Hydraulic/Mechanical Buffers

[Dave L.]

Does anyone have any useful info on either the Enidine Hydraulic Recoil Buffer or the MGI Mechanical Rate-Reducing Buffer. All I know is they are expensive. Enidine-$90 and the MGI- $165.
Also wondering if they would have a positive effect when shooting .458 socom or the .50B-wolf-
Please let me know if I am crazy for considering one of these- or if you own one, let me know what you think-
Thanks
Dave

[Voodoochild]

I have an Enidine buffer in my RRA along with an ISMI buffer spring and I can tell you it is a joy to shot it. Almost feels like my buddies Olympic 45 AR when shooting. According to the Enidine website tests have shown the buffer to produce a reduced rate of fire by approximatly 200 rounds per minute. As for the positive effect on a 458 or 50 I dont know. Talk to Cold he has a 458 Sledgehammer.

[Dave L.]

Thanks for the Info- Is that the same chrome silicon buffer spring that Magpul sells on their website? (If it is, I just ordered it about 2 hours ago). On MGI's website they claim that a Mechanical Buffer is better than a Hydraulic buffer- Do you know any valid reasons why they would make that claim(besides to get me to spend another 75 bucks more than the cost of the Enidine)?

[Griz]

On MGI's website they claim that a Mechanical Buffer is better than a Hydraulic buffer- Do you know any valid reasons why they would make that claim(besides to get me to spend another 75 bucks more than the cost of the Enidine)?


The one reason I don't like the Endidine is the way it requires extra effort at the end of the stroke when manually pulling the charging handle for whatever reason....

It's twice as hard on the old ones. On the new CAR ones it's quite easy on the rifle it feels the same as stock when locking the bolt back.

I've shot my Enidine right next to a MGI and prefer the Enidine better YMMV.

[twl]

I can tell you why the MGI RRB buffer works as well as it does.
I'll let others discuss the Enidine.

When the trigger is pulled and the round fired, the expanding gasses move thru the gas port, back thru the gas tube and into the expansion chamber in the bolt carrier.
The energy in the expanding gas then will begin to move the masses of the carrier assembly and buffer rearward, thus unlocking the bolt.
The masses of the carrier assembly and the buffer are added together, and move together as a unit.
The heavier the masses are, the longer it takes the energy to excite them into rearward movement. This causes a slight delay in bolt unlock timing, and provides extra time for the pressure-swelled cartridge case to release its grip on the chamber wall, so that extraction can be easier and more reliable.
Thus, a heavier buffer will provide delayed extraction timing, and will provide a more reliable extraction portion of the cycle. The MGI buffer weighs 7.1 ounces, similar to a 9mm buffer weight.
Then, as the moving masses of the bolt/carrier/buffer begin moving rearward, the energy input is finite, so a heavy buffer will travel at a slower rate, thus slowing cyclic rate. The MGI buffer will slow cyclic rate at approximately 20%-25%, depending on the gas system in the weapon involved.
When the moving masses approach the rearward end of the recoil cycle, the mechanical plunger in the MGI buffer strikes the back end of the receiver extension(buffer tube) first, which propels the tungsten weights inside the MGI buffer forward at a high rate of speed. These weights then contact the rearward moving buffer body(internally) and the "live hit" of two opposing masses in motion, cause a cancellation of the rearward movement just prior to bottoming out at the back end of the receiver extension(buffer tube). The masses then come to a complete stop, eliminating much of the felt recoil that would otherwise be transmitted to the shooter's shoulder, as with other systems. Then, the recoil spring begins to accellerate the buffer/carrier/bolt assembly forward.
Again, the heavy mass creates a slower forward movement under the power of the recoil spring, again slowing cyclic rate, but it is a movement with much momentum, due to the high mass. This is helpful in overcoming any dirt or other foreign matter that might impede the forward motion of a lighter buffer.
Also, this slower forward motion allows the magazine spring to have plenty of time to position the next round into the magazine feed lips for proper feeding.
The bolt then strips the round off the feed lips and pushes it into the chamber while the bolt closes and rotates into lockup. The tungsten weights inside the MGI buffer then provide a follow-up hit into the front end of the buffer, which will counteract any propensity of the bolt to try to bounce, so bolt bounce is eliminated.

The MGI buffer has effect in virtually every aspect of the recoil cycle, and not only aids extraction, reduces recoil, and aids positive feeding and eliminates bolt bounce, but it also assists in reducing muzzle flip. Muzzle flip is generated when the recoil impulse axis is above the point of contact of the buttstock on the shoulder. The moment of rotation is generated around that point of contact. The less force imparted to the back of the receiver extension in the recoil stroke, the less moment of rotation around this shoulder contact point, and muzzle flip is reduced.

