Pretty darn impressive. I wonder if this entry will get any of the “Well the M4 type weapons are just not up to modern combat standards like the piston guns” folks?
On July 6, 2021 at 2:04 pm, Unknownsailor said:
Pat Rogers had a BCM that went over 40 thousand rounds without being cleaned. Filthy 14 even has a SWAT article about it. I’ve heard that the rifle eventually went to 70 thousand rounds before Pat passed away, and the rifle was returned to BCM. Was on its 2nd barrel, had numerous parts replaced, and was always run dripping wet with Slip2000 EWL.
Piston guns are a solution to a problem that doesn’t exist.
On July 6, 2021 at 7:53 pm, Barnacle Bill said:
@Unknownsailor:
Piston guns are a solution to a problem that doesn’t exist.
Spoken like a man who can’t afford a piston gun.
On July 6, 2021 at 8:50 pm, Georgiaboy61 said:
@ Unknownsailor
Re: “Piston guns are a solution to a problem that doesn’t exist.”
Forgive me for being pedantic, but would you mind if I modified that statement to end “…a problem that no longer exists”?
What I mean is that today’s state-of-the-art rifles/carbines based upon the AR15, have come a very long way since the 1950s when Eugene Stoner and James Sullivan finalized what became the AR15 and later the M-16. And it isn’t just the rifles themselves, and the materials & workmanship in them, but the ammunition they fire, and the lubricants and cleaning agents and procedures now used to keep them running.
I am no materials engineer, but it doesn’t take a specialist to see that the advanced coatings and surface treatments alone used in today’s carbines and rifles are world’s removed and better than the ones used fifty or sixty years ago.
Piston-driven AR15-platforms today may be superfluous (at least for some individuals) and therefore an answer in search of a problem, but that wasn’t always the case. Elite special ops units around the world – including Britain’s famous Special Air Service (SAS) have adopted the H&K 416, which is in essence a piston-driven M4, over competing direct-impingement and modified direct-impingement systems, for this very reason.
I knew that companies like BCM had been doing yeoman work on improving the reliability of the direct-impingement M4-type carbine, but 7,000 rounds and still going strong is very impressive work indeed. And 40K rounds?? Wow. That begs the question: What model of BCM is that, and what makes it so special and durable?
The thing that gets me is that I can’t figure out why anyone would want one, much less be willing to spend lots of money on it.
Something else to move, cannot be cleaned or lubed, weighs down the front end.
Useless. No point. Unnecessary.
On July 6, 2021 at 10:06 pm, George 1 said:
It is interesting to note that the Battlefield Vegas company in Las Vegas, has these weapons to rent and they put a ton of rounds through them. The staff reports that the H&K 416 and the M4 tend to break parts at about the same rate. These are full auto weapons.
The weapon that has lasted the longest (for the Battlefield Vegas operation) is the SCAR light by a significant margin. So a piston gun but a different design.
Whatever. Most people I’ve heard who ran the SCARs in Afghanistan hated them. They couldn’t run an entire magazine without a FTF.
On July 6, 2021 at 10:28 pm, George 1 said:
I meant to add that while the SCAR light may last longer with no parts breakage, you can certainly buy or build at least three premium AR15s for the price of a SCAR Light.
When the parts availability/supply chain is considered it is a no brainer in favor of the AR15.
On July 6, 2021 at 10:32 pm, George 1 said:
@Herschel Smith.
“Most people I’ve heard who ran the SCARs in Afghanistan hated them.”
Were those SCAR Heavies? I have also heard from some sources that the Heavies were problematic. I have not heard anything bad about the SCAR light. But that doesn’t mean they don’t have issues.
SKS uses gas impingement, and it is not considered to be unreliable. I am happy with my AR’s that I have. round counts are low and I take care of them. Still if thing go hot I will probably grab the ruger bolt as I like it and I control the action.
Lot of air has been spent on this subject and so far opinions seem to be pretty frozen.
