.300 Blackout

[Onajoyride]

I love mine, I have gotten rid of all my verticals and switched over as well as most of the guys I shoot with.

 

[Page.k]

Blitz with the Mag Pul AFG it's more of a place to rest the rifle on for longer ranges. Like resting it on your hand but it froce you to put your hand in the same location each time. It's like the E-2 Stocks you can buy.
The other (VFG) will be better for close in and things like room clearing. Some do hold a Bi-pod in side them to take up a little less space.

 

[Mecanik]

Update: I got my .300 Blackout barrel from Midway. It's an SI defense carbine length 1-8. Got it assembled on an A4 upper with open sights mounted so far. Fired about 40 rounds so far with about half of them not ejecting. They stove pipe in the action most of the time. Shoots fairly accurate for open sights but my purpose was to test the functioning. I fount out that Military 20 round clips work terrible but 30 rounders function perfect. Hmmmm I purchased a 20 round Magpul Pmag and it functions perfectly. My loads are 17gr of 296 with 150 gr Military pulled bullets. So the load is fairly hot. The port in the barrel of SI defense barrels are notoriously small from what I read on the net so I will open it up a bit and try again in a few days. By the way I fired a few 220 grain round nose bullets for the fun of it. (they don't feed well at all) but they shot incredibly accurate. Hmmmmm

 

[PBinWA]

Update: I got my .300 Blackout barrel from Midway. It's an SI defense carbine length 1-8. Got it assembled on an A4 upper with open sights mounted so far. Fired about 40 rounds so far with about half of them not ejecting. They stove pipe in the action most of the time. Shoots fairly accurate for open sights but my purpose was to test the functioning. I fount out that Military 20 round clips work terrible but 30 rounders function perfect. Hmmmm I purchased a 20 round Magpul Pmag and it functions perfectly. My loads are 17gr of 296 with 150 gr Military pulled bullets. So the load is fairly hot. The port in the barrel of SI defense barrels are notoriously small from what I read on the net so I will open it up a bit and try again in a few days. By the way I fired a few 220 grain round nose bullets for the fun of it. (they don't feed well at all) but they shot incredibly accurate. Hmmmmm

I had to open up the port in my SI-Defense Barrel for sub-sonics - I had some 130Gr super-sonic loads that worked fine before the port was opened. It works great now. I have a JP Adjustable Gas Block on it so I can restrict it for super-sonic loads.

 

[Mecanik]

How far did you open it up. I haven't measured the hole yet but I figure it won't take much as it ejects about half of them now.

 

[Blitzkrieg]

Blitz with the Mag Pul AFG it's more of a place to rest the rifle on for longer ranges. Like resting it on your hand but it froce you to put your hand in the same location each time. It's like the E-2 Stocks you can buy.
The other (VFG) will be better for close in and things like room clearing. Some do hold a Bi-pod in side them to take up a little less space.

I went wth the 5 position folding grip for her, it was $13 and works great. She is very unlikely to seriously ever get in prone position as she is as far from Rambo as it gets. It can fold fully horizontal

<broken link removed>

 

[PBinWA]

How far did you open it up. I haven't measured the hole yet but I figure it won't take much as it ejects about half of them now.

It's been a while but I think it was around .120. It wasn't much more.

 

[Globemaster]

here's an update on my 300F


Olympic Arm® 300/Fireball Details …


Upper: Forged Flat Top w/ Picatinny Rails
Chambering: Olympic Arm® 300/Fireball
Barrel: 416 ‘SS’
Handguard: YHM® FF/Handguard
Bore: Long-Life non-Chromed Bore
Twist Rate: 1:8 Twist, with 6in. Gas System.
Muzzle: A2 Flash Suppressor


Lower: Sun Devil®
Grip: Standard USGI A2
Trigger Guard: Troy® Winter Trigger Guard
LPK: Stag®
ButtStock: Magpul® MOE
Optics: Bushnell® TRS-25
Rings/Mount: UTG® High Profile w/ 3-Slot Picatinny
Forward BUIS: NA
Rear BUIS: NA
Magazine: Magpul® 20/Round









• Bullets: Hornady® V-Max™ 110gr ... $25.99 x (2)
• Brass: AAC® 'R-P' 300/BO ... $26.99 x (2)
• Powder: Hodgdon® Lil’ Gun™ ... $23.00 x (1)







I got 200-rounds of 300 Fireball loaded up and ready for this range outing ...


Bullets: Hornady® V-Max™ 110gr
Brass: AAC® 'R-P' 300/BO
Powder: Hodgdon® Lil’ Gun™ 17.4gr.







