300 Blackout Barrel Length

contenderv07

contenderv07

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Hey everyone, I've got a question for ya. I've got a 300 blackout 10.5 inch barrel rifle that I hunt with. My longest shot would only be about 50 yards TOPS. I just got a Dead Ai Sr Sandman S, but figured out that teh barrel is too short and the hand guard is too narrow to add the suppressor. So in saying that, I was going to get a 7.5 inch upper, so I could add the suppressor to it. Is 7.5 inch barrel too short (even with a suppressor added)?? I've killed a ton of deer with the 10.5 inch, but this is probably my last year hunting and want to have the 7.5 be teh truck/home gun. Let me know what ya think!!
 
What kind of ammo are you using? The main concern would be the bullet type achieving appropriate velocity to expand. I’d also get a fast twist rate barrel so heavy bullets in that length are stabilized

The Sandman can should handle even supers in a 7.5” like a champ
 
My only concern would be velocity loss from the 10.5 to the 7.5, probably not a game changing velocity loss at 50 yards and in but I'd think load selection becomes much more important.

A particularly proven bullet like an A-max or Tsx might be the way to go? Hoping to learn from others! I have a 8.5" 300blk and a sandman in jail myself.
 
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11B CIB said:
What kind of ammo are you using? The main concern would be the bullet type achieving appropriate velocity to expand. I’d also get a fast twist rate barrel so heavy bullets in that length are stabilized

The Sandman can should handle even supers in a 7.5” like a champ
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Thanks I'm running Gorilla 110 gr TAC-TX, and it sure puts em down quick
 
Midwest industries makes a line of rails designed for tucking a can. 1.67” ID, lengths from: 7.25" 9.25 10.50" 12.625" 15.0" 18.0"

midwestindustriesinc.com

Suppressor Series One Piece Free Float Handguard, M-LOK™

AR-15 suppressor compatible handguards from Midwest Industries, a U.S. manufacturer of quality tactical rifle accessories. Quality components, competitive pricing, and top notch customer service.
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@contenderv07 Barnes has stated their .30 cal 110gr TAC-TX bullet will begin achieving expansion at 1350fps. So as long as your 7.5” is getting enough speed at 50 yards to expand, your bullet choice is fine, however, there are some bullets made to expand under slower speeds in case you need to go that route
 
11B CIB said:
Midwest industries makes a line of rails designed for tucking a can. 1.67” ID, lengths from: 7.25" 9.25 10.50" 12.625" 15.0" 18.0"

midwestindustriesinc.com

Suppressor Series One Piece Free Float Handguard, M-LOK™

AR-15 suppressor compatible handguards from Midwest Industries, a U.S. manufacturer of quality tactical rifle accessories. Quality components, competitive pricing, and top notch customer service.
midwestindustriesinc.com midwestindustriesinc.com


@contenderv07 Barnes has stated their .30 cal 110gr TAC-TX bullet will begin achieving expansion at 1350fps. So as long as your 7.5” is getting enough speed at 50 yards to expand, your bullet choice is fine, however, there are some bullets made to expand under slower speeds in case you need to go that route
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Awesome thanks!!!! I did find this one on PSA‘s site that I think will work
 
I would just swap the handguard for something a little shorter. I’d go this route because I like thin handguard much better than ones large enough to tuck a can.

To your original question, though, @Bigdave0924 gave the perfect answer since you’re both shooting the same bullet (TAC-TX). Ive also found that Aero/BA 8.5” barrels are the sweet spot for 300BLK; both of mine reliably function subs and supers, suppressed and unsuppressed without adj gas blocks.
 
contenderv07 said:
Thanks I'm running Gorilla 110 gr TAC-TX, and it sure puts em down quick
Click to expand...

On Gorilla’s review page of that ammo, a customer stated they were getting 2324fps from a 16” barrel with the 110gr TAC-TX. MrGunsAndGear tested a Gorilla 110gr Lehigh Controlled Chaos round and with a 16” barrel it achieved 2412fps, 10.5” was 2203fps, and a 7.5” came in at 2118. While it’s a different bullet, they’re both copper so I’d assume some similarities in performance, charge weights etc. If you take the customer’s 110gr TAC-TX speed of 2324fps and even subtract 400fps (which is probably over compensating), you’re still well above Barnes’ minimum speed for that bullet to function.

