NEVER TRUST A MEC BAR
 

I was loading what I thought were 1 1/8 ounce dove loads for 12 gauge on a MEC 9000. Even though the bar was 1 1/8, I noticed that the 1 1/8 ounce wads were too low, so I had to go to the 1 ounce wads. After loading a few hundred I decided to weigh the shot charges. In both 8s and 7 1/2 loads it was dropping exactly one ounce. Of course the powder was correct for the bar uses bushings. But not the shot side. One will find that all of MEC's info is light. They do sell on EBAY an aftermarket bar that uses bushings on both sides, which I did buy for my 20 ga 9000 since the 1 ounce bar does not drop 1 ounce either.

I did not have drill bits that big so using a step drill on the bottom I kept opening the bar until it dropped 1 1/8 ounce. I did not go from the top so as not to mess up the rubber in the bar. Here is the bar that now drops the true amount. If one has bigger drill bits that would work better, but hey, it works with the step drill bit.

This has come up regularly on the reloading forum at Shotgun world. The concensus of opinion is that MEC calibrated the bars using soft shot, no antimony, which is the heaviest compared to high antimony which is lighter. Size of shot also plays into what the actual throw weight comes out. Their target bars are smaller yet in order to keep you under the required weight no matter what type shot you use. I have not found soft shot for sale for years so have no idea why they do this but the drill will fix it.

The problem is one drops the exact amount of a powder designed for 1 1/8 ounces but you are pushing only one ounce of shot, which would either require a different amount or even a completely different powder. I imagine the one ounce of shot with that powder is moving pretty fast.

I guess MEC thinks you are going to use their chart to select their recommended bushing, which will always be lighter, and are not going to weigh the powder charges and change bushings to get the exact amount.

C.Y.A. liability probably plays a part also.

It’s a volume measure dropping shot that varies in size and composition. Any loader same variance in drop weights are common, depending on how the shot packs and antimony content.

Ponsness Warren round drop bushings easy to open up in a lathe. Have a 3/4 & 7/8 bushing modified to drop the volume needed AA hulls shot & wad I use. Modified bushing drops are closer to 3/4 & 7/8 than factory. Mark them with a punch prick either side of the bushing # to indicate modified.

You can do the same to square MEC bars in the 4 jaw. Easiest method use a bar that drops heavy, lined with blue painters tape to desired. I use tape to check the hull-wad-shot fill before modifying . Measurement taped bushing gives a rough indication size needed to modify the 2nd bushing that’s too small. Best open in the lathe gradually sneaking up on the correct drops . In and out of the chuck several times.

I would bush out too large with tape before opening too small using less than precise machine methods. Over drill means use a new bar. Might consider keep using the taped one. Have taped bushings, volume pistol powder measure infrequently used, that lasted well, just check the drops before each loading session.

William

I discovered years ago that most powder and shot bushings are approximate, the shot will vary quite a bit depending on size. I'm in the habit of actually weighing a set of 5 throws out of any bushings with the intended powder or shot charge before I use them. I have several I have chucked up on the lathe and "tuned" to get exactly what I want.

I've stepped drilled several over the years, but the shot doesn't always fill in the upward direction, so the last two I did, I set them up in the Bridgeport and, using a boring head, bored them out straight thru, stepping out a few thous each time until they dropped what I wanted. Another method, which I considered, but haven't done, was to use an expanding reamer.

I have modified quite a few over the years, both bars and bushings. I try to dial the bars in for the size of shot I am using. The bushings are adjusted for the type of powder and weight. For patterning I weigh both powder and shot. Some powders meter a lot better than others.
C.G.B.

I could set MEC Bar up in my half Bridgeport size Rockwell mill but am better at boring on the lathe . I use the mill to tune powder drops on brass fixed rotor bonanza pistol measures. There clean the hole up with an end mill Adjust charge with depth measured with a indicator, rotors no longer available buy small ones off eBay & alter to suit

I know many here don't like them but I have used the adjustable charge bars for years with good results. Just saying.....:cool: