.300 BO, how to spot thick brass that creates a bulge?

[gun'sRgood]

Making your own case for .300 BO's is a lot fun but! As I understand it, some brass has a thicker wall. Or after cutting the case down and resizing, some brass has a thicker wall and will not allow a projectile to be seated. A bulge in the neck. It seems there is a list of brass that will have this issue. Trying to read a few hundred head stamps really takes the joy out of reloading. Anybody got a quick way to judge brass?

While here, here's the jig I made to cut brass. I think it's self-explanatory but what makes this little guy a huge help is the: 1 - little lock nut that allows you to set the depth or length by use of the screw then locking in that measurement with the nut. 2 - the small amount of play under the mounting bolts. Ya can't see this but there is enough "warble" in the mounting holes to square the jig to the blade. Really simple jig. I had planned to take this beta model and fine tune the milling. This first try works great. Looks like a first try but does the job.

 

[AJC1]

Making your own case for .300 BO's is a lot fun but! As I understand it, some brass has a thicker wall. Or after cutting the case down and resizing, some brass has a thicker wall and will not allow a projectile to be seated. A bulge in the neck. It seems there is a list of brass that will have this issue. Trying to read a few hundred head stamps really takes the joy out of reloading. Anybody got a quick way to judge brass?

While here, here's the jig I made to cut brass. I think it's self-explanatory but what makes this little guy a huge help is the: 1 - little lock nut that allows you to set the depth or length by use of the screw then locking in that measurement with the nut. 2 - the small amount of play under the mounting bolts. Ya can't see this but there is enough "warble" in the mounting holes to square the jig to the blade. Really simple jig. I had planned to take this beta model and fine tune the milling. This first try works great. Looks like a first try but does the job.

If you use a fine thread bolt you will get finer adjustments. Possibly less trimming.

 

[Anchorite]

Nice. You might have a side business in making and selling these jigs.

 

[Soonerpesek]

This first try works great.

That's always a +...................................nice job...!

 

[25-20 WCF]

…Anybody got a quick way to judge brass?

You could weigh them on a reloading scale and sort them. Still tedious.


.

 

[Walkalong]

Measure the neck thickness

 

[dredd]

Measure the neck thickness
View attachment 1191470

^^^^^ This is the winning answer.

Years & years ago when we were making 300BLK Brass, we experimented with all of the head stamps we could find.
It may have only been around 7 or 8.

Only one Mfr was too thick. That was S&B Brass.
I'm sure there are others out there.

 

[berettaprofessor]

A list that I keep: (copied from here, I think)

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"

 

[gun'sRgood]

If you use a fine thread bolt you will get finer adjustments. Possibly less trimming.

This pitch allows up to 0.001 change. But ur right. Again, this was a beta attempt. A flat surface on the end of the screw was supposed to be there. So was up scaling to allow greater ease of use. Now, about a shield.... naw, if your gonna be that far in need, I'd recommend buying the stuff.

 

[AJC1]

This pitch allows up to 0.001 change. But ur right. Again, this was a beta attempt. A flat surface on the end of the screw was supposed to be there. So was up scaling to allow greater ease of use. Now, about a shield.... naw, if your gonna be that far in need, I'd recommend buying the stuff.

A set secrew would finish it off nicely as once set it would likely never change. Then again adjustment might not be nessary with a milled vertical, which you could skim cut till perfect. The adjustment does mean it could be used for 300bo and 300hmmr

 

[gun'sRgood]

^^^^^ This is the winning answer.

Years & years ago when we were making 300BLK Brass, we experimented with all of the head stamps we could find.
It may have only been around 7 or 8.

Only one Mfr was too thick. That was S&B Brass.
I'm sure there are others out there.

Yeah, thought of that. For those who don't know. You can buy a lot of brass for the $$$ of one of those. You can also watch most of the series Breaking Bad for the amount of time it takes to meter 1k rounds of field brass. Then there's all the stuff about neck tension. Getting to work/play with a SOT 7, neck tension isn't much of an issue at some 900/min. But! It might be more time banging out all the rounds. I'll toss out the 5-10 9's /1K of field brass reloads. But these .300's are in the 15 - 20%. Tooooooo much to toss. I think?

 

[gun'sRgood]

A list that I keep: (copied from here, I think)

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"

Holy Dear Mother of Re-loading Data! Not with these aging eyes! Awesome amount of data! I think the idea you've given me is make a chuck that holds cut brass that I can run a mandril through in some 5sec per case. I'd get equal neck tension [?] and know the brass would work [?]. It, the chuck, wouldn't need a ton of grip... At first I was thinking of using a lathe, now I think a drill press is all you would need. A friction grip on the brass, keep the neck of the brass close to the mandril. Ram the mandril, rise and repeat. Thoughts?

