First observation, most carbine length buffers suck. The worst are the solid ones. Then make the gun feel lousy and make gun bounce worse. Most 9mm bolts are fairly heavy dictated by the nature of blow back. But the space available makes them still too light in AR. So everybody puts a heavy buffer in.  Problem also that carbine buffer doesn't leave enough room for the buffer to work like the ones in a rifle.
A Rifle buffer is made of light metal, with heavy weights inside that have lots of room to move.

Movement is the key what I call decoupling of reciprocating weight.

When a bolt is closing the weights help with bolt bounce, but they do something else more important. In a 9mm the bolt doesn’t have the floating rotating bolt carrier design to prolong an eat up energy rotating/locking the bolt. It is just two pieces of metal slamming into each other, thus the forward down pitch of 9mm’s which cause dot bounce. Solid buffers make this worse. More weight stopping quickly/abruptly.

So back to the rifle buffer, as the bolt is closing driven by the recoil spring when it finally comes to a stop. The amount of weight that stops is not the total weight of the buffer, bolt/carrier, and spring. The weights inside the buffer are still moving forward and thus do not contribute to momentum that is converted into felt energy.  Eventually they will finally stop, and contribute to the total energy but the time delay greatly reduces the felt impact.  So they stop bounce by reducing the effective weight and then delivering delayed impacts to counter the bounce. Upon firing the weights are forward and contribute to the total mass of the inertia needed to be overcome to cause bolt rearward movement.

So the 9mm carbine needs the same things in spades.

So with help of my friends we have developed a 9mm buffer that maximizes the decoupling of reciprocating weight to mostly eliminate closing bolt bounce.  Reduce bolt velocity by coupling the weight on bolt open and having total weight of 7.5 oz and length of 4.125” to reduce bolt travel and further limit bolt speed.  Still recommend slightly heavier bolt spring. The combination drops the empty’s cases about eight feet out for both heavy and light loads.

So lets hear the comments about my bolt buffer operation

all of mine seem to be working fine. I seem to be missing your point???

Seems to be plenty of options out there if someone has a problem.

So...

Let's see some solidworks drawings of the product, pics of the machined and finished prototypes, video's of the testing of the prototypes.
And you did do the testing using different barrel lengths, different bolts, and some  suppressors too ??
And  a list of the various ammo tested including the bullet weights, and fps you encountered during testing would also be helpful.
When you post some of that info, then I will change my opinion from what it is now.


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Working on it, just ordered some tungsten weights and rear bumpers. Made first bumper out of nylon too hard with steel weights . Testing just one rifle with a 16" barrel, working to reduce dot bounce to a minimum, also limiting to one ammo 124 gr about 1100 fps.

This came about from noticing that a fixed stock version of the gun bounced less. Which lead to investigate springs and buffer weights. Then the reading of the formula for weight of the bolt. Pondering with a rifle buffer in one hand and carbine in the other, while shaking one then other I noticed the carbine buffer doesn't rattle much.  I remembered how early 223 carbines would fail to extract and tear up extractors. Then came heavy buffers, donuts in the extractors, and moving the gas port forward 2 inches.  Kind of sounds like same problem as many 9mm have experienced from my reading. Some reading discovered that colts sold long ago had their 9mm conversion with 8oz and 10oz buffers. Maybe that was just to reduce the full auto rate? So as soon as the Brown truck brings my goodies, and we'll finish our subjective tests. I post pics of the design, it is different any you'll probably why didn't I think of that. Then feel free to copy, but you'll need a lathe and end mill but simple as hell to make.

I do notice in my 16" RRA 9mm with an 8.5 oz dedicated length buffer when I run a Wolff extra power spring the carrier seems to slam home pretty hard. Initial rearward travel is lighter than return to battery.

Welcome to the world of blowback, it's all about balancing your weight & spring weights with the force you're trying to manage. For mine, ST-9X & std. spring seems to have best tolerance for both light range loads & +P. If I was running +P exclusively I'd probably go up to a 10oz. buffer.

If you're focused this much check out the DI uppers for pistol calibers. Although you'll find out real fast just how dirty your pistol powder is...

KAK makes a extended buffer 10 OZ  using 4X sliding tungsten weights  kak

I've ordered my Tungsten weights and end bumper from them. I would say they have the best Buffers on the market.

You are right.  They suck, so all ARs should use the JP silent captured spring system.