Smokeless powder in brass shotshells

[Cookie]

Long story short - I'm trying to load some 20 gauge Magtech brass shotshells using International Clays, and I'm having no success. So, I'm wondering if anyone has shot smokeless using these shells.

I normally load them with blackpowder and have no problems, but since the wife refuses to shoot BP, I'm using what I have on hand but substituting smokeless powder instead.

Basically I'm getting very inconsistent results, with the most common result being a mild pop instead of the normal boom. After many failed loads variations, I'm pretty sure it's an ignition issue since these brass shells use a large pistol primer, rather than a standard shotgun primer.

Is that it? And if so, do I have any alternatives, like magnum primers? Or do I just need to get some regular plastic hulls plus shotgun primers? Or is there something I'm missing here?

[Abilene]

Howdy Cookie,
I have not loaded smokeless in brass hulls, but have read some info over the years from folks that have.  Others report that they had similar results to yours until they went to a thicker over-shot card, like a nitro overpowder card.  Seems that with smokeless it was blowing out the thin overshot card before sufficient pressure had built up.  And a magnum primer probably wouldn't hurt.  Good luck.

[Sir Charles deMouton-Black]

There is usually some 20 gauge plastic hulls in the discard barrel at your local skeet range.  A LEE Load-All press might be a good place to start in reloading.  I know Magtechs are easy to load, but plastic isn't that much more difficult.

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[maldito gringo]

I load smokeless in rocky mtn brass for 10ga with excellent results, I doubt that the problem relates to ignition. what are you using to build the wad column? If youy are using cork or a loose fitting material you might want to find something like fiber or cardboard wads that fit a bit snugger, in particular, you need a good seal in the nitro card, and you need to seat it just over the
powder. Unique and Clays work well for me, I build using fiber and cardboard, double os card and seal with hot glue. The lp primer should work fine. Look to the seating of that nitro card.

[Cookie]

Seems that with smokeless it was blowing out the thin overshot card before sufficient pressure had built up.  And a magnum primer probably wouldn't hurt.  Good luck.

That was pretty much my guess at what's happening, although I hadn't thought of beefing up the overshot card. I'll try that next.

@ Sir Charles - If I have too I'll invest in the tooling to reload plastic. I was just hoping I wouldn't.

@ gringo - For my load column it goes:
Powder
Circle Fly Nitro Card
2 Circle Fly Fiber Wads
Shot
Circle Fly OS Card

All the wads and cards are slightly oversized, since the Magtech brass is so thin.

[Sir Charles deMouton-Black]

I was just over on 16 ga.com;

http://www.16ga.com/forum/index.php?sid=449430e028c5804d4d9851f252e5af54

There is a current thread on a very similar topic.  Members report use of smokeless with satisfaction. Plastic wads fit loosely which poses a bit of an obstacle to some.  I don't use fad powder in magtechs, but might if I can't find an endless source of 16 gauge plastic hulls.

I don't think that the over shot card is the problem.  I cut my own out of waxed paper milk carton material and it does the job.  I think extra O/S card would give more problems, not less.

[Delmonico]

Get a good shotgun reloading manual such as the Hodgdon one.  Read it from cover to cover especially the section where they pressure test what changing components can do to pressure, such as cases, wads and primers.  Now think long and hard if you want to wander around in the dark on loading data.  If you don't have good lab tested loading data from a reliable source don't do it.  You can jump into the nether regions of an over-load so fast your head will spin. Smokeless powder in shotgun shells is nothing to experiment with.  Something like a modern 870 may hold together, a lot of doubles, even modern ones might not.

[maldito gringo]

Brass hulls will always have a larger internal volume than plastic or paper hulls of the same gauge, so moving a published load from
paper or plastic to brass is acceptable. Larger internal volumes yield lower pressures, all other things being equal. Card and fiber
wads with roll crimps ( or no crimp ) will also yield lower pressures than one piece wads with star crimps. Cookie is on pretty solid ground here, as long as we are working with appropriate powders and shot weight. This is generally the part of these threads where the moderators get nervous- See Sherman Bell's articles in double gun journal on building smokeless loads for antique guns.

