300 BO brass, use commercial or mil?

[wonderwolf]

I'm working on 300 BO brass for my "poor mans 30 carbine" project. I have tons of .223 and 5.56 brass and wondering which case I should use for the development of loads? I have a bunch of range pick up to go through first but its all mixed of course, I'm wondering if it matters to use mil or commercial brass that much so long as I have a midrange or slightly above load.

[Omega]

I would use LC brass, it is a known good brass with a thickness that will allow the seating of a .308 projectile without the need for neck turning. There is a list on 300blktalk of known good/bad brass. PM me your email address, I'll send you a PDF with some good info on 300blk with said list in it.

[popper]

Almost any works, some end up with thick necks after converting so may need neck turning or scrap. Normal max LOADED neck O.D. is > .331. Chamber neck I.D. is nominally 0.333.

[Smoke4320]

LC is great to convert to blackout .. Any US Brand will be OK .. some foreign brands will have varying neck thicknesses and can cause you some issues
If using multiple brands and shooting groups or Hunting I would separate by brand

[Loudy13]

Start with one and stay with one, you may have fluctuation between civilian and military brass due to case capacity. I have used both and for me it is easier to use LC brass due to availability and once the crimp is removed its all good to go.

[BK7saum]

I have converted quite a bit of LC and RP. Both work, but are kept separate for different loads.

[wonderwolf]

Many thanks for the help guys, as always great info! I'll go through and sort for LC headstamp as I know I have a bunch of it currently. This 300 BO has been a interesting project for me, I see it as a sort of modern M1 Carbine...a little more useful than .223 but not really a .308....something that would be useful for every household in my opinion for home defense and taking deer etc.

[FLINTNFIRE]

Funny thing with some of the lake city brass is the depth of the primer pocket , having bought some with swaged pockets I was still having some difficulty in seating primers . Running a primer pocket uniformer I found some to be very shallow and requiring a lot of reaming .

[Texas by God]

LC here as well. I'll have a few hundred rounds of mixed brass that I use for plinking ammunition and experimental loads. I was going to set myself up to make my own brass, then I found a man who converts military 223 brass to 300 Blackout on a Exchange basis. If I give him 200 223 brass he gives me 100 300 Blackout brass-LC headstamp.

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[Randy Bohannon]

There are a bunch of people who have pretty elaborate set up's for converting .223/5.56 brass to 300BO. My last 2K pieces came from Fancy Brass for less than $200.00 all LC.With so many people doing it for cheap it's hardly worth the time anymore.

[popper]

I'm seeing a lot of real BO brass at the range now. A caveat to purchasing converted brass is it may not H.S. correct in your gun. For quality jacketed stuff, most works fine, cast - you still get to measure and decide. Chop saw, trimmer, chamfer & swager costs may decide for you. If you purchase you might ask for 'long' H.S. sized cases that you then resize to fit your gun. I have a bucket of mixed range pickup I converted and I treat them like pistol brass- shoot em till the neck splits of PP wear out. I can't tell the difference in any HS.

[OTShooter]

I’ve converted GI and commercial brass without any issues. But I think it’s a great idea to just stick to one source headstamp, like LC. You should get more consistent case qualities that way, particularly if you stick to ONCE fired LC brass.

[fatelk]

This 300 BO has been a interesting project for me, I see it as a sort of modern M1 Carbine...

I see I'm not the only one who compares the Blackout to the old Carbine, at least a little. My first reason for comparison was because the cost to load the two rounds is nearly the same: a cast bullet with a gas check and a very similar charge of H110. It get about the same velocity, except with a 50 grain heavier bullet.

It makes for a fun plinker that's significantly more powerful and generally a lot more accurate than the average M1 carbine.

[Reverend Al]

I've stuck with commercial .223 brass in my 700 Remington bolt action .300 BO, but the big thing is that you ensure that the formed cases headspace properly in your rifle. I bought a "good deal" on 500 rounds of formed .300 BO made from commercial FC cases and it was all at least 10 thousandths short on headspace in my Remington! I had to re-neck expand all 500 rounds until they were oversized and then adjust my sizing die to resize and form the shoulders at the correct length to headspace correctly in my rifle ... then they were fine.