I say go short and have fun
 
Isn’t that round designed around an 8-8.5” barrel?
 
10” 300BLK SBR with Seekins ~10” rail. I did have a 15” rail with the can tucked and it looked cool. With the longer rail it wasn’t short enough as a truck gun (being able to point to the left while shouldered).
The Minimalist stock makes it handy to hang.603C921A-569E-4368-B95B-E7B38761C8B2.jpegA287D66E-C87F-4155-9AC1-5385DB42CE12.jpeg116552D4-F630-49A1-922C-83CC7DF4B1CE.jpeg
 
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BigWaylon said:
Isn’t that round designed around an 8-8.5” barrel?
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11B CIB said:
If it is, it’s not in the description on Barnes’ website and they test their 300BLK ammo with a 16” barrel

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I stand corrected. Turns out it was 9”. 😁

Not saying that’s what all the ammo is designed for, but I believe that was the original intent. I’d assume most ammo manufacturers aren’t basing their testing on the fact a customer has a pistol/SBR.
 
BigWaylon said:
I stand corrected. Turns out it was 9”. 😁

Not saying that’s what all the ammo is designed for, but I believe that was the original intent. I’d assume most ammo manufacturers aren’t basing their testing on the fact a customer has a pistol/SBR.
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Did you mean 300BLK is made for 9” in general, or the Barnes round specifically? I was referring to this specific round based on the manufacturers data. It was supposed to be a ‘superior to 9mm’ sub gun option. And the manufacturer testing is ammo specific, especially if it’s marketed for subsonic and suppressor use
 
11B CIB said:
Did you mean 300BLK is made for 9” in general, or the Barnes round specifically? I was referring to this specific round based on the manufacturers data
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The caliber in general.
 
wow great info everyone!!!. I think the best (most cost effective) thing would be to just get another handrail. It doesn't HAVE to have the suppressor tuck inside, but it would make things a lot easier inside of a blind/car
 
I have two 300 BO uppers (9 &10.3) with 9.5 Odin rails. The 9” with can goes about 1/4 inch under handguard.

They can be picked up around $100 when on sale.

AR 15 Free Float Handguards For Sale | M-LOK and Quad Rails

An AR-15 Free Float Handguard is easily the most common type of handguard for the AR15 as they allow better accuracy and modularity over a traditional rail.
www.primaryarms.com
 
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300 blackout uses a magnum handgun powder. It's velocity isn't effected by barrel length as much as some other cartridges that used rifle powder. 10-12 inch barrels are a good comprise for that cartridge.

Oh yeah....if you like that rifle, look for a different handguard.
 
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contenderv07 said:
now we're cooking. After some youtubin, I got the handguard off and the sandman loaded on. I think I decided to get the 9" handguard from PSA

View attachment 516052
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I’d make sure that handguard is 9” exactly and that there’s no overhang with the can/mount.

I have a 13.9” Criterion barrel with a 13” Centurion rail; actual rail length is like 13.4” or something so due to the barrel threads, there’s NO extra space. I almost needed either a 12” rail or a 14.5” barrel

Fortunately the can I use had either a taper mount adapter that fits in that narrow rail and the can itself is 1.1” and tucks just under the rail if direct threaded

XvPOqeK.jpg


1WD0Jx8.jpg
 
contenderv07 said:
now we're cooking. After some youtubin, I got the handguard off and the sandman loaded on. I think I decided to get the 9" handguard from PSA

View attachment 516052
Click to expand...

11B CIB said:
I’d make sure that handguard is 9” exactly and that there’s no overhang with the can/mount.

I have a 13.9” Criterion barrel with a 13” Centurion rail; actual rail length is like 13.4” or something so due to the barrel threads, there’s NO extra space. I almost needed either a 12” rail or a 14.5” barrel

Fortunately the can I use had either a taper mount adapter that fits in that narrow rail and the can itself is 1.1” and tucks just under the rail if direct threaded

XvPOqeK.jpg


1WD0Jx8.jpg
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contenderv07 said:
I think I'll be good (hopefully) haha
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I have one that doesn’t have the cross cuts on it. If it’s the same one with that slight difference, it’s almost dead-on the 9” mark.

59A8DC21-3FE8-4226-BF67-D5D86E4EF83A.jpeg
 
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