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Gunsmithing I need help choosing BEST 300 Blackout in 10.5

KCode

Sergeant of the Hide
Full Member
Minuteman
Mar 25, 2019
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Well while doing searches I run across either really old threads or barrels that no longer are made. I had my mind set on a Rainier Arms Ultra Match but it is only offered in 16" now. I then thought of Noveske but read some people that said for the money they are nothing to write home about. Not really interested in the cheaper brands (BA and Faxon). Centurion is a thought... I see WOA doesn't make a 300 Blackout barrel.
 
I’ve made a couple 10.5s out of top notch components and was satisfied with accuracy and reliability. Someone wanted one bad enough so I sold it and I purchased a Seekins complete upper and put it on a Seekins sbr and I’ve been very impressed
 
What is your definition of best? Precision? Reliability?

You can not turn a 300 blackout into a benchrest cartridge and most $500 barrels do not shoot any better than $200 barrels with the optics most would put on a 10" SBR.
 
What is your definition of best? Precision? Reliability?

You can not turn a 300 blackout into a benchrest cartridge and most $500 barrels do not shoot any better than $200 barrels with the optics most would put on a 10" SBR.

Wouldn’t best be all of the above? Mainly looking for accuracy and ability to keep accuracy and not random flyers. Not wanting to ring steel at 1000m. Just would like coffee saucer hits out at 300m.
 
JP Enterprises is a good bet, I would let them make the upper. Even with that upper, the 300m goal is aggresive.
 
So the ultra match 10" is too short? I use the Faxon match series in 10.5" and it's pretty damn accurate despite the cost. Comes with the teflon barrel extension and it was an interference fit with my V7 upper. Conversely I have a Rainier Arms match in 8.5" and it isn't half bad either although I didn't finish dialing that one in. Rainier makes the match in a 10.5". I'm not a fan of the bead blasted finish though as I had issues with gas block sealing.

 
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I've got a Robinson Armament with an 11" that is great. It is the fattest shooting gun I own.
 
I've done this test already with 5 or more 300blk barrels at 10-10.5"

There was nothing even close to as accurate as this





With my 125TMK supers load it's a 0.5moa shooter @ 100yd and I have zero issues going 5/5 on steel from 200-500M every time.. I didn't build it for that but once I saw the accuracy I threw a high powered scope on it and tested accuracy out to 500M
 
I've done this test already with 5 or more 300blk barrels at 10-10.5"

There was nothing even close to as accurate as this





With my 125TMK supers load it's a 0.5moa shooter @ 100yd and I have zero issues going 5/5 on steel from 200-500M every time.. I didn't build it for that but once I saw the accuracy I threw a high powered scope on it and tested accuracy out to 500M

Did you compare this to the V7? Read AMAZING things about the V7 and talked with them on the phone and it seems its pretty nice.

This 10" Ultra Match (WHY such an odd length?!) would be very difficult to find a nice rail. I think the V7 10.25 would still allow 9.5 rails.
 
I own both an 8" and 10.5".

I love the extra rail space I get with the 10.5", but I prefer using my 8" for HD because of it's compactness. Therefore, if I had to choose one, it would be the 8".

If I hunted, that may be enough of a reason to push me to choose the 10.5.
 
Did you compare this to the V7? Read AMAZING things about the V7 and talked with them on the phone and it seems its pretty nice.

This 10" Ultra Match (WHY such an odd length?!) would be very difficult to find a nice rail. I think the V7 10.25 would still allow 9.5 rails.

Not that difficult at all. I run a DD MFR MLOK 9" on mine...love that rail.


 
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I have an Odin Works 10.5″ .300 BLK Barrel w/ a magnesium rail, works great!

 
I've assembled SBRs and cheek pistols with Aero Precision barrels with better than expected results.
Great nitride finish and accurate.
 
What are you guys calling great results out of these barrels youre recommending?? What kind of "consistent" accuracy? And with what ammo? Supers? Subs? I tested Odin, Aero, AAC, BHW, PSA, BA....they didn't come close to the UM barrels...nowhere close.. some of those barrels shot hand size groups or bigger.. looked like a shotgun blast

Of all the 300blk 9"-11" barrels I tested....none came close in accuracy to these Rainier UM 10" barrels.

