I can explain it to you, but I cannot make you understand

I designed the UltiMAK optic mount for the Kalashnikov to align itself with the barrel (fancy that). There is a radius on the underside, which engages the barrel (something like. V-block, but we’ll call it an “interrupted radius”) so as the clamp screws are tightened, it simply WILL align with the barrel unless something interferes with that process. The “something” that can interfere is the gas block or the rear sight block, or more specifically, a radical misalignment of the gas block with the rear sight block.

The mount has several features that allow it to accommodate a slight to moderate misalignment of those two parts, and so there is a fraction of one percent of AKs (usually Romanian) that cannot properly accept the UltiMAK mount, but I digress.

There is a range of barrel diameters within what I call the “standard” AK barrel weight, which runs from about 0.675″ to about 0.710″. The farther the barrel diameter is from the middle of that range, the less misalignment of the gas block and rear sight block the mount will accommodate.

It’s very, very simple; the piston tube bore (incorporated into the optic mount) can move around the piston, up down, right or left (depending on barrel diameter and block alignment) only so much before cycling of the carrier and it’s piston starts to encounter interference. You can make it bigger inside, which I did, but only so much bigger– At some point the piston starts to have a problem finding its way back into the gas block during the forward stroke, so the mount’s bore is enlarged only as much as still allows an easy transition of the piston forward into the gas block. This is “Junior high school stuff” as I like to put it. Self evident, that is, I should say, if you care to look.

Apparently some Russians have tried to copy my mount, but without caring to look. Flattery and all that, etc. It has not been successful.

This is a long-winded way of getting around to the point, which is that one of the mount’s many “features of accommodation” is the fact that it is shorter than any piston tube that it was designed to replace. It simply MUST be shorter than the original tube, unless your AK is among the tiny fraction of one percent of AKs that has a nominal barrel diameter (I’ve never seen one, if by “nominal” we mean “median average”) AND your rear sight block and gas block are PERFECTLY aligned. There is then the fact that no two AK, even with consecutive serial numbers, necessarily have the same exact piston tube fit. I got around all that very easily by making the mount a little shorter.

No. It doesn’t have any influence on cycling whatsoever, and you wouldn’t ask if you understood how the the AK, or any other gas gun, operates. I could explain it, but this already going to be a wordy post. Just look.

An original AK can accommodate a LOT of misalignment of the rear sight block and gas block, but not an optic mount which mechanically aligns with the barrel. See?

Anyway, we received two separate returns so far this week (as of Monday) with customers stating that their mounts were “too short”. Too short for what exactly, neither was able to contemplate, much less endeavor to explain. It just didn’t look right to them I suppose. One even went so far as to send us photos (actual prints no less) showing his mount fitting perfectly, as evidence that he was not crazy in asserting that his mount was “too short”.

I put up this page in hopes of dispelling this problem-without-a-definition, but alas. We also dedicate a whole page in the instructions that come with the mount, explaining that it is shorter than the original and that is all well and good. Sometimes a person simply has to SEE what he expects to see, rather than read the instructions. It is a fact, too, that some people cannot read.

I find it all somewhat amusing. Also I’m fond of saying that my design is so absolutely, wonderfully innovative that some people actually, truly can not believe it. It is also amusing that we’ve sold millions of dollars worth of them, and that they’re still quite hot among those who understand the problem they’re trying to solve, or the question they’re trying to answer.

If a person calls or writes in advance of taking pictures for evidence and returning the mount, I can, at least 99.9% of the time (this has happened almost every day for near fifteen years, so I CAN use that number with authority) talk them into at LEAST trying it. My answer often begins with; “Be thou not of troubled mind” and that does usually settle a person down to where he can listen AND hear (it usually takes three explanations) and then begin to understand. My other answer, when told how the mount is “at least an eighth of an inch too short” as though I’m being condemned, or the person talking has been victimized through an inexcusable oversight, or some misfortune, is, “Perfect! You have a perfect fit.” Some people I have to lull into taking a leap of faith, understanding not having been achieved. “Trust me” I must say. Once a person tries it of course it’s a done deal. All the fears and hang-ups are washed away in a tsunami of fun, realization and understanding. Ah HAH! Life is good.

7 thoughts on “I can explain it to you, but I cannot make you understand

  1. Honestly, it makes sense once you explain that it is intentional, but I would have rejected a gas tube with a visible gap — despite knowing in the back of my head that it’s irrelevant.

    Long story short for those STILL puzzled — LONG before the piston head ever gets to the back of teh gas block, the piston isn’t being “pushed” by the gas — it’s coasting on inertia. Really. ALL gas piston guns, short or long piston, work that way. Once the bullet leaves the barrel and “uncorks” it, pressure in the barrel (and thus the gas system) drops to near ambient immediately (for all practical purposes). Since the bullet is moving so fast, the bullet leaves the bore about the time the piston actually starts moving any significant amount at all.

    Those “gas relief holes” on the AK gas block (or gas tube, depending on rifle) aren’t there to vent excessive gas pressure — they’re really holes for the carbon the piston head knocks loose to go out.

    • Quite so, and then there is the deeply fluted bore inside the piston guide tube, as I like to call it, which is designed specifically to prevent any further significant impulse upon the piston (gas blows right by the piston inside the tube). This is analogous to the operation of the AR-15, and any other gas gun I can think of, in that there’s roughly 20 mm or so of “acceleration length” followed by complete disengagement and rearward coasting of the carrier group on inertia. The little 30 Carbine’s piston travel is much shorter. Oleg tells me that the Russian term for what most Americans call the “gas tube” on an AK translates to “gas dissipater” tube. As I demonstrated in the linked page, an AK would run the same without the tube in place as it does with it, except that, due to loose fitting, the piston will usually wander off axis and miss its return into the gas block during the forward stroke. Some AKs will actually run without the tube because of tighter fitting between the carrier and the receiver. Cycling energy is the same either way.

      Some AKs are shipped without any holes in the gas block or the tube, and so slightly more of the exhaust gas ends up in the rear sight block, lower handguard and receiver, but the cycling is the same. In any configuration, firing an AK in the rain will result in black carbon stains on your face, as the exhaust is pushed clear back and out the take-down hole in the back of the receiver cover. I like to think that the UltiMAK mount reduces this somewhat, being that it vents more, farther forward.

  2. Cool vid, “you learn something new every day”. I had never thought about the operation of the gas piston, but your video made it click immediately for me.
    Now I have something else to pine for (like I need THAT, heh). UltiMAK goes on the ‘want’ list 😀

  3. Then there is this photo which shows the muzzle flash in full bloom after the bullet is gone, and the bolt carrier appears still to be in or very near to its forward position. That’s a millisecond or three after the bullet has left the muzzle. I’ve likened the gas impulse to hitting the front of the piston hard and fast with a rubber mallet.

  4. Waaaaay off topic (but it is your fault because you posted the link) but is there a reason you do not make an optic mount for universal M1 carbines? I have a nice little universal, and I want to mount an optic to it, but until now I have not seen a mount that didn’t look like a duct tape and baling wire job.

    I also want to know if there is a way to make your fancy stock with the shoulder thing that goes up fit. I know your site says it does not fit, but I am not adverse to a bit of modding if it will work.

    • Scratch that, I just fond your disclaimer on the site. No need to answer a second time.

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