12 gauge reloading press not accurate

[cajuntec]

I bought an older MEC 600 (not the newer 600 MK V), and it came with 5 charge bars and a ton of powder bushings.

The load that I want to use calls for 17.5 grains of Red Dot. In MEC's catalog / website, they have the "recommended" bushings and the relation of grains for various powders. There is a warning that it isn't exact, and that the table is just to show the relation / changes between bushings / powders.

However... They list a 29 to throw a 17.1 grain charge, and a 30 to throw a 17.8 grain charge. Mine is WAY lower, and the weights vary quite a bit. My 29 throws between 15.5 and 16 grains of powder. My 30 throws between 15.7 and 16.3 grains of powder. When I get to the 32, that's when I'm in my range - but it throws between 17.4 and 17.8 grains of powder.

Granted, I'm shooting lighter target loads of 1 1/8 of 7 1/2 shot, but I still think the variances in weight are concerning.

I'm using two different scales to verify my weights - a Redding balance beam scale and a Hornady digital. Both have been calibrated. Both show the same weight for every one of these measured charges.

Is this considered acceptable for shotgun reloading? I'd never accept these variances in metallic reloading, but the powder drop on these shotgun presses don't seem like they are designed for precision.

All the best,
Glenn

[berettadave]

Glenn,

It's pretty normal for the actual loads to be lower than listed in the manual. One thing to keep in mind is that when the powder hopper is full, it will tend to throw a little heavier charge being the weight of the powder on the bushing is greater than when it's getting empty. What I do is use a screw in powder baffle between the powder canister and charge bar which will help keep your loads more consistent. If you want your bushing to throw closer to what the manual says, you can take a size smaller bushing and start boring it out with a dremel tool or a flapper wheel a little at a time until it throws exactly the amount you want. Just remember to mark it so you don't accidentally mistake it later for the wrong bushing. You can also get a universal charge bar which is adjustable. Some machines don't work as smooth with the universal bar though. If you're not changing loads I would just bore out a bushing to throw what your looking for.

Dave

[az2tx]

Mec sell a baffle that helps keep the charge a little more consistant

[cajuntec]

berettadave / az2tx,

Thank you both. I'm interested in that powder baffle, but the description says to use it with a universal charge bar, which I am not using. I use the individual bars with the bushings. It also mentions a brass washer, which I do not have on either of my MEC's. I just have rubber grommets between the charge bar and the bottles.

I have tons of bushings, and the 32 does throw the charge I want, so I'm going to hold off from modifying any of the ones I have.

Alliant Powder was great and fast with their reply. They said the .4 variance I was seeing was perfectly acceptable with the formula I was using. In reading the chart in the Lyman's manual, it looks like a difference of 200 psi and 25 fps across a half-grain (.5) variance, so I think I'm better off than I thought I was. Although I would really like it if I could throw a 17.5 grain drop every time.

MEC also replied this morning, and also said the powder charges would be safe as long as they are within a .5 grain + / - of what the charge calls for. They also gave a tip of using a thin strip of Bounce or Cling Free inside the powder bottle to eliminate static. He said to hang it from the red cap and ensure it doesn't clog the hole in the bottom.

Something I also saw last night, but MEC just confirmed it - the first 3-4 charges will not be accurate as the powder has settled from sitting. I noticed that the first couple of charges after each "bottle flip" (after changing bushings in the charge bar) had a large variance.

Both Alliant and MEC responded quickly - a testament to good customer service.

Thanks again for the replies. I'm interested to know if that powder baffle can be used with individual bars, or if it has to be used with a universal charge bar.

All the best,
Glenn

[berettadave]

The powder baffle I use is the Multi-scale brand. I have used it with both types of charge bars and it works well with either one. It has a spring loaded sleeve in the bottom which helps hold tension on the rubber gasket/washer assembly. You can find them around at gun shops or online. The brass washer is definitely helpful to have if you are ever having issues sliding your charge bar. When you remove the powder container you should lay the washer in the threaded hole against the charge bar with the four dimples facing up. Then install the rubber gasket(square cut 0-ring) on top of the brass washer and then screw the powder container down on top. The brass washer is just to help the charge bar slide without shearing the gasket. If you have issues moving the charge bar, you can loosen the container slightly to help. Also, powdered graphite can be your friend on the charge bar.

Dave

[cajuntec]

Thanks Dave. Greatly appreciate the advice.
All the best,
Glenn

[kparker158]

Any interest? Sorry to hijack thread. I don't reload and I came Across this

[berettadave]

Thanks Dave. Greatly appreciate the advice.
All the best,
Glenn

Being you are in San Antonio, check out Trainer Hale Supply in Marion. It's off of I-10. Vernon Winkleman owns it and he normally has a lot of reloading supplies for shotguns. He may have the powder baffles in stock. I know he use to carry a lot of Mec parts too.

[cajuntec]

Well, as a matter of fact, yes I am. Shoot me a price. As long as they are Win AA hulls with brass bases, I'm interested.

All the best,
Glenn

[cajuntec]

Thanks again Dave. Very helpful. I'll check that out. Sorry - the post above this one was meant for the barrel of AA hulls.
All the best,
Glenn