Thoughts on 11.5" barrel options, or, should I re-build this?

[TGS]

Both groups were shot with that AAC M4-2000 pictured. I probably need to shoot another group with the setup as is. It was a cold, rainy day and the big dot in the center of the NX8 reticle covers a lot of that little white box. The gun was hot too so mirage from the suppressor. Lot's of "modifiers" as Defoor calls them or "bitch factors" as they probably really are excepting maybe the target and the mirage.

A lot of it is the mental "FWI" factor just because. Accuracy is one thing, terminal ballistics is another. Neither are probably as relevant as my OCD brain tries to pretend they are.

I do appreciate the conversation though.

Yeah, totally. I do the same thing.

@Clusterfrack, trying to find the PDF for specifics. It was a test of 8 Mk18s, suppressed and unsuppressed firing schedule, using M855A1. Conducted in 2013, published 2015. As part of overall service life, they weren't just measuring the bolt life but also accuracy to detect shortened barrel life.

Of interest, they found the average bolt life on Mk18s firing both suppressed and unsuppressed M855A1(!) to be over 9k rounds. They also found that almost all stoppages were fixed by lubrication of the BCG.

I'm angry that I'm having trouble finding it, as I was just reading it a few weeks ago when @HCM and I were talking about 10.3" vs 11.5" bolt lives.

[Sig_Fiend]

I'll preface this by saying, I normally lean towards the more expensive side of things as I prefer quality. So don't think this recommendation means I'm a peasant or have low standards.

I recently discovered a brand, Expo Arms. Best I've been able to tell, their barrels appear to be sourced from Rosco. I've heard mixed reviews, but more positive than not.

These Expo barrels are so cheap and the profile is so unique (close to an HRT profile I believe plus .070" ports), I figured why not try a few for the hell of it. I got an 11.5 and 10.3, but have not been able to make it to the range yet. That said, fit, finish, feed ramps, chamber, and chrome lining look good so far.

10.3 barrel
11.5 barrel

If you have the ability to easily swap out barrels yourself, the price is an attractive proposition IMO. Even if only as a gateway drug to figure out if you want to go with a Colt HRT barrel.

[HCM]

I'll preface this by saying, I normally lean towards the more expensive side of things as I prefer quality. So don't think this recommendation means I'm a peasant or have low standards.

I recently discovered a brand, Expo Arms. Best I've been able to tell, their barrels appear to be sourced from Rosco. I've heard mixed reviews, but more positive than not.

These Expo barrels are so cheap and the profile is so unique (close to an HRT profile I believe plus .070" ports), I figured why not try a few for the hell of it. I got an 11.5 and 10.3, but have not been able to make it to the range yet. That said, fit, finish, feed ramps, chamber, and chrome lining look good so far.

10.3 barrel
11.5 barrel

If you have the ability to easily swap out barrels yourself, the price is an attractive proposition IMO. Even if only as a gateway drug to figure out if you want to go with a Colt HRT barrel.

Expo is a "house brand" for Primary arms. The Expo Barrels are made by Rosco, the Expo rails by CMT etc.

I have one of their 10.3" barrels. They are decent general purpose barrels but not what I would want if trying to build something like a "mini Recce."

Like the "FN barrels" all Rosco barrels are not equal. You get what you pay for. Rosco does make a 12.5" barrel which is used in the SOLGW Sage Dynamics pistols / uppers and has decent accuracy.

Then again I've learned buy once cry once is cheaper overall than "placeholders."

[awp_101]

I'm angry that I'm having trouble finding it, as I was just reading it a few weeks ago when @HCM and I were talking about 10.3" vs 11.5" bolt lives.

Is THIS it?

[TGS]

Is THIS it?

Nope, we're talking about Mk18s here.

[Sig_Fiend]

Expo is a "house brand" for Primary arms. The Expo Barrels are made by Rosco, the Expo rails by CMT etc.

I have one of their 10.3" barrels. They are decent general purpose barrels but not what I would want if trying to build something like a "mini Recce."

Like the "FN barrels" all Rosco barrels are not equal. You get what you pay for. Rosco does make a 12.5" barrel which is used in the SOLGW Sage Dynamics pistols / uppers and has decent accuracy.

Then again I've learned buy once cry once is cheaper overall than "placeholders."

Understood. I generally prefer going DD, Centurion, or other similar quality, so I totally get you on that.

[JSGlock34]

ETA: Well, that being said, I have heard Noveske isn't what they used to be....

Really? Someone better tell these guys...

The War Zone: About Those Custom Rifles Navy SEALs Were Seen Carrying On A Recent Training Mission

'

Interestingly, they're using 10.5" barrels for both 5.56mm and .300 Blackout, keeping the same form factor and setup regardless of caliber.

[Old Man Winter]

Really? Someone better tell these guys...

My understanding is those have been relegated to the arms room and there's a new flavor of the day.

[rd62]

Noveske has certainly taken an interesting marketing turn the last few years that's definitely not my flavor but I'm hoping the known commodity of their stainless barrels is still GTG.

[littlejerry]

I've been very happy with my BRT 12.5 barrel. It does use a proprietary gas tube though, an "intermediate" length between car and mid.

Paired with an A5 system it's been great suppressed and unsuppressed. Also very accurate. It has a "medium" tapered contour.

I've been tempted to buy a 16" barrel of theirs with the intermediate length gas system.