C. Reed Knight gives an excellent technical description on why gas piston systems are sub-optimal for the AR platform:
“If there is anything that I am really convinced of, it’s that you should not go and think that the piston-driven upper system, based on the AR-15 chassis, is some type of a major improvement, because in fact, we have found it not to be. If the M4 is properly maintained, and if the gun is kept clean, it will run and do the job that is needed to be done. On the other hand, if you don’t use the tool as what it was designed to be, it was designed for, then it probably is going to cause you some issues. The major thing that we’ve seen with pistons is the bolt cracking of the locking lugs at maybe a higher rate than what we think it should be. The gas piston system does not help that issue, and it exacerbates the bolt cracking. If you take the things that were allowed to be done to improve the gun, such as some of the things that they’ve done for the HK 416, if they were allowed to do that or do some product improvements on the M4, the M4 itself I believe could have a higher reliability in its own design. Unfortunately, there are some things that you help when you go to the piston-driven upper, but there’s also some things that you don’t help. One of the major things is that in a gas impingement system, when the gas pressurizes the chamber in the bolt carrier, it actually pushes the bolt forward, and that pushing of the bolt forward, as it unlocks, takes a good amount of load off the back of the locking lugs as it’s unlocking.”
> when the gas pressurizes the chamber in the bolt carrier, it actually pushes the bolt forward, and that pushing of the bolt forward, as it unlocks, takes a good amount of load off the back of the locking lugs as it’s unlocking.
—-
Interesting; something I’d not considered.
Yet I can find plenty of pictures of AR bolts with broken lugs.
This article is filed under the category(s) AR-15s and was published July 5th, 2021 by Herschel Smith.
If you're interested in what else the The Captain's Journal has to say, you might try thumbing through the archives and visiting the main index, or; perhaps you would like to learn more about TCJ.
On July 6, 2021 at 12:14 pm, George 1 said:
Pretty darn impressive. I wonder if this entry will get any of the “Well the M4 type weapons are just not up to modern combat standards like the piston guns” folks?
On July 6, 2021 at 2:04 pm, Unknownsailor said:
Pat Rogers had a BCM that went over 40 thousand rounds without being cleaned. Filthy 14 even has a SWAT article about it. I’ve heard that the rifle eventually went to 70 thousand rounds before Pat passed away, and the rifle was returned to BCM. Was on its 2nd barrel, had numerous parts replaced, and was always run dripping wet with Slip2000 EWL.
Piston guns are a solution to a problem that doesn’t exist.
On July 6, 2021 at 7:53 pm, Barnacle Bill said:
@Unknownsailor:
Piston guns are a solution to a problem that doesn’t exist.
Spoken like a man who can’t afford a piston gun.
On July 6, 2021 at 8:50 pm, Georgiaboy61 said:
@ Unknownsailor
Re: “Piston guns are a solution to a problem that doesn’t exist.”
Forgive me for being pedantic, but would you mind if I modified that statement to end “…a problem that no longer exists”?
What I mean is that today’s state-of-the-art rifles/carbines based upon the AR15, have come a very long way since the 1950s when Eugene Stoner and James Sullivan finalized what became the AR15 and later the M-16. And it isn’t just the rifles themselves, and the materials & workmanship in them, but the ammunition they fire, and the lubricants and cleaning agents and procedures now used to keep them running.
I am no materials engineer, but it doesn’t take a specialist to see that the advanced coatings and surface treatments alone used in today’s carbines and rifles are world’s removed and better than the ones used fifty or sixty years ago.
Piston-driven AR15-platforms today may be superfluous (at least for some individuals) and therefore an answer in search of a problem, but that wasn’t always the case. Elite special ops units around the world – including Britain’s famous Special Air Service (SAS) have adopted the H&K 416, which is in essence a piston-driven M4, over competing direct-impingement and modified direct-impingement systems, for this very reason.
I knew that companies like BCM had been doing yeoman work on improving the reliability of the direct-impingement M4-type carbine, but 7,000 rounds and still going strong is very impressive work indeed. And 40K rounds?? Wow. That begs the question: What model of BCM is that, and what makes it so special and durable?
On July 6, 2021 at 9:04 pm, Herschel Smith said:
@Barnacle Bill,
The thing that gets me is that I can’t figure out why anyone would want one, much less be willing to spend lots of money on it.