[muta4warrior]

I run LC mostly for the head stamp or lack of caliber specific markings.. Plus I have a source for once fired LC brass.

[krallstar]

Found the same issue with mine. I am converting LC for 7.62x40. All pockets were shallow and needed a bit to swage.

Funny thing with some of the lake city brass is the depth of the primer pocket , having bought some with swaged pockets I was still having some difficulty in seating primers . Running a primer pocket uniformer I found some to be very shallow and requiring a lot of reaming .

[Grmps]

Good ;
ADI , PERFECTA, Aguila, PMC, A USA , PS, FC, PSD, GFL, RA , HB, RP, Hornady, SSA, Hornady (nickel), TAA, IK03, Tula , IMI, TW , IVI, TZZ , LC, WCC, M193, Winchester, Norinco, WIN NT, NOSLER, WMA 15,



Thick neck wall, bad without neck turning:

AB 556 , L2A2, ATI, MKE13, CBC, MPA , CJ6, Norma, CJ 8, NPA, DNL, PMC, FNM, PMP, FRONTIER, PPU, GECO, RAM , Hot Shot, RORG , HRTRS, RWS , ICC, S&B, IK03 , SADU, IMI, TAA, IVI, KFA, Wolf Brass

[nagantguy]

Good ;
ADI , PERFECTA, Aguila, PMC, A USA , PS, FC, PSD, GFL, RA , HB, RP, Hornady, SSA, Hornady (nickel), TAA, IK03, Tula , IMI, TW , IVI, TZZ , LC, WCC, M193, Winchester, Norinco, WIN NT, NOSLER, WMA 15,



Thick neck wall, bad without neck turning:

AB 556 , L2A2, ATI, MKE13, CBC, MPA , CJ6, Norma, CJ 8, NPA, DNL, PMC, FNM, PMP, FRONTIER, PPU, GECO, RAM , Hot Shot, RORG , HRTRS, RWS , ICC, S&B, IK03 , SADU, IMI, TAA, IVI, KFA, Wolf Brass

My thick neck/no go list isn’t as comprehensive as your but all that I’ve tried that don’t convert easy peasy match brands on your list!

I haven’t made any in a spell as a dentist and his son are big shooters and hunters but not reloaders so they gave me about 500 Remington and Hornady once fired factory brass.

[James Wisner]

I use either LC or FC brass and no problems forming either of them to fit my two rifles. One is a CMMG barrel on the AR and a Shilen barrel I chambered on a Remington 600

Right off the go when I started I had lots of sooty cases, so started to anneal my necks and that problem went away.

JW

[skeet1]

The following I got from the 300 blackout forum and may be of interest to you folk making your brass from 5.56 / .223.

Ken



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"
HB - 0.013"
Hornady (223 headstamp) - 0.011"
Hornady (nickel 223) - 0.012"
IMI - 0.012" [Note 4]
IVI - 0.013"
IVI ('85) - 0.012" (runs great)
LC - 0.011"
LC (converted blank) - 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"
Tula - 0.0115"
TZZ - 0.012"
WCC - 0.010/0.011"
Winchester - 0.011"
WIN NT - 0.011"

Thick neck wall, bad without neck turning:

ATI - 0.015" [Note 3]
CBC - 0.014/0.015"
CJ6 - 0.015"
DNL - 0.016"
FNM - 0.016" [Note 3]
GECO - 0.015/0.016"
Hot Shot - 0.014" [Note 3]
HRTRS ( Herters?) - 0.017"
IK03 - 0.015"
IMI - 0.015" [Note 4]
KFA .223 REM - 0.015"-0.019"
MKE13 - Anecdotally reported as troublesome
MPA - 0.015"
NPA - [Note 3]
PMC (old headstamp) - 0.015"
PMP - 0.015"
PPU - 0.014/0.015" [Note 3]
RORG - 0.015"
RWS - 0.014-0.015"
S&B - 0.015/0.017"
Wolf Brass .223 - 0.014"

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.