308 maten build- low mass vs high mass systems ...... (slash heavy vs jp lmos)

[kenndapp]

Hello all. I have am almost finished with a mega maten mkm build and am having a hell of a time choosing between a low mass buffer system or a High mass buffer sytem. The goal is to end up with the softest shooting 308 I can get. Something the wife and grandkids could enjoy aswell. It will have an slr ajustable gas block so no matter what the rifle will be tuned.

Right now I need to choose between a slash heavy buffer set up or a jp silent captured spring set up. I usually just run the heaviest buffer the build will run reliably and this has always made for a smooth weapon. I have never attempted to achieve this result with a low mass system. After reading all about jp lmos systems and the jp scs, it may be worth stepping out of my comfort zone to try. My main concern with stepping in a direction other than heavy buffers is bolt bounce and a general violent operation. I don't like how the jp scs has no wieghts "slamming home" upon return to battery. It just doesn't seem a possative of an action. Again an ajustable gas block will be in play.

If you have ever used a low mass set up ( specificaly the silent captured spring set up) please chime in and share with me you experiences in high vs low mass systems. Two very differnent methods of achieving a smooth low recoiling action have me very perplexed. Please advise.

 

[jasonfaz]

I did the same back and forth. I ended up buying both set ups and I really couldn't tell a lot of difference in felt recoil. I did feel the impulse itself was "smoother" with the JP. I ended up weighing the buffer + spring of each. Both are exactly the same weight at 7.4 oz. The reciprocating mass of the JP is only .9oz lighter than slash's buffer. I recently bought the spring pack for the JP and I think the addition of being able to modify the spring tension now sets the JP in a class of its own. One thing I have never liked about Slash's buffers is the clanking sound of the weights - especially noticeable when shooting suppressed. The JP SCS set up gets rid of that too. All that said, I'm trying to now get rid the one CAR-10 XH buffer and the proprietary 308 spring Clint sells as an option with those. So if you end up making the call to go with the CAR-10 let me know. Hope that helps!

 

[LawnMM]

I went the JP route for the gas system on my 6.5 Creedmoor and it's working out quite well. It's a soft and smooth recoiling rifle. I need to buy the spring kit for the SCS, its cycling a tad faster than it needs to be but that's hardly worth mentioning.

 

[problemchild]

The S heavy buffer has a kool-aid cult following and I am not sure why. It seems that people like putting band-aids on skin cancer to cover up the real issue.
If you need a heavy buffer the gun is over gassed. Buy an adjustable gas block and a barrel with the correct size gas hole. Make sure the bolt carrier (AR-10) has the correct size exhaust hole as well. Some BC's have too small an exhaust hole and cannot vent gas quick enough.

My experiments have brought me to the following setup---> No weights in the buffer (yes empty). I run a hollow buffer, a low mass carrier and an adjustable gas block. The gun (AR-15) has the recoil and felt impulse of a 10-22. The gun will run ANY ammo and NEVER misses a beat, 100% reliable!

So what does that tell you about slashes heavy buffer?

Would I take this gun into combat, hell NO! Would I take it to the range, yes!

Hello all. I have am almost finished with a mega maten mkm build and am having a hell of a time choosing between a low mass buffer system or a High mass buffer sytem. The goal is to end up with the softest shooting 308 I can get. Something the wife and grandkids could enjoy aswell. It will have an slr ajustable gas block so no matter what the rifle will be tuned.

Right now I need to choose between a slash heavy buffer set up or a jp silent captured spring set up. I usually just run the heaviest buffer the build will run reliably and this has always made for a smooth weapon. I have never attempted to achieve this result with a low mass system. After reading all about jp lmos systems and the jp scs, it may be worth stepping out of my comfort zone to try. My main concern with stepping in a direction other than heavy buffers is bolt bounce and a general violent operation. I don't like how the jp scs has no wieghts "slamming home" upon return to battery. It just doesn't seem a possative of an action. Again an ajustable gas block will be in play.

If you have ever used a low mass set up ( specificaly the silent captured spring set up) please chime in and share with me you experiences in high vs low mass systems. Two very differnent methods of achieving a smooth low recoiling action have me very perplexed. Please advise.