Here are first rounds out of the 10" UM at 100yd.. Gen1 5-25 Razor on it just for load development and load confirmation before putting the 1-5 back on it.


Here is the target showing the first rounds ever fired down the barrel. Starting top left and going left to right and moving down to the next 2 lines. You can see after it had about 10rd through it, it really started to group and after 30rd those groups really became consistent. That was just with H110 and 125SMK supers..









Here is load development with 125 TMK next which shoot lights out in these UM barrels.







Here is load confirmation @ 100yd with the 125TMK 18.6gr supers load. 7x5 agg 0.521" 90% of the barrels out there cant do that with an AR15, let along a 10.5" 300Blk AR... I shoot this load out to 500M and its 10/10 every time with 1.5-5x MR/T CM-R2 optic..










Here is a 220SMK CFE Black subs load I worked up at 50yd. Stupid accurate and is insanely quiet.


















Here is another 100yd accuracy test with just 125 SMK I did on a newly purchased Mod2 10" UM 300blk barrel.. Did even fire my lights out 125 TMK load out of it...








This is why I mostly shoot the 125 TMK supers. They are stupid accurate and are nasty. They expand nicely. Black Hills uses them in their 300blk defensive ammo..













 
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I only have two .300 BO SBR's; KAC SR-30 and PWS Mk109 easier with the S&B short dot mounted. . For my purposes both quite capable of taking out 9-banded armadillos at 200 meters suppressed.

KAC 300 Blackout Eotech XPS2 with SurefireIMG_4499 copy Annotated Nov 2020 copy.jpg
Screen Shot 2022-08-12 at 5.43.06 PM.png
IMG_5121 copy.JPG
IMG_5155 copy 2.JPG
 
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Guess I need to get out and test my 10.5 barrel. Best I remember, it is an old FN overrun, but I bought it 10 years ago so who knows.
 
Yeah, that's wicked accurate.
I haven't tested that is in my Aero with a scope.
My last build was a cheek pistol and my accuracy needs we're not that tight....I was looking for quarter minute of mal-intentioned street person or anarchist.
 
My PSA premium CHF BLK shoots just as good as my Noveske barreled upper, the premium barrels are made by FN and are worth a look.
 
I bought a Mos-tek 7” barrel recently. Haven’t finished the build yet but my main reason for looking at Mos-tek was the 1:5 twist rate. I really only plan to shoot heavy subs with it so wanted the faster twist.

I’ll have to test some Maker bullets at super velocities and see how that works before I’ll put them through the can.
 
Guess I need to get out and test my 10.5 barrel. Best I remember, it is an old FN overrun, but I bought it 10 years ago so who knows.
"If" you bought that "overrun" FN barrel from Primary Arms... you might check the gas port size.

Mine is crazy small gas port sized , I want to say .063" ( I just checked. ) ... PLGS
 
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I've done this test already with 5 or more 300blk barrels at 10-10.5"

There was nothing even close to as accurate as this





With my 125TMK supers load it's a 0.5moa shooter @ 100yd and I have zero issues going 5/5 on steel from 200-500M every time.. I didn't build it for that but once I saw the accuracy I threw a high powered scope on it and tested accuracy out to 500M


Is this barrel still available? Meaning are they using the same blanks as you tested?

Also if I read correctly you tested 2 of these barrels that performed similarly?

At 400$ is it worth it or just spend 525 for a craddock bartlien?
 
My McGowen 14.5" 300BO barrel shoots like that with 110 TAC TX at 2450 - 2500fps. I never would've thought it would or decided to build a 300BO for sub half moa accuracy. It just did, much to my surprise. Pretty cool when load development takes a surprising turn for the better.
Is this a cut rifle blank?

I had an origin 308 win cut rifled built by them and it shot .5 with several bullets but always threw a cold flyer and had rough threads.
 
Sounds like Padom has your answer. If you're willing to be a little flexible about barrel length you might look at Wilson Combat. No personal experience with one, but I think they have a pretty good reputation for accuracy.
 
