Single Edge Polygonal Rifling

[joeg26er]

Was getting some errors on the chrony so battery maybe low
I’ll retest next week and report back

[Sparky5019]

Molon’s testing put IMI 55gr 556 at 3000 fps with a colt 14.5” barrel. Cut 2 inches off and I bet the track barrel and the colt would be even at around 2800 fps for both.

Edit: Thank you for the testing. This is something that has been on my mind since I stumbled upon this thread.

Hmm. Interesting. Provided his chrony isn’t incorrect or low battery, maybe the the SEP bore doesn’t give that extra velocity that it’s advertised as giving. I’ll be interested to see the retest!!


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[joeg26er]

What velocity is everyone else getting out of their barrels with wolf gold?
Length brand and twist rates?

[Sparky5019]

What velocity is everyone else getting out of their barrels with wolf gold?
Length brand and twist rates?

I was getting 2750-2800 from my DD 10.3 with M193 clone hand loads. I have clocked my BCM BFH 11.5 yet.


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[joeg26er]

Should I be pretty happy with my triarc 12.5 velocity being so close to a 16” hk roller lock barrel ?
I’m within 50fpsish
Or is 2970-3000 fps slow for the hk 16” ?

[Skeeter98]

I just ordered a triarc upper with a 14.5 track 2.0 barrel with a p/w sf3p and a giessele mk14. All in all I spent around $850. Plus I have a np3 sionics bcg. Did I pass the point of diminishing returns when spending around 1k for an upper? I wanted this to be my end all be all, do it all carbine but I'm not so great of a shot. What I have is a probably extremely accurate, easy to clean, well built upper. I would still pick this over the urgi.

[Skeeter98]

That was my review. Ordered June 18th. Received and emailed Triarc the following on June 25th - no answer to repeated emails on June 29th and through their site contact form either

"I am a bit disappointed that the weight stated on your website for the 12.5 is 1.37lbs
Mine weighs 1.459 lbs and has no markings except for a tiny s and a 4 on the breech end

Is this weight an error with the barrel or does your site need correcting?"

I guess I'll call them and see if they want to swap me for the 12.5inch 1.2lb barrel? That would be nice...
I weighed this with a scale that's accurate to 5grams and verified with multiple other parts so my scale is accurate

They updated the site. I ordered a 14.5 when it said 1.37 lbs, now its 1.66. These are pretty much medium weight barrels which I guess is good. I was hoping for something a tad lighter. Ill see how it feels once I get it.

[Skeeter98]

Should I be pretty happy with my triarc 12.5 velocity being so close to a 16” hk roller lock barrel ?
I’m within 50fpsish
Or is 2970-3000 fps slow for the hk 16” ?

that's a similar velocity to a 16 inch ar with a standard chrome lined barrel.

[joeg26er]

I just ordered a triarc upper with a 14.5 track 2.0 barrel with a p/w sf3p and a giessele mk14. All in all I spent around $850. Plus I have a np3 sionics bcg. Did I pass the point of diminishing returns when spending around 1k for an upper? I wanted this to be my end all be all, do it all carbine but I'm not so great of a shot. What I have is a probably extremely accurate, easy to clean, well built upper. I would still pick this over the urgi.

You might have. But if it fits your purpose and you’re happy with it that’s what matters
For me I built the 12.5 with the goal of having the power of a 16” as small as possible and with light weight but high accuracy at a reasonable cost
I don’t need to mount precision lasers to the hand guard so could go much lighter on it

[Skeeter98]

You might have. But if it fits your purpose and you’re happy with it that’s what matters
For me I built the 12.5 with the goal of having the power of a 16” as small as possible and with light weight but high accuracy at a reasonable cost
I don’t need to mount precision lasers to the hand guard so could go much lighter on it

it Is almost exactly what I wanted, I only wish the barrel was the advertised 1.37 lbs instead of 1.66 lbs which is still ok. Ill probably get another AR 15 upper once this one is shot out which Is years from now. Its so cool how the world is your oyster with ar 15's. At least I didn't spend 2500$ on a scar or mr556.