Help me out choosing my SBR

[PappyM3]

If I cared about such things, the dudes shooting 300blk at actual people are doing it with barrels a bit shorter then 9".

Yup. But the original request was for 9” because of the reasons mentioned. And that initial use case is likely what tumbled into the (300BLK is optimized for 9”) lore.

 

[ReluctantDecoy]

While the internet lore is that 300BLK gets most of its performance out of a 9” barrel, it’s not really true. Very smart people like DocGKR say 9” is a good minimum length, and it is a good length. But shorter barrels are still very effective. The original 300BLK gun for a special mission unit was 9” because that allowed it to fit nicely in existing vehicle racks when mounted with their existing 7.62 suppressors. If they didn’t have that requirement, there’s no reason it couldn’t have been less than 9”.

I think that 9" barrel length number comes from the comparison to 5.56 at 16", which is kind of an industry standard for compromise between performance and barrel lenth. .300 blackout at a 10" barrel is comparable in terms of foot pounds to 5.56 at 16" with super sonic loads, so I think that's why a lot of people said 9" is the minimum. Again, just a guess though. After reading your posts about this subject in other parts of the forum, it sounds like you have real experience with the caliber so I'll defer to you on this.

 

[PappyM3]

I think that 9" barrel length number comes from the comparison to 5.56 at 16", which is kind of an industry standard for compromise between performance and barrel lenth. .300 blackout at a 10" barrel is comparable in terms of foot pounds to 5.56 at 16" with super sonic loads, so I think that's why a lot of people said 9" is the minimum. Again, just a guess though. After reading your posts about this subject in other parts of the forum, it sounds like you have real experience with the caliber so I'll defer to you on this.

I don’t have professional experience with it. And you may be right as well. The initial DoD use case for it is my guess as to why the 9” thing propagated through the industry and Internet forums. But I don’t think we could ever nail it down to one reason. And it’s entirely plausible that your explanation had a hand as well.

 

[ChevyGuy91]

I don’t have professional experience with it. And you may be right as well. The initial DoD use case for it is my guess as to why the 9” thing propagated through the industry and Internet forums. But I don’t think we could ever nail it down to one reason. And it’s entirely plausible that your explanation had a hand as well.

I am sure it is like every urban myth in the gun world, someone with some level of industry/.mil credibility said it and the rest of us took as gospel.

 

[paul73]

While the internet lore is that 300BLK gets most of its performance out of a 9” barrel, it’s not really true. Very smart people like DocGKR say 9” is a good minimum length, and it is a good length. But shorter barrels are still very effective. The original 300BLK gun for a special mission unit was 9” because that allowed it to fit nicely in existing vehicle racks when mounted with their existing 7.62 suppressors. If they didn’t have that requirement, there’s no reason it couldn’t have been less than 9”.

or you put a 300blk conversion kit into a tavor.
i will eventually get both of those kits for mine, 9mm and 300blk, the latter first. it is a good round to have a gun for.

 

[ColdDayInHell]

CZ 805 (Bren 1)?

/thread

Considering new options for an AR pistol and saw this one from PSA. One big plus is it uses CZ Scorpion mags that I already have. I'm leaning toward another 9mm platform because shooting .223/5.56 is too freakin' expensive. I know PSA gets some hate on here but does anyone have first hand experience with their build quality if not this specific gun? Review are sparse but good.

https://palmettostatearmory.com/psa-ar-v-4-9mm-1-10-lightweight-m-lok-moe-ept-sba3-pistol.html

View attachment 417910

if you already have the godly Evo, why the hell would you get a shitty PSA knockoff?

 

[42!]

Well it's my fault for not updating the thread. But I've settled on what I'm doing and even have most of the parts. I ended up going with a build because, as has been noted, getting everything was going to be near impossible, and I've gone with a longer barrel 10.5". But I just couldn't make up my mind on 556 or 300............ so I'm doing two, sort of a matched set.

Uppers are BRN-180 10.5" , one in 300blk and one in 223 wylde
lowers are aero procession
KNS Precision Sig stock adapters
both will be getting a Holosun 510C
eventual, after I get the SBR paperwork approved, I'll be getting Sig folding stocks for them.

*Puts his propeller hat on*

What you do, is you get yourself a modular lower like the MGI Hydra, you SBR the frame and then you get a quick change upper or a bunch of uppers you like.

Why? With the modular lower you can SBR any caliber you want for $200.

