JP LMOS - Why only Competition Use?

[Desert_Racer]

Does anyone have any insight as to why JP's Low Mass Operating System (LMOS) is recommended only for competition use?

My assumption would be that its lighter weight would not make it want to cycle as reliably in harsh and dirty conditions as compared to a full mass BCG and full power buffer spring.

 

[MarkCO]

Because it is not mil-spec. Remember, it is a "system." The carrier is better in every way...provided you have solved the over-gassed problem. To me, adjustable gas is the component that gives me pause in a "must work" scenario. But, if you have solved the excess gas problem with a Noveske switchblock, or a smaller diameter gas port, or rockset the gas adjustment screw on a steel block, then a low mass system is a good solution and will provide better reliability in a harsh environment. Also realize that the JP barrels use a relatively tight chamber, so they need to be kept clean a bit more than some others.

 

[Sebben]

So run the LMOS with a noveske SB on the suppressed setting? What about with a suppressor?

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[thmpr]

Mil-spec to me is the minimum a design for combat readiness. Anything above that is a better design.

 

[Temper]

Because it is not mil-spec. Remember, it is a "system." The carrier is better in every way...provided you have solved the over-gassed problem. To me, adjustable gas is the component that gives me pause in a "must work" scenario. But, if you have solved the excess gas problem with a Noveske switchblock, or a smaller diameter gas port, or rockset the gas adjustment screw on a steel block, then a low mass system is a good solution and will provide better reliability in a harsh environment. Also realize that the JP barrels use a relatively tight chamber, so they need to be kept clean a bit more than some others.

Mil-spec is not the end-all-be-all. The JP LMOS carriers are made from stainless steel and have a QPQ finish, which is nicer and more slick than a phosphated carrier. There's plenty of adjustable gas systems that are reliable, the Syrac gas block works extremely well and the screw which adjusts it is held by a detent. For added durability, you can pin the Syrac block like any other low profile gas block. The LMOS is about 2oz lighter than a semi-auto carrier, which to me only means that your buffer and spring choice become more important in making the gun reliable. I believe a gun with the LMOS system can be made "combat reliable" pretty easily.

 

[MarkCO]

Um, the OP asked why. I agree that MilSpec is the minimum and I have about a half dozen JP LM carriers, even in my must work AR. The Syracs have been plagued with numerous failures, glad yours works, but there are a lot of folks that no longer trust them due to the failures. There are a few better designs out there.

 

[DavidAR10]

Um, the OP asked why. I agree that MilSpec is the minimum and I have about a half dozen JP LM carriers, even in my must work AR. The Syracs have been plagued with numerous failures, glad yours works, but there are a lot of folks that no longer trust them due to the failures. There are a few better designs out there.

Where may I learn of these failures? I have a 0.963" SS II on order and have not heard of any bad news on their products.

Just asking because I don't run around in the circles that are free of liable.

Thanks

 

[redneckbmxer24]

I have no idea why they say competition use only but I've shot rifles with the. In the past and have t personally experienced a failure. I was going to run one in the 6mmAR I'm putting together for DMR matches but I had concerns about the short far 6mmAR around and decided I'd rather have the forward assist ability. I went with the Seekins low mass bolt carrier, JP enhanced Grendel bolt, JP silent capture, and a seekins adjustable gas block. I'm hoping everything works well together, they're all high quality parts so they should.

 

[Regalkismet]

Even if an adjustable gas block fails... It really doesn't fail... Usually. The screw gets bound up with carbon and doesn't allow further adjustment till cleaned. Effectually becoming a standard gas block so to speak.... Not exactly Catastrophic Failure. Moving the adjustment screw on a regular basis or cleaning it resolves this pretty effectively.

 

[Desert_Racer]

I'm glad we reestablished what milspec means and that an adjustable gas blocks can fail, but lets get back to my original question: Why is the JP LMOS recommended for "competition only"?

 

[Millionaire]

I too would like to know, I will email JP then post their reply here.

 

[LawnMM]

If you run a lightweight carrier it will overgas an already overgassed platform without an adjustable block. If talking about self defense, military, or law enforcement roles you want absolute reliability even at the expense of smoother and/or lighter recoil.

You see full weight carriers and wide open gas systems on 'duty rifles' for that reason. Its over gassed, its more recoil, more wear on the system, but no follies of the race rigs. No gas screws losing adjustment, no high cyclic rate missing a round pickup or causing feeding problems.

