Barrel Length Accuracy Nodes

[EDX2308]

I saw that the Diemaco 15.7 barrel is an "accuracy node" and I hear all sorts of things online. The things I want to address is

1. Does the lengths matter at all if your ammo is a different grain weight? Or even different types of ammo, does the length of the barrel accuracy matter?
2. I understand that Colt Canada probably blew hundreds and maybe even a few million into researching accuracy nodes of barrel lengths, maybe I should ask them what the best lengths/accuracy nodes are?

I am quite impressed at how they (Colt Canada) stated "15.7" and lots of research was put in to get that answer. That can't be the only answer that is discovered.

 

[cr5]

Every barrel will shoot differently than another, even two barrels that came off the line one after another. Some ammo seems to work well in most barrels but not in all barrels. Federal Gold Medal Match is a good example of this, most barrels love it but some don't.
You will need to test a few different types of ammo in any barrel you use to find it's favorite bullet and velocity. Even two different bullets of the same weight shot at the same velocity will make different size groups. That's why a handloader never really finishes load development, it can always be tweaked and made better.

 

[Hitzy]

I'm sure it's as much equal marketing as it was testing...plus there is the choked bore, and modified chamber added into the equation as well. If a normal mid-end rifle that doesn't have any of those characteristics can shoot MOA (and some are marketed as guaranteed MOA by certain manufacturers), then how much better performance are those 3 modifications really providing?

 

[Gunnerlove]

Accuracy usually comes at the cost of reduced reliability, and the opposite is also usually true.
What you can make a rifle do with custom ammo is irrelevant to military customers. What a lot (read as a batch or lot, not a bunch or some) of rifles will do with issued ammo is what matters to them.

 

[BattleRife]

They probably determined this using Finite Element Analysis (computer modelling) of their own guns/barrels with typical pressure curve data from C77 ball ammo. The validity of the result likely deteriorates with any other ammo and with any changes to the firearm setup.