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Sounds like Padom has your answer. If you're willing to be a little flexible about barrel length you might look at Wilson Combat. No personal experience with one, but I think they have a pretty good reputation for accuracy.

I have not been happy with three different Wilson, 300hamr barrrels…. Maybe 300 BLK is different??
 
Is this barrel still available? Meaning are they using the same blanks as you tested?

Also if I read correctly you tested 2 of these barrels that performed similarly?

At 400$ is it worth it or just spend 525 for a craddock bartlien?

I mean I tested a Gen1 (Shilen) and their newer Mod2 (Criterion) which is made for them by Craddock and it was just as accurate as my Gen1 shilen.. unless something has changed..
 
I mean I tested a Gen1 (Shilen) and their newer Mod2 (Criterion) which is made for them by Craddock and it was just as accurate as my Gen1 shilen.. unless something has changed..
Awesome...thats the info I needed. Thanks
 
Well while doing searches I run across either really old threads or barrels that no longer are made. I had my mind set on a Rainier Arms Ultra Match but it is only offered in 16" now. I then thought of Noveske but read some people that said for the money they are nothing to write home about. Not really interested in the cheaper brands (BA and Faxon). Centurion is a thought... I see WOA doesn't make a 300 Blackout barrel.
Odinworks has treated make well
 
I have 1 psa and 1 faxon.

They both shoot everything I put through them.


That said, I settled on a 2moa red dot and sighted them for 220 subs that 50 yards. The cartridge is just only so useful, and they always land under the dot.

I have a lot of other guns I'll grab for anything beyond the fenced yard. The only thing the blackout does well is be hilariously quiet with subs and a can.
 
Idk about all that.. 0.5moa all day with 125TMK supers @ 2400 are pretty nasty.

I see no need. I have a ton of fast guns. The 300 does it's job in the yard with subs being quiet. There is such drastic changes between subs and supers it's a waste trying to flip back and forth.

If I didn't want the quiet, I'll just grab a 556 and get the flat shooting.
 
I see no need. I have a ton of fast guns. The 300 does it's job in the yard with subs being quiet. There is such drastic changes between subs and supers it's a waste trying to flip back and forth.

If I didn't want the quiet, I'll just grab a 556 and get the flat shooting.

I shoot 220smk subs and 125 TMK supers out of my 10.5 300blk with can with ZERO changes in my setup. Both run stupid accurate like a Swiss watch. A 125tmk super expands like a federal.hst 9mm with razor sharp pedals, but with WAY more energy and speed. I tested how far this load was accurate, went 10/10 on steel .at 200, 300, 400 and 500 meters. It's more than capable...
 
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I'll just throw this out there. A barnes 110 tac tx out of a short barrel 300 blackout is the perfect East Coast deer rifle. My opinion. And I'd rather hunt with that than a 62gr .223.

And this is the only other 300blk super bullet I shoot. Its stupid accurate as well...
 
I have a 300 Bo barrel but it’s 16 in and its very impressive
Not to derail BUT.....I was not happy with 300 Hamr as a whole, specifically the (3) WC barrels I tried AND the customer service I received from the manufacturer.

Ill leave it at that for now. My resources will go elsewhere in the future.
 
And this is the only other 300blk super bullet I shoot. Its stupid accurate as well...
I have yet to try this bullet in a barrel it did not shoot 1" or better. Even 100$ and freebie no name beater barrels like it. I have also yet to meet anything with a heartbeat that received one disagree with the terminal performance.

At 2500 +/- fps they are +/- 3" out to 200yd.....pretty similar in trajectory to a heavy 556. Minimum expansions threshold has been reported to be 1300fps also.
 
I have a Noveske 300BLK. I’m very happy with it and would buy it again. Suppressed and subsonic ammo, one of my favorite guns.
 
Not to derail BUT.....I was not happy with 300 Hamr as a whole, specifically the (3) WC barrels I tried AND the customer service I received from the manufacturer.

Ill leave it at that for now. My resources will go elsewhere in the future.

Same, I tested it heavily then moved on. I couldnt get enough powder in the case to make it worth my time over 300blk...
 
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