I've experienced failures to lock fully into battery with a lightweight carrier that was lightly dirty from less than 50 rounds after a good cleaning. I'm thinking of switching to a cheapass dpms full size carrier to give it a bit more oomph as the carrier slaps forward.

 

[Regalkismet]

I'm glad we reestablished what milspec means and that an adjustable gas blocks can fail, but lets get back to my original question: Why is the JP LMOS recommended for "competition only"?

My guess would be because it doesn't have forward assist and possibly due to it may be more susceptible to cycling issues due to having less reciprocating mass....

 

[Sebben]

Seems to me like the "competition use only" is because the JP systems are made and tuned for competition. Not combat or a duty rifle. That's the thing is its not just the carrier its the entire system. The bcg, spring and gas system are all tuned together specificly for better split times and faster everything.

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[Desert_Racer]

If you run a lightweight carrier it will overgas an already overgassed platform without an adjustable block. If talking about self defense, military, or law enforcement roles you want absolute reliability even at the expense of smoother and/or lighter recoil.

You see full weight carriers and wide open gas systems on 'duty rifles' for that reason. Its over gassed, its more recoil, more wear on the system, but no follies of the race rigs. No gas screws losing adjustment, no high cyclic rate missing a round pickup or causing feeding problems.

I've experienced failures to lock fully into battery with a lightweight carrier that was lightly dirty from less than 50 rounds after a good cleaning. I'm thinking of switching to a cheapass dpms full size carrier to give it a bit more oomph as the carrier slaps forward.

That makes sense to me. Thanks for the reply!

Regalkismet mentioned the absence of the forward assist serrations as another reason. For a long time, I thought the forward assist wasn't necessary up until recently when we did a pro-shoot at work:16,000 rounds between 15 people in an 8 hour span..... That was the first time I had to use the forward assist, but it did its job.

 

[Cobracutter]

If you run a lightweight carrier it will overgas an already overgassed platform without an adjustable block. If talking about self defense, military, or law enforcement roles you want absolute reliability even at the expense of smoother and/or lighter recoil.

You see full weight carriers and wide open gas systems on 'duty rifles' for that reason. Its over gassed, its more recoil, more wear on the system, but no follies of the race rigs. No gas screws losing adjustment, no high cyclic rate missing a round pickup or causing feeding problems.

I've experienced failures to lock fully into battery with a lightweight carrier that was lightly dirty from less than 50 rounds after a good cleaning. I'm thinking of switching to a cheapass dpms full size carrier to give it a bit more oomph as the carrier slaps forward.

DING.

The place to find out your gun doesn't work, or doesn't work as intended is not on the side of a mountain in afganistan or as first man in the stack.

Milspec means much more than just the materials and build quality. It means it works, usualy interchangably or without fitting (VERY IMPORTANT) within a system. One cog in the system gets fucked up the whole system fails.

When your or your buddies life is on the line, you use tested and proven gear. And not this "I shot 200 rounds so its good to go bullshit" . One gun or even 10 guns doesn't mean shit with respect to the quality of a manufacture.

 

[Strykervet]

Basically it's not heavy enough and that results in reduced reliability, particularly in less than ideal conditions. Competitions are usually ideal conditions, so that's why the discrepancy.

Their full mass carrier is by far the nicest one I've ever used and the only one I use in builds today. Their bolt is nice too. I'd get this is if reliability is a big concern. They're well made and super slick and I've yet to see one malfunction.

 

[Cobracutter]

Seems to me like the "competition use only" is because the JP systems are made and tuned for competition. Not combat or a duty rifle. That's the thing is its not just the carrier its the entire system. The bcg, spring and gas system are all tuned together specificly for better split times and faster everything.

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It's because it is unreliable, un-durable or both. When a Manuf comes out and says not to use for duty, then you KNOW it will fail. Otherwise they will say nothing and let the sales roll in. By doing so, they know otherwise people would buy it and drop into a duty rig, it have an unacceptable failure rate, and hurt their brand.

To alleviate this problem, they say for competition use only.

 

[MarkCO]

So how many of the JP carriers have you used Cobracutter?

 

[Sebben]

It's because it is unreliable, un-durable or both. When a Manuf comes out and says not to use for duty, then you KNOW it will fail. Otherwise they will say nothing and let the sales roll in. By doing so, they know otherwise people would buy it and drop into a duty rig, it have an unacceptable failure rate, and hurt their brand.

