Ballistic Advantage 13.9 vs Triarc 13.9

[emjbe]

On 10/31/2021 at 9:06 PM, TonytheTiger said:

I wouldn't expect any non nitrided or chrome lined barrel to go beyond 10k.

 

My Rosco 13.7 replaced a BCM 14.5 BFH that made it about 6000 rounds.  I had hoped for more from a hammer forged bbl … but i guess that’s what i get for shooting hot loads and lots of rapid fire in matches.  

[TonytheTiger]

13 hours ago, emjbe said:

 

My Rosco 13.7 replaced a BCM 14.5 BFH that made it about 6000 rounds.  I had hoped for more from a hammer forged bbl … but i guess that’s what i get for shooting hot loads and lots of rapid fire in matches.  

Wow. That seems awfully fast regardless of rate of fire. Was it chrome lined too? I smoked a Black Hole barrel in less than 3k once, but that was fed a steady diet of 75ELD's at 2900 fps. 3k is still too soon to die though.

[emjbe]

On 11/5/2021 at 12:10 PM, TonytheTiger said:

Wow. That seems awfully fast regardless of rate of fire. Was it chrome lined too? I smoked a Black Hole barrel in less than 3k once, but that was fed a steady diet of 75ELD's at 2900 fps. 3k is still too soon to die though.

yes -  chrome lined hammer forged.  I think BCM is "double chrome lined" or something like that.  

 

I'm no gunsmith but I bought a cheap bore scope because I couldn't believe it had shot out at 6000 rounds.  attaching a view of the freebore and start of rifling showing the fire cracking. I think the darker metal is the chrome chipping out. The symptoms I had were frequent shots going way off target.  I'd have 3 hits in a row at 300 yards then 5 shots going 3+ feet around the target.  Also, people kept telling me they could see a vapor trail on a lot of my rounds.  Eventually I figured out that the "vapor trail" was the copper jacket spinning off of the bullet (hornady 2266) in a long puff.  My hypothesis is that the fire cracking was slicing the jacket enough that it would come apart.  Same loads in other barrels shot fine and FMJ loads in this barrel didn't have a "vapor trail" ... but they didn't group well.  Interestingly, it shot fine if I used all copper bullets like the Barnes LRX.  I could still get consistent groups at 535 yards on a steel plate with LRX, but as soon as I switched to affordable ammo accuracy was unacceptable.

 

to be fair, I ran this bbl pretty hard. I got it right after I started shooting 3 gun so lots of rapid fire.  I was learning to reload at the same time. My 55g load is pretty hot and it had a suppressor on it occasionally and I ran test groups that showed high pressure signs when I had no idea why the ejector was imprinting on the brass.  So I'm actually pretty glad to get the education without hurting myself due to my own poor education..

 

It was really accurate ... until it wasn't.  If I had funds to shoot all copper bullets I could still use it ...

 

So overall I'm happy with it ... but like you I wish it had lived a longer life.

 

[Shooter212]

Off topic but what is a good muzzle brake that is long enough for the 13.7 Rosco to get it over 16”?

[TonytheTiger]

6 hours ago, Shooter212 said:

Off topic but what is a good muzzle brake that is long enough for the 13.7 Rosco to get it over 16”?

Off the top of my head? Cobalt Kinetics Pro Brake, SJC Titan or Titan Extreme, Sparrow Dynamics 3 Port, Tooth and Nail Cannibal, Armalite tunable brake, Ultradyne Apollo S, although its jam nut system might make pinning a little complicated.

[Shooter212]

I have wanted to try one of the ultradynes might be a good excuse. I have a drill press welder and a dremel I am Gunsmif!

[TonytheTiger]

Do you have a hammer? Preferably like a waffle head framing hammer? Can't be a gunsmith without one.