new build - SLR sentry 7 adj GB issue

[ScottsBad]

Maybe it would be better to ask your opinion as to what over gassing actually is, perhaps my view is flawed?
A span of function for use has many timing events that we could look into. Some of these can induce additional stresses and strains, some of these can induce reliability issues. If we take the total span in range of function, then look into a cap on stresses/strains and a limit on timing for some events, we can end up in a narrower range than what we consider for function for a a more desired combination.
There is a given that is known, that porting for the carbine H2 action and the base rifle action systems can be an overall standard to compare these. Not saying that all carbine actions require an H2 for proper function, or a rifle like action, they just happen to be in a place that can suit the span width well within the confines of reduced stresses and more optimal timing for reliability.
So is the carbine action H1 and H3 bad when looking at this? No, they aren't necessarily that way, both have an operational overlap that is just offset compared to the H2. Either could be looked at deeper, much of this operation does overlap, their prefered operation may be a little lower in span, but nothing dramatic for most unless you end up in either extreme of the margin, that's not the best place to be in.
In looking at rifle actions, or the rifle like actions, you can end up with finer increments for a buffer mass alternative and a better span when looking at the timing events. Basically, a base with a carbine action with a H2 is a more course adjustment to a H1 or H3 than a A5H2 to a A5H1 or A5H3.
I would tend to prefer a porting that aligns with the carbine H2 or more so with the A5H2. While this may seem unpopular here for some, remember that I'm looking at the span of function and further limiting that to a reduced range that maintains reliability and durability.
Components consume and wear with use, throats, ports, tubes, keys, etc.. Sometimes wear can be a compliment, sometimes to a detriment, depending on specific situations that we can look at further.
For a base 5.56 AR, I would tend to prefer a fixed proper gas port for that application than an adjustable one for non suppressed use only with the A5H2. I'm not sure what gains that most would get by using a larger barrel's base port with an added adjustable gas block. I can really only see negatives, mostly with the erosive gasses.
For a base 5.56 AR, I would tend to prefer a fixed proper gas port for that application than an adjustable one for suppressed only with the A5H2. Still not sure what you would gain with erosion at a higher level than a dedicated port.
For a base 5.56 AR, I may find something that could be suppressed for only half the time. As I may have decided that the can needs to be there or not for whatever reasons. Either application does not need a dedicated gas adjustment on top of an oversized port. There are circumstances that could be had with a single sized port, this size may overlap either for function for either usage. For that scenario, a dedicated port can be used with a reduced overall span of function for both combined, but not ideal for either. A pair of buffer masses may be required to widen the span of desired use for either pretty well. Larger increments are not really needed for most, but when one step up or down maybe needed, it's not much overall.
There are ways to suit a combination's action mass with confidence with the porting. When will the adjustable gas block get the micrometer indications for repeatability?
There's a lot more that could be brought up, from the base combinations to changes.

^^ Real wisdom and some common sense here.

[MistWolf]

We can argue about it all day, but we are just talking past each other. When I refer to tuning I always mean using buffers to slow the cyclic rate to the point where the rifle will operate with the weakest ammo I use, with a little margin for cold weather or dirty rifle. I just assume that I will be using a strong enough spring to strip the next round and put the round into battery.

You on the other hand consider the power of the spring to put the round into battery as a major aspect of tuning, not just the cyclic rate adjustments.

If I've recounted your position correctly, we are both right. I would always consider getting the next round into battery as a crucial step. But I take it for granted because I always use the same spring in 8 rifles (Sprinco Blue...well I have one white and one green too to make 10). And I assume that if the system will lock back on the last round, it is strong enough, with inertia, to strip the next round and put it in battery.

I can see that it is possible to have too much reciprocating weight with a weak spring to get the round into battery. Or too little reciprocating weight. In my opinion, those are extremes.

So, you are correct. I just don't see springs as a major factor if they are at least quality standard springs in good shape. Usually, the magazines are the problem.

EDIT: Let me expand on one last point. A dirty gun is one reason that a round might not go into battery. You are correct to be concerned about that.

I see it as two guys having a meaningful dialogue and hammering out a mutual understanding. In that spirit, I define a well tuned AR as one that runs reliably and smoothly. I'd also like to point out that the spring has an affect on carrier speed, both in extraction and feed.

Changing springs may not be the best way to fine tune an AR, but the spring must match the gas flow and reciprocating mass. To operate reliably, the action has to move with a certain amount of momentum. Too much and the action will batter the rifle and recoil sharper than necessary. Too little and reliability will be negatively affected. Momentum is speed and mass and for reliable function, mass and speed must balanced. More mass and less speed can give the same momentum as less mass and more speed but both are less than ideal for a wide range of function. Span of operation (as Tom so aptly describes it) is narrowed. The rifle will be ammo sensitive or susceptible to fouling or magnify other problems like extraction.

The BCG and buffer is the mass. Gas and spring handle the speed.

I can see in my head how the three parts work together. My difficulty is explaining it clearly, but I'm trying

[BufordTJustice]

BufordTJustice,

Thank you for that. I'm glad to hear that I won't have any problems. I appreciate your experience. Allow me to remain cautious until I've done my own shooting however. You can understand my position I have several ARs, none of which have an adjustable GB. I am interested to try the SLR out.

I did a meticulous installation, with a good quality dimple jig, a quality torque wrench, fresh 272 (high temp) Red. I only drilled one dimple on this one however, because I may at some point want to change the GB.

EDIT: I continue to believe that adding another component, like an adjustable GB, is adding another potential problem point whether it be user error or component induced problems. Therefore, I cannot see myself ever using an Adj. GB in a go-to rifle.

Again, thanks for you input.

I completely understand wanting to investigate for yourself.

The only other block I've used that I can report as 100% reliable is the Black River Tactical MicroTune gas block. And it's considerably cheaper, as well. The owner of BRT, Clint, is a great guy and is painfully knowledgeable about the AR platform. You could always call him to discuss gas port sizing.

I only ever make one dimple. That's always been fine for me. Loctite red 271, 272, or Rocksett all work great. And believe me that the knurled-cup-tip set screws like don't need threadlocker at ALL. When you roll that knurling over at about 20-30 inch pounds, it ain't going ANYWHERE, even bone dry. Using my bi-directional torque wrench, after you roll the knurling, it takes at least an additional 10 inch pounds to defeat it. So, in my experience torquing to 25 inch pounds requires roughly 35 to break the fastener loose. And this is when bone dry.

It's a huge value add for my builds. The dimple being just so that the screw gas to back out several turns before the block can shift much in any direction. And I always glance at the GB before going 10-8 with it.

Good luck in your testing. Holler if you have any questions.

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