Can a mid-length system be made as soft as a rifle-length gas system?

[RAZZ]

I was out shooting a couple of my rifles today. Both SS 18" barrels, and both similar in weight and accuracy. However one of them has a rifle length gas system, and the other is a mid-length. The mid-length recoiled noticeably harder than the rifle length. I have never been too interested in an adjustable gas block, but now I guess I understand why people look into them. Can an adjustable gas block make the mid-length gas system feel like a rifle-length gas system? And as long as I'm here asking questions, which adjustable gas block to you recommend?

Thanks

[michael1778]

Certainly, the mid-length gas on the 18" barrel would feel harder than the rifle length gas system on the same length (fixed gas block).

Assuming similar size gas ports (huge assumption!), the initial port pressure will be larger/higher (propellant hasn't expanded as much so gas pressure larger) and overall dwell time will be longer in the 18" mid-length gas system (port to muzzle distance is longer in the mid-length gas system on equivalent length barrels). So, there is the basic mechanics of the systems comparison.

The adjustable gas block can reduce the volume of gas flow for the operating system (by restricting the functional gas port size), but it won't change the pressure or dwell times. In the end we get down to perceptions. What does it "feel like" to the operator? Many different factors come into play. If we do a mechanical measurement (non-human), then no I don't think you are likely to get the measured total recoil impulse to be less than the rifle length system on the same barrel; close perhaps. However, could you get close enough to be imperceptible by the operator? That could be. To be clear, I'm comparing to a fixed gas block 18" rifle system for comparison.

Others with more experience may come along to enhance our conversation, but the fundamental mechanics are reasonably well defined and point toward a general answer.

Edited April 29, 2015 by michael1778

[gose]

You could probably get a mid length with an adjustable gas system shoot softer than an rifle length without. Then, otoh, a rifle length with adjustable gas system would be smoother still.

Everything else equal, Id' say that a rifle length is always going to be smoother, so the better question would be, can I get a mid length smooth enough so there's no practical difference compared to a rifle length. Only testing and tweaking with your stuff can answer that, but you should be able to get pretty close.

[RAZZ]

Well, we'll find out in a few days. I just ordered a JP adjustable gas block. Stay tuned.

[BitchinCamaro]

I know you already ordered the JP, but I was going to suggest researching the SLR (I think that's correct) block.

I have the Syrac Gen 1, which I believe is the same as the JP. It gets gunked up pretty good during a match, and after everything gets cemented while it sits in the safe, it becomes a real chore to change settings if you choose to dink around with new loads.

The gen 2 still has a detent system that can get fairly sticky.

The SLR uses a big leaf spring which I imagine is more user friendly, and has to be easier to disassemble for cleaning than my current setup.

I do love the function of the JP/Syrac, but if you're not committed to it yet, maybe have a look-see at the other offerings because there is a downfall to the tiny detent system.