A few other neat MAC related things from "back in the day"
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SecondAmend
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IIRC, there was also another version that used an AR hammer and spring. Neat, though that technology doesn't provide much rate of fire reduction, but should smooth out the bolt reciprocation somewhat. The most effective way to get ROF reduction is a hydraulic buffer. Could be done in the MAC platform, pricy though. Tungsten bolts are also effective for ROF reduction, but expensive, and have somewhat of a "bowling ball in a shoe box" feel.
MHO, YMMV, etc.
You know, I've never though of testing a hydraulic buffer on a M11. Interesting. It does make a big difference in ROF reduction on an AR15. I guess I would need to drill a hole in the back plate for a TASK style bolt extension and AR15 buffer tube mount.
The new hotness on AR15 recoil reduction is in magnets and eddy currents. This might be something to explore.
The new hotness on AR15 recoil reduction is in magnets and eddy currents. This might be something to explore.
SecondAmend
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That's been tried before. I don't know if Google AI will find much, but a well conducted U.S. Patent Office search should bring up some historical examples of such firearms buffers. A few years ago I was trying out AR buffers for M16, 9mm (and .45 ACP and 5.56x45) ROF reduction. Among those I tried was a magnetic buffer which was better than a standard moving weight buffer, but I also tried four hydraulic buffers and the worst performing hydraulic buffer was better than any other buffer. FWIW, in the M16 for 9mm, .45ACP and .223/5.56x45, the best buffer (i.e., lowest ROF) was always the B & T 9mm AR hydraulic buffer. It's all I use in ARs anymore.
And a related concern with magnetic related buffers has always been potential interference with electronic accessories from magnets that are strong enough to provide appreciable recoil reduction.
IIRC, Olympic Arms and TACCOM have tried air bag AR buffers which worked well, but both vendors eventually dropped them. I suspect that over time, the air bag developed leakage. Automotive manufacturers who tried using airbag shock absorbers found that out.
MHO, YMMV, etc.
The Suomi M31 does an "air bag" style with a one way valve. The receiver tolerances are very close. Automotive has used and still uses air bags across all platforms, even heavy trucks.
SecondAmend
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No doubt things have improved, especially in materials science. I knew a guy who had a Lincoln and when his air bag shocks went out, he bought readily available coil spring replacements that were made because the air bag shocks were known to fail over time. IIRC, the Crown Vic and Mercury cars had an optional trailer tow package with the same type of air bag rear shocks that eventually leaked and had to be replaced. And from what I recall, a lot of owners replaced the air bags with coil springs.
MHO, YMMV, etc.
Airbags have been aftermarket and OEM on pickups for decades. Pretty standard stuff. semi trucks use them and have more miles than anything else on the road. it's not really that materials are better. Some things really cheap out and a LOT of people are terrible with maintenance and tend to leave vehicles in conditions where plastics rapidly fail such as out in the sun around the clock.
Suomi is from the late 1920s. Uses a rubber flap in the receiver cap to make a one way valve. Lowers ROF by slowing the bolt as it opens then allows it to chamber a round and full speed. It's a really neat design. I haven't built my kit yet to see how it works.
Truck airbags are built like a tank, even deflated the rubber is extremely thick and stiff. The ones used on Lincoln's and such is built around a shock absorber or strut and is not known for being heavy duty. In addition the steel part going through the middle seems to rust and now you have abrasion every time you hit a bump. Not to mention the air compressor, valving, and airlines to support them. Many times when it comes to replacing them people looking at a $1,000 or more to replace the airbag struts or a few hundred to switch over to the coilovers owners choose the cheaper option.
Wasn't there a time when people were installing the closed bolt Hammer only into the open bolts? The extra force needed to Cock it supposedly slowed the fire rate IIRC.
Wasn't there a time when people were installing the closed bolt Hammer only into the open bolts? The extra force needed to Cock it supposedly slowed the fire rate IIRC.
Yeah, a 15,000lb tractor weighs a LOT more than a Lincoln so it'll have thicker and heavier components. Yes, it can be cheaper to go to coil overs which is why people go to coil overs. Neither of those facts have any bearing on automotive manufacturers decision to use airbags or not. In fact many still offer them as original equipment and some models only have airbags without metal springs.
I think the hammer idea is what that rate reducer is but nobody has explained it and would rather try to argue that Lincoln has a crappy suspension design therefore everyone using a similar idea has a crappy suspension design and thus nobody uses that suspension design anymore.
I keep trying to point out how the Suomi does a rate reducer with air. It is quite trick. I think that could be adapted to an AR buffer tube. For most things I see anything more fancy than a spring as being over complicated and unnecessary.
I think the hammer idea is what that rate reducer is but nobody has explained it and would rather try to argue that Lincoln has a crappy suspension design therefore everyone using a similar idea has a crappy suspension design and thus nobody uses that suspension design anymore.