 

[smschulz]

Right now I need to choose between a slash heavy buffer set up or a jp silent captured spring set up.

I have three MA TEN's and the first two used Slash's Heavy Buffer.
They ran great!
I bought a JP for the third after all it is cool, different and I even have one on a 223/556 Seekins build.
It ran like crap, wouldn't cycle, FTE's.
Sold it.
Went back to brother Slash!

 

[JRM83]

Since you are running an adjustable gas block I would run the low mass carrier and silent captured spring. My experience with .308 AR-type rifles has been that they are typically overgassed and extremely sensitive to changes in the buffer/spring system. Without the adjustable block adding the LMOS carrier and JP spring is very likely to cause reliability issues. Running an adjustable gas block lets you tune the gas to run reliably with different carrier, buffer, and spring weights. As problemchild stated, the heavy buffer is really just a method of mitigating the overgassing issue without actually addressing it.

 

[biner626]

308 maten build- low mass vs high mass systems ...... (slash heavy vs jp lmos)

Since you are running an adjustable gas block I would run the low mass carrier and silent captured spring. My experience with .308 AR-type rifles has been that they are typically overgassed and extremely sensitive to changes in the buffer/spring system. Without the adjustable block adding the LMOS carrier and JP spring is very likely to cause reliability issues. Running an adjustable gas block lets you tune the gas to run reliably with different carrier, buffer, and spring weights. As problemchild stated, the heavy buffer is really just a method of mitigating the overgassing issue without actually addressing it.

Exactly my experience as well. I got the LMOS and Silent spring system before getting the adjustable gas block. As a result I was causing FTF. This system is optimal in a adjustable gas system. In fact it requires it.
Soft recoil indeed.


Sent from my iPhone using Tapatalk

 

[kenndapp]

Thanks every one. Especially jasonfaz...... Exactly the type of imput I am looking for. Pm me about your car10 buffer might take it if I can ever make a choice between the two systems.

I think there may be some confusion about my goals and intentions.
To restate, I AM running an adjustable gas block. I AM NOT trying to fix an over gassing issue with a heavy buffer (ajustable gas block).

I simply would like to know when gas is adjusted optimally for either system ..... Then which system is the smoother, lighter, "better" operating system? When adjusted accordingly, which system operates more optimally? Can you fell a difference? Also, while reliability is important, this is a "fun gun". It isn't meant for SD or HD and a few finiky malfunctions while figuring out the sweet spot in the gas adjustments is fine.

At this point, due the the minimal weight differentials between the two systems I am leaning towards the slash heavy buffer system with optimally adjusted gas. As this seems to be a rock solid method. For some reason the reciprocating weights in a conventional buffer are important to me..... The whole "slamming home" dead blow thing. Is this as important as i think it is? With gas dialed in I am sure it will be a very smooth recoiling rifle.

Good info jasonfaz, thanks again. And thanks everyone else for the experience shared! Please keep it coming, especially if you have tried both systems!

 

[jasonfaz]

You bet buddy. And hey, I overlooked mentioning one other option you might want to look into. You could also grab a Vltor A5 tube or PWS's new 308 EBT (only $200) and run any standard AR-15 buffer (unfortunately, the A5 buffers won't work) on your 308 which would open up Slash's 8.5oz and PWS's 7oz H4 as options. However, unless you're running it suppressed the 8.5oz XH might be too heavy and cause you to increase gas to get it to run. I'll PM you on that CAR-10...

 

[Rthur]

I can't speak for the Slash system but here is my experience with Jp's low mass. I am running the Low mass BCG with their silent spring set up with a pri adjustable gas block. This is in a JP lrp-07 in 6 creed. As I developed a load for this rifle some adjustment was needed on the GB. It is pushing a berger 105 at 3030ish(24" barrel). The recoil impulse is extremely soft. I would say keeping within a .1 0r .2 at 100 on recoil through follow through is the norm. I've ran it from 20 degrees to 95+ with great reliability.

