Would you first adjust buffer weight/spring rate or gas for tuning?

[Shagnasty]

If you were to use an adjustable gas block in combination with a VLTOR A5, would you first tune the gas and then play with buffer parts or vice versa?

[rcoodyar15]

If you were to use an adjustable gas block in combination with a VLTOR A5, would you first tune the gas and then play with buffer parts or vice versa?

If it won't run with an A5 you have a problem.

Is this some short barreled suppressed homemade gun?

If so I would definitely start with gas tuning.

[Clint]

The buffer can usually be selected first and then the gas drive adjusted for proper operation.

The standard A5H2 at 5.4 oz is a great weight for nearly any configuration.

[Ryno12]

I have a Syrac GB & an A5 RE on my 11.5" SBR. In my experience, the adjustable GB almost negated any real "need" for the A5. Once I set the Syrac to where it needed to be, the A5H2 was perfect.

[tom12.7]

First off, I prefer dedicated porting any day of the week over adjustable gas blocks. If an adjustable gas block is used, port it to the the most normal use with the standard A5H2 buffer for that combination. You can add or remove reciprocating mass when major changes happen, silencers, ammo, etc.

[MistWolf]

With an adjustable gas block, you first set the rifle up with the proper buffer, spring and ammo. Then you fine tune the gas. This keeps the gas exhausted by the carrier to a minimum helping to keep the air around your face clear. This makes the adjustable gas block a better option if you are going to switch between shooting suppressed and unsuppressed. The irony is, an adjustable gas block is useless unless the gas port is too large to start with.

This by no means implies that an adjustable gas block is necessary to have a well tuned AR. Without an adjustable gas block, it's essential the barrel has the proper diameter gas port for a smooth running rifle

[markm]

With an adjustable gas block, you first set the rifle up with the proper buffer, spring and ammo. Then you fine tune the gas.

I agree. Put a USGI spring and an A5H2 (standard A5 Buffer) in the gun and tune from there.

If you have a Carbine RE, then tune it to the H2 buffer.

[tom12.7]

I agree. Put a USGI spring and an A5H2 (standard A5 Buffer) in the gun and tune from there.

If you have a Carbine RE, then tune it to the H2 buffer.

Agreed, but with a preference for the A5 and known good springs.

[StainlessSlide]

I don't mind a little extra weight towards the rear of the carbine, so I use the heaviest Vltor buffer, the A5H4. This gives lower initial bcg velocity for the same initial energy. The lower initial bcg velocity makes unlocking and extraction a bit less violent, and makes them occur at a bit lower chamber pressure.

Then I tune the gas block so that the bcg barely locks back with the MGI recoil spring. When used with the A5 system, this spring stores 20-30% more energy in the fully compressed state than the milspec rifle spring. Then I swap back to the milspec rifle spring (I like 17-7).

This gives me an energy reserve that I estimate is equal to that in the milspec carbine set-up, but with a slower bcg (lower cyclic rate) due to the ~30% larger bcg/buffer mass.

Obviously this method does not lead to the smoothest recoil pulse, since the buffer is striking the aft end of the receiver extension with some force. But I think it's worth it to get the mil-spec energy reserve.

[Clint]

Interesting approach.

Rather than swapping springs, I've always done lockback tests with a loose/floating hold.

If the weapon functions in free recoil, it should also function with any type of firm shoulder hold.

*****

The other aspect to buffer selection is the "nose dive" on return to battery, which increases based on spring strength and buffer weight.

IMO, the 5.4 oz A5H2 is ideal for most configurations.