Testing APS PainKiller muzzle brake

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by ss7mm, Jun 8, 2008.

  1. ss7mm

    ss7mm Writers Guild

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    First of all I need to apologize for the time frame in which I finally got around to testing the new PainKiller brake that Kirby installed on my gun. A couple of days in the hospital and a couple of days to get back on my feet put me a little behind but I got out today to try it out...............sweeeet;)

    I also need to apologize for the quality of the video. I never noticed that the setting on the camera was all screwed up and a couple of quick reviews while shooting looked o.k. but that was on a small camera screen. You can see the results and do the comparison but it's not very good. I'll get back out as soon as I can and try and get something that looks half way decent.:cool:

    This is the photo Kirby had posted showing his smaller 3 port PK brake plus the bigger 5 port PK on my gun barrel with the QD sitting on it.
    [​IMG]

    In the shots of the gun on the white plywood, the recoil pad toe and the bipod are both sitting on frisbees. I use a frisbee under my bipod a lot when shooting prone to eliminate variances in resistance and friction between the bipod feet and dirt/rocks etc. The trigger was tripped by a string applying easy pressure to make it as close to a normal trigger brake as I could. The frisbees sliding hopefully eliminated any human errors or variances so in the sliding shots it's just frisbee against painted plywood.


    You can see the differences in the three methods but I can say without hesitation that the physical sensation of the PK brake compared to the others was very noticable. It flat out works. Almost, notice I said almost, makes me want to try free recoil, but when burning 100 gr. of powder plus and pushing a 200 grain bullet, I don't think I'll take a chance with my poor ol eyebrow.:rolleyes: I can say it's very relaxing to sit behind something with that capability and see any hit at any distance and remain motionless and comfy while doing it.:)

    TestingAPSPainKillerMuzzleBrake.flv - Video - Photobucket - Video and Image Hosting
     
  2. Len Backus

    Len Backus Administrator Staff Member

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    Dick

    You can easily see the difference in the 2 brakes. And your "sled" method is exactly what Answer Brakes used to test theirs 10 or so years ago.
     

  3. lazylabs

    lazylabs Well-Known Member

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    What's the height across the flats of both brakes?

    Thanks
     
  4. ss7mm

    ss7mm Writers Guild

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    I don't know about the 3 port but the 5 port is 1.000" across the flats. Maybe Kirby will chime in with the 3 port.
     
  5. landcbeitner

    landcbeitner Well-Known Member

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    Very impressive recoil reduction
     
  6. ss7mm

    ss7mm Writers Guild

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    One thing I forgot to mention was the gases exiting the muzzle. If you watch the 3 different methods on the sliding shots you can see the angle of the gases and the gases from the angled ports of the PK show the angle affecting the gas angle.
     
  7. Ernie

    Ernie SPONSOR

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    Even with the video quality it shows the difference-Very Good
     
  8. Coues Sniper

    Coues Sniper Well-Known Member

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    Agreed. Ingenious test method too, I would never have thought of that :cool:. I about laughed out of my chair thinking about being behind the rig on that first shot without the brake :D

    Great test Dick.
     
  9. ss7mm

    ss7mm Writers Guild

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    I did the bench testing first so I had a general idea about the recoil with the 3 different methods. I also did one on the plywood without the brake before I did the video of the test. I was right at the back edge of the plywood to catch it just in case. I wasn't sure where it would end up and I didn't want a gun wreck caught on video with me providing the background audio.:rolleyes::rolleyes: So.......when I videoed the sliding test without the brake I knew it would go just to the edge of the plywood.:)
     
  10. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Most impressive test proceedure, the old addage still stands true, in most cases the simplier the better and in this case that is certainly true.

    For those wanting the dimensions of Painkiller brakes as far as across the flats, the large 5 port is right around 1.000", the medium 3 port is roughly 0.850" and the soon to be released small 3 port will be roughly 0.725" across the flats.

