the primer. Some of the euro type primers are more cylindrical than the US brands and some just a bit larger in dia. The first time you insert them it takes more force. This is especially true for Rem hulls where the Rem primer is much more rounded. Some use a #1 drill to clean up the plastic to make primer insertion easier. The other problem you might look for is at the priming station. The hulls on some 650's want to move out of the back of the shell holder notch. Give them a slight push in, this will better align the primer hole in the primer station. This is exasaberated if you are using the cylindrical euro style primers. If you are off just a little it makes for inserting primers harder, the tapered US style primers allow for a bit of miss alignment. I have seen case heads slightly dished when primers have been slightly misaligned to the case and forced.

I hope one of these helps.

Thanks for the ideas guys!

After some more research and everyone’s thoughts here, I'm thinking I'll just buy the MEC Supersizer. I believe it will probably be the best fit for me - since this was my dads’ 650, well….it ain’t going nowhere! (Have an option to buy another one with 20, 16, and 12 die sets too. Thinking about going ahead for that as I have a 16 that needs to be fed occasionally too!) Interesting comment on resizing the gun barrels……… my one drawback on that is, one of them is not mine. I guess I could keep the “free shells” and the one’s from the 1187 separate and load them specific to each and others to the old SxS but, bothersome. Anyhow, all information is welcome. (Think it was asked what the hulls were: all plain Remington’s, RX20 wads, 20/28 pwd, 7/8oz #8’s, W209 prim)

And interestingly enough, I ran through 200 shells loading this week using exclusively out a brand new box of Winchester 209’s and never had the first primer stick! I had started out awhile back with about 1000 old primers that may have been causing my issue with the “hard to press in” problem. (Now, when I say “old” that’s a relative thing – half MY age but, 25 yrs at least!) Though WHY they would work fine in un-sized shells stumps me……… Good news is, all of them went “BANG”! So hopefully that issue has solved itself. Never thought the primers would have been the culprit. I had measured a sample of them with calipers and didn’t see anything out of the ordinary – odd.

Anywho, had the boys get out and let them shoot through 300 or so over the weekend. Good times!

Cordially,

Mickey Collins

"In the beginning , there was nothing........and then, even THAT exploded!"