AA2230 .223 loads for 55 Gr FMJBT

Aspect · May 18, 2009, 04:32 PM

AR 15 with 1/9 Twist.

Ran into an interesting situation.

Accurate's lastest reloading guide has a maximum load of 25 Gr for the 55 Gr FMJBT.

Multiple failures to cycle. Even at 25.5 Gr I see a few failures to cycle.

Brass is Lake City with some Winchester brass mixed in.

I should note that this rifle works flawlessly with WW 748 at 26 Grains.

My other reloading guide published 2004 lists out at 26 Gr for 2230 in this combo.

I dug up an old Accurate reloading guide from 1991 that has the maximum load at 27.3 gr.

What's up? Did Accurate change the formulation of this powder? What are other folks loading this at?

FlyFish · May 18, 2009, 04:52 PM

Don't know what to say - 25 gr 2230/55 gr FMJBT cycles my unmodified Bushie M4 just fine.

Alleykat · May 19, 2009, 12:42 PM

If your AR won't cycle with 25gr. of AA2230, then something's not right.

**Mal H** · May 19, 2009, 05:33 PM

Agreed - I settled on 24.0 gr of AA2230 long time ago when the max was 26.0 and it works flawlessly with the same weight bullet (a 55 gr. Hornady SXBT).

I suspect Accurate starting lowering the max load when they changed over from CUP to PSI pressure measurements and found that even though the pressure didn't reach the max CUP SAAMI limit, it was getting very close to the PSI limit.

oldcspsarge · May 19, 2009, 08:08 PM

Might be time to clean the inside of your gas tube or verify the hole diameter of your gas port. You didn't mention if it were a home build...many manufacturers ship barrels with an under sized gas port for liability reasons.

That load should work without any issues.

Alleykat · May 20, 2009, 12:29 PM

Buffer spring too strong;buffer too heavy? Leaking gas rings?

Aspect · May 20, 2009, 02:08 PM

Bushmaster, unmodifed. Bought back in 93.

Less than 10000 rounds through it.

Leaky gas rings sounds interesting. I'll double check to see if the gaps are lined up.

I have an ultrasonic cleaner I dump the bolt carrier and it's contents into for cleaning.

You shouldn't have to clean the gas tube. Most of the opinions I read say it's self cleaning. It was just some of the powders used in the very beginning that caused issues with calcium carbonate buildup.

http://www.thehighroad.org/showthread.php?t=35571

May 18, 2009, 04:32 PM	#1
Aspect Member Join Date: May 18, 2009 Posts: 20	AA2230 .223 loads for 55 Gr FMJBT AR 15 with 1/9 Twist. Ran into an interesting situation. Accurate's lastest reloading guide has a maximum load of 25 Gr for the 55 Gr FMJBT. Multiple failures to cycle. Even at 25.5 Gr I see a few failures to cycle. Brass is Lake City with some Winchester brass mixed in. I should note that this rifle works flawlessly with WW 748 at 26 Grains. My other reloading guide published 2004 lists out at 26 Gr for 2230 in this combo. I dug up an old Accurate reloading guide from 1991 that has the maximum load at 27.3 gr. What's up? Did Accurate change the formulation of this powder? What are other folks loading this at?

May 18, 2009, 04:52 PM	#2
FlyFish Senior Member Join Date: January 20, 2009 Location: Overlooking the Baker River Valley Posts: 1,723	Don't know what to say - 25 gr 2230/55 gr FMJBT cycles my unmodified Bushie M4 just fine.

May 19, 2009, 12:42 PM	#3
Alleykat Junior member Join Date: July 26, 2007 Posts: 3,668	If your AR won't cycle with 25gr. of AA2230, then something's not right.

May 19, 2009, 05:33 PM	#4
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,955	Agreed - I settled on 24.0 gr of AA2230 long time ago when the max was 26.0 and it works flawlessly with the same weight bullet (a 55 gr. Hornady SXBT). I suspect Accurate starting lowering the max load when they changed over from CUP to PSI pressure measurements and found that even though the pressure didn't reach the max CUP SAAMI limit, it was getting very close to the PSI limit.

May 19, 2009, 08:08 PM	#5
oldcspsarge Senior Member Join Date: January 11, 2008 Location: Rocky Mountains Posts: 441	Might be time to clean the inside of your gas tube or verify the hole diameter of your gas port. You didn't mention if it were a home build...many manufacturers ship barrels with an under sized gas port for liability reasons. That load should work without any issues.

May 20, 2009, 12:29 PM	#6
Alleykat Junior member Join Date: July 26, 2007 Posts: 3,668	Buffer spring too strong;buffer too heavy? Leaking gas rings?

May 20, 2009, 02:08 PM	#7
Aspect Member Join Date: May 18, 2009 Posts: 20	Bushmaster, unmodifed. Bought back in 93. Less than 10000 rounds through it. Leaky gas rings sounds interesting. I'll double check to see if the gaps are lined up. I have an ultrasonic cleaner I dump the bolt carrier and it's contents into for cleaning. You shouldn't have to clean the gas tube. Most of the opinions I read say it's self cleaning. It was just some of the powders used in the very beginning that caused issues with calcium carbonate buildup. http://www.thehighroad.org/showthread.php?t=35571