.45 acp chrono results

nwgunman · December 28, 2000, 11:06 PM

I ran some Rem 185gr jhp .45acp handloads across the screens today and found some interesting items I thought I'd share. The loads were all 9.7gr of AA#5, using Win large psitol primers. This has been my "practice" round for a while and I finally had some time to check it out. The first batch was using old, beat up "recycled" brass and an OAL of 1.215: max fps = 1055; min fps = 981, for an average velocity of 1010 fps. The extreme spread was 74 and the standard deviation about 28.
Next I ran the same load except used brand new Starline brass. Average velocity dropped to 987 fps but the extreme spread was only 15 fps. The ammo may have been getting cold by this time.
Now I fired some rounds with a shorter OAL (1.205) and using more of the old beater brass. Velocities increased to an average of 1032 fps and the standard deviation was only 14 fps...nice.
Needless to say, I'm gonna stay with this "shorter" load. None of these rounds fell below 1005 fps, even after sitting out in the 40F temp in the shade with a breeze. Accuracy was...well, I'm the worlds worst shot, which is why I burn up so many rounds. I was glad just to avoid blowing up a sky screen! Hope you found this interesting. Stay safe.

Quantrill · December 29, 2000, 08:13 AM

Interesting Indeed!!! Quantrill

Field-dressed · December 31, 2000, 04:42 AM

Thanks nwgunman, noted and logged. My buddy and I are working up a hardcast 230 gr TC (I'm casting, he's loading). I'll post our results when we get 'em.

Archie · January 1, 2001, 03:37 AM

One of the things I have noted is that any given powder burns best (most uniformly) is near the top of it's pressure range. By seating the bullet deeper, you have lessened the volume of the burning chamber, giving higher pressure and therefore a more uniform burn.

What you don't want to do is work up a hot load and then seat the bullet deeper. Start from the beginning with the deeper seated bullet.

Sounds like it was okay this time. I've gotten away with stuff that terrifies me now.

muzzletalk · January 3, 2001, 02:30 AM

I find this also interesting. Since I started realoading, I have always seated the bullet close to the max OAL. ie.. the .45 acp has a max OAL of 1.275 so I would be seating the bullet depth to 1.273 or so. But from reading your post, I see where there would be increased pressure if you seat the bullet deeper.

I do have a question thought. I was told to try large pistol magnum primers. will this increase the pressure also?

Bogie · January 3, 2001, 12:25 PM

Yeah, magnum primers will increase pressure.

You shouldn't need 'em with AA5. I use magnum primers only with powders that generally require that I more or less fill the case, such as 296 or 110...

nwgunman · January 5, 2001, 09:06 PM

What got me started was checking out the different OALs given by different loading manuals. I always take a middle road with this stuff. Then I checked the OALs for different factory 185jhp loads. Of course, different bullet shapes will have slightly different OALs but I thought I'd just do a little check myself. Thanks to Archie for the tip about the burn rate efficiency and pressure correlation. My load is mid range for all given data with 185gr jhp. Maybe the pressure is up there anyway, eh? No signs of pressure, but that's always iffy unless you have all that costly gear. Stay safe.

December 29, 2000, 08:13 AM	#2
Quantrill Senior Member Join Date: February 28, 1999 Location: Arizona, USA Posts: 725	45 Reloads Interesting Indeed!!! Quantrill

January 1, 2001, 03:37 AM	#4
Archie Senior Member Join Date: May 26, 2000 Location: Hastings, Nebrasksa - the Hear Posts: 2,209	One of the things I have noted is that any given powder burns best (most uniformly) is near the top of it's pressure range. By seating the bullet deeper, you have lessened the volume of the burning chamber, giving higher pressure and therefore a more uniform burn. What you don't want to do is work up a hot load and then seat the bullet deeper. Start from the beginning with the deeper seated bullet. Sounds like it was okay this time. I've gotten away with stuff that terrifies me now. __________________ There ain't no free lunch, except Jesus. Archie Check out updated journal at http://oldmanmontgomery.wordpress.com/

December 28, 2000, 11:06 PM	#1
nwgunman Senior Member Join Date: July 16, 1999 Location: Olympia, WA Posts: 312	I ran some Rem 185gr jhp .45acp handloads across the screens today and found some interesting items I thought I'd share. The loads were all 9.7gr of AA#5, using Win large psitol primers. This has been my "practice" round for a while and I finally had some time to check it out. The first batch was using old, beat up "recycled" brass and an OAL of 1.215: max fps = 1055; min fps = 981, for an average velocity of 1010 fps. The extreme spread was 74 and the standard deviation about 28. Next I ran the same load except used brand new Starline brass. Average velocity dropped to 987 fps but the extreme spread was only 15 fps. The ammo may have been getting cold by this time. Now I fired some rounds with a shorter OAL (1.205) and using more of the old beater brass. Velocities increased to an average of 1032 fps and the standard deviation was only 14 fps...nice. Needless to say, I'm gonna stay with this "shorter" load. None of these rounds fell below 1005 fps, even after sitting out in the 40F temp in the shade with a breeze. Accuracy was...well, I'm the worlds worst shot, which is why I burn up so many rounds. I was glad just to avoid blowing up a sky screen! Hope you found this interesting. Stay safe.

December 31, 2000, 04:42 AM	#3
Field-dressed Senior Member Join Date: August 21, 2000 Location: Alaska Posts: 148	Thanks nwgunman, noted and logged. My buddy and I are working up a hardcast 230 gr TC (I'm casting, he's loading). I'll post our results when we get 'em.

January 3, 2001, 02:30 AM	#5
muzzletalk Member Join Date: January 3, 2001 Posts: 85	I find this also interesting. Since I started realoading, I have always seated the bullet close to the max OAL. ie.. the .45 acp has a max OAL of 1.275 so I would be seating the bullet depth to 1.273 or so. But from reading your post, I see where there would be increased pressure if you seat the bullet deeper. I do have a question thought. I was told to try large pistol magnum primers. will this increase the pressure also?

January 3, 2001, 12:25 PM	#6
Bogie Senior Member Join Date: June 5, 2000 Location: Job hunting on the road... Posts: 3,827	Yeah, magnum primers will increase pressure. You shouldn't need 'em with AA5. I use magnum primers only with powders that generally require that I more or less fill the case, such as 296 or 110...

January 5, 2001, 09:06 PM	#7
nwgunman Senior Member Join Date: July 16, 1999 Location: Olympia, WA Posts: 312	What got me started was checking out the different OALs given by different loading manuals. I always take a middle road with this stuff. Then I checked the OALs for different factory 185jhp loads. Of course, different bullet shapes will have slightly different OALs but I thought I'd just do a little check myself. Thanks to Archie for the tip about the burn rate efficiency and pressure correlation. My load is mid range for all given data with 185gr jhp. Maybe the pressure is up there anyway, eh? No signs of pressure, but that's always iffy unless you have all that costly gear. Stay safe.