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Discussion Starter #1
Whats the diffferance of a compensator (like Barsto does)
and a 1inch longer barrel, ported of course (either EFK F.D. or Barsto)
 

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XD 40 mike said:
Whats the diffferance of a compensator (like Barsto does)
and a 1inch longer barrel, ported of course (either EFK F.D. or Barsto)
Reduces recoil. Same basic theories for both
 

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Discussion Starter #3
Any speculation to either one being any better than the other?

I haven't seen a compensator on an XD before, I think that would be pretty cool looking. Bar-stro threads purtruding barrels, and they sell compensators. I would assume they put 2 and 2 together.

That would be awesome looking! lol
 

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GunSlinger,

Is there a difference between a compensator and a ported barrel though? I thought a compensator pulled the gun forward to ease recoil, and ported barrels simply push the barrel down to ease muzzle-flip.

You said a compensator pushes the barrel down, which for all I know could be true, but that it's useless in most pistol calibers. Which to me says you're saying an XD40V10 isn't significantly different in recoil from an XD40. In which case, I take issue, and smack you with my white cotton gloves. :)
 

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Porting like in the V10 also reduces recoil. Certainly the ports are orienteer to primarily control muzzle climb but they also reduce recoil. Porting or a compensator both divert propellant gases. This diversion of the propellant gas will reduce recoil and possibly produce a moment to controll muzzle climb. If the gases are diverted in symmetric direction around the axis of the barrel as in a muzzle brake then they produce no moment. If the ports are asymmetric around the axis of the barrel, like the porting of a V10, they will also produce a moment. That said I highly doubt any type of porting or compensator will noticeably reduce recoil by more than 10% at best in a pistol shooting an automatic pistol cartridge. Control muzzle climb for sure reduce recoil just a little at best. There is simply not enough mass in the propellant gases to offset the heavier pistol bullet.

mcb
 

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I think there is a lot more going on, felt recoil is a nasty can of worms to discuss because a lot of it is subjective. The compensator certainly is keeping the muzzle from climbing and making a small difference in recoil in a similar manner to a muzzle brake but I think due to the reduce muzzle flip this may feel better than it actually is.

Remember recoil is the change in momentum. The gun has to recoil with the same amount of momentum that the bullet and propellant gases left the barrel with. So if a bullet weighs 180 grains and is pushed but 5 grains of propellant then a perfect compensator (one that diverts all the gases perpendicular to the path of the bullet) would result in a 2.7% reduction in recoil. It’s simple physics. The total recoil impulse can only be reduce by a maximum of the percentage the propellant mass is of the total of the propellant and bullet mass. This can be increased up to twice if you are willing to redirect the gases more back at the shooter but this is not practical.

Now given that we have put the compensator on the slide this add mass which always helps reduce felt recoil it also does other things. That pull you guys talk about will not only reduce the total recoil impulse (by the percentage above) but it can also be used to slow the slide. This does not reduce the total momentum change of the weapon but can be used to lengthen the recoil impulse lowering the peak acceleration. This feels like a lighter recoil even though it the same total recoil impulse.

Think of it similar to the felt recoil deference between the recoil of a pump shotgun and a semi-auto shotgun that both weigh the same and are shooting the same shell. The recoil is exactly that same, but the semi-auto sure feels a lot softer. Not because there is less recoil but because the recoil impulse is spread out over more time.

mcb
 

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Discussion Starter #7
Well actually I am not talking about the v10 either, sorry I guess I wasn't clear on that. So which is better for a 40cal Tactical. One of those badass compensators or this barrel, but in 6 inch...

 

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Hmmm… Please don’t take this as an insult but have you had college physics or dynamics course? I spent 12 years getting a PhD in mechanical engineering specializing in Dynamics and Robotics. Don’t worry I have already broken my arm patting myself on the back and I know I know “big whoopy I still wrong!” and you can believe that if you like but I am pretty sure I am correct on this one. We can discuss it more if you like but if you try to look at recoil through kinetic energy you’re doing it the hard way. Momentum is the correct way to look at any recoil problem that involves projectiles, even if those projectiles are explosive gases; they still have mass and velocity, hence momentum.

