STICKY - Good/Bad brass list converting 5.56->300blk
Posted: Fri Apr 04, 2014 8:37 am
Originally compiled by tlee_20, updated with user reports. In general, the wall thickness around 1.360 inches from the base will determine success or failure. As a rule of thumb, if the wall thickness is greater than 0.014, there may be problems with the loaded diameter of the neck being too large to chamber easily.
Neck thickness data:
Factory Blackout brass
Gemtech (factory 300 BLK) - 0.011"
PNW Arms - 0.011"
RP - 0.010"
Converted brass
Good:
ADI - 0.012"
Aguila - 0.012"
A USA - 0.012"
FC - 0.013/0.014" [Note 1]
GFL - 0.012" (Fiocchi) Some GFL may have different thickness
HB - 0.013"
Hornady (223 headstamp) - 0.011"
Hornady (nickel 223) - 0.012"
IK03 - 0.012" [Note 4]
IMI - 0.012" [Note 4] Listed on both lists, but seems like more often good than bad.
IVI - 0.013"
IVI ('85) - 0.012" (runs great)
LC - 0.011"
LC (converted blank) - 0.012"
M193 - 0.011/0.012"
Norinco 223 - 0.010"
NOSLER - 0.012”
PERFECTA 223 rem. - 0.012"
PMC - modern "bronze" and "X-tac" are good, older PMC with small letters may have problems
PS - 0.011/0.012"
PSD - 0.011"
RA - 0.013"
RA ('69) - 0.012"
RP .223 - 0.011"
SSA - 0.012"
TAA - 0.013-0.014" [Note 4]
Tula - 0.0115"
TW 67 - 0.012”
TZZ - 0.012"
WCC - 0.010/0.011" (Some less common WCC headstamps run thicker, but the majority are good to go)
Winchester - 0.011"
WIN NT - 0.011"
WMA - 0.011" (Winchester Military, equivalent to WCC)
Thick neck wall, bad without neck turning:
AB 556 - .015" to .016"
ATI - 0.015" [Note 3]
CBC - 0.014/0.015"
CJ6 - 0.015"
CJ 8 - .014"
DNL - 0.016"
FNM - 0.016" [Note 3]
FRONTIER - 0.015"
GECO - 0.015/0.016"
Hot Shot - 0.014" [Note 3]
HRTRS ( Herters?) - 0.017"
ICC - Reported as bad
IK03 - 0.015" [Note 4]
IMI - 0.015" [Note 4]
IVI - 0.015"
KFA .223 REM - 0.015"-0.019"
L2A2 - Reported as bad
MAST - Reported Bad
MKE13 - Anecdotally reported as troublesome
MPA - 0.015"
Norma - 0.015"
NPA - [Note 3]
PMC (old headstamp) - 0.015"
PMP - 0.015"
PPU - 0.014/0.015" [Note 3]
RAM 223 - .014"
RORG - 0.015"
RWS - 0.014-0.015"
S&B - 0.015/0.017"
SADU - 0.014/0.015”
TAA - 0.013-0.014" [Note 4]
T - 0.015
SADU 5.56 - 0.014-0.015"
Wolf Brass .223 - 0.014"
General notes:
There's no consistent difference between "5.56" and "223" when it comes to brass.
Many manufacturers may use different sources for casings at different times. This means that even within the same headstamp, it is possible that a particular batch was from a different source and may be different. Treat this list as a rule of thumb, and double check before processing a large quantity.
Note 1:
"FC" brass includes several types of brass that don't seem to come from the same factory. Most of them are good to go, but the "thin web" FC that turned up a few years back tends to have thicker walls and will cause neck thickness problems. Some FC that runs thicker is the newer stuff. Has beautiful annealing marks on it. Has FC @ 12:00, numbers @ 3:00 and/or 9:00 (May have both, could just have one), and the year @ 6:00
Note 2:
NPA is very low quality brass, with a super small flash hole, and is likely to cause broken or stuck decapping pins, or other problems.
Note 3:
The brass marked with this note may require extra sizing force, and machine flex may cause them to headspace too large if the machine is not set up specifically to do this "harder sizing" brass. This is due to thicker brass, alloy variations, or variations in factory anneal. This isn't always universal within a headstamp, for example, some older PPU had the problem and others did not.
