Author Topic: "Reclaimed" shot charges off weight (Read 1908 times)

the rifleman · « **on:** June 03, 2003, 10:10:38 PM »

As I have been just getting into the 12ga. shotshell reloading fun and games, I have been using some reclaimed shot, that available from our gun club. (I have heard all the cons about deformed shot not throwing good patterns etc., thats not my concern in this post.)

I have weighed several charges of shot from my MEC, while in the process of loading. Many of them are light for a 1-1/8 oz load. They seen to average around 475grains, instead of the 492 grains that a 1-1/8oz carge bar should be throwing. I presume its because of the mix of shot sizes in the reclaimed shot, not filling the charge bar completely.

Question. How will this effect my overall pressures. I am loading quite light with 18grains of green dot, as per the Alliant load data for the AA compression formed hull with the WAA-12 wad, and the w209 primer.
The loads shoot beautiful, and I can't say I am dissapointed by them at all, but I wonder what happens when you are actually getting slightly less weight shot charges compared to the data's listed weight.

Any ideas, as to whether my pressures are lower or higher than the load data's listed pressures, and what of velocitys? Faster or slower.

Funny thing which I also haven't been able to figure out is why do they list a larger powder charge for the 1oz. loads vs the 1-1/8oz load, in Alliant load data. You would think the lighter the shot weight, the less powder youwould have to use?

Ideas?

Thanks, Bill

Graybeard · « **Reply #1 on:** June 04, 2003, 03:07:49 PM »

Your thinking on the shot charge weight vs. powder weight is not correct. With shotshell loading as with centerfire ammo loading the lighter projectile usually has a heavier powder charge using same powder.

The small difference is not going to affect your ballistics enough to matter. It could be if you used new shot you'd also see a similar error. Charge bars approximate the charge, they are not perfect. They likely could be perfect ONLY with a single shot size and shot metalurgy. For all other shot sizes and hardnesses they will be off some. Very small differences are of no consequence.

If you have a good source and wish to you can open up the bar a wee bit at a time until you get the desired weight. But be aware it will only be right with that source of lead and if you change it will again be off somewhat.

GB

the rifleman · « **Reply #2 on:** June 04, 2003, 07:42:52 PM »

Thanks for the answer Greybeard!

I still don't understand "why" a lighter projectile should require a heavier powder charge, unless its simply to get a higher velocity, as the lighter projectile should be capable of.
Shotshell load data would seem to indicate higher velocitys, with the 1oz loads vs the 1-1/8oz. Perhaps it is so the shot pattern will remain tighter, and that the shot that does hit the clay will have a better chance of breaking it at the higher velocity, as there is a lesser amount of shot?
This is just my reasoning for it......

So you honestly dont feel that the slightly less weight of shot, when using data for the 1-1/8oz load, should cause any pressure problems?? As it is the load data I am using is fairly low on the pressures anyway, so there should be some room for variance without hitting the maximum safe pressure.

Bill

Graybeard · « **Reply #3 on:** June 05, 2003, 01:28:52 AM »

As a percentage of the total weight the variance is rather small. Pressures in shotshells is quite low anyway in comparison to centerfire ammo. For instance even the lowly old black powder rounds in centerfire calibers usually generate 16,000-18,000 psi. Shotshells operate in the 5,000-12,000 psi range. Mostly on the middle of that range.

Lighter charges and lighter projectiles offer less resistance so more powder is used than with heavier loads to maintain equal or similar pressures.