I have also never claimed compensators don’t work but I think they do more to spread out the recoil impulse on a pistol a lot more then actually reducing the total impulse absorbed by the shooter.

mcb
 

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Discussion Starter #11
Another question I have is I know I read somewhere atleast on two different occasion that adding a ported barrel can reduce recoil up to 40%. I thought of it as a bit much myself, thats why I am asking.
 

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Your correct XD 40 mike you can get 40% or more reduction in recoil with a muzzle brake on a rifle. Most rifle cartridge use a quantity of propellant that can approach the same mass as the bullet they push. Thus you have significantly more mass in propellant gases to be redirected through the porting and thus reducing the recoil.

I must also eat a small bit of crow here. I have forgotten that the gases exiting the muzzle will actually have significantly higher average velocities then the actual bullet they are pushing. This results in the propellant producing more recoil then the equivalent mass of projectile would have (this effect is even more noticeable in rifles that operate at even higher chamber pressures). So in the earlier example were I use a 180 grain 40 S&W bullet bushed by 5 grain of propellant at 1000 fps and stated that the most recoil reduction is only 2.7 % is incorrect. You can probably realize closer to four times that if you have a muzzle break or compensator that can redirect ALL of the gases perpendicular to the axis of the barrel. Redirecting all of the gases is not possible with designs being produced so you will probably only realize about 50% of that possible 10.8% reduction.

mcb
 

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Discussion Starter #14
So the 40% less recoil thing is a hoax? Because when I read it, it was not talking about rifles, it was definitaly refering to a ported barrel in handguns.
 

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Gunslinger45 I apologize if I got under your skin it was not intentional. I have no doubt you have a lot of experience with firearms and their build up. I still have less the 3000 round total through all my handguns combined. I was merely pointing out that there is a definite limit to how much recoil a compensator or muzzle brake can suck out of a weapon and pistols firing pistol cartridges are at a serious disadvantage due to the low propellant mass and high projectile weight and low chamber pressures compared to rifle cartridges.

Obviously they do something or gunsmiths like yourself would not be putting them on pistols for shooters. But I don’t think they reduce the actual recoil impulse as much as they spread it out and control the muzzle climb. And even 5-10% reduction in recoil combine with recoil buffers, added weight, thumb rests, etc can add up to make the recoil much easier to control. Felt recoil and measure recoil are two vastly different animals.

Sorry
mcb
 

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XD 40 mike said:
So the 40% less recoil thing is a hoax? Because when I read it, it was not talking about rifles, it was definitaly refering to a ported barrel in handguns.
My guess is that they are talking about a 40% reduction in peek acceleration. My guess would be they are not reducing the total momentum change by that much. If you still have the link I would love to check it out maybe they are doing something different.

mcb
 

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Comp's work in 3 basic ways...........The first is by adding weight to the muzzle of the gun. The added weight reduces muzzle flip, and slows the barrel/slide unlocking which reduces pressure in the barrel prior to the barrel unlocking which in turn reduces slide velocity. When the slide velocity is reduced it will strike the frame with less energy, reducing felt recoil. Additionally the extra weight results in less energy stored in the recoil spring which reduces forward slide velocity imparting less force to the frame when it goes back into battery, reducing felt recoil. Shooters tend to experience muzzle flip and muzzle dip as all muzzle flip but they are two different animals and are controlled two different ways

The second is by creating a baffle (or baffles) just forward of the muzzle into which escaping gases slam into which has the effect of reducing the rearward slide/barrel speed resulting in the same effect as above. It also imparts a small forward push which because the grip of the gun is at the rear (the pivot point of the muzzle flip arc) effectively pulls the muzzle downward reducing muzzle flip as well as rearward recoil.

