Went to the range with Charles St.George yesterday. His Leader 50 rifle is a ten-shot semi-auto bullpup that is light enough at 17 pounds to be fired off-hand if necessary. Recoil is very similar in character and force to M1 Garand. The version shown isn’t the final production variant but it already impressed me as very useful. A matching reflex sound suppressor has been designed for it.
What sets this gun apart from others I’ve seen is the compact form, relatively light weight and genuinely free-floated barrel. Nothing touches the barrel except the receiver — the gas system is ingenious and gets away from any close clearances as well. The rifle will be produced by Micor.
Wear your earplugs!
Earplugs won’t be enough. The muzzle brake looks insane. This level of sounds would likely be damaging even if you had no ears.
Just the overpressure..
It could use a really big can though.
There are anti-materiel rifles for 14.5 and even 20 mm cal. But people use them and even survive. Still if you suggest a butt plug is indispensable to keep blast wave outside, i won’t stop you… 😛
People fire guns without hearing protection and survive.
What I remember was reading that people who use very big rifles, even though they use hearing protection still suffer from neurological problems caused by overpressure. I’ll post a link to the abstract, once I find it.
What’s a butt plug?
So this is what the a “supersized P90” looks like. Nice photography Oleg.
I wonder.. a big can isn’t as effective in killing recoil as a big muzzle break? Internally.. a supressor looks a bit like a canned round muzzle break I think.
Did the designer own a Bushmaster M17S? Because that really looks a heck of a lot like an oversized version of the M17S…
The designer, not only owns a 17-s Bullpup, but was the original designer of it, way back in 1986
Excellent. Mine’s always done well for me.
A muzzle brake reduces recoil by redirecting a portion of the high velocity gases backward towards the shooter (also increasing the sound pressure. A 50 cal without a muzzle brake can be safely fired with both earplugs and muffs on at the same time. With the brake, it is dangerous (and a violation of OSHA job-safety regulations), but only with significant repeated exposure.), which puts force in the shooting direction. A suppressor slows down the gases slightly by redirecting them internally, which does reduce the back-pressure created by them when they exit the barrel, but they are still moving very fast and still exit the barrel in the shooting direction, which puts force back on the shooter. Most of the actual recoil is caused by the gases exiting the barrel. The recoil absorbed by redirecting the gas is significantly greater than the recoil absorbed by slowing them down slightly.
Most of the recoil is caused by gases… hmm. Have you seen any calculations on that? Recoil is mass times velocity….
Though. Makes sense. There’s a lot of powder in the cartridge, that converts into an equal amounts of fast gas.. and once the projectile leaves, it’s like a rocket engine.
BTW.. wouldn’t it be possible to mitigate recoil on these kinds of rifles by putting the whole gun/scope into a lightweight frame where it’d be fixed in place by recoil dampers?
Kinetic energy is 1/2 the mass, times the square of the velocity.
The recoil results from the mass of the bullet and the powder, both accelerating rapidly. Recoil is actually power (work done over time), not energy (an instantaneous sample), but it all happens so quickly that it really doesn’t matter much.
What does matter is that velocity is the far-larger component of the effect. The gasses do exit the barrel at higher velocity than the bullet, but only after the bullet has cleared the barrel. I wouldn’t say that it’s accurate to claim that either causes the majority of recoil; it would depend upon the specific bullet and powder combination. There’s usually quite a bit less mass of powder than there is mass of bullet. That velocity component makes up for much of that, but it’s still fighting a battle against the lower mass, and it can’t even come into play until the bullet leaves the barrel.
As far as recoil reducers, yes, they are possible. They are even used in some firearms. But they negatively impact accuracy by introducing another moving component with tolerances and such.
Leader 50 cycles VERY slowly. I took a couple of photos in response to report and the fired brass was still up in the air. It’s the only semi-auto with which I’ve seen this happen. No wonder recoil feels mild — it’s spread over a very long time. Same is true for Boberg XR9S, by the way.
Slow cycling does that. Hence why a 1911 in .45ACP is often more comfortable than a 9mm, even when using hot loads in the 1911 and mild loads in the 9mm. Spread the impulse out, and the recoil is much more manageable.
The recoil must meet or exceed the muzzle energy of the bullet. A short, sharp spike represents less of a cartridge than a long, low curve, but the absolute magnitude of the maximum impulse may be higher for the sharp spike. As long as the area under the curve meets or exceeds what the bullet is carrying, conservation of energy is happy, but the shooter may be much happier with the slow recoil impulse…
If the scope and stuff was on the recoil reducers, how it’d negatively impact accuracy?
The barrel would be in motion, while the bullet is still in it.
Anyway.
Rifles like these are the best reasons for self-aiming guns.
What if you put the recoil dampers do the barrel would just move in exactly the opposite desired trajectory of the bullet? That wouldn’t lower accuracy? I’m not sure it’s possible though.
You know .. a lightweight tripod with servoces that can be deployed, hammered into the ground and be fired by a computer or a sniper from a different location.
Israelis are already working on these, I think.
“What if you put the recoil dampers do the barrel would just move in exactly the opposite desired trajectory of the bullet? That wouldn’t lower accuracy? I’m not sure it’s possible though.”
It’s not. There are always tolerances, so there’s always going to be some movement on the other two axes. The tighter you make the tolerances, the more accurate things become, but the less reliable.
How about letting the dampers work only after the bullet has left the building?
You can’t worsen accuracy then, the bullet leaves very quickly..
I was the lucky guy to fire the weapon while having the pictures taken. I wore .99 cent marshmellow plugs. Oleg wanted me to wear muffs but I wanted to get the real feel for just how loud it really was next to my head. It lets you know it was just fired but I could still hear everyone talking in the background even enough to make a comment about a conversion two other fellows were having while we were in the firing stages of the shoot.
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That looks like a ton of fun! How’s it do at long distance?
tweaker
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Flint says:
May 20, 2011 at 9:49 am
Recoil is actually power (work done over time), not energy (an instantaneous sample).
Close, but exactly the opposite. 🙂
Power is instantaneous. Energy is power integrated over time. Energy is work.
http://en.wikipedia.org/wiki/Recoil
http://en.wikipedia.org/wiki/Physics_of_firearms
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