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View Full Version : Help, I want to get high pressure with tiny slug charge



Clark
12-26-2007, 01:16 AM
All the gas is getting by the 11 ga wads from 12 all brass hulls.

What slug and what wads will get me very high peak pressure with a tiny powder charge?

All the wads and hulls are made to keep the pressure down.
I am trying to get the pressure up for increased expansion ratio and efficiency for low noise with a Metro barrel.

9.3X62AL
12-26-2007, 02:31 AM
Hello, Clark--long time no see, sir.

What are your thoughts or experiences using the plastic shotcup columns with expand-on-pressure over-powder construction characteristics?

Greg5278
12-26-2007, 06:26 PM
What slug weight are you loading? Is the Metro barrel the 30" extension to minimize noise? Subsonic loads would be quieter, and BPI has some 900FPS loads using Red Dot, and the like. I would pick a proper powder, but not go for high pressure loading, over SAAMI spec. What are you trying to accomplish, low noise for shooting in urban areas, crop destruction permit?
Greg

Clark
12-30-2007, 02:09 AM
I have the Lee mold that is hollow base and .69" diameter.
I have the 12 ga balls mold.

I have a large quantity of S&B 12 ga slug loaded ammo that I can take apart for the slugs.

I can't seem to get a seal behind the slug.

I have the Rem Choke tap, reamer, and pilot system from Brownells.

pic of my shotgun with noise reducing extensions (http://www.thehighroad.org/attachment.php?attachmentid=47387&d=1162758471)

Greg5278
12-31-2007, 08:19 PM
Clark, are these loads for hunting deer? The slug or ball will have very little penetrative power at subsonic velocity. The Ball will be better, because it has more mass. The Dixie Predator would even be better. Why are you using brass cases? Plastic hulls utilize a better high efficiency gas seal.

What is the ID of your brass hulls? Perhaps a BPI X10X will fit inside, and help. If you insist on multiple card wads, use larger sizes, available from Cirle Fly. A waxed Nitro card will help seal better than unlubed ones, I generally put one directly under the slug. Fast burn powders wouldn't hurt either, Red Dot, Unique, 700X and so on. In some 12ga Brass hulls, you might be able to use 10ga gas seals, cut from Factory wads.

Email me if you need some more help.

gksappington@aol.com
Greg

Clark
01-01-2008, 02:18 AM
I am 56 years old, have ~100 deer rifles, and aspire to someday shooting a deer.
I got a shot off at a deer in Montana this year.
One of my fantasizes is shooting a deer with a 500 gr or 750 gr shotguns slug at less than 1130 fps with gas escapement at less than 1130 fps.

The reason I am looking at brass hulls is the flat web.
The plastic hulls I have all have a powder cup that keeps me from compressing a 5 gr charge of powder.
I can get a pellet gun sound from a 45/70 with .5 gr or less of Bullseye. If the ball is in the mouth of the case, the ball bounces off wood. But if the ball is seated so deep it compresses the powder, the same noise gets 1" of penetration into wood.

Greg5278
01-01-2008, 12:19 PM
Clark, what powder are you using? I cheked a few manuals, and even 5gr of fast burning Bullseye would not be enough to get what you want. The loads look like 19gr Bullseye at minimum. You need at least 6500PSI chamber pressure to get a decent powder burn, and avoid a Blooper with shotgun loads. I don't think then powders I mentioned would give more noise, the barrel length would concume all the powder. The pressure at the muzzle will affect the sound, but should be fine with the advice I gave you.

Please be careful with fast powders in reduced loads, sometimes freaky pressue spikes, and flame outs occur. I had a SEE event when working up a load with a 770gr 12 ga slug with H110. It opened the action, and left the slug lodged in the bore just ahead of the forcing cone. No gun damage was found, except pounding a Hard slug out of the bore with a brass rod.

I would recommend calling Tom Armbrust at Ballistic Research for help Developing a load at
815-385-0037
Greg

Clark
01-01-2008, 01:10 PM
If the slug compresses that powder, the pressure should go very high.
Most handloading amounts to keeping the pressure down.
This quiet game is "how to get the pressure up" with a minimum of powder.

I have also shot a lead ball from a 32acp cartridge in a 7.62x54 adapter with a 29" barrel and 1/2 gr Bullseye. Again, no power with the bullet in the mouth, but a killer when the bullet compresses the powder.

I can try 10 ga wads.
What I don't want to do is start making wads on the lathe.