AR-15 223 Proof barrel - thoughts?

[hlee]

I don't recall that, but people still say Creedmore, Grendal, Bartlin etc. so there's that. Don't get me started on the use of loose when lose is the appropriate choice.

It was in reference to early proof barrels melting down under high high round counts. Like “up in a poof of smoke.” Or, carbon wrapped barrels were “smoke and mirrors.”

 

[SuperBoot]

Ya, I don't speak Marine. It all sounds like woof, woof, woof! ooh Ray!

I’ve been out of it for a few years but I think that dude wants to bang your mom

 

[SuperBoot]

What if it was just me?

Maybe wear a second belt and lay low a couple days.

 

[B Man]

Mild hijack of OP’s thread since it looks like he’s sorted.
@RTH1800 @bigjake83 @reubenski

Curious to hear your thoughts on a 20” Proof barrel, steel or carbon.
I plan to use probably a Steiner 3-18 on it and use it as a general killer-of-4legged-shit less than 50lbs, so weight savings would be cool.
Secondary use would be as a game gun for positional gas gun matches, etc but doubt any strings of fire would be higher than like 40rds in that application.
Will be suppressed w/ an Ultra 7 the majority of the time.
My major concern with the carbon is repeated heat cycles using it on prairie dogs and other high volume critters during the summer, but maybe I’m just psyching myself out there.

Take Jake’s opinion seriously. He has multiple top barrels and has a proof that shoots like a laser and is not overly happy with them.

For a game gun like hogs or predators that are short string fire I could really see your interest in the proof. But extended fire on prairie dogs I think a normal steel barrel. Cheaper and not a huge need for weight savings. I do like proof and have a SS 20” in 223 Wylde that shoots like a laser and is extremely reliable in it hits what I want and where it should every time it’s picked up and shot long range. I would recommend it. For predators go for weight saving, prairie dogs heavy stainless. Also know, the proof carbon will put off heat mirage much much faster than a heavy stainless barrel.

Also consider a happy medium and let Compass lake or WOA cut you a tactical profile. Cheaper and cut some weight without going to light. I have a Douglas by CLE to meet that requirement that’s a hammer.

 

[bwo44]

Build is complete
Built by Cobalt
Craddock Precision Barlein 13.9” 223 wylde

 

[Peterpan]

Ok, but SHTF isn't about varmints.

The fact that you (nor 99+% of the population) can't effectively hit a 50 lb yote with a short barrel 5.56 at 200+ yds doesn't mean anything when it comes to SHTF.

That pudgy bloke I engage at 300 yds with my 11.5" is going DOWN.

unless you hit the folded tissue paper in his shirt pocket.

 

[aika]

That's a fancy setup. I was just going to say buy a reputable complete rifle since it's for defensive purposes, and don't mess around with a build. DD, BCM, LMT, KAC, Colt. Take your pick. I had a BCM 14.5" heavy barrel and an LMT MWS 16". I let them both go. I just got an LMT MLR with factory 14.5" barrel, and I'm going to pin a KAC flash hider for 16" OAL. I chose this over the others because as a defensive rifle, it is factory complete, has military track record, and because it's iron sight only, I thought the receiver/rail made the most sense (no flex). I didn't like how the KAC is proprietary and bolts are never in stock.

 

[Tex68w]

LMT Defender 2000 NFA lower, LMT MRP-L 13.25" Quad, Proof Carbon 14.5" 1:8, Vortex Gen II HD-E, AAC Mini4, Modlite PLHv-2.

 

[aika]

Nice rifle.

 

[bwo44]

First weekend out

 

[bwo44]

This thing has been crushing it. 55gr VMax
3 shots, 3 boars

Second weekend out:

 

[Tex68w]

Cold bore three-shot group with run of the mill 55 grain ball ammo, .667 moa. I haven't shot any heavier grain match ammo through it yet but I am more than happy with those numbers with that ammo. I imagine it'll be a 1/2 moa shooter with match grade pills. 14.5" Proof 1:8 twist, AAC Mini4.

