Taurus Firearm Forum banner

1 - 20 of 48 Posts

·
Registered
Joined
·
4,730 Posts
Discussion Starter · #1 ·
After customizing and personalizing my 1st AR, it has ended up being something of an intermediate to long range gun with an 18" .223 Wylde barrel, a fairly heavy muzzle brake, and 1 4.5-18x .223 Dropzone scope. I built my son's AR from the spare parts left behind by my earlier efforts and, in comparison, discovered that it is really light.

This prompted me to start working up a parts list for a lighter, purpose built AR. I had initially planned on a standard 16" barrel but got to looking at a friends .300 BO pistol with a 10.5" barrel. It looks snazzy and is very light (especially when compared to my 18" AR) so I began researching. Main thing I found is that if you want to lean toward economy, odd barrel lengths are out, the best I could do seems to be either 10.5 or 14.5". I'm leaning toward the 14.5" to keep velocities up (I won't be suppressing this any time soon, unless the Hearing Protection Act ever goes through) and get some reach out of it (nothing beyond 250-300 yds) while keeping energy levels high.

Anyone have any experience with both?

Thanks!
 
  • Like
Reactions: kruizer

·
Premium Member
Joined
·
11,235 Posts
I've built both and enjoy the 300 more than the 5.56. I currently have a 10.5 inch barreled 300 pistol. In all honesty though that upper will go to my SBR lower when the tax stamp comes through.
 

·
Registered
Joined
·
20,085 Posts
300 BLK uses fast burning powders and does not lose much if any power after 8-9”.
223/556 uses barrel length to an advantage with slower burning powders. This will produce a lot of muzzle flash with unburned - late burning powders in shorter barrels = lost power & velocity.
 

·
Registered
Joined
·
904 Posts
.300 makes ballistic sense in a short barrel(i have an 8.5" pistol and boy does it feel handy). .223 need the velocity you get from a longer barrel. A 62 gr .223 bullet out of an 8" barrel probably has a MV of 2100fps or a bit more and a bullet meant to expand at 2900 or 3200 fps may not at 2100.
A 120 gr .300 is going to have a MV of around 2000-2100 fps and there are bullets that are designed to expand at those velocities.

If I have a pistol option of a 120gr .30 cal bullet at 2100fps or a 68gr 22 cal bullet at 2200, adding in a much reduced muzzle flash with the .300, i go with the .300 BO.
 

·
Registered
Joined
·
4,730 Posts
Discussion Starter · #8 ·
300 BLK uses fast burning powders and does not lose much if any power after 8-9”.
223/556 uses barrel length to an advantage with slower burning powders. This will produce a lot of muzzle flash with unburned - late burning powders in shorter barrels = lost power & velocity.
Not a ton of "official" load data out there. Looks like I'll have to invest in another powder too...and a jig for cutting down .223 cases...and a mini circular saw...
 

·
Registered
Joined
·
4,730 Posts
Discussion Starter · #9 ·
I tend to think redundant when it comes to firearms. If you only have 1 .223/5.56 I would build another in the caliber whether a pistol or rifle. Then move to another caliber. As for having experience in both, I don't!
Got a couple of AR's in .223/5.56. The initial idea wasn't for a pistol, but a light weight carbine, which led me to the pistol concept. I know that you give up a lot of performance when you shorten the barrel of a .223, but not so much (if at all) with the 300 BO. Seems that they peak in the performance to weight ratio at around 9" due to, as Mingaa said the fast burn rate of the powders used (mostly magnum powders). Adding length to the barrel doesn't bring much added velocity since the powder is already burnt and the expanding gasses are basically done by the 9-10 inch mark.
 
  • Like
Reactions: pegasus and darbo

·
Registered
Joined
·
2,511 Posts
I have both the 300blk and the 223 Wylde with 7 1/2" barrels. The 300blk hands down unless you do not reload and just want a range toy.

Out of the short barrel the 223 Wylde has a lot of flash and blast. Enough that after the first range trip I replaced the muzzle break with a linear compensator. The velocity is reduced to the point that it is a glorified 22 magnum.

It is a ton of fun to shoot though. The 300 BLK is just more practicable, if practicable is a word you can use with an AR pistol.
 
  • Like
Reactions: Yissnakk

·
Registered
Joined
·
12,468 Posts
I will say that my 7.5 inch 556 is smoky.

300 BLK uses fast burning powders and does not lose much if any power after 8-9”.
223/556 uses barrel length to an advantage with slower burning powders. This will produce a lot of muzzle flash with unburned - late burning powders in shorter barrels = lost power & velocity.
 

·
Registered
Joined
·
12,813 Posts
I built a 10.5" 5.56mm NATO pistol for my DIL, because she wants to shoot what her hubby shoots. It is the most god awful loud and flash producing AR I have ever shot. With double hearing protection on it still leaves my ears ringing. Now I am hearing that the SF community is going back to 14.5" barrels due to not only the noise and flash, but also the collateral damage to operators around you and yourself. I am hearing of several incidences resulting in the loss of fingers from hands extended to far out in training exercises. That is also the reason everything shorter than 14.5", regardless of caliber, that I have or have made has a flash can on it.