GB

dakotashooter2 · « **Reply #4 on:** June 05, 2003, 03:48:56 AM »

Keep in mind there are many variables with shotshell loading. More than with cartridge loading. Velocity/performance is often a determining factor in building a load. While it is possible to crank a 1/8 oz target load up to up around 1550 FPS, 2 oz magnum loads (3") generally max out at around 1250 FPS. Velocity can be a friend or enemy. It can increase pellet energy but destroy a pattern. Wads perform differently too. Change the wad and it may take another grain of the same powder to get the same performance as a load with a different wad. As far as the shot weight being dropped, when measuring by volume there are always variables that can effect the actual weight being dropped. Charge bars are generally calibrated for a certain range of shot sizes. Larger shot will drop light because it does not pack or nest as tightly as smaller shot. It is logical to assume that reclaimed shot ,which is probably a mixture of 7 1/2, 8 and 9 shot and is deformed will probably be off a few grains when dropped. The speed at which shells are loaded can effect the drop weight of shot and powder due to the packing effect. Slow or fast operation of a loader can effect how much the shot or powder settles in the measuring device. Mec bushings are notorious for dropping a different charge than listed. I usually have to go one or two bushing sizes up or down to get the correct charge (by weight). As greybeard mention a minor variation (lighter) in shot weight is not likely to cause problems.

the rifleman · « **Reply #5 on:** June 05, 2003, 06:42:19 PM »

Thanks GB, dakotashooter, for the info!
As I mentioned I have been happy with the loads so far, they seem to smoke targets.
I have heard a lot about the powder bushings that are used on a MEC charge bar, being a bit finicky. Different shapes of powder, amount in bottle etc, seem to make a difference.
I have done away with that process. I use my RCBS powder measure, after I have primed 50 or so hulls, and get consistant drops. I have scaled many powder drops throughout the process, and the RCBS does a fantastic job!
After all 50 are charged, I run the wad in, drop the shot, move shell to crimp start position. I then put another wad in the next hull, drop the shot, move the first shell to the final crimp position, and so on and so forth. There is then 3 shells in positions at one time on the Mec, and I can bang thru 50 in just a few minutes. Its a single stage unit but I am using it like a progressive, and love it. The biggest time consumer is depriming/priming hulls.

Bob_K · « **Reply #6 on:** June 08, 2003, 03:32:52 AM »

A reason that your loads may be a bit light is that the charge bar rating is for chilled shot, and your reclaimed shot may have a higher proportion of hard or magnum shot. The most dense shot (smallest volume for the weight) will be pure lead. Any alloying components used to make the shot harder (antimony) will make the shot slightly less dense. Shot density drives the volume for a specified weight, and conversely, a fixed volume will weight differently depending on density. A simple test is to weight out 1 oz of Heavishot, clilled shot, and Magnum shot, then count the pellets in each. Heavishot has the least, Magnum has the most, chilled is in the middle.

Shot size also affects the weight drop by a charge bar. Your charge bar may well drop 1 1/8 of chilled #9, but will be a tad light for #8, and lighter still for #7.5.

I use an adjustable charge bar so I can set my charge weight specifically for the type and size of shot I'm loading.

the rifleman · « **Reply #7 on:** June 08, 2003, 06:01:37 PM »

Bob, I have to get myself one of those adjustable charge bars. They sound slicker than deer guts on a door knob.

I think I'll keep an eye open for one on e-bay!

Bill

Bob_K · « **Reply #8 on:** June 09, 2003, 12:19:58 PM »

Just be sure you get the correct one. The C or C/CS model is for the single stage presses. The D or D/DS model is for the progressives. The main difference is the powder is on the left on progressives, and their shell plate rotates counter clockwise. The right bottle is the powder bottle on single stage MEC's, and the shells are moved around in a clockwise direction.

Bullseye · « **Reply #9 on:** June 09, 2003, 03:39:06 PM »

I use the adjustable charge bar and would use nothing else. Just be careful not to beat yourself up with the whole weight issue. Even with a brand new bag of shot, you will still get some variation, it is not like dropping powder for all the reasons mentioned above. You can dial it in and get very close charges, just accept a small variation with the shot.

Savage · « **Reply #10 on:** June 12, 2003, 04:09:15 AM »

I use the adjustable charge bar with my MEC 600 Jr. Just be sure to verify your drops with a good scale durring setup, and away you go!
Stay Safe,
Savage