 

[gun'sRgood]

A set secrew would finish it off nicely as once set it would likely never change. Then again adjustment might not be nessary with a milled vertical, which you could skim cut till perfect. The adjustment does mean it could be used for 300bo and 300hmmr

I finish these with trimmers. Inside/outside mouth and square to 0.0001. Just because the trimmer can do that.

 

[gun'sRgood]

Measure the neck thickness
View attachment 1191470

If you got a moment, what inside neck diameter are you looking for? Thx.

 

[JohnMc]

Making your own case for .300 BO's is a lot fun but! As I understand it, some brass has a thicker wall. Or after cutting the case down and resizing, some brass has a thicker wall and will not allow a projectile to be seated. A bulge in the neck. It seems there is a list of brass that will have this issue. Trying to read a few hundred head stamps really takes the joy out of reloading. Anybody got a quick way to judge brass?

While here, here's the jig I made to cut brass. I think it's self-explanatory but what makes this little guy a huge help is the: 1 - little lock nut that allows you to set the depth or length by use of the screw then locking in that measurement with the nut. 2 - the small amount of play under the mounting bolts. Ya can't see this but there is enough "warble" in the mounting holes to square the jig to the blade. Really simple jig. I had planned to take this beta model and fine tune the milling. This first try works great. Looks like a first try but does the job.

If the expander ball is set up right in the sizing die, the ID of the case mouth should be OK to seat a bullet. The problem with too thick neck walls is that the OD of the neck + bullet can be too large for the chamber.
SAAMI spec OD neck is .3340". The bullet is .308, the wall thickness of the first one in berettaprofessor's post that's too large is 0.015", times two for both sides of it on the diameter.
.308" + .015 + .015 = .3380" also known as too big.

Either read the headstamps and sort into good or bad or measure the neck thickness after cutting. Personally, I do the headstamp sorting before cutting, so I don't expend effort to cut .223/5.56 brass which will need to have the neck turned.

 

[Walkalong]

If you got a moment, what inside neck diameter are you looking for? Thx.

I like .012 and under, even though my chamber's neck is fat. (I can run 7.62X39 .310 Z-Max bullets in it.)

.012 or less may be overkill, but I know it's good in any SAMMI spec chamber, and maybe even some tight ones.

Two choices with thick necked cases, scrap them, or neck turn them. Well, or ream them.

 

[gun'sRgood]

I like .012 and under, even though my chamber's neck is fat. (I can run 7.62X39 .310 Z-Max bullets in it.)

.012 or less may be overkill, but I know it's good in any SAMMI spec chamber, and maybe even some tight ones.

Two choices with thick necked cases, scrap them, or neck turn them. Well, or ream them.

Thx. I'm asking the wrong question. Post cutting brass to length I run the brass to full size and de-cap. The full length sizing gives all the brass a neck dia. of 0.3255 regardless of head stamp. At this point I think it is the wall thickness of the neck that varies from the head stamp. I don't think I want to introduce a ball expander until the neck ID of the brass is uniform. I think that reaming with a ball endmill will give me that uniformity. To me it seems backwards to turn the neck and then utilize a ball expander? My question, albeit poorly asked, is what dia. end mill would I look for? Thx for putting up with me.

 

[Walkalong]

I did mention "ream", but did not go into detail on it.

For reaming, you need to uniform the outside diameter as best you can, then ream the necks,
taking out however much is needed to get the neck thickness you want.

So, it depends on what you size with.

A FL die with no expander will do it, then pick a reamer size that gives you the neck thickness you want.

Wilson reamers that work with their trimmers. But your method should work just fine.

 

[gun'sRgood]

I did mention "ream", but did not go into detail on it.

For reaming, you need to uniform the outside diameter as best you can, then ream the necks,
taking out however much is needed to get the neck thickness you want.

So, it depends on what you size with.

A FL die with no expander will do it, then pick a reamer size that gives you the neck thickness you want.

Wilson reamers that work with their trimmers. But your method should work just fine.
View attachment 1191733

My mind must be a brick. So, my full-length sizing gives all my brass to a neck of 0.3255. If I take your wall thickness of 0.012 multiply X2, for both sides, and subtract that from my 0.3255, I get an ID 0.3015? This 0.3015, is that a reamer size I'd look for?

 

[gun'sRgood]

A list that I keep: (copied from here, I think)

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"

Howdy, back with trying to find a reamer size. My full-length sizing gives all my brass an OD of 0.3255. A wall thickness of 0.012 apears to be the gold standard. I'm guessing that if subtract the wall thickness 0.012 X 2 from my OD of 0.3255
I end up with 0.3015. I'm surmising that this would be the reamer size? Thx.