How important is wad pressure?

[Kelly]

I just started loading 2 1/2" 410 shells on my new Mec 600 jr. and I am having trouble getting a decent crimp. I am using Remington STS shells with 12.9 gr. of Lil Gun and a WAA 41 wad. Trouble is, if I seat the wad just on the powder (very light pressure) I have too much room left to get a proper crimp. If I seat the wad off the powder about 3/16", the shot comes up to within 1/8" of the shell mouth and I get a good crimp. Any suggestions, am I doing something wrong? Is there a problem with the wad not being seated firmly on the powder?

[tony212]

I have had the same problem. If you check in the manual that came with your 600 jr. there will be a section that tells how to adjust your "Wad collum height"  This is what the problem is.  After I made the adjustments on mine everything worked fine.
hope this helps
Tony212

[rickyp]

I have the same troubles, this must be very common porblum.

[texasbilly]

The problem you are facing is one of hull capacity.  The Remington STS 410 hulls have a greater capacity than others (eg Winchester AA).  To solve the problem, consider using a bulkier powder like 4227.  This powder fills the case, and allows a better crimp.  Furthermore, the powder is excellent in the 410 bore.
Avoid allowing an air gap to form between the powder and the wad in any shotshell.  The cause of many squib loads can be traced to this gap, which causes poor ignition of the powder.

[Throckmorton]

I"'m no sg shell expert but have loaded a BUNCH o f'em.Trying to get the 'wad column' to come out where it should is pretty much hit or miss.And yes I follow recipes.They still don't always work out right.....ususally too short.I just throw in a few extra bb's.I've read of folks who throw in a red bead or some such 'space filler' to make it come out right.
One thing I have learned....when a load works,stick with it.!