I keep trying to point out how the Suomi does a rate reducer with air. It is quite trick. I think that could be adapted to an AR buffer tube. For most things I see anything more fancy than a spring as being over complicated and unnecessary.
As far as I know there were 2 manufacturers of the DIRR (drop in rate reducer) for the mac series. There may have been more, but I wasnt familiar with them.
I was a beta tester for one of them. I am so sorry I have forgotten the last name of the guy that made the one I tested. His first name was John. He was a machinist and IIRC he passed away in a motorcycle accident. Anyway, the DIRR I tested did not allow the bolt to retract fully. The hammer sat too high in the bottom of the receiver. I shaved off the back of the hammer a bit at a time until the bolt did retract. The amount of rate reduction was so negligible that it was pretty useless. Maybe a stronger spring would have helped. Anyway, that project was shelved.
Am I correct in the assumption all it is is something like a hammer to add drag to the bolt in order to reduce cyclical rate?
That's how I feel about my M10 task setup. It's ROF is way, way, way higher than my Lage Max10/45. So much so the Lage upper feels very choppy. I have not yet put an unmodified bolt in my M10 to see what it does even though there is another complete OEM style upper in the safe next to the gun.
That's how I feel about my M10 task setup. It's ROF is way, way, way higher than my Lage Max10/45. So much so the Lage upper feels very choppy. I have not yet put an unmodified bolt in my M10 to see what it does even though there is another complete OEM style upper in the safe next to the gun.
A&S Conversions
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I had Jim Weaver do the Task conversion to my first M10 for use with the S.A.B.R.E. 5.56X45 upper, as the hole for the Task and the 5.56X45 upper is in the same location. I also had Jim modify several M10 bolts for the Task system by adding a rod to the back of the bolts and modifying the back plate to weld the spring guide rod and ejector rods to it. Since the gun had already had the Uzi magwell conversion, he also added the extra mag clearance on the bottom of the bolts.
I played with spring coil reduction and a super heavy custom AR buffer to go in the stock. The buffer had so much mass, even with a light pistol caliber buffer spring, the mass of the buffer and M10 bolt was so much that the upper would short stroke. I lightened the buffer up enough that the rounds would just barely eject. But because of the short distance between the back of the receiver and the sear catch, the best I could manage was doubles. Very consistent doubles, with a very occasional single shot, but I couldn’t get consistent singles.
A member here, told me that he had once had a Task style M10. He had added an over travel screw to the back of the trigger. With that modification, he could get consistent singles. I need the full trigger throw to use the Tenko, so I am not interested in that modification.
What I would like to do is cut one of the bolts just behind the extractor, redrill the hole in the back of the bolt and rethread the hole to install the buffer connecting rod. That would lose some mass from the bolt. But if I used the Veltor receiver extension, with the longer buffer I think that I could make up the mass loss from shortening the bolt. Maybe someday I’ll get around to trying that.
Scott
But there is a difference in the bolt throw between the original M10 bolt only going just beyond the sear catch point and the back wall of the lower receiver. Off the top of my head, it is a small distance like a 1/4” or 3/8” from the back of the frame to the sear catch point of the M10 bolt. The original Task system was designed for the M11/NINE. Again, I don’t know the dimension, but I think that the M11/NINE has 3/4” or 7/8” between the back of the receiver that would stop the bolt and the sear catch of the M11/NINE bolt.
I had Jim Weaver do the Task conversion to my first M10 for use with the S.A.B.R.E. 5.56X45 upper, as the hole for the Task and the 5.56X45 upper is in the same location. I also had Jim modify several M10 bolts for the Task system by adding a rod to the back of the bolts and modifying the back plate to weld the spring guide rod and ejector rods to it. Since the gun had already had the Uzi magwell conversion, he also added the extra mag clearance on the bottom of the bolts.
I played with spring coil reduction and a super heavy custom AR buffer to go in the stock. The buffer had so much mass, even with a light pistol caliber buffer spring, the mass of the buffer and M10 bolt was so much that the upper would short stroke. I lightened the buffer up enough that the rounds would just barely eject. But because of the short distance between the back of the receiver and the sear catch, the best I could manage was doubles. Very consistent doubles, with a very occasional single shot, but I couldn’t get consistent singles.
A member here, told me that he had once had a Task style M10. He had added an over travel screw to the back of the trigger. With that modification, he could get consistent singles. I need the full trigger throw to use the Tenko, so I am not interested in that modification.
What I would like to do is cut one of the bolts just behind the extractor, redrill the hole in the back of the bolt and rethread the hole to install the buffer connecting rod. That would lose some mass from the bolt. But if I used the Veltor receiver extension, with the longer buffer I think that I could make up the mass loss from shortening the bolt. Maybe someday I’ll get around to trying that.
Scott
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