Something else to move, cannot be cleaned or lubed, weighs down the front end.
Useless. No point. Unnecessary.
On July 6, 2021 at 10:06 pm, George 1 said:
It is interesting to note that the Battlefield Vegas company in Las Vegas, has these weapons to rent and they put a ton of rounds through them. The staff reports that the H&K 416 and the M4 tend to break parts at about the same rate. These are full auto weapons.
The weapon that has lasted the longest (for the Battlefield Vegas operation) is the SCAR light by a significant margin. So a piston gun but a different design.
Again these are full auto weapons.
On July 6, 2021 at 10:18 pm, Herschel Smith said:
Whatever. Most people I’ve heard who ran the SCARs in Afghanistan hated them. They couldn’t run an entire magazine without a FTF.
On July 6, 2021 at 10:28 pm, George 1 said:
I meant to add that while the SCAR light may last longer with no parts breakage, you can certainly buy or build at least three premium AR15s for the price of a SCAR Light.
When the parts availability/supply chain is considered it is a no brainer in favor of the AR15.
On July 6, 2021 at 10:32 pm, George 1 said:
@Herschel Smith.
“Most people I’ve heard who ran the SCARs in Afghanistan hated them.”
Were those SCAR Heavies? I have also heard from some sources that the Heavies were problematic. I have not heard anything bad about the SCAR light. But that doesn’t mean they don’t have issues.
On July 6, 2021 at 10:43 pm, RHT447 said:
https://www.pinterest.com/pin/385550418069557667/
Two different design philosophies.
I learned the AR when I went through the Small Arms Repair School at Aberdeen Proving Grounds in ’74. Have learned many more since.
Beware the man who owns one gun. Likely he knows how to use it. Best advice is to have a spare.
On July 6, 2021 at 11:33 pm, Herschel Smith said:
@RHT447,
I’ve chosen mine.
@George 1,
Good question. I’ll pay more attention next time.
On July 7, 2021 at 10:05 am, Paul B said:
SKS uses gas impingement, and it is not considered to be unreliable. I am happy with my AR’s that I have. round counts are low and I take care of them. Still if thing go hot I will probably grab the ruger bolt as I like it and I control the action.
Lot of air has been spent on this subject and so far opinions seem to be pretty frozen.
On July 9, 2021 at 6:40 pm, Bill Buppert said:
C. Reed Knight gives an excellent technical description on why gas piston systems are sub-optimal for the AR platform:
“If there is anything that I am really convinced of, it’s that you should not go and think that the piston-driven upper system, based on the AR-15 chassis, is some type of a major improvement, because in fact, we have found it not to be. If the M4 is properly maintained, and if the gun is kept clean, it will run and do the job that is needed to be done. On the other hand, if you don’t use the tool as what it was designed to be, it was designed for, then it probably is going to cause you some issues. The major thing that we’ve seen with pistons is the bolt cracking of the locking lugs at maybe a higher rate than what we think it should be. The gas piston system does not help that issue, and it exacerbates the bolt cracking. If you take the things that were allowed to be done to improve the gun, such as some of the things that they’ve done for the HK 416, if they were allowed to do that or do some product improvements on the M4, the M4 itself I believe could have a higher reliability in its own design. Unfortunately, there are some things that you help when you go to the piston-driven upper, but there’s also some things that you don’t help. One of the major things is that in a gas impingement system, when the gas pressurizes the chamber in the bolt carrier, it actually pushes the bolt forward, and that pushing of the bolt forward, as it unlocks, takes a good amount of load off the back of the locking lugs as it’s unlocking.”
http://smallarmsreview.com/display.article.cfm?idarticles=1211
Read the whole interview, worth the time.
On July 18, 2021 at 10:59 am, TRX said:
> when the gas pressurizes the chamber in the bolt carrier, it actually pushes the bolt forward, and that pushing of the bolt forward, as it unlocks, takes a good amount of load off the back of the locking lugs as it’s unlocking.
—-
Interesting; something I’d not considered.
Yet I can find plenty of pictures of AR bolts with broken lugs.