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Bump stock ban overturned in the 5th circuit
- Thread starter Aguila Blanca
- Start date
I went and looked at the linked site. I don't find the claim of 1400+ rpm to be credible.
The claim was made by a guy who posted his Utube video on AR15/com.
He describes his firearm as a "Bumpfire SAW" which is obviously just his nickname for it, since it is an AR15 class rifle and NOT the SAW.
He said he calculated the rate of fire, but gives no indication HOW he did that, or what data he used.
Additionally there is mention of an aluminum bolt carrier, so at a minimum, what he's playing with is a highly modified AR15 NOT a standard rifle.
I'm not saying a highly modified AR won't run that fast, but the standard ones, don't.
I's say its kind of like building a funny car off your family sedan. The highly modded car will go really fast, the regular one, won't go that fast.
The claim was made by a guy who posted his Utube video on AR15/com.
He describes his firearm as a "Bumpfire SAW" which is obviously just his nickname for it, since it is an AR15 class rifle and NOT the SAW.
He said he calculated the rate of fire, but gives no indication HOW he did that, or what data he used.
Additionally there is mention of an aluminum bolt carrier, so at a minimum, what he's playing with is a highly modified AR15 NOT a standard rifle.
I'm not saying a highly modified AR won't run that fast, but the standard ones, don't.
I's say its kind of like building a funny car off your family sedan. The highly modded car will go really fast, the regular one, won't go that fast.
44 AMP said:I'm not saying a highly modified AR won't run that fast, but the standard ones, don't.
The cyclic rate would be tied to bolt velocity. I'm sure one could get a nutty rate, well above the 700 to 900rpm that might be the normal range. A weightless buffer and lightweight carrier, a big gas port and some warm ammunition would produce the high bolt velocity, but the rifle would beat itself to death in short order.
There's also a constant recoil variation that has a heavier bolt that travels a little farther that runs below 600 rpm. That's neat in that it better allows a shooter to put all his rounds on a target rather than just the first couple.
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The cyclic rate would be tied to bolt velocity.
BOTH ways.
Force from the fired round, mass of the moving parts and pressure from the recoil spring are all BALANCED against each other by the designer /design team, to obtain a given cyclic rate, the one chosen for best continued operation and service life.
You can futz with any or all of those, and get faster or slower rates than original factory specs.
Its a frequently done thing with semi auto pistols to get them to run reliably with "non standard" ammo. With pistols, the actual cyclic rate doesn't matter to most people, functional reliability does.
Somewhere in the volumes of "The Machine Gun" by Col Chinn (might be in vol 6, I forget) is a calculation to determine the proper bolt mass for a 9mm SMG with X lb recoil spring. It used as an example of part of the work designers do when creating those things.