Third, the escaping gases are vented upward (sometimes to the side) creating a downward pressure on the muzzle helping to reduce muzzle flip. Side porting in a comp doesn't work very well at reducing muzzle flip, helps a little with rearward recoil, but works very well in stabilizing the muzzle thru the yaw axis (side to side movement instead of up and down). There is often times a lot more movement in the yaw then most shooters realize. Especially when shooting with a dot scope the buzzing movement of the dot is thru the yaw and not the vertical. Side porting is excellent for controlling this.

All of these factors are dependent on the pressure and volume of the gases produced by the cartidge in question except for the weight of the comp. As a general rule the higher the pressure and volume, the better the comp will work. The weight of the comp is dedicated by the fact that as weight increases you will get to a point that the gun will no longer cycle. Also it has a big effect on the balance of the gun which shooters either like or don't like. That is why you have comps made from alum and Ti as well as S/S and carbon steel.

Barrels that are extended and have ports cut directly into them are the least effective of all. They lose the advantages of the extra weight, don't have any baffles for the gases to work off of, and usually are so close to the muzzle that the barrel is unsealed by the bullets leaving the barrel so quickly that there isn't time for the high pressure gases to work before the pressure drops to low. Hybrid barrels attempted to address this issue by beginning the direct barrel porting much closer to the chamber and further from the muzzle. This allows the ports to 'see' a much high pressure and longer pressure impulse then otherwise would be available thru barrel porting. They still don't have the advantage of the additional weight or the baffling, but work fairly well when overall length of the gun is important. Often times they are used in conjuction with a conventional comp attempting to gain the benefits of both systems.
 

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A Muzzle Brake on a rifle would have greater leverage when exerting the downward force on the tip of the longer rifle barrel, as compared to a shorter barreled Pistol, wouldn't it? Seems like this would make its job easier, and the potential (like a 40% reduction in Muzzle Flip) of the Rifle Muzzle Brake easier to realize than on a Pistol. Make Sense?

Signed: The Amazing King of Obvious Intuitive Physics...... :D

P.S. Wouldn't this also be true for a relatively longer Pistol Compensator?
 

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The lower pressure guns will tend to work better with heavier comp's due to the fact the extra weight makes up for the fact that they don't have enough pressure or gas volume to really take advantage of the baffling/porting.

The extra weight would also benefit the smaller bore/higher pressure rounds but is not usually needed because the higher pressure/volume makes the baffling/ports more effective. Most shooters, especially those with a higher skill level, will prefer a lighter comp because the guns balance will be more neutral and it will index easier/quicker from target to target. The one top shooter who seems to be different is Robbie Leathem who likes a heavy gun with a heavy comp. Even his Limited guns are heavy...........

One last thing, soft shooting and flat shooting are two different things. A longer, heavier, gun will normally shoot softer then a lighter, shorter, gun. I build (and shoot) mostly short Open guns (4.3" slide with a 2" comp). They shoot very flat but they are not soft shooting. Recoil is sudden and hard, cycle speed is high, and the recoil event is very short. But they are very flat and back on target ready to shoot again very quickly. Not everyone likes that style of gun..........

Willbond, first thing to remember, the recoil pivot point for a rifle (or a shotgun) is your shoulder where the buttpad contacts your body. This moves the leverage point out a longgggggg ways which as you stated helps lot. Rifle cartridges also tend to run at a much higher pressure and produce a lot more gas volume, both of which make the comp more effective. Plus they tend to weigh more which absorbs more energy that would be otherwise felt as recoil. Would a pistol comp be more effective on a longer barrel? Probably not because even though you would gain leverage, you lose effectiveness because of the lower pressure available at the baffles resulting from the larger expansion area of the longer barrel. Additionally any advantage you might gain in reduced muzzle flip would probably be offset by an increase in transistion times between targets. A longer or heavier gun, tends to accelarate slower and stop slower when moving to different index points. The idea, ultimately, is to be able to complete the course of fire as quickly as possible, and pass a certain point a reduction in split times, especially when gotten at the expense of something else, is not the answer. There is a lot more to be gained in the area of moving from box to box and target to target, then in shot to shot. Fast splits sound good but they rarely win matches.........
 
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