R

 

[problemchild]

I can't speak for the Slash system but here is my experience with Jp's low mass. I am running the Low mass BCG with their silent spring set up with a pri adjustable gas block. This is in a JP lrp-07 in 6 creed. As I developed a load for this rifle some adjustment was needed on the GB. It is pushing a berger 105 at 3030ish(24" barrel). The recoil impulse is extremely soft. I would say keeping within a .1 0r .2 at 100 on recoil through follow through is the norm. I've ran it from 20 degrees to 95+ with great reliability.

R

Seems the OP is not interested in "soft recoil" as he has opted for MORE reciprocating mass over less.

 

[BLDTYLRY]

Go with the lightest BCG and buffer setup you can find. Add an adjustable gas block and you should be good to go.

 

[kenndapp]

Seems the OP is not interested in "soft recoil" as he has opted for MORE reciprocating mass over less.

Whoa now. Didn't say all that. The two systems don't seem to vary more than a few ounces and in light of that I would think the recrocating weights of a conventional style buffer might be more effective. If I am off base... Teach me.

 

[BLDTYLRY]

Jasonfaz - I think the correct way of weighing the two would be to weigh only the reciprocating mass as that's the weight which moves went the BCG is operating.

 

[JRM83]

Whoa now. Didn't say all that. The two systems don't seem to vary more than a few ounces and in light of that I would think the recrocating weights of a conventionalism style buffer might be more effective. If I am off base... Teach me.

I just finished a 5.56 ar with an adjustable gas block and JP lmos carrier. I had a silent captured spring around and called JP to ask if it was preferable to use the lightweight buffer or silent captured spring. The short version was that there would be a slight difference in recoil but not much. They explained there is more going on with the captured spring than just reciprocating mass. I didn't retain enough of the explanation to repeat it with any confidence that I am not talking out my ass. Give them a call and talk with them about it.

 

[Rthur]

My point was with a well adjusted system they can be a joy to shoot. Also less mass moving around should be a plus in a precision system.


R

 

[jasonfaz]

First off, I did measure difference in reciprocating mass. It is essentially 1 ounce. But it doesnt really matter in this case because JP's design is far from any other system out there - including all the hydraulic recoil mitigation systems.....

......All right, so I am glad you started this thread kenndapp, because I think it will help some people understand some of the more complicated concepts associated with recoil reduction via modifying the buffer system and how that coincides with adjustable gas, caliber and BCG/carrier weights needed to reliably and accurately cycle a rifle. Here's the deal. Having "the lightest buffer and the lightest carrier" along with an adjustable gas set up DOES NOT always produce the perfect cycling gun - ESPECIALLY in an AR-10 platform where we are pushing heavier rounds into the chamber and dealing with higher pressures. There are many other factors coming into play that affect cyclic rate, reliability, recoil reduction, etc. Some of those are spring tension, friction w/buffer surface, concentricity of rearward velocity impulse, reciprocating mass and antogonist mechanism (reactionary behavior of mechanism in use, i.e. rubber band vs. spring). Hence, we must take into account not only the effect of reciprocating mass on recoil, but also every other aspect to ensure that reciprocating mass has the velocity it needs to be effectively and reliably chamber another round and continue to do so regardless of the rate of fire. You need to move 14.4 ounces of BCG if you are running a JP LMOS BCG at 'X' velocity in order to effectively chamber the next round. What's X? You need to return a full mass BCG of around 17.1 ounces - sometimes more - at minimum velocity 'X' in order to chamber the next round. What is min velocity there? So often we think about mitigation of recoil and then it stops, but the gun doesnt. It still has to send that mass home and do so with authority. It's not "whats the lightest recoil" its "whats the lightest recoil I can acheive and still run X load". There is no common demoninator. If you have a piston gun for example and you have three gas settings - unsuppressed, suppressed and off - guess what? You might just run a load that doesnt run just like you want it to with any of those pre-determined gas settings/. Therefore, you might need to use buffer weight to do a number of things. The list of use cases and applications are long......but distinguished. A heavy buffer - just like a heavy rifle, heavy handgun, or any other heavy inanimate object of any kind - will absorb more kinetic energy of a recoil impulse than that of something of lighter weight. Reciprocating mass should really be targeted at the BCG for the most part rather than include the buffer. The buffer DECELLERATES reciprocating mass. So, depending on 1. how much weight is moving rearward and 2. at what velocity will along with 3. what adjustablility is available within the gas/piston system, will determine 4. what combination of spring tension, bufferweight, and reciprocating mechanism would best suit your efforts in reliably chambering the next round,