    I would like to add a bit to give some perspective to the performance of the large PK brake on ss7mms rifle. He contacted me about wanting to try one of these brakes on his rifle to test it against the Holland QD brake that was already on his rifle. I would also like to state that he paid for the brake so he could remain and offer an unbiased report on the results that would be credible.

    In talking with him I made it clear that the big 5 port PK was designed specifically for use with my 408 based wildcats or any other chambering of similiar case capacity and expansion ratio. The port sizes are designed as such to work best with a case capacity of roughly 130-150 grains of powder in the class of H-50BMG.

    As such, they are really oversized for the class of chambering that this rifle has which is the 7mm AM with a roughly 100-110 gr powder capacity. I really had no idea how it would perform with this class of case capacity but I was just as curious to try it out and see how it worked with the smaller then intended case capacity.

    When I finished the conversion, I was very happy with the results. Not surprised that it worked as expected but very happy with what I was feeling on my shoulder compared to the very well estabilished Holland QD brake.

    While I did not free recoil test the rifle I did shoot the rifle with air between my shoulder and the recoil pad with both brakes. You will say that is free recoiling but I made sure my shoulder was positioned close enough so that the recoil pad would contact my shoulder long before I was introduced to mister NXS!!!

    In shooting the rifle, and perhaps Dick can add to this some, I also noticed a dramatic difference in how the gas was vented off the muzzle. Certainly the back rake angle on the ports dramatically redirects the venting gas but I was suprised at the difference in the apparent velocity of the venting gas.

    With the Holland, the gas plume was instantly there at the shot. With the Painkiller, it seemed that the gas volume flowed out of the ports MUCH more slowly, in fact after the shot remaining gas could be seen exiting the brake long after the shot was released.

    I believe this is caused by two things, the main one being that the ports are simply larger then need be for this capacity of chambering. Had the ports been reduced from 3/8" width down to around 1/4" width, the venting gas would have been forced out of the brake at a much higher velocity then it is. That may or may not add to the effectiveness of the recoil reduction.

    Two, on the internal design of the PK brake, there are sharp wedges at the top and bottom of each bore hole. Wanted something that would SHAVE the venting gas and redirect as much as possible away from the base of the bullet. The theory here is that there would be very little if any turbulance ahead of the bullet as it passed through the ports. With the 30 degree back rake on the ports, if there was no diverting wedges, I believe that the venting gas would be directed directly ahead of the bullet which would create turbulance. Is this a fact, I did not test it to see but from what I have seen so far, accuracy is extremely good with these brake. On my 300 AX rifle, the rifle shot much better after the PK brake was installed then before. When I say much better, I am saying average groups were around 0.47 moa at 100 yards before and averaged 0.35 moa after with the 240 gr SMK. Noticable, measureable difference.

    This added level of accuracy may simple be from the added weight at the end of the muzzle dampening barrel harmonics but simply put, they seem to help.

    Now some will say this is really not a fair comparision simply because of the size of the Painkiller compared to the Holland QD. That is true, the QD does extremely well for its size, no arguement here. The PK brake was designed for one purpose and that is to reduce recoil as much as possible while staying relatively attractive in appearance. So far, the design seems to be working as expected!!

    Thanks for the report Dick, hope your happy and let us know how the rifle performs as far as being able to spot your hits down range.

    Kirby Allen(50)
     
  11. ss7mm

    ss7mm Writers Guild

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    I was mainly paying attention to the target and my ability to see the hits when shooting off the bench. With the QD brake before, I've had some problems at shorter ranges spotting my own hits. For the bench test I was shooting at small rocks at 125 yards. Normally at this short range the scope would probably be on 5.5 or close but for the test I had the scope on 15 power to limit the field of view. With the QD brake I didn't see the hit. With the PK brake there was no problem seeing the hit. Without a brake it was not even close to being able to see the hit. All the gasses straight out the front means the rock is dead and the dust is flying while the gases are in the way.