'GO' - 'NO GO' gauges for the 300/BO



I was on bench #6 for this session … all targets are 50 yard, as I’m just now getting the 300/Fireball dial-in with the new handloads.

getting it dialed in; the first three rounds are low, and then I made a sight adjustment, ‘UP’ 12-clicks

loading one round through the ejection-port and having to re-acquire acquisition, after each shot fired … 1.510in.

I loaded (3) rounds onto the magazine, and then stayed on target acquisition … 0.850in.

I took the 300FB back out to the range a few weeks ago, as I mounted a 6.5-20x50mm Simmons® Whitetail Classic™ to the carbine ... then I shot the 5 round group recorded at 1.175 … and after you deduct the .308 you get 0.867

note: the single round inside of the one inch square was from the initial sighting in, as that was the 3 round fired, before I made an ‘UP’ doping of 4-clicks before I shot the string of five-rounds; I have one other target that I haven’t uploaded yet, as I made a ‘R’ adjustment of 4-clicks, and left it there, until I get a chance to get it on the 100-yard bench.

 

[tfbit]

Why are so many Blackout people concerned with go/no go guages? If you don't trust the barrel manufacturer to install the extension and check the headspace then you should be buying your barrel from someone else...

'GO' - 'NO GO' gauges for the 300/BO

 

[Globemaster]

Why are so many Blackout people concerned with go/no go guages? If you don't trust the barrel manufacturer to install the extension and check the headspace then you should be buying your barrel from someone else...

I've never used a set of Go, No Go gauges 'EVER' ... the 'SET' pictured in the image above were borrowed (loaned-out) from a friend, who offered me the set to use on my build, as he built a couple 300/BO units in the past year.

and just like all of my other Olympic Arms® 'Barrels' ... this 300/FB is a proven tack-driver!


Edited for Spelling and Punctuation; as I was originally working from an iDevice on the go!

 

[Kevatc]

The only thing I disagree about with your statements is the conversion of .223 brass. From what I have been researching it seems a lot of labor would be involved in the sizing and trimming. The 300 shoulder starts below the current 223 shoulder etc. Not as easy to convert as say if you were doing 7mm TCU. However, new 300 brass is fairly inexpensive and that is what I will be doing myself. Unless you have a power trimmer and a lot of time - I would skip the .223 route.

I just bought a Harbor Freight cut-off saw and Hornady dies and while you are right it is kind of labor intensive to convert .223 brass it is kind of fun ... for now. I suppose the novelty will wear off eventually. I have to laugh at myself though. I have months and months of saving to do before I can actually buy a 300 upper but I just couldn't wait to get started so it's brass conversion that will have to scratch my 300 BLK itch.

 

[jeepinjoe]

I just bought a Harbor Freight cut-off saw and Hornady dies and while you are right it is kind of labor intensive to convert .223 brass it is kind of fun ... for now. I suppose the novelty will wear off eventually. I have to laugh at myself though. I have months and months of saving to do before I can actually buy a 300 upper but I just couldn't wait to get started so it's brass conversion that will have to scratch my 300 BLK itch.

I'm in the same vote right now, but my weapon on choice for the conversion is a Daewoo K1. I have bought Hornandy dies and Harborfreights cut off saw. So far it's been an interesting project. Joe

 

[Burt Gummer]

My 300blk SBR paperwork got refused dammit. After six+ months. Filled out the 4H part on form one with the caliber that appears on the lower (.223) and the inspector said FU, he wants to see what I am engraving onto the lower for my trust.

The opposite of what I've read everywhere. The engraving normally isn't 'there' until the Form 1 approval, etc. Oh well. Maybe another few more months .

 

[Mecanik]

Update again. Still terrible ejection from .300 braclout. I did some testing and I put a single round in the magazine and fired it to see if the bolt stayed back. And it did after firing but the case was left laying in the receiver loose. Hmmmmm The only explanation is that the extractor is slipping off the back when it tries to extract. Tried same bolt in different upper in normal .223 caliber and it works great. Perfect ejection. So my guess is that it's trying to eject when the pressure is still too high in the case and it's sticking in the chamber. Remedy in my mind is to delay it some with heavier buffer or carrier but I'm using a standard rifle butt stock and no one seems to make heavier buffers for them. Lot's for carbines but not rifles. Hmmmmmm Anyone with some suggestions!

 

[PBinWA]

I have two SI-Defense Barrels, I polished the chamber on each of them to get smoother extraction. You may want to make sure the chamber is clean and even spend some time doing some light polishing.