With respect to the JP SCS...... it is a captured spring. Why? How does one reduce recoil impulse without increasing buffer weight? Well, you increase spring tension. How do you increase spring tension? You essentially have two options. More coils which increases length and takes itself out. The other is reduce the diameter of a spring to concentrate tension into a smaller area and as a result, increase return force 25+% using the same number of coils and overall length. How do you fit that into a tube with a diameter that is already set though? You capture it. Place retainers at either end and run a guide rod through the middle of it to ensure reliable and concentric function.............and now you have the JP Silent Captured Spring.

A hell of a lot more science to it, but that is the best I can do in Lehman's terms. Hope it helps....

 

[BLDTYLRY]

Technically the rod and the delrin stopper are not reciprocating in the JP System, just the front weights and spring.

So you are saying the non-reciprocating parts weigh an ounce?

 

[BCP]

I've seen the JP ones and they work but only with the lightened carrier and adj gas block. If you aren't running those I would just stick with regular, ordinary, OEM parts.

 

[jasonfaz]

Nope. I mentioned in my initial post that the JP SCS's reciprocating mass is .9oz lighter that that of the S buffer. Slash's XH 308 carbine buffer is 6.5 oz, JP's reciprocating mass, aka the three weights located at the front of their captured spring seperated by o-rings weighs in .9oz lighter - or 5.6oz. But again, that is misleading in itself because it is not a free floating weight. It is retained (or captured) therefore not representing the same type of wieght a traditional buffer would be imparting on the cyclic rate. JP's system uses spring tension, retained weight and more bearing surface (causing more friction) to reduce felt recoil. Again, not apples to apples here. Ill try and work in some of the more scientific stuff later this week, take measurements and post the results.

 

[LRRPF52]

jasonfaz's explanations of the AR buffer system touch on one of the most over-looked aspects of the cycle of functions, namely the return stroke, stripping, feeding, and chambering time window.

I learned that the standard AR15 is under-sprung, gassed pretty hard, and relies on one critical component on the buffer to increase the inertia of the return stroke so that the system has enough force to strip, feed, and chamber the next cartridge.

That critical component is the buffer pad or bump pad on the rear of the buffer. It needs to kiss the rear of the extension tube hard enough to bounce back and generate more forward speed, which combined with the drive spring, will get the job done.

If you tune a system so that there is no secondary recoil from buffer impact, the gun will become finicky.

JP went around this by springing up, as jasonfaz explained in very good detail, and incorporating important design elements into the SCS to provide sufficient operating characteristics for reliability, while eliminating secondary reciprocating mass effects. When you break the trigger on one, you can clearly feel the difference with the SCS.

 

[Texar2]

Standard components. Adjust your gas until you have just enough to lock back on an empty mag and you are done.

 

[Mute]

I just run a standard system and use a muzzle brake. Several thousand rounds on my Mega and not a single hiccup.

 

[kenndapp]

I just run a standard system and use a muzzle brake. Several thousand rounds on my Mega and not a single hiccup.

Boarder line off topic as the topic is mostly fine tunning gas and buffer systems, but thanks for the the input anyway.

 

[*Nine]

When I had my 6XC maten I had my smith machine my carrier to lighten it, then I cut a number of coils off my recoil spring and I lightened my standard buffer. I then used an adjustable gas block to tune the whole thing. In the end I had a rifle that cycled quickly and felt more like an AR15 than other AR10 type stuff I've owned/shot where it feels like there's just a ton more steel slamming around in there.

 

[Mute]

Boarder line off topic as the topic is mostly fine tunning gas and buffer systems, but thanks for the the input anyway.

Not at all. I'm suggesting that unless he's trying to achieve some very specific benefit from the non-standard buffer system, why even use all these non-standard parts which, as you say, requires much more fine tuning? If he just wanted to tame the recoil, better to use a brake, unless he's against the idea.

 

[jasonfaz]

......aaaaaand here's where it all goes to shit