[Delmonico]

Brass hulls will always have a larger internal volume than plastic or paper hulls of the same gauge, so moving a published load from
paper or plastic to brass is acceptable. Larger internal volumes yield lower pressures, all other things being equal. Card and fiber
wads with roll crimps ( or no crimp ) will also yield lower pressures than one piece wads with star crimps. Cookie is on pretty solid ground here, as long as we are working with appropriate powders and shot weight. This is generally the part of these threads where the moderators get nervous- See Sherman Bell's articles in double gun journal on building smokeless loads for antique guns.

No it's not, because pressures can also drop off the other way, powders also have a minimum pressure that they burn properly also.

Go back and read the original post, inconstant results, a sure sign of erratic pressures caused by a powder burning below the pressures it was intended to burn.   So one or more of the components need changed to raise the pressure, but of course not to high.  So what do you suggest, more powder?  With out a strong pressure gun to do the testing you are fumbling around in the dark.

Get the Hodgden book, read the section on shotgun pressures VS component change and learn why smokeless shotgun data should be spot on with proper tested data.

[maldito gringo]

Delmonico, first let me say that the points you rase are perfectly valid. All handloading needs to be approached with caution. Ill summarize my views here and sign off on this.
1. yes, smokeless powders are progressive, they need to develope pressure to burn efficiently. Simply "adding more powder" would be reckless, and no sane person would suggest such a thing.
2. inconsistant results can be the result of a number of factors, including inconsistant wad seating. The nitro card needs to be seated just above the powder charge, under NO CIRCUMSTANCES compressing it. Also, a weak seal at the case mouth may let the column start moving before adequate pressure developes.
3. Always start with a published and tested load. Yes, changing ANY component in the load will affect pressures and performance. Ideally, we would all have an RSI pressure trace system to verify results, but common sense and a good chrono can go a long way.
4. Everyone has their own tolerance for risk. My son thinks it's safe to jump out of airplanes. My Aunt Tess didn't think it was safe to leave the house. I'm in between. 

[kg6qs]

I've been using Magtech brass hulls with smokeless powder in 12, 16, & 20 ga for about 6 years.

There was a bit of a learning curve.

209 primers work quite well. Plastic wads not so well. I use Circle Fly fiber wads and glue the over shot card in place with a good quality waterproof aliphatic resin wood glue.

For load data, I've used data from reloading books printed in the days of fiber shot-shell wads. However, these old load recipes often list obsolete components and often seem very hot.  Alternatively, I've used modern data for slower powders like Herco, Green Dot, & PB. I have a Chrony chronograph. For each ga, powder, & shot weight, I start low and experiment 'till I get to about 1,100 fps. 

I've tried 2 methods of enlarging the primer pocket; drill it out and countersink so primer doesn't stand proud or use a cone shaped mandrel made from the shank of a # 14 flat head wood screw to reshape the pocket.

The mandrel works best. Be sure the shank is full dimension. With a little patience, you can chuck a new screw up in a hand drill and shape it properly on a bench grinder. This takes a bit of fussing about, but you only need one.

To use the mandrel, insert a short piece of pipe into the new hull and drive it over the mandrel with a heavy hammer. It's a bother, but you only do it once for each hull & the hulls seem to last forever.

Most of the folks in my club think I'm a little strange for doing all this, but I like to putter about.

Of course, you can by Rocky Mountain brass hulls ( http://rockymountaincartridge.com/products.htm ) for about $6 each. I'm told that these take 209 primers and have inside dimension suitable for plastic wads. I ordered some today just to see.

One final comment: when the primer pocket wears and the primer fits too loosely, clean the hole and just wet it out with solder. This reduces the diameter by about about 2/1000 th of an inch. Ballistic Products sells a primer pocket conditioning tool, which also works.