How can you have Subsonic loads that aern't low pressure?

Lavid2002 · April 27, 2009, 09:42 PM

How can you have a subsonic round that doesnt dirty up your chamber because of the low pressure?

If any of you have read my other posts youll know im having ALLOT of trouble with my .22 loads. The walls are dirty and I can only fire 40 rounds, then my chamber gets so dirty a round wont fully chamber, and I have to stock slam to get the round out. Im currently testing a load with 24 grains of 2015 behind a 55 grain bullet.

darkgael · April 28, 2009, 11:14 AM

Lavid:
I do not consider 24 grains of AA 2015 and a 55 grain bullet a low pressure round by any means. It's not subsonic. Not even close.
According to Accurate's load manual, the max load (.223 Rem) for a 55 grain bullet is 25 grains of 2015 (@ 49800 CUP). Velocity that loading is 3281 fps. You are only 4% from max. Nothing low pressure about that. Lyman lists the same maximum but with slightly higher velocity and 1K more pressure.
BTW - I read through the other posts and the references to 61K. Most of the data that I have looked at so far is in CUP - hard to convert - but none of the max loads was over 54K CUP. None of the PSI max pressures was very different. The highest CIP max that I saw for that load was 52214.
The point being that your loads are not at all low pressure.
As to why you are getting such a dirty chamber - it should surely shoot more than .40 rounds, way more - I'm at a loss. It sure isn't lack of pressure.
Pete

Magnum Wheel Man · April 28, 2009, 01:55 PM

agreed... I also don't understand where the "subsonic" is coming from, by the charges you are using, & your listed bullet weight... ( BTW... most subsonic loads are with a heavy for caliber bullet, so often pressures are the same or still at max of a regular load )...

if you are talking 223 ??? you'll have a tough time finding a load that will be even close to consistant with a 55 grain bullet... do you not have a twist rate fast enough to stabilize a "proper weight" subsonic bullet???

jmorris · April 29, 2009, 07:00 AM

You might as well bust out your old .22lr it will give you about the same energy and be much more clean than a 55 grn in a .223, both going subsonic.

If you want clean subsonic power get a 458 socom and load a 600 grain bullet to 1050fps with Vita Vouri powder.

MADISON · April 29, 2009, 09:18 AM

When shooting sub Sonic loads have a cleaning rod and brush with you.
I have Sub Sonic loads for .223 and 22 Hornet.
.223 Remmington......5.6 grains of Unique with a 55 grain bullet
.22 Hornet.......4.1 grains of Unique with either a 45 or 55 grain bullet.

Lavid2002 · April 30, 2009, 10:31 AM

Quote:

I do not consider 24 grains of AA 2015 and a 55 grain bullet a low pressure round by any means. It's not subsonic. Not even close.

Im not trying to make subsonics....I have had .223 low pressure problems. I have just made the batch with 24 grains of 2015 and I havn't shot them yet...I want to see fi this will fix my problem.

I was just thinkin to myself...If im having trouble with a dirty chamber and my responce is to add more powder...how in the heck do they have subsonic loads.

SL1 · April 30, 2009, 05:40 PM

Subsonic loads in center-fire rifle cases are usually done with heavy bullets and fast powders. The idea is to get the pressure up high enough to let the powder burn relatively cleanly, but not produce enough gas volume to keep the pressure high as the bullet moves down the barrel. The heavy bullets move slower for a given energy level, so it is easier to make them travel slower than the speed of sound.

Be careful with working-up subsonic loads with small charges of fast powders in large cases. There have been some allegations of irratic burning and pressure spikes, but others claim that these events are really due to accidental double-charges. Either way, the events have been MAJOR gun damage. So, reaearch the load recipes and load them carefully.

SL1

darkgael · April 30, 2009, 06:29 PM

Lavid: Need to know more.

Quote:

I have had .223 low pressure problems.