    You can see in the video that the gases are directed quite differently with the two different brakes. Shooting, with good hearing protection, it was hard to tell much difference but the PK brake seemed to have a duller sound and the QD had more of a sharp sound. My wife did the videoing and was wearing hearing protection. I deliberately had her stand to the side for the QD and to the side and back for the angled ports of the PK brake. She said the PK had a slightly softer sound also, probably from the size and number of ports combined with the angle.

    Like Kirby said, I knew going in that this brake was oversized for my gun but I've always been one to try different stuff and I am results oriented first, visually please second. Kinda like when someone I know decided to stuff a big 7mm Wildcat 200 grainer into a fat little Lapua case to see what would happen. Weren't to sure about the final results but I liked the idea. The results with the PK are as good as with the 7mm AM. I'm a happy little camper and that's what matters to me.

    If I was going to do it again, I'd probably go with the 3 port brake. It would probably perform on a par with the 5 port on my gun. But......would I change what I have? Not on a bet. I wanted maximum braking for spotting my own shots and I've got it. That 7mm AM just lays there on the bipod and gives a slight little twitch and that's it.
     
  12. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    I am glad you brought up the noise difference, I was wondering if you would notice anything different.

    We have tested alot of muzzle brakes over the years. We do, or used to do alot of long range coyote hunting, not so much anymore, to much time in the shop and with the little one!!! But, we tested many different designs to see how the down range noise signature was compared to each other.

    To do this we would position a shooter roughly 1/2 mile from the target and then position the "listener" if you will in a safe location about 75 yards from the target itself. By safe location I mean that this person was sitting safely behind a pile of rocks that no conventional rifle or 50 BMG would even put more then a chip into. The idea was to shoot the different brakes and see how they sounded down range.

    It was our experience that a coyote could easily pin point your location with a rifle with no brake, even at long to extreme range. Now you say you should not miss that first shot, yes that is the goal but it does not always happen, AND, in our area, seldom would the yotes be alone, if was pretty uncommon to see anything less then a pair of yotes and in some cases 3 to 4 would be crusing the low creek bottoms hunting together.

    With a bare muzzle, at the first shot, if you hit your intended target, you would get one on the ground but the rest of the dogs would pinpoint your location and hit cover if possible or put her in high gear dead away from you.

    We noticed one day while testing one of my first 50 BMG rifles with a down range spotter that the muzzle blast was dramatically different in sound with the muzzle brake. In fact, my bare muzzled 6-284 has a dramtically louder and more distinctive CRACK when it was fired. The big 50 simply was a muffled boom. You could still hear it but it was not so sharp and clear that you instantly knew where the sound came from.

    So we got to thinking, maybe this would help us increase our kills on yotes allowing multipule kills. We tested several muzzle brake designs, the most notible were the Holland QD, the Vias and the Gentrey "quiet" muzzle brakes.

    We found the partition style brakes dispersed the muzzle blast signature MUCH better then any other design that we tested. The Vias and Gentrey, both being radial port muzzle brake designs both changed the sound signature but it was still distinctly sharper and easier to pinpoint the location it came from then the Holland.

    Several years later I did some more testing to see how the Holland would be effected as far as down range sound signature depending on the bore clearance to the bullet. Standard clearance is to be set at 20 thou over bullet diameter.

    For this test, I took a 257 AM and fitted a Holland QD but only reamed it 7 thou over bullet diameter. If fitted properly to the muzzle, this works perfectly fine. Recoil reduction is amazing and we found muzzle blast dispersion is also VERY good.

    I then opened it up to the standard 20 thou over bullet diameter. To be honest, it was hard to tell any real difference. At times it would sound like there was a sharper crack but others did not seem to.

    Then I opened it up to 40 thou clearance. This made a noticable difference. While the sound signature was still softer and more dispersed then the radial port brakes, it was noticably sharper then the with the bore hole properly reamed. Why? Well, in my opinion, its a simple matter of how much of the venting gas is allowed to exit the front of the brake along with the bullet. The tighter the bore, