Small primer 45 for suppressed load

Ike Clanton · February 19, 2024, 10:30 AM

Just a random idea but do you think using small pistol primer 45 acp brass for my suppressed loads would lower the overall sound?

rc · February 19, 2024, 11:18 AM

I don't think it would be measurable and if it was, I can't imagine the difference would be 1 decibel. The blast is almost completely coming from the powder charge. You could reduce that and get more of a reduction of sound until your gun starts to malfunction below 700fps or so. You might get it to function down to the 500s with a light recoil spring.

chris in va · February 20, 2024, 10:40 PM

I don't think there's a bit of difference between the SPP and LPP regarding sound or primer potency.

Ike Clanton · February 21, 2024, 10:15 AM

Fair enough. I suppose a bigger suppressor would make the biggest difference.

RKG · February 21, 2024, 12:35 PM

Nope. The sound of a gunshot has two components: (a) the sudden release to atmospheric pressure of a large mass of highly compressed, usually very hot, and usually high deoxigenated gas, and (b) in the case of supersonic rounds, the cracking of the sound barrier by the projectile once it has exited the muzzle. The primer size has zero contribution to (b) and probably all but zero contribution to (a).

Suppressors work, in essence, by lengthening the time over which the pressure is released to the atmosphere. Since the sound would be the same with either size primer without a suppressor, it will be the same with either primer size with the suppressor.

zeke · February 22, 2024, 06:52 PM

Instead of primer size, might consider using fastest burning practical powder. At least in the pistols tried, there is a noticeable difference.

Ike Clanton · February 23, 2024, 09:34 AM

My load as of now is 4.2 grs N-310 which is almost the fastest available. They are pretty dang quiet at around 790 FPS from my 8 inch barrel. I could go with less powder but I like spinning steel. More or less just trying to find a use for small pistol primer brass I come across.

zeke · February 23, 2024, 12:02 PM

Have segregated some small primer 45 acp brass, but never actually loaded any. Didn't want them to get inadvertently mixed in with a batch of regular sized primers. Always wanted to try some N-310, as the V V pistol powders tried have been very clean burning.

Suppressed 45 acp at steel is pleasurable, and your longer barrel definitely helps out. If no one else is there like shooting without the muffs, even if it is not recommended.

Marco Califo · February 23, 2024, 03:15 PM

The correct use of 45 ACP SPP brass is to melt them and cast something useful.

reddog81 · February 23, 2024, 03:23 PM

Quote:

Originally Posted by Ike Clanton

My load as of now is 4.2 grs N-310 which is almost the fastest available. They are pretty dang quiet at around 790 FPS from my 8 inch barrel. I could go with less powder but I like spinning steel. More or less just trying to find a use for small pistol primer brass I come across.

8" 45 ACP? Just out of curiosity, what are you shooting? Do you already have the suppressor?

Paul B. · February 23, 2024, 05:05 PM

"The correct use of 45 ACP SPP brass is to melt them and cast something useful."

I strongly disagree. I always check to insure I don't get them mixed up and other than that, they load and shoot just as nice as the larger primer cartridge. But I do have more time than money so it's no problem.
Paul B.

Ike Clanton · February 23, 2024, 07:50 PM

Quote:

Originally Posted by reddog81

8" 45 ACP? Just out of curiosity, what are you shooting? Do you already have the suppressor?

It’s a CMMG Banshee with a Rex Silentium MG7 suppressor. It’s quite pleasant to shoot. The radial delayed blowback lends itself well for suppression.

**Unclenick** · February 24, 2024, 01:57 PM

Based on some old primer data you can find online, the difference between SP and LP primer energy is about 2 or 3 ft-lbs. If your 45 Auto load is 350 ft-lbs, I think you can begin to see the order of magnitude of the difference the primer itself will contribute is less than 1%. For hearing, a power difference of less than 10% (1 decibel) is generally considered below the ability of the ear to detect, and we are nowhere near that much.

**Aguila Blanca** · February 25, 2024, 02:43 AM

Quote:

Originally Posted by Ike Clanton

Just a random idea but do you think using small pistol primer 45 acp brass for my suppressed loads would lower the overall sound?
Ike Clanton is offline Add Infraction for Ike Clanton Report Post IP Edit Message

No.

hdwhit · February 26, 2024, 10:46 PM

In my experience, No!, and I load small primer brass preferentially to large primer, so I have a basis from which to judge.

February 19, 2024, 10:30 AM	#1
Ike Clanton Senior Member Join Date: August 3, 2017 Location: Oregon Posts: 120	Small primer 45 for suppressed load Just a random idea but do you think using small pistol primer 45 acp brass for my suppressed loads would lower the overall sound?

February 23, 2024, 03:15 PM	#9
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,602	The correct use of 45 ACP SPP brass is to melt them and cast something useful. __________________ ............

February 23, 2024, 05:05 PM	#11
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,803	"The correct use of 45 ACP SPP brass is to melt them and cast something useful." I strongly disagree. I always check to insure I don't get them mixed up and other than that, they load and shoot just as nice as the larger primer cartridge. But I do have more time than money so it's no problem. Paul B. __________________ COMPROMISE IS NOT AN OPTION!

February 24, 2024, 01:57 PM	#13
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Based on some old primer data you can find online, the difference between SP and LP primer energy is about 2 or 3 ft-lbs. If your 45 Auto load is 350 ft-lbs, I think you can begin to see the order of magnitude of the difference the primer itself will contribute is less than 1%. For hearing, a power difference of less than 10% (1 decibel) is generally considered below the ability of the ear to detect, and we are nowhere near that much. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 19, 2024, 11:18 AM	#2
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,770	I don't think it would be measurable and if it was, I can't imagine the difference would be 1 decibel. The blast is almost completely coming from the powder charge. You could reduce that and get more of a reduction of sound until your gun starts to malfunction below 700fps or so. You might get it to function down to the 500s with a light recoil spring.

February 20, 2024, 10:40 PM	#3
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	I don't think there's a bit of difference between the SPP and LPP regarding sound or primer potency.

February 21, 2024, 10:15 AM	#4
Ike Clanton Senior Member Join Date: August 3, 2017 Location: Oregon Posts: 120	Fair enough. I suppose a bigger suppressor would make the biggest difference.

February 21, 2024, 12:35 PM	#5
RKG Senior Member Join Date: June 18, 2009 Location: Boston Posts: 562	Nope. The sound of a gunshot has two components: (a) the sudden release to atmospheric pressure of a large mass of highly compressed, usually very hot, and usually high deoxigenated gas, and (b) in the case of supersonic rounds, the cracking of the sound barrier by the projectile once it has exited the muzzle. The primer size has zero contribution to (b) and probably all but zero contribution to (a). Suppressors work, in essence, by lengthening the time over which the pressure is released to the atmosphere. Since the sound would be the same with either size primer without a suppressor, it will be the same with either primer size with the suppressor.

February 22, 2024, 06:52 PM	#6
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	Instead of primer size, might consider using fastest burning practical powder. At least in the pistols tried, there is a noticeable difference.

February 23, 2024, 09:34 AM	#7
Ike Clanton Senior Member Join Date: August 3, 2017 Location: Oregon Posts: 120	My load as of now is 4.2 grs N-310 which is almost the fastest available. They are pretty dang quiet at around 790 FPS from my 8 inch barrel. I could go with less powder but I like spinning steel. More or less just trying to find a use for small pistol primer brass I come across.

February 23, 2024, 12:02 PM	#8
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	Have segregated some small primer 45 acp brass, but never actually loaded any. Didn't want them to get inadvertently mixed in with a batch of regular sized primers. Always wanted to try some N-310, as the V V pistol powders tried have been very clean burning. Suppressed 45 acp at steel is pleasurable, and your longer barrel definitely helps out. If no one else is there like shooting without the muffs, even if it is not recommended.

February 26, 2024, 10:46 PM	#15
hdwhit Senior Member Join Date: June 22, 2017 Posts: 1,011	In my experience, No!, and I load small primer brass preferentially to large primer, so I have a basis from which to judge.