14.5 barrel velocities comparison

[markm]

We took out 6 14.5 barrels and shot them against a 6920 16" Colt barrel (first column on the chart) using the same run of 69gr RMR bullets with VV N135 and Wolf SRM primers.

Interesting results.. some shot faster, some slower. The BCMs seem to hang together, and the Minnies Machine took the top spot.

5 Shots only per Barrel. NO ACCURACY considerations taken due to all of them having different sight systems. All of them are completely within chrome lined barrel accuracy expectations.

(Best S.D. BCM ELW at 8, worst S.D. Sabre Defense at 22)

[ViniVidivici]

Most apparent surprise to me, is the 14.5s that're showing higher velocity than the 16. That's wild.

Papabear's thread makes me ask, are all those at about the same round count in their lives?

[markm]

Most apparent surprise to me, is the 14.5s that're showing higher velocity than the 16. That's wild.

No kidding. We knew that going in though. And that was the reason for the test.

Papabear's thread makes me ask, are all those at about the same round count in their lives?

Negative, Ghostrider. The fastes barrel has maybe 1500-2000. The Colt Govt profile has the lowest round count. However, the BCM middies and the Sabre Middy have been shot extensively.

[Uncas47]

Damn nice plunder pile!!

[markm]

I struggle to pass on a 14.5 barrel/upper.

[gaijin]

Same Mark. I’ve ended up with lopsided bunch of 14.5s.

Good report, and I’m also a bit surprised at 16” vs 14.5” velocities.

[lysander]

Tighter chambers and/or throats.

The difference between the two Colt barrels is about the drop you expect from calculations.

[Uncas47]

I struggle to pass on a 14.5 barrel/upper.

It's all I have left, 3 Colts, 2 gummint, 1 SOCOM. All FSP quad rails, SOCOMs got a Razor 1/6, it rides the 4 wheeler on the farm. If i'm totin or around la casa, it's a gummint profile with an Aimpoint. 14.5 quads for life!

[markm]

Tighter chambers and/or throats.

The difference between the two Colt barrels is about the drop you expect from calculations.

I measured the Jump/Leade on the Minnies and the 6920 with the mediocre Hornady tool. They seemed to both be about .135-.145.

Of course that's just a rough estimate on one dimension of the chamber/barrel.

Now that you mention it... The Minnies (which is the fastest) does tend to be the first barrel to pop primers on hot hand loads.

[markm]

Perhaps the best comparison is in the Colts. 14.5 to 16" gains 59 fps.