Problems with Brass Shotshells

[notjustsomeone]

I'm getting a lot of delayed ignition of the main powder charge, with occasional failures to ignite at all but never a misfire from the primer.

Magtech 12ga brass shotshells
TulAmmo Large Pistol Primers
20gr Unique Powder
1/4in leather over powder wad
1/2 compressed cotton patching as filler wad
450gr of 32-caliber lead round balls
- or - about 275gr of .177 steel shot
thin plastic overshot wad
rubber cement around rim to keep wad in place

I'm new to reloading shotshells. At first I thought the issue may be that the flash hole is above the base of the shell, but after trying to fill that space with a leather wad, with a hole for the primer pocket, the results were only marginally better. I've read about people having problems with the tula primers, but so far I haven't had any primers fail to ignite. I don't think the powder's bad because I'm using the same powder in pistol rounds with wsp standard primers without issue. The shot doesn't seem to affect the odds of getting a misfire, but I didn't label them very well. I get the feeling that the cotton patch as a filler wad could be the culprit. I've read about similar materials being used, though I believe mainly with black powder. Can the lack of pressure from a fairly loose filler wad allow enough expansion that the primer would fail to ignite the powder charge?

I thought I'd try to get some feedback from this site before I try anything else.

[jmort]

You should be over in the casting for shotguns forum. Read this thread
http://www.cascity.com/forumhall/index.php/topic,48392.0.html
and this thread
http://castboolits.gunloads.com/showthread.php?202246-Brass-Shells-and-Smokeless

OP seal seems critical.

[runfiverun]

yes you need solid compression on the powder.
if you take your load and substitute just a plastic wad it will fail the same way.
you have to get an initial burn going on the powder for it perform properly that's the job of the over shot disc and cement.

i'd switch that cotton out for a cork type filler in that area.
you also don't have much of a gas seal with just the leather.
a cardboard disc, the cork filler, and another cardboard disc would work much better for you.
a plastic gas seal would do better if you have an over bored barrel.

[notjustsomeone]

Thanks, sorry I didn't see the shotguns section when I was looking through the site, probably skipped over it because it starts with the word castings.

I'll try using cardboard and find some cork material to try out tomorrow. I've been cutting my own wads with an 11ga (.75 cal) punch.

[1876dan]

Do you have any Idea where I can buy 10 ga. Brass Shotshells for my 1887 Winchester 10 Ga lever action shotgun???????

[Mk42gunner]

No idea on the brass 10 ga shells.

For the Original Poster, I would not run steel shot down the bore of my shotgun with no protection, especially air rifle bb's.

Robert

[Four-Sixty]

There is a thread in the "casting for shotguns" forum about 10 gauge brass shells. In the threads is a link to a supplier in the USA.

http://castboolits.gunloads.com/showthread.php?177565-On-Brass-10-gauge-shells-What-length-did-these-come-in

[Walter Laich]

I do remember that the Magtech brass shells run 11 ga inside--thinner walls I guess.
I use an 11 ga over powder wad then a cut off cup from a 12 ga plastic wad. Seal over shot wad with water glass. It's the thickness if honey and dries solid over the OS wad

wad