Upgrading AR's to BRT EZ gas tubes & VLTOR A5 at the same time - should I tune the buffer first?

[gigabels]

Because ordering a BRT EZ-tune requires you to select exactly what buffer and buffer spring you will use, I'm not sure if I should first find the right A5 buffer/spring combination that gets me ejecting at 4:00, and THEN order a BRT EZ-tune based on that info, or just select a commonly suggested buffer for each rifle and trust BRT's calculations. I can always tune it further by adjusting the buffer later.

I figure if I tune the buffer to eject at 4:00 and then add a BRT tube, there will be less gas and thus the buffer will have to be readjusted to eject at 4:00 anyway, right? So it seems I'd be better off ordering BRT tubes now. The only problem is I don't know what A5 buffer weights are best for each gun. However people seem to say H1, H2, and H3 buffers all work really well in A5 extensions no matter what upper is on there, and I don't see a universal consensus on which should be the standard, besides that VLTOR names H2 as the standard.

I want all the guns to work with or without a can. I also want to give them all springco springs, and it seems for A5 the only option is green, right?

The guns are an 11.5" carbine, 14.5 carbine, 16 mid, 18 rifle, 16 mid in 6.5 grendel, and 9.5" pistol-length in 300blk. Do you have any suggestions or principles to select a buffer for these?

 

[maximusdecimusmeridius]

It is going to take some trial and error to get it right

 

[tucaz]

i was able to lighten up on my buffers with the BRT tubes but i am using carbine length too.

 

[LRRPF52]

I’m more convinced these days that spring weight and adjustable gas are better ways to tune the cyclic rate.

I’ve been through everything from 2.9oz to 5.4oz buffers across ARs with the same barrel lengths and gas ports (including A5s), didn’t see any real difference.

When you change the spring weight, you will immediately see differences.

I like using Bootleg carriers for adjustable gas, which are easy to adjust with a small flat head through the ejection port, no carbon-welding.

Remember that heavier buffer weights are mainly for full auto guns and heavier barrels to counter carrier-bounce, not to deal with the cyclic rate. The cyclic rate is mainly determined by gas port location and size.

The other major factor in cyclic rate is propellant type and charge weight.

Slower-burning ball powders will hit your port with higher pressure, whereas faster-burning powders will hit the port with lower pressure, generally speaking.

 

[PBWalsh]

A5 has various spring weights. I’d highly recommend checking out the A5 kit from Revival Defense and calling them and/or BRT to find what you need.

Revival Defense Custom A5 Buffer Builder Kit

www.revivaldefense.com

My 11.5” rifle has an A5 kit in it with Springco green springs and (I believe) and A5H2 buffer with the BRT custom gas tube. My 16” is a BRT optimum barrel with their gas tube and recommended A5 settings.

TLDR: Buy the A5 kit with a standard A5 buffer and Springco green spring. Measure your gas tube hole on the barrel and order the custom BRT tube spec’d with the A5 kit you choose. In in short, buffer system, then gas tube.

 

[1911hombre]

I want all the guns to work with or without a can

If so, I doubt you can achieve 4:00 ejection suppressed.

 

[PBWalsh]

If so, I doubt you can achieve 4:00 ejection suppressed.

Yeah, I’d agree with this. Go 100% can or no can. Optimizing for one will generally lead to less success with the other. Some cans with less back pressure may mitigate the issues, but then your overall muzzle suppression may not be as quiet.

Its all a give and take. I shoot my two rifles 100% suppressed 100% of the time and am 100% happy with that.

 

[LRRPF52]

If so, I doubt you can achieve 4:00 ejection suppressed.

I use Bootleg adjustable gas carriers to achieve this, though I keep guns that I like to suppress, suppressed all the time.

It also works when dialing in 18” MLGS with all that extra plug dwell when you shoot different ammo.

 

[Cascade Hemi]

I’m more convinced these days that spring weight and adjustable gas are better ways to tune the cyclic rate.

I’ve been though everything from 2.9oz to 5.4oz buffers across ARs with the same barrel lengths and gas ports (including A5s), didn’t see any real difference.

When you change the spring weight, you will immediately see differences.

I like using Bootleg carriers for adjustable gas, which are easy to adjust with a small flat head through the ejection port, no carbon-welding.

Remember that heavier buffer weights are mainly for full auto guns and heavier barrels to counter carrier-bounce, not to deal with the cyclic rate. The cyclic rate is mainly determined by gas port location and size.

The other major factor in cyclic rate is propellant type and charge weight.

Slower-burning ball powders will hit your port with higher pressure, whereas faster-burning powders will hit the port with lower pressure, generally speaking.

YHM sells a small aperture mini gas block. They have a base .063" gas port. Take a few drill bits to the range and drill out to the size necessary for function. The gas block has .130" of material in the port instead of less than .040" wall thickness of the gas tube. The gas blocks are $15 each, drill bits are $2.50 from McMaster-Carr.

Agreed on the lighter buffer and higher rate spring. It's a much better shooting experience than heavy buffers.

 

[gigabels]

Thanks all. Yeah I wasn't thinking straight about working with and without a can at 4:00. Might pick one or two designated unsuppressed rifles then. Seriously considering the YHM gas block... just means more work

 

[Cascade Hemi]

Thanks all. Yeah I wasn't thinking straight about working with and without a can at 4:00. Might pick one or two designated unsuppressed rifles then. Seriously considering the YHM gas block... just means more work

AGB's are easier but more expensive. KAK sells buffer kits with an assortment of weights as well as empty buffer bodies. Try setting up one gun first and then work on the rest. A good baseline is a SprinCo Blue spring and Carbine or H weight buffer. For carbine length gas systems you may like a red spring better but it shouldn't be mandatory. A5 in semi-auto guns does not bring anything to the table besides added weight and length.