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Joined: 28 Jan 2009 Posts: 107

I posted a while back asking if other's had concerns of maybe not getting as much wad pressure with a roll crimp (using paper cheddite) as you would with a six point using a plastic hull.

I loaded a couple 2 1/2" --paper cheddite--7/8's-using sg-16 wad.......looked perfect, I saw a very slight doming of the over shot card and thought that was indicating some wad pressure.
all was well I set them on the coffee table to be sent to tom for testing.

This morning I needed a couple shell to run through my m-12 (new purchase) so I grabbed a couple plastic.........very smooth..... I grabbed the roll crimped paper's and pumped them through (not firing,just running the action)

When I picked the loaded shells of the easy chair I could now hear shot rattling..........crimp still looked good.........overshot card still ok.........

Any ideas ?

Joined: 09 Jul 2009 Posts: 510 Location: Central CT

Hi

Wad pressure is over obsessed about. The wad, be it plastic or cardboard and fiber only needs to sit on top of the powder with no air space. With the crimp applying some pressure to keep it all together. Whether the actual pressure applied is high or not the ballistic outcome will be unaffected.

Pick up any loaded shotshell, they all rattle a bit, unless they are buffered loads. Even some brand new Federal papers #8's I have rattle a bit. I don't think the rattle tells you anything but the fact that you remembered to put the shot in, heck that isn't a bad sign is it.

I too have found the rattle disconcerting, but it hasn't affected performance any as far as I can tell either. I use a vintage hand crank roll crimper (I find it faster than a drill), and if I hear rattling I usually do run it through again with a bit more pressure, and it almost always does the trick. The rattle may not matter, but it's annoying nonetheless.

Member Joined: 08 Nov 2005 Posts: 3438 Location: Illinois

I run wad pressure at 40lbs--if the shell rattles I turn the knob up a little on the bar and the problem is solved--usually only takes a few pellets to quell the noise Wink

Joined: 28 Jan 2009 Posts: 107

I guess what is bothering me is that they appeared to be fine ,(no rattling) and after being run through the gun a couple times something changed.

I'm sure it's not a big deal, just trying to get them as perfect as possible so when sent in they are consistent

BRUCE

Joined: 09 Jul 2009 Posts: 510 Location: Central CT

They are going to be consistent, just the way they are. As long as you have weighed the powder and shot charges and crimped each one to the same overall length.

If they aren't consistent, it won't be because of wad pressure or pellet rattle. Peak Chamber Pressure is not affected by wad pressure, unless you haven't seated the wad on the powder and/or the crimp is not properly holding all the components together.

Think about it like this, you have 40 lbs of wad pressure in one load, you have 10 lbs of wad pressure in another load with the exact same components as the first, you light it off and the PSI goes to 8,000, 30 lbs. of wad pressure one way or another cannot influence the next load. 30 lbs. is less than .4% of 8,000 PSI. The peak pressure occurs within 2 or 3 milliseconds, it doesn't even see that initial 10lbs or 40 lbs or even 100lbs. of wad pressure if you could get it that high. There are too many other inconsistencies and variables that effect the peak psi, a lot more than whatever little bit of wad pressure can produce.

All loads rattle, you are obsessing needlessly. For them not to rattle every pellet would have to be perfectly round and the shape of the shot column would have to let each pellet nestle into the space between every other pellet in the load.

Have confidence everything is fine.

Member Joined: 06 Oct 2007 Posts: 2350 Location: West MI

I too notice more rattle after they get handled or spend the afternoon bouncing around in the vest pockets. I figured it is from the pellets settleling into the wad cup. Havn't noticed any performance issues, but have never tested for it either and probably wont. Although, I don't notice it as much once a bird goes up. Very Happy

Try this it helped reduce rattle in my shells; I use a MEC 600 JR and after dropping the shot and setting the OSC or Polywad insert I usually tamp/tap the card or insert with the rammer tube a couple few times up to maybe half the wad seat preasure (10-20lbs +/- nothing specific) to seat/settle the shot in place. The rattle is reduced and usually notice that I've picked up a little more head space for the roll crimp tool to start the crimp.

Another rattle reducer is when I need to use a filler especially in the 10ga stuff. If something that has a cushioning effect is used like a felt, styrofoam or cork the ratteling is greatly reduced when compared to a filler that isn't compresable or bouncy like hard cork or card stock. I once tried the collapsable/crushable fillers like cereal, puffed rice, etc. and after a few outings the filler turned to dust and there was all sorts of rattling going on in there.

This is what I've experienced, hope it helps, Mike

Member Joined: 26 Jun 2005 Posts: 376 Location: North ID.

In the late 60's-early 70's, as a warm up for goose hunting, I'd take my double 10 ga out after ducks, using Remington factory 2 7/8" roll crimped loads. The shot rattled around, which annoyed me, but it didn't affect performance a bit!

Member Joined: 02 Oct 2007 Posts: 1975

If the crimp is not tight enough to hold the wad tight it may effect ballistics. I know this is the case when roll crimping slugs. I don't know why it would be different with shot. With fiber wads you apply the pressure wnen installing the wad. With plasic wads the pressure is decided by the crimp. I have roll crimped quite a few and never had rattling of the shot. Here's a picture of four hulls, all loaded with the same amount of powder. Two have 1 oz of shot and 2 have 7/8 oz of shot. You can see that there is a difference in the finished shells. Those with 7/8 oz are shorter as it took more pressure when roll crimping All the hulls were cut to exactly 2 1/2" to start. The only way I can see you will get loose shot is by not applying enough pressure or the shotcup was not full.
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