SBR registration requires you to list ONE caliber, so no you can't just swap uppers to any caliper you want, at least not legally.

 

[Drix]

SBR registration requires you to list ONE caliber, so no you can't just swap uppers to any caliper you want, at least not legally.

Isn't that what box 4h is for?

 

[42!]

Isn't that what box 4h is for?

Huh?
h. Additional Description (Indicate required maker’s markings to include maker’s name (as registered), city and state as each will appear on firearm)

but this
c. Caliber or Gauge (Specify one)

 

[PappyM3]

Huh?
h. Additional Description (Indicate required maker’s markings to include maker’s name (as registered), city and state as each will appear on firearm)

but this
c. Caliber or Gauge (Specify one)

In the instructions on other pages, it says 4h can be used to add additional configurations. And if you run out of room, you can upload another document with your eForm. I uploaded one with pretty much every permutation of barrel lengths and overall lengths I might do, as well as other calibers.

However, as long as you have a way to easily revert your gun back to the original length/caliber on the form, you don’t need to report any temporary lengths or calibers. So just keep that original upper on a shelf, or one of the same caliber and length(as well as Buttstock for overall length).

“
k. Description of Firearm and Markings. (1) ...; (3)
Item 4c. Specify one caliber or gauge. If there is another designation, indicate the designation in item 4h. ...“

 

[Drix]

Huh?
h. Additional Description (Indicate required maker’s markings to include maker’s name (as registered), city and state as each will appear on firearm)

but this
c. Caliber or Gauge (Specify one)

If you read the instructions on the form it specifically states that extra calibers go in 4h. Its in section N under preparation of application.

 

[Da_lucche]

looks like that might be hard to find. I saw a couple in 556 but can't find a source for a 300 barrel, also looks like 11" is as short as I could go.

Until I wanted to get away from the AR style charging handle I was looking at the MCX with a 5.5" barrel, with the can that gets me out to about 11" and there is a Sig handguard that will cover most of the can. I just may have to suck it up and live with the rear charging handle.

Unless you reload, it is not a good time to get into 300BLK - that is of course if you don't mind spending 2 bucks a round for even the cheap stuff.

9" is the best performance length for the cartridge as well (of course AAC says this, so it might just be marketing but there is a ton of agreement around that 9" burns through all the powder, no under or excessive).

 

[PappyM3]

Unless you reload, it is not a good time to get into 300BLK - that is of course if you don't mind spending 2 bucks a round for even the cheap stuff.

Just recently I’ve seen Barnes 110 TAC-TX for $2 a round. Expensive, but far from the cheap stuff. It sat at that price for at least a day. Don’t know if it’s still available.

But yeah, plinking/training ammo for 300blk is nearly as expensive now. At least $1-$1.5 a round anyway.

 

[Da_lucche]

Just recently I’ve seen Barnes 110 TAC-TX for $2 a round. Expensive, but far from the cheap stuff. It sat at that price for at least a day. Don’t know if it’s still available.

But yeah, plinking/training ammo for 300blk is nearly as expensive now. At least $1-$1.5 a round anyway.

Yea it is pretty disappointing. I only shoot subs and subs seem to garner more $$ over supers, even for cheap stuff. Sucks because I was piecing together a poor mans NVG set up and wanted to use my 9" BLK but since I can't stock up on 300, I have been regulated to switch my night shit over to my 12.5 556 upper. MEH.

 

[enbloc]

My favorite Short Barrel Revolver is the 438 J-frame...

 

[Dennis in MA]

Unless you reload, it is not a good time to get into 300BLK - that is of course if you don't mind spending 2 bucks a round for even the cheap stuff.

9" is the best performance length for the cartridge as well (of course AAC says this, so it might just be marketing but there is a ton of agreement around that 9" burns through all the powder, no under or excessive).

There are still places that, with work, you can get reasonably priced 300 ammo. "reasonably" is a relative term, but Brownell's had 110gr Hornady Black for $1.20 a round. While I hate paying that, it wasn't THAT crazy in light of what practice ammo is going for lately and is already premium ammo.

But if you haunt Brownell's and such, you can find not-super-terrible deals.

 

[Da_lucche]

There are still places that, with work, you can get reasonably priced 300 ammo. "reasonably" is a relative term, but Brownell's had 110gr Hornady Black for $1.20 a round. While I hate paying that, it wasn't THAT crazy in light of what practice ammo is going for lately and is already premium ammo.