I don't know what your purpose is for your AR, but I have two .300 Blackouts. One is a 8.5" barreled, pistol length gas port that is set up for subs only. In the house it is my favorite SD option. It is just so quiet compared to other options, even without being suppressed, and a 208-225 grain bullet is going to stop anything, including Bigfoot, that I might run into around here. My other .300 BLK has a fixed stock Cav Arms lower, a 16" barrel with carbine length gas port and is set up for hunting and has a 1x4 scope. The pistol carries a Bushy TRS-25 red dot. Not to say that the pistol is not capable of being used for hunting, but its best use is under 150 yards. If I remember the numbers on the sub rounds, I am only looking at a loss of only 50-60 fps at 200 yards, but drop is over 20 inches.
 
  • Like
Reactions: Yissnakk

·
Registered
Joined
·
3,908 Posts
Well as usual on this forum you've gotten great advice. If you want to build a short barrel, 300 BO is the best choice. I was of the same mind as you to make mine as light as possible. I love the way my build turned out. As was mentioned reloading is a huge plus as the ammo is expensive otherwise. I opted to just buy the brass. I lucked out as a friend sold me 500 at a good price. It just didn't seem worth it to me to go through the whole cutting thing. I mean you still have to come up with the 223 brass to start with.

Here's mine with a 10.5 inch barrel and Aero Precision upper and lower. I chose everything to go light but not to a great expense either.

ARPistol3.jpg
 
  • Like
Reactions: darbo and Yissnakk

·
Registered
Joined
·
20,085 Posts
My 300 BLK has never seen factory ammo. I do the chop and form method with shorter than trim spec ( >1.750) .223/5.56 - mine and LOTS that I swapped for.

I built a gun for super loads - wanting to make major power factor (320) for competition. It has a 14.5” barrel with a pinned & welded muzzle device that brings it to 16”. Can’t use an SBR in the class/matches I was shooting. 300 BLK can just make major with the right bullet, powder, primer combinations and has less recoil than .308.
 
  • Like
Reactions: Yissnakk

·
Registered
Joined
·
904 Posts
Just remember, buy a virgin lower and once you assemble it in pistol configuration, you can make it into a rifle and back legally. If you have a less than 16" barrel or a pistol buffer tube lying around, you better have possession of a lower that has been originally configured as a pistol or the ATF can screw with you. 20170716_163136.jpg
 

·
Registered
Joined
·
4,730 Posts
Discussion Starter · #16 ·
Sweet! Thanks for all the first hand knowledge. This has made the decision easy. 10.5" barreled upper with a flash can and a 12.5-13" keymod along with one of those Shockwave Blade stabilizers should fit the bill. Got a RedDot and a flip-up 3x magnifier lying around too...Just waiting for tax/bonus time :)
 

·
Premium Member
Joined
·
11,235 Posts
Not a ton of "official" load data out there. Looks like I'll have to invest in another powder too...and a jig for cutting down .223 cases...and a mini circular saw...
Get a dremel with a cutting wheel, clamp it in a vise and just hold the 223 cases and cut them at the shoulder. Run them through a sizing die and trim the excess brass. Violla. I use range brass whenever I want to make some new cases, however, I've been seeing more and more factory brass at the range and for sale online. As far as powder goes, I only shoot supersonic so Hodgdon H110 works just fine.
 
  • Like
Reactions: Yissnakk

·
Registered
Joined
·
4,730 Posts
Discussion Starter · #19 ·
Get a dremel with a cutting wheel, clamp it in a vise and just hold the 223 cases and cut them at the shoulder. Run them through a sizing die and trim the excess brass. Violla. I use range brass whenever I want to make some new cases, however, I've been seeing more and more factory brass at the range and for sale online. As far as powder goes, I only shoot supersonic so Hodgdon H110 works just fine.
Kinda what I was thinking. I don't really have an application for subsonic and won't suppress unless the HPA goes through in my lifetime. H110 looks like the way to go for super. The loads all seem to favor what you'd normally think of as magnum loads...Bluedot may work also...may have to try that out...
 

·
Registered
Joined
·
904 Posts
I have a basic problem with the commercial stabilizers. they all neglect to consider that the balance of the AR platform pistol is muzzle heavy and the buffer tube wants to lift up. the one i built is a "J" shape that hooks under your fore arm and the weight of the muzzle lifts it up against the bottom of your fore arm. No velcro strap is needed to hold it in position. it also means you grab the pistol grip and the hook naturally and instantly slips into place. you get the sideways support of the shockwave blade but also vertical support. If you want to bring it to your shoulder, you arm instantly comes free.
Anyone know if i should patent and how to start?
This one was made from a piece of thin wall PVC pipe(i think i started with a piece of drainfield pipe), a heat gun, a bit of black spray paint, and a couple of small stainless steel bolts and lock nuts. total cost? zero as i had it all lying around
Sweet! Thanks for all the first hand knowledge. This has made the decision easy. 10.5" barreled upper with a flash can and a 12.5-13" keymod along with one of those Shockwave Blade stabilizers should fit the bill. Got a RedDot and a flip-up 3x magnifier lying around 20171227_202816_resized.jpg too...Just waiting for tax/bonus time :)
20171227_202835_resized.jpg
 
1 - 20 of 48 Posts
Top