First of all, I appreciate the discussion.
Talk to instructors at carbine courses.
That isn’t reason. That is a bold assumption. Perhaps a rare rifle reasonably be assumed to become a safe queen. But just expense alone is not a good guideline for safe queen rate. I know a whole lot of KAC SR15s and SR25s that are used and abused. Sure, some people buy them strictly for the gram, but those people aren’t shooting cheaper guns more. They just don’t shoot a lot to begin with.
There are some barrels with undersized gas ports in an attempt to make the gun shoot softer, but I’ve seen that cheaper barrels actually tend to have larger gas ports to account for the lower energy of cheap 223. Then people complain about them being too gassy with full power 5.56.
And carbine length vs mid/rifle doesn’t necessarily change the dwell time. A 16” with carbine gas system actually has more dwell time than a 20” with rifle length gas system. And a 16” mid-length actually has less dwell time than both the M4 and the M16.
Dwell time only becomes a factor when you get really short dwell time like the 10.3/10.5” barrels or 16” dissipators. In the 10.3/10.5”, the gasses don’t have much time to cycle the system and so you need more gas, which results in sharper recoil and increased parts wear.
The downside to a carbine gas system is the increased peak pressure. The farther away the port is, the less pressure there will be at the port as the gasses have more volume to expand. There is also the factor about time to unlock.
I do find rifle gas systems smoother and they can shoot some higher pressure match ammo before getting pressure signs. And I prefer mid-length on 13.7-16” barrels because it is smoother than carbine. Mid-length exists now and it’s a improvement in feel for those M4-ish length carbines/rifles.
Make no mistake though, carbine gas systems have been around for a long time and are extremely reliable. If a cheap rifle’s gas ports are jacked up, that’s a reason not to buy that rifle. Not a reason to avoid carbine gas systems.
But yes, burrs in gas ports are an example of poor QC. Along with poorly secured gas keys, gas tubes that are slightly too long or short, bolts that weren’t properly heat treated, firing pins that out of spec, overly large firing pin holes, or un-staked castle nuts, etc.
I don't think there is any data to support the claim that more expensive ARs fail less. And since there is NO data to support either claim,
Talk to instructors at carbine courses.
I am going to use reason: The more expensive ARs are far more likely to become safe queens than the inexpensive "bang about" ones and therefore will get far less usage, in general.
That isn’t reason. That is a bold assumption. Perhaps a rare rifle reasonably be assumed to become a safe queen. But just expense alone is not a good guideline for safe queen rate. I know a whole lot of KAC SR15s and SR25s that are used and abused. Sure, some people buy them strictly for the gram, but those people aren’t shooting cheaper guns more. They just don’t shoot a lot to begin with.
That’s not going to happen. Extractors may wear earlier than normal (for any AR, expensive or not). But extractors are one of the shortest round count wear items in an AR. They should be replaced at appropriate intervals and you should have a spare or two on hand.… I don't want to ruin my Gucci AR with these steel-cased abominations. …
Two ARs owned by different people? Or owned by the same person? If by different people, yes it’s possible that owners of cheaper ARs may not follow an appropriate maintenance cycle. That would be an interesting study but I have nothing to support it. If by the same person, maybe that’s your SOP, but not what I’ve noticed. People generally train with the carbine they intend to use defensively to get familiarity and confidence with it. The only exceptions are with 22lr uppers for cheap training or designated simunition uppers.When there are two ARs, Gucci and El'Cheapo, the less expensive one is far more likely to get used and less-likely to get appropriate level of maintenance.
The only point I think I failed to get across is the "good enough" approach when it comes to gas systems. If one were to start with inexpensive AR, it is more likely to have a gas system that hasn't been sorted out. , When it comes to cheap barrels, the most common issue I see on AR15.com forums is the diameter of the barrel gas port. The hole is usually undersized or has burrs that lower the amount of gas going back. By far, the most common problem! at it is most prevalent in Carbine length systems the time for pressure build-up is limited by the barrel length. in a Carbine, gas has to do a lot with very limited dwell time. The issue with the gas system appears a lot less with longer barrels and gas systems. This is why I believe that if one were to go with "good enough", low-cost AR as a starting point, avoiding a Carbine-length gas system is a good idea.
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There are some barrels with undersized gas ports in an attempt to make the gun shoot softer, but I’ve seen that cheaper barrels actually tend to have larger gas ports to account for the lower energy of cheap 223. Then people complain about them being too gassy with full power 5.56.
And carbine length vs mid/rifle doesn’t necessarily change the dwell time. A 16” with carbine gas system actually has more dwell time than a 20” with rifle length gas system. And a 16” mid-length actually has less dwell time than both the M4 and the M16.
Dwell time only becomes a factor when you get really short dwell time like the 10.3/10.5” barrels or 16” dissipators. In the 10.3/10.5”, the gasses don’t have much time to cycle the system and so you need more gas, which results in sharper recoil and increased parts wear.
The downside to a carbine gas system is the increased peak pressure. The farther away the port is, the less pressure there will be at the port as the gasses have more volume to expand. There is also the factor about time to unlock.
I do find rifle gas systems smoother and they can shoot some higher pressure match ammo before getting pressure signs. And I prefer mid-length on 13.7-16” barrels because it is smoother than carbine. Mid-length exists now and it’s a improvement in feel for those M4-ish length carbines/rifles.
Make no mistake though, carbine gas systems have been around for a long time and are extremely reliable. If a cheap rifle’s gas ports are jacked up, that’s a reason not to buy that rifle. Not a reason to avoid carbine gas systems.
But yes, burrs in gas ports are an example of poor QC. Along with poorly secured gas keys, gas tubes that are slightly too long or short, bolts that weren’t properly heat treated, firing pins that out of spec, overly large firing pin holes, or un-staked castle nuts, etc.
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