 

[MontanaMan]

That's a fancy setup. I was just going to say buy a reputable complete rifle since it's for defensive purposes, and don't mess around with a build. DD, BCM, LMT, KAC, Colt. Take your pick. I had a BCM 14.5" heavy barrel and an LMT MWS 16". I let them both go. I just got an LMT MLR with factory 14.5" barrel, and I'm going to pin a KAC flash hider for 16" OAL. I chose this over the others because as a defensive rifle, it is factory complete, has military track record, and because it's iron sight only, I thought the receiver/rail made the most sense (no flex). I didn't like how the KAC is proprietary and bolts are never in stock.

My thoughts are similar for a true SHTF rifle.

14.5" or similar is a home defense / vehicle in/out rifle; I'll take 16" or even a lightweight 18" instead.

And much as I love Paul Craddock's barrels, stainless doesn't belong on a SHTF rifle for a working gun...............not a single major builder of serious fighting rifles that I can recall, uses SS including KAC, LMT, Centurion, BCM or FN, to name a few. (KAC does make an 18" SPR type rifle, the LPR, with an SS barrel & I do have one of those as well)

While the high end SS barrel will certainly have better precision accuracy, but that's just not the primary purpose for a SHTF rifle.

Otherwise, the OP built a fine gun, just not my idea of a gun for the described use...................my 2 primary SHTF rifles are a 16" KAC & a 16" with a BCM built upper. Plenty of others similar, built by me, including 14.5", 16" & 18" will fill similar or other specialized roles.

JMHO, YMMV

MM

 

[PappyM3]

Thread resurrection because I came across it in a search. Tangential comment below.

I can hit far smaller targets than a coyote at much greater range than 200 yards with my short uppers. They shoot very well. Might work well on live targets so long as bullet expansion is not needed. Wild animals are tough. To get consistent kills expansion is needed. The lower initial velocity results in lower rotational velocity (RPM) thus less bullet jacket stress and little or no expansion. I have found no bullet weight that consistently works at any range from 20 yards to 500 yards in the short barrels. A few kills will be made but failure is never far. I have the data and results in my rifle log book. Iirc initial velocity from my 11.5” barrels for the 77 grain SMK is about 2200 FPS. In my 18” barrels it runs from 2740-2820 for actual Mk 262 issue ammo.

From a longer barrel, even when velocity falls below the MV of the shorter barrels due to range bullets still expand and work well. The RPM is maintained and initial jacket stresses result in expansion.

I have posted my experience, you have posted your theory. The OP can take his pick. I don’t care what he decides. Just sharing what I have learned.

Good luck to you both.

I don’t doubt your experiences, but I think your hypothesis is incorrect. Here are some thoughts:

1. I doubt your 11.5” is sending 77gr at only 2200 fps. Mk262 and BH 77gr TMK are ~2,500 out of my 11.5” and that seems to jive with others online.

2. MV does indeed have an effect on bullet stability factor, but twist rate has a much more significant factor.

Example:
77 SMK from 1:8 twist @ 2,500 fps: 1.66 stability factor
77 SMK from 1:8 twist @ 2,800 fps: 1.72 stability factor

BUT, bump those up to a 1:7 twist and the spin is much greater
77 SMK from 1:7 twist @ 2,500 fps: 2.17 stability factor
77 SMK from 1:7 twist @ 2,800 fps: 2.25 stability factor

3. So that leads me to ask what the twist rates are for your short barrels vs the long. Because the faster muzzle velocity of the longer barrels is not imparting a significantly greater spin on the bullet, just because of the MV.

4. What bullets are you actually using? You mentioned weight ranges between 45-77gr, but what bullets specifically? 77gr SMK isn’t actually as good/reliable of a terminal performer as people make it out to be. I’d be shocked if you were experiencing unreliable performance from SBRs/pistols using bullets like the TSX or TMK. However, I could understand subpar short barrel performance in various lighter varmint bullets. 55gr V-Max, for example, won’t fragment from an 11.5” the way it does from an 18”. The bullet just isn’t designed for a low velocity fragmentation threshold.