But if you haunt Brownell's and such, you can find not-super-terrible deals.

Subs seem to sell for a bit higher price than supers from what I have seen. I don't like shooting supers.

 

[mav]

Just received my approved tax stamp for my CZ Scorpion 9mm SBR. Submitted in July... It's Miller time!

 

[Diesel6393]

Well it's my fault for not updating the thread. But I've settled on what I'm doing and even have most of the parts. I ended up going with a build because, as has been noted, getting everything was going to be near impossible, and I've gone with a longer barrel 10.5". But I just couldn't make up my mind on 556 or 300............ so I'm doing two, sort of a matched set.

Uppers are BRN-180 10.5" , one in 300blk and one in 223 wylde
lowers are aero procession
KNS Precision Sig stock adapters
both will be getting a Holosun 510C
eventual, after I get the SBR paperwork approved, I'll be getting Sig folding stocks for them.



SBR registration requires you to list ONE caliber, so no you can't just swap uppers to any caliper you want, at least not legally.

Hey late into this convo but as long as
You keep your original configuration nothing says you can’t build another upper to throw on your SBR lower receiver but you must always be able to return it back to the original format you filed for unless you wanna send the atf that you are permanently changing your configuration and caliber I have not done that yet so I don’t know what you send them but I don’t see
Why not you can have as many uppers
Made for a
SBR as long as you keep the original configuration what do you think?

 

[42!]

And I'm waiting and waiting and waiting, seeing that incomplete pile of parts is killing me..........

 

[evalance]

CZ 805 (Bren 1)?

why not 2?

 

[42!]

why not 2?

I am doing 2, it's just that they are a set of AR180s, one in 300BLK and one in 223 wylde. Next choice is suppressors.

 

[Diesel6393]

And I'm waiting and waiting and waiting, seeing that incomplete pile of parts is killing me..........

Waiting for your stamp? I got mine in 37 days filed on 1-17-21

 

[Diesel6393]

I am doing 2, it's just that they are a set of AR180s, one in 300BLK and one in 223 wylde. Next choice is suppressors.

Suppressor what state you in?

 

[42!]

Waiting for your stamp? I got mine in 37 days filed on 1-17-21

I filed on 1/26, so real soon hopefully

Suppressor what state you in?

I live in a state where suppressors are on display in the LGS and there is a kiosk that will file all the paperwork for you. After a lifetime in the PRMA I now live north of the wall with the Free Folk.

 

[Diesel6393]

I filed on 1/26, so real soon hopefully

I live in a state where suppressors are on display in the LGS and there is a kiosk that will file all the paperwork for you. After a lifetime in the PRMA I now live north of the wall with the Free Folk.

Lucky sob hahahah

 

[ScottS]

Hey late into this convo but as long as
You keep your original configuration nothing says you can’t build another upper to throw on your SBR lower receiver but you must always be able to return it back to the original format you filed for unless you wanna send the atf that you are permanently changing your configuration and caliber I have not done that yet so I don’t know what you send them but I don’t see
Why not you can have as many uppers
Made for a
SBR as long as you keep the original configuration what do you think?

Absolutely false. There's no requirement to be able to return it to the original configuration. If you permanently change the configuration, the ATF requests you send a letter to update the Registry , but there's no requirement to do so, and not such requirement to be able to return it to any specific configuration.

 

[Diesel6393]

Absolutely false. There's no requirement to be able to return it to the original configuration. If you permanently change the configuration, the ATF requests you send a letter to update the Registry , but there's no requirement to do so, and not such requirement to be able to return it to any specific configuration.

Really I like that answer better so your saying I can always change up my barrel length and caliber but should let atf know but not required?

 

[ScottS]

Really I like that answer better so your saying I can always change up my barrel length and caliber but should let atf know but not required?

Correct. Change caliber, barrel length, etc. at will. No requirement to notify; permanent changes are requested only. The precise wording from the ATF is : ATF recommends written notification to the NFA Branch when a firearm’s configuration is permanently changed or removed from the purview of the NFA.

 

[Diesel6393]

Correct. Change caliber, barrel length, etc. at will. No requirement to notify; permanent changes are requested only. The precise wording from the ATF is : ATF recommends written notification to the NFA Branch when a firearm’s configuration is permanently changed or removed from the purview of the NFA.

So basically Put any size Barrel on it as you like? But keep your original one so you can return it to the original configuration? And if not you could notify them that you are permanently changing the barrel size due to you sold the old one?