To alleviate this problem, they say for competition use only.

That's not the case. Its designed for a specific application. Not a multi-use general purpose one. You wouldn't use a scale as a screw driver.

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[Cobracutter]

So how many of the JP carriers have you used Cobracutter?

Other than inside JP gas guns? None. I only use trusted, proven and reliable componets in my builds. If I want a softer shooting gun that is as reliable/durrable as Colt/DD/LMT then I will pick one of the Sr-15's out of the safe. Nothing comes close to that system.

That's not the case. Its designed for a specific application. Not a multi-use general purpose one. You wouldn't use a scale as a screw driver.

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Please tell me what is "not the case". The fact is, people will try and use them in duty/hard use rigs and when they fail, they will Blame JP. JP proactivley fixed this problem. There is nothing wrong with this, and it's actualy wise on their part.

Do you need me to explain the idiocracy in comparing a Lowmass Carrier/ Normal Carrier to Scale / Screwdriver?

The question was asked why is not not used for duty/Non compeititon use. He was given the awsner he was asked for.

When you can start weighing items with a screwdriver, let me know....sounds interesting.

 

[Cobracutter]

Oh and MarkCO,

Do you plan on paying the advertising fee to Snipershide/Lowlight since you are using HIS website to advertise your company?

https://twitter.com/Markpcolo
https://www.facebook.com/pages/Carbon-Arms-Corp/495735763781812
And a WHOLE bunch of youtube videos seem to indicate this is you.

Everyone else has to pay to advertise here, why are you different.

 

[Sebben]

Stupid auto correct. Meant scalpel. Lol

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[jevan126]

The JP LMOS is used in many police departments as well as in the military. And as far as MIL spec goes it sucks, that is why JP rifles are so reliable and accurate ther is nothing mil spec about them. Think about it for a minute, if you are shooting competition you want a 100% realiable gun and if JP LMOS are recommended for competition then they are going to be 100% reliable for duty. You just have to break it in and find the right ammo that works for your rifle.

 

[LRRPF52]

Mil-spec to me is the minimum a design for combat readiness. Anything above that is a better design.

Only problem is, there are maybe ~3-7 companies on the market who even have a clue what Mil-spec and the TDP are, and hardly any of the other companies meet those "minimum" standards.

When you start to look at the certs on components, materials sources, metallurgy, manufacturing methods, and QC, we're talking about a handful of companies left.

Simply slapping a NiB BCG, stainless barrel, billet receiver set, and BCM GF or Raptor CH together with the pet handguard of the season does not equal anything near the Mil-spec or TDP. A lot of people have been misled to believe this is the case, when most of the guns that fall under the description above fall way short of anything resembling the TDP in critical components or certs.

JP is one of the few that knows what he is doing, and really gears a lot of his blasters towards a particular field in the competitive action shooting sports, but has also made gov't type blasters along the way.

A lot of low standard companies point out one area of self-proclaimed expertise in their components (which are usually way below the TDP standards), then tell the new customer that they are better than "...the lowly Mil-spec, since that's the lowest bidder", or some similar craphouse lawyer spiel.

Bushmaster made millions that way. Turns out not one of their components was anything near the Mil-spec.

Mil-spec and the TDP for even the M16 are things that most AR15 companies don't, and won't ever have a clue about, because they simply can't be told. They already know better in their minds.

JP knows this, and is trying to avert the situation where some knucklehead drops the lo-mass carrier into a rack-grade duty rifle, thinking he will gain some performance advantage, not understanding that the lo-mass carrier is designed to be used as one of many components in a race-ready rig, to include the gas system, recoil system, being fed a very particular load for competition use.

 

[jevan126]

well said LRRPF52

 

[Dark Horse]

The JP LMOS is used in many police departments as well as in the military. And as far as MIL spec goes it sucks, that is why JP rifles are so reliable and accurate ther is nothing mil spec about them. Think about it for a minute, if you are shooting competition you want a 100% realiable gun and if JP LMOS are recommended for competition then they are going to be 100% reliable for duty. You just have to break it in and find the right ammo that works for your rifle.

Did someone pay you a lot of money to actually post this? You couldn't be more incorrect with every single statement you made if you tried.

Yup, screw MIL spec, don't want those steel targets shooting back at you.

 

[Desert_Racer]

The JP LMOS is used in many police departments as well as in the military.

I am curious as to the validity of this statement. I have yet to hear of this or read about it. Do you have a reference?

 

[Dark Horse]

I am curious as to the validity of this statement. I have yet to hear of this or read about it. Do you have a reference?

Didn't you know that if someone posted it on the internet that it must be true?

 

[redneckbmxer24]

Didn't you know that if someone posted it on the internet that it must be true?

If it goes in Facebook it's official as a fucking whistle.

 

[HKpirate]

I am curious as to the validity of this statement. I have yet to hear of this or read about it. Do you have a reference?

My local PD has a few JP lrp07's in the safe.. But that's a complete system not just the carrier.

 

[Cobracutter]

The JP LMOS is used in many police departments as well as in the military. And as far as MIL spec goes it sucks, that is why JP rifles are so reliable and accurate ther is nothing mil spec about them. Think about it for a minute, if you are shooting competition you want a 100% realiable gun and if JP LMOS are recommended for competition then they are going to be 100% reliable for duty. You just have to break it in and find the right ammo that works for your rifle.

I wonder how many JP rifles have been tested to destruction....not even talking about a sample... just 1 gun?

Mill spec means MUCH more than reliability of one gun. It comes along with a metric shit load of testing. Most companies have the benefit of the AR and can use the same/very similar parts.

When parts are changed they also change how the system operates. MANY of the things we know about the AR system, we only know because they have been tested to destruction over the years.

Be careful painting a broad brush or making assumptions for a product that HAS NOT been tested and proven to the levels of your game gun.

 

[Cobracutter]

My local PD has a few JP lrp07's in the safe.. But that's a complete system not just the carrier.

I bet many more have Mini-14's...........

Point is when there are tens of thousands of "agencies" and hundreds of millions of firearms in this country, chances are someone is running one of them.

This is not a knock to JP, they make kick ass guns. But words have meaning and IMO it's dishonest to not understand the difference between handful of guns and a comprehensively fully tested weapon system by CRANE/Aberdeen. You would not believe the shit those nerds make guns go through.

 

[LRRPF52]

Read this series of tests that was done on the original Armalite AR10 in 1960. Then ask yourselves if any of the civilian AR15's have undergone anything even close to that.

http://www.dtic.mil/dtic/tr/fulltext/u2/245709.pdf

 

[N0mad]

Never been deployed or active duty but over the last 10 years I've worked in engineering departments for both the US Army and the US Air Force as a civilian.

I've never seen a piece of equipment, weapon, helicopter or airplane that wasn't over engineered as to the point of obsession including thousands of man hours in testing and re-testing for certification.

Step inside a C-17 Globemaster or a C-5 Galaxy maybe pick up an M60; every nut, bolt, tie down, fastener, rivet, cartridge belt, cargo strap you name it has been over engineered (Mil-Spec) even the training of soldiers, marines and airmen is over engineered and repetitive because it works.

Not once have I ever heard the terms Low Mass, Light Weight, Feather Like used in the same sentence as reliable, dependable and bet your life on it. I’m just sayin...

 

[jevan126]

DarkHorse can you read if you can then read what HKpirate just said. Also do some research if you know how and you will see that the U.S. Army Snipers use JP LRP-07 rifles. So I guess I am not so wrong.

 

[cal50]

Also do some research if you know how and you will see that the U.S. Army Snipers use JP LRP-07 rifles. So I guess I am not so wrong.

Yep, some shooters used them during competition.

JP Rifles See Use By AMU Team Winners Of The 2012 International Sniper's Competition : The Tactical Wire

 

[bm11]

This is an interesting debate, in that I have a hard time believing it has gone on this long. To me, it doesn't take an engineering degree to understand that if you take a complete rifle system and tune it for one specific ammunition that recoils the absolute minimum so that you can drop .01 second off your splits, that is NOT the rifle system that you want to choose if you end up in an extended firefight where hundreds of rounds get fired, the gun gets real dirty, and you may have to improvise and use different ammo.

Two different purposes, and JP even says so.

 

[DT1]

John Paul addressed this exact question by the OP in a recent magazine article.

"I will be the first to tell you that low-mass carriers chambered in 5.56x45mm are great for competition but a poor choice for combat. The 5.56 AR rifle needs the additional mass of the standard weight bolt carrier to help ensure reliable operation when it is dirty and insufficiently lubricated. It takes some extra gas to get the heavier carrier moving, but the weight ensures that the BCG makes it all the way back into battery when it counts."

JPE makes standard weight bolt carriers which are indeed used in JP rifles by many PD's across the country. JP rifles have also been occasionally deployed in combat by US operators who have the ability to choose their weapon systems.

 

[DT1]

I wonder how many JP rifles have been tested to destruction....not even talking about a sample... just 1 gun?

Mill spec means MUCH more than reliability of one gun. It comes along with a metric shit load of testing. Most companies have the benefit of the AR and can use the same/very similar parts.

When parts are changed they also change how the system operates. MANY of the things we know about the AR system, we only know because they have been tested to destruction over the years.

Be careful painting a broad brush or making assumptions for a product that HAS NOT been tested and proven to the levels of your game gun.

It may interest you to know that the JP LRP-07 was evaluated a couple of years ago in the exact manner you describe to replace the Knights rifle for the M110 platform. A dozen of them went through a battery of tests at Ft. Bragg and received rave reviews from the operators who evaluated them. The reason cited for non-adoption was that there was failure of the small machine screws that secure the free float tube to the barrel nut. That system has since been modified. Other than that, the rifles performed flawlessly. It will be interesting to see what happens the next time that contract comes up.

 

[Cobracutter]

BUH BUH DA AMREY SNIERZ I SAWD ON MUHZ LAURES VIDOES USEZ DID.

AMU could have won that comp with a DPMS or Bushmaster. Its about much more than shooting or even shooting the smallest group. Skill/experience is going to trump equipment almost EVERY time. This is why those men are trained the way they are......They can take shit end of the stick and turn it into mission accomplishment.

Arguing or even questioning why this product is not used in Duty/combat weapons just shows you have a complete fundamental lack of understanding of the entire subject matter and would be wise to read MUCH more and post MUCH less.

 

[Cobracutter]

It may interest you to know that the JP LRP-07 was evaluated a couple of years ago in the exact manner you describe to replace the Knights rifle for the M110 platform. A dozen of them went through a battery of tests at Ft. Bragg and received rave reviews from the operators who evaluated them. The reason cited for non-adoption was that there was failure of the small machine screws that secure the free float tube to the barrel nut. That system has since been modified. Other than that, the rifles performed flawlessly. It will be interesting to see what happens the next time that contract comes up.

Got any documentation or proof to back up this claim?

Would be interesting to read.

 

[Dark Horse]

DarkHorse can you read if you can then read what HKpirate just said. Also do some research if you know how and you will see that the U.S. Army Snipers use JP LRP-07 rifles. So I guess I am not so wrong.

You are kidding right? You make a blanket statement that le and the military uses the LMOS and then try to justify it because some local pd purchased a few JP rifles and the AMU team won a comp with them?

Let's break this down a bit.

1."And as far as MIL spec goes it sucks, that is why JP rifles are so reliable and accurate there is nothing mil spec about them".

JP rifles are reliable because they are tuned to be reliable for a specific load. Change that load and what do you have? MIL spec is reliable because it HAS to be because lives depend on it. It has to work in every environment for every load every time. Get it?

JP rifles are more accurate because they are using match quality barrels and chambers that are again tuned for a load. Your average combat M4 does not.

2."Think about it for a minute, if you are shooting competition you want a 100% realiable gun and if JP LMOS are recommended for competition then they are going to be 100% reliable for duty".

How you can even equate competition and combat is beyond my comprehension. First, the LMOS isn't recommended for comps because it's any more reliable than anything else out there. It's recommended because it allows faster follow up shots due to a lower reciprocating mass which in theory translates to less perceived recoil. Whether this is true or not remains debatable. I have heard from shooters that swear by it and some that say there was no difference. Regardless, this has zero to do with reliability. Secondly, inanimate targets do not shoot back. Your shit better function in combat every time. So when your lightened bcg fails because it doesn't have enough mass to cycle properly when it's dirty guess what happens next?

3."You just have to break it in and find the right ammo that works for your rifle".

MIL spec is MIL spec for a reason. This statement is one of them. No one in combat is tuning their rifle to a load so that is functions properly.

If you want a shiny new toy to show off to all your buddies then buy a JP rifle with the LMOS and use it for was it was intended for. BM11 hit the nail on the head.