I have a new MEC Grabber and reloading Rem hulls. I get 5-10 out of 100 reloads that won't go into SxS gun. It is a 2 1/2" chamber gun but I think the brass isn't resizing enough or my chamber rims aren't cut big enough.
Anyone ever have similar problem?

I have and a MEC Super Sizer solved the problem.

I'm not certain how a Grabber sizes the "brass" but if it is like a Junior make certain the sizer ring is running the whole way down to the rim.

Yes, absolutely. But with a Pacific reloaded. All my guns are fine with it, except the newest (to me), Osborne. I bought a MEC Super Sizer that uses a collet system that sizes only the brass, but does so very well. Problem solved. If the Grabber does not use a collet, that may be the issue. Measure a few of your reloads. Then try dropping in a factory round. If it fits, measure that for comparison.

The Mec SuperSizer is the cat's meow. I have collets for it for all gauges I reload except 12. My main 12 ga. loader is a MEC 9000G, which has the same collet resizer as the SuperSizer.

It also doubles as the best shell holder you can buy for roll crimping shells with a drill press.

The Grabber has a collet sizing system. That may need adjustment, check you tube. It's also possible the crimp is not adjusted correctly. Measure a factory load or at least one that fits, and see where the problem is. There are good videos on line to show you how to make these adjustments.

The information I have on the MEC Grabber (8567N) says this:

"Power Ring resizer gives consistent, accurately sized shells for optimum gun performance, without interrupting the reloading sequence."

This sounds like it isn't a collet sizer, like the SuperSizer, as I understand it. I copied this from the MEC website.

Correction: I misunderstood MEC's naming of the Power Ring, evidently. My bad. Readjusting the amount of resizing with a collet sizer is a simple matter. I'd just adjust it until one of the hulls that would not chamber before, will chamber. It's only going need a few thousandths more.

This. The grabber is basically a 9000 that you have to rotate by hand. Everything else on the new ones is the same between them. The old Grabbers would not resize high brass shells but that was when they first came out years ago.

I only own 9000's one of the 12's is setup with one of Ben's first automates that MEC purchased the patent for and became the 9000E.

Shooting multiple guns in different gauges I resize all shells for the smallest chamber in that gauge that I own. During the ammo shortage last few years I have loaded for others and a few of them have had problems with my shells not fitting in their guns, mainly older SxS guns. I don't resize any smaller than I have to. When reloading for myself.

MEC has youtube videos for pretty much any adjustment or problem you run into. You can also call them they are great at helping you if you need it. Here is the video on how to adjust the resizing die on a Grabber and 9000.

[video:youtube][/video]

Cold Iron's point is pertinent regarding shooting multiple guns which fire forms the head to the largest diameter chamber. The MEC ring falls behind the collet system of the Sizemaster and MEC presses that utilize a collet system. My 10 ga. MEC press uses the collet system. My Ponsness Warren 375 C uses a full length die which resizes not only the "brass" head and shell rim, but also holds the entire shell length exposing 3/16" of hull outside the die for crimping. This prevents hull buckling. In developing loads for my 2" 12 ga. guns, I test fire them in an 870 pump which requires hull resizing for my doubles. I use a full length die which rides on a Manufrance assembly that de-primes, primes and resizes with the two tools lying to the right of the screw-press. The smallest diameter tool contains a removable de-priming pin. Note the far end of the press on which sits a three leaf metal tool which fits in a slot. The small hole allows the spent primer to pass through, the flat side primes and the large hole ejects the primed and resized hull. Slower than the MEC collet system, but I don't do high volume loading for the 2" shells. Gil

I don't believe it was the resizing of the brass. I compared the rim cut on the offending gun to another antique, just not as old and the was a very small difference. One gun was made in 1922 and the other in 1905, both English/Scot made. The 1905 was tight by the smallest amount. I polished the rim cut with a dremel stone and now shells drop in completely.

I was going to say that rim cut is too often overlooked with regard to chambering issues. Looks as if you have found, and solved, the problem.

I use a shell checker from mec when I have concerns about if shells will go into my tighter gun chambers. Found mine on EBay for about ten bucks.