Additionally, in full-auto firing, the heavy buffer moving forward on the bolt closure, also generates a forward momentum at the time of the next round being fired, so that there is some cancellation of the initial recoil impulse of the next round going off, and all subsequent rounds fired in that burst. The additive effects of this reduce the muzzle climb effect in full auto.

The major benefits received by the user are improved cycling reliability, improved control of the weapon during fire, less battering of parts, improved feeding, no bolt bounce, keeping sight picture during follow up shots, faster time onto next target, more comfortable shooting. This is especially noticeable in the carbine gas system configuration. In full auto, rate reduction is significant, aiding control, reducing overheating conditions in the barrel because of fewer rounds fired in the short time periods of the burst, keeping entire bursts on a small target area, as well as the previously mentioned things.

There are very few things which can go wrong with the simple mechanical process used in this buffer, so reliability is high.
The only issue ever found is an occasional walking of the roll-pin, which is easily dealt with by staking or rocksetting of the pin. We'll warrantee replace the pin if it is found to be walking and reported to us. After 10k rounds the pin should be checked for wear, and we recommend replacing the pin after 20k rounds. Nothing else ever goes bad.

User reports over the 7 years of this buffer being available on the market are that it exceeds the performance level of any other AR15 buffer available. We guarantee that it is, or we'll refund your money.

[Dave L.]

Thanks twl,
I think maybe I will spend the $165 on the MGI.
One last question;do you know how this will affect the weapon when cycling the .458 socom(I ordered an upper from RRA 3 weeks ago)?

[twl]

Works great with the 458 Socom, and other hard recoiling calibers.

Please email me or call me, and I'll personally take care of your order and follow up.
Satisfaction guaranteed or money back.

423-746-9019
twlyons@juno.com

[Griz]

I have an MGI RRB buffer and it works very well for reducing the rate of fire. With that said, parts of your description of how it works seem to defy the laws of physics, so I must be missing something.



When the moving masses approach the rearward end of the recoil cycle, the mechanical plunger in the MGI buffer strikes the back end of the receiver extension(buffer tube) first, which propels the tungsten weights inside the MGI buffer forward at a high rate of speed. These weights then contact the rearward moving buffer body(internally) and the "live hit" of two opposing masses in motion, cause a cancellation of the rearward movement just prior to bottoming out at the back end of the receiver extension(buffer tube). The masses then come to a complete stop, eliminating much of the felt recoil that would otherwise be transmitted to the shooter's shoulder, as with other systems. Then, the recoil spring begins to accellerate the buffer/carrier/bolt assembly forward.

When the buffer begins moving rearward, the weights should move to the front of the buffer. I don't understand how they are in the rear to be struck by the plunger. Are they spring loaded so that they move to the rear while the buffer itself is traveling to the rear?

Ignoring that first problem and assuming that the weights are indeed in the rear of the buffer against the plunger when the plunger hits the end of the buffer tube, the weights shouldn't be "propelled" forward, rather they would simply stay in contact with the plunger as the rest of the buffer body continues moving to the rear. The only way they could be propelled forward is if the plunger is not a simple plunger and has a mechanical advantage, or maybe if there is a spring or other energy storing device between the plunger and the weights.

Again, I know that it works because I have one, it's just that as an engineer the way that you describe it bugs me because the math doesn't work.

Assuming there is nothing between the plunger and the weights to store energy, I suspect that the "live hit" described between forward moving weights and the buffer body does not happen and that the perceived recoil reduction is from the plunger design preventing a "dead blow" effect when the buffer hits the end of the buffer tube (while allowing the dead blow effect on the forward stroke to prevent bolt-bounce).

[twl]

There are springs in there with the weights.
The buffer operates as I described.
The math calculation is included in the patent.

It was designed by Gwinn and Sullivan to approximate the Sullivan constant-recoil principle as closely as they could get it in the short AR15 recoil system.
In the Ultimax LMG(Sullivan design) the true constant-recoil principle is acheived, and the long spring absorbs the recoil and the buffer never hits the back end. It just stops moving backward against the spring, then the spring moves it back forward again.
The MGI RRB is not quite at that level, but it was made as close to that as they could get it, in the AR15 platform.

Received a report yesterday from Cap'n Crunch using our MGI RRB on a couple suppressed AR15 shorties. He seemed to think that the guns blew less gas and smoke back in his face, when using the MGI RRB(possibly because of slight delay of unlock). One of the shorties(before the RRB was installed) was running so fast that the magazine spring couldn't get the rounds up into the feed lips fast enough, and the bolt was closing on an empty chamber. After RRB installation, the gun ran fine, at a much more suitable rpm. Of course, it also made a big difference in taming the cyclic rate increase when the suppressors were on there, and the control was very good.

Hope that helps.

[Griz]

There are springs in there with the weights.


That's the piece that was missing from your description. I guess I should have thought to read the patent (or take mine apart) rather than ask you for a more detailed description. :o

[Heavy Metal]

I am an RRB believer. Noticable improvement, even in semi.