Note 4:
This brass is included in both the good and the bad list based on differing user reports. It is important to keep in mind that sometimes a single headstamp can be made at multiple factories on multiple differing manufacturing processes. Other times a manufacturer that has their own brass factory might bring in brass from another manufacturer during times of high demand or to fulfill a large contract.
Neck thickness data:
Factory Blackout brass
Gemtech (factory 300 BLK) - 0.011"
PNW Arms - 0.011"
RP - 0.010"
Converted brass
Good:
ADI - 0.012"
Aguila - 0.012"
A USA - 0.012"
FC - 0.013/0.014" [Note 1]
GFL - 0.012" (Fiocchi) Some GFL may have different thickness
HB - 0.013"
Hornady (223 headstamp) - 0.011"
Hornady (nickel 223) - 0.012"
IK03 - 0.012" [Note 4]
IMI - 0.012" [Note 4] Listed on both lists, but seems like more often good than bad.
IVI - 0.013"
IVI ('85) - 0.012" (runs great)
LC - 0.011"
LC (converted blank) - 0.012"
M193 - 0.011/0.012"
Norinco 223 - 0.010"
NOSLER - 0.012”
PERFECTA 223 rem. - 0.012"
PMC - modern "bronze" and "X-tac" are good, older PMC with small letters may have problems
PS - 0.011/0.012"
PSD - 0.011"
RA - 0.013"
RA ('69) - 0.012"
RP .223 - 0.011"
SSA - 0.012"
TAA - 0.013-0.014" [Note 4]
Tula - 0.0115"
TW 67 - 0.012”
TZZ - 0.012"
WCC - 0.010/0.011" (Some less common WCC headstamps run thicker, but the majority are good to go)
Winchester - 0.011"
WIN NT - 0.011"
WMA - 0.011" (Winchester Military, equivalent to WCC)
Thick neck wall, bad without neck turning:
AB 556 - .015" to .016"
ATI - 0.015" [Note 3]
CBC - 0.014/0.015"
CJ6 - 0.015"
CJ 8 - .014"
DNL - 0.016"
FNM - 0.016" [Note 3]
FRONTIER - 0.015"
GECO - 0.015/0.016"
Hot Shot - 0.014" [Note 3]
HRTRS ( Herters?) - 0.017"
ICC - Reported as bad
IK03 - 0.015" [Note 4]
IMI - 0.015" [Note 4]
IVI - 0.015"
KFA .223 REM - 0.015"-0.019"
L2A2 - Reported as bad
MAST - Reported Bad
MKE13 - Anecdotally reported as troublesome
MPA - 0.015"
Norma - 0.015"
NPA - [Note 3]
PMC (old headstamp) - 0.015"
PMP - 0.015"
PPU - 0.014/0.015" [Note 3]
RAM 223 - .014"
RORG - 0.015"
RWS - 0.014-0.015"
S&B - 0.015/0.017"
SADU - 0.014/0.015”
TAA - 0.013-0.014" [Note 4]
T - 0.015
SADU 5.56 - 0.014-0.015"
Wolf Brass .223 - 0.014"
General notes:
There's no consistent difference between "5.56" and "223" when it comes to brass.
Many manufacturers may use different sources for casings at different times. This means that even within the same headstamp, it is possible that a particular batch was from a different source and may be different. Treat this list as a rule of thumb, and double check before processing a large quantity.
Note 1:
"FC" brass includes several types of brass that don't seem to come from the same factory. Most of them are good to go, but the "thin web" FC that turned up a few years back tends to have thicker walls and will cause neck thickness problems. Some FC that runs thicker is the newer stuff. Has beautiful annealing marks on it. Has FC @ 12:00, numbers @ 3:00 and/or 9:00 (May have both, could just have one), and the year @ 6:00
Note 2:
NPA is very low quality brass, with a super small flash hole, and is likely to cause broken or stuck decapping pins, or other problems.
Note 3:
The brass marked with this note may require extra sizing force, and machine flex may cause them to headspace too large if the machine is not set up specifically to do this "harder sizing" brass. This is due to thicker brass, alloy variations, or variations in factory anneal. This isn't always universal within a headstamp, for example, some older PPU had the problem and others did not.
Note 4:
This brass is included in both the good and the bad list based on differing user reports. It is important to keep in mind that sometimes a single headstamp can be made at multiple factories on multiple differing manufacturing processes. Other times a manufacturer that has their own brass factory might bring in brass from another manufacturer during times of high demand or to fulfill a large contract.