Gas-port regulating gas-block insert install and DIY manufacture.

[markm]

It would be a nightmare to deal with the idiots who screwed up port reaming of under size port barrels.

[MQ105]

In my opinion this would be an option available to those who ask and who are competent to do the work. This is not for everyone. I think an extra charge would be appropriate.

[scooter22]

I agree with the under-sized GP barrel option.

You can always just buy an 16" Carbine barrel with 0.0595" GP (DD, Aero) and have it cut down.

[scooter22]

What port size would you recommend for an 11.5 with A5 system, 50/50 suppressed/unsuppressed? Thinking about using an A5H0 unsuppressed and up to an A5H4 suppressed if needed.

I'm running a 0.067" on a BCM 11.5" + Surefire 556 SOCOM suppressor + A5H3 + Sprinco Green + Wolf Gold

Works great 50/50

Could probably go smaller

[MQ105]

My Colt 16 is .062" and my DD 16 is .060". My DD 14.5 is .067".

[scooter22]

My Colt 16 is .062" and my DD 16 is .060". My DD 14.5 is .067".

Correct. Edited my post.

[tom12.7]

I would be against suggesting a base barrel with undersized porting for most to customize preferred porting. There are too many ways for this to go towards a net negative. May work for a few, but not most users.
However, I would not be against the possibility of a choice of specific base barrel port selections to better suit intended user requirements for general barrel selections. The given though, would need to include the attributes and the deficits of that choice as part of the selection for the intended use. i.e. For the 11.5" carbine gas 5.56 AR, we can look at a span of preferred function and where we need to fall into with the variables involved. Even a simple 3 variable diagram could help with operational temperature span, ammunition port pressure span, distortion of the the operational preferred span with the introduction of some common cans that have a large influence in regards to preferred function for their own general porting. Combining those could fit a user better than one extreme to the other, be it selected ammunition, temperatures, cans, etc.. Maybe start with with 3 gas port options for something like this, rather than combining opposing extremes that could end up operating outside what we would rather be in.
Until manufacturers can learn how to market to cater more to intended uses, you will continue to see porting selections that are less than ideal. Look at the ranges of preferred span of operation for a port for varying temps, port pressure changes, adding a can, etc..
How well would a -40F made port for low pressure ammo run in a 110F day with higher port pressure ammo? Now add a can to that in the heat with the higher port pressure ammo. how does that work out?
There's better solutions to be had. When the market demands those, better solutions can be had.

[Eric D.]

Thanks that was about what I was thinking.

I'm running a 0.067" on a BCM 11.5" + Surefire 556 SOCOM suppressor + A5H3 + Sprinco Green + Wolf Gold

Works great 50/50

Could probably go smaller

[tom12.7]

The .067" ported 11.5" carbine gassed 5.56 AR is a great combo. That combo can allow a large span of function with ammo and can variables with simple buffer swaps to optimize most. That port is not quite small enough for a DSR, but may fall into being insufficient in colder temps that vary depending on ammunition selected.

[pezboy]

Fired my FN 16.1" barrel with carbine length gas system and .060" insert. Locked back with an A5H4 and Federal 55 gr .223. Seems like you could go quite a bit smaller with a lighter buffer.