What load was that, exactly? The load that you mentioned - the one that you are going to test - is not a low pressure load as noted already.
What was?
Is your gun in good condition, everything fitted properly, gas tube, bolt rings, etc.?
Pete

April 27, 2009, 09:42 PM	#1
Lavid2002 Senior Member Join Date: April 6, 2007 Posts: 2,568	How can you have Subsonic loads that aern't low pressure? How can you have a subsonic round that doesnt dirty up your chamber because of the low pressure? If any of you have read my other posts youll know im having ALLOT of trouble with my .22 loads. The walls are dirty and I can only fire 40 rounds, then my chamber gets so dirty a round wont fully chamber, and I have to stock slam to get the round out. Im currently testing a load with 24 grains of 2015 behind a 55 grain bullet. __________________ Math>Grammar

April 28, 2009, 11:14 AM	#2
darkgael Senior Member Join Date: February 9, 2006 Location: Homes in Brooklyn, NY and in Pennsylvania. Posts: 5,473	lo pressure Lavid: I do not consider 24 grains of AA 2015 and a 55 grain bullet a low pressure round by any means. It's not subsonic. Not even close. According to Accurate's load manual, the max load (.223 Rem) for a 55 grain bullet is 25 grains of 2015 (@ 49800 CUP). Velocity that loading is 3281 fps. You are only 4% from max. Nothing low pressure about that. Lyman lists the same maximum but with slightly higher velocity and 1K more pressure. BTW - I read through the other posts and the references to 61K. Most of the data that I have looked at so far is in CUP - hard to convert - but none of the max loads was over 54K CUP. None of the PSI max pressures was very different. The highest CIP max that I saw for that load was 52214. The point being that your loads are not at all low pressure. As to why you are getting such a dirty chamber - it should surely shoot more than .40 rounds, way more - I'm at a loss. It sure isn't lack of pressure. Pete __________________ “Auto racing, bull fighting, and mountain climbing are the only real sports ... all others are games.” Ernest Hemingway ... NRA Life Member Last edited by darkgael; April 28, 2009 at 11:26 AM.

April 28, 2009, 01:55 PM	#3
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	agreed... I also don't understand where the "subsonic" is coming from, by the charges you are using, & your listed bullet weight... ( BTW... most subsonic loads are with a heavy for caliber bullet, so often pressures are the same or still at max of a regular load )... if you are talking 223 ??? you'll have a tough time finding a load that will be even close to consistant with a 55 grain bullet... do you not have a twist rate fast enough to stabilize a "proper weight" subsonic bullet??? __________________ In life you either make dust or eat dust...

April 29, 2009, 09:18 AM	#5
MADISON Senior Member Join Date: January 1, 2000 Location: Roanoke, Virginia Posts: 2,678	subsonic round that doesnt dirty up your chamber When shooting sub Sonic loads have a cleaning rod and brush with you. I have Sub Sonic loads for .223 and 22 Hornet. .223 Remmington......5.6 grains of Unique with a 55 grain bullet .22 Hornet.......4.1 grains of Unique with either a 45 or 55 grain bullet.

April 29, 2009, 07:00 AM	#4
jmorris Senior Member Join Date: November 22, 2006 Posts: 3,077	You might as well bust out your old .22lr it will give you about the same energy and be much more clean than a 55 grn in a .223, both going subsonic. If you want clean subsonic power get a 458 socom and load a 600 grain bullet to 1050fps with Vita Vouri powder.

April 30, 2009, 05:40 PM	#7
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	Subsonic loads in center-fire rifle cases are usually done with heavy bullets and fast powders. The idea is to get the pressure up high enough to let the powder burn relatively cleanly, but not produce enough gas volume to keep the pressure high as the bullet moves down the barrel. The heavy bullets move slower for a given energy level, so it is easier to make them travel slower than the speed of sound. Be careful with working-up subsonic loads with small charges of fast powders in large cases. There have been some allegations of irratic burning and pressure spikes, but others claim that these events are really due to accidental double-charges. Either way, the events have been MAJOR gun damage. So, reaearch the load recipes and load them carefully. SL1