Q About powder charges

Thx1138 · September 23, 2005, 05:05 PM

This may sound simple but I was wondering how do they have different number of grains of powder for the same cartridge. For example if a round has normally 150 gr. how do they reduce the grains of powder? How can they have a gap in the catridge?

Zak Smith · September 23, 2005, 05:18 PM

Still have no idea what you're asking.

Very few rifle cartridges use more than 100gr powder.

Read the introduction of any reloading manual for background info.

HS · September 23, 2005, 05:27 PM

Ummm, I dont chastise people at all but this should be in the Reloading section.

There can be a significant air gap with no ill affect, heck if u shake it n it sounds like a pinyata its still ok.
Basically the heavier projectile offers more resistance & creates a higher back pressure that in turn uses less powder to get it out.

But if you want it to have more velocity you dont reduce the charge.
Simple eh?
BUT if the charge is too big for the heavier projectile....BOOM - Gun go by byes

LHB1 · September 23, 2005, 07:28 PM

THX1138,
In MOST rifle and pistol cartridges, the powder does NOT fully fill the case under the bullet. Limiting factor for amount of powder in a given case with a specific bullet is MAX PRESSURE WHEN FIRED, NOT WHETHER THE CASE IS FULL OF POWDER. You adjust the amount of powder up with lighter bullets and down with heavier bullets to keep the max pressure below a given max for that gun/cartridge combo. The fact that the powder may not fill the case is not critical unless the load is GREATLY reduced with some slow burning powders.

Good shooting and be safe.
LB

Ozzieman · September 23, 2005, 09:35 PM

One other reasion that you wont want very low charges is that the powder may not make contact with the primer hole or be forward toward the bullet and the primer will flash across the powder and you can get poor ignition.
Actualy compressed loads in pistol cases can be dangerious and should never be done.

Al Norris · September 23, 2005, 10:22 PM

LHB1, different powders have differnet burn rates. Faster burning powders produce a peak pressure sooner than the slower ones. Lots of variables to take into account. That's part of what makes handloading such an interesting hobby/pastime.

HS, yes. This should be in the Handloading forum.

edited to add: Moved

Dave R · September 23, 2005, 11:29 PM

THX, when you say 150 grains, are you talking about bullet weight, or powder charge? As previosuly mentioned, 100 grains is a HUGE powder charge. My .308 uses 150gr bullets, but only 46gr of powder (H335), and that's a max published load in one book.

When moving to a heavier bullet--like a 180gr. in a .308--you can't use as much powder. The increased inertia of the heavier bullet, and the increased bearing surface and drag (in some cases) means a higher level of pressure for the same amount of powder. If that doesn't make sense, read a reloading manual that explains it better than I can when my brain is tired.

m0ntels · September 24, 2005, 08:13 AM

Blackpowder loads I believe need to be seated with the bullet in slight contact with the powder level, smokeless does not. I think it has something to do with how blackpowder explodes and smokeless just burns, but I dont have any real blackpowder experience to give any more info than that. If you shake a smokeless cartirdge, it will probably rattle from the air space left in there.

Randy

September 23, 2005, 05:05 PM	#1
Thx1138 Member Join Date: April 13, 2005 Posts: 20	Q About powder charges This may sound simple but I was wondering how do they have different number of grains of powder for the same cartridge. For example if a round has normally 150 gr. how do they reduce the grains of powder? How can they have a gap in the catridge? Last edited by Thx1138; September 23, 2005 at 05:06 PM. Reason: Explaining question more

September 23, 2005, 05:18 PM	#2
Zak Smith Senior Member Join Date: December 12, 1999 Location: Fort Collins, Colorado, USA Posts: 2,682	Still have no idea what you're asking. Very few rifle cartridges use more than 100gr powder. Read the introduction of any reloading manual for background info. __________________ Zak Smith . DEMIGOD LLC . THUNDER BEAST ARMS CORP . COLORADO MULTI-GUN *My PM inbox full? Send e-mail instead.*

September 23, 2005, 05:27 PM	#3
HS Senior Member Join Date: October 11, 1998 Location: Brisbane.....Australia Posts: 1,258	Ummm, I dont chastise people at all but this should be in the Reloading section. There can be a significant air gap with no ill affect, heck if u shake it n it sounds like a pinyata its still ok. Basically the heavier projectile offers more resistance & creates a higher back pressure that in turn uses less powder to get it out. But if you want it to have more velocity you dont reduce the charge. Simple eh? BUT if the charge is too big for the heavier projectile....BOOM - Gun go by byes __________________ *Some* people are like Slinkies ... Not really good for anything...... But they still bring a smile to your face when you *push* them down a flight of stairs. *Unfortunately* everyone has an opinion [q] ME [/q] "The Gun from Down Under !" Gordon Cross Brisbane Australia [email protected] ICQ # 68806935

September 23, 2005, 09:35 PM	#5
Ozzieman Senior Member Join Date: December 14, 2004 Location: Northern Indiana Posts: 6,117	All good words here and to add One other reasion that you wont want very low charges is that the powder may not make contact with the primer hole or be forward toward the bullet and the primer will flash across the powder and you can get poor ignition. Actualy compressed loads in pistol cases can be dangerious and should never be done.

September 23, 2005, 11:29 PM	#7
Dave R Senior Member Join Date: January 7, 2000 Location: Idaho Posts: 6,073	THX, when you say 150 grains, are you talking about bullet weight, or powder charge? As previosuly mentioned, 100 grains is a HUGE powder charge. My .308 uses 150gr bullets, but only 46gr of powder (H335), and that's a max published load in one book. When moving to a heavier bullet--like a 180gr. in a .308--you can't use as much powder. The increased inertia of the heavier bullet, and the increased bearing surface and drag (in some cases) means a higher level of pressure for the same amount of powder. If that doesn't make sense, read a reloading manual that explains it better than I can when my brain is tired. __________________ I am Pro-Rights (on gun issues).

September 23, 2005, 07:28 PM	#4
LHB1 Senior Member Join Date: March 25, 2005 Location: Houston, TX Posts: 1,545	THX1138, In MOST rifle and pistol cartridges, the powder does NOT fully fill the case under the bullet. Limiting factor for amount of powder in a given case with a specific bullet is MAX PRESSURE WHEN FIRED, NOT WHETHER THE CASE IS FULL OF POWDER. You adjust the amount of powder up with lighter bullets and down with heavier bullets to keep the max pressure below a given max for that gun/cartridge combo. The fact that the powder may not fill the case is not critical unless the load is GREATLY reduced with some slow burning powders. Good shooting and be safe. LB

September 23, 2005, 10:22 PM	#6
Al Norris Moderator Emeritus Join Date: June 29, 2000 Location: Rupert, Idaho Posts: 9,660	LHB1, different powders have differnet burn rates. Faster burning powders produce a peak pressure sooner than the slower ones. Lots of variables to take into account. That's part of what makes handloading such an interesting hobby/pastime. HS, yes. This should be in the Handloading forum. edited to add: Moved

September 24, 2005, 08:13 AM	#8
m0ntels Senior Member Join Date: November 2, 2004 Location: Perkasie, PA Posts: 263	Blackpowder loads I believe need to be seated with the bullet in slight contact with the powder level, smokeless does not. I think it has something to do with how blackpowder explodes and smokeless just burns, but I dont have any real blackpowder experience to give any more info than that. If you shake a smokeless cartirdge, it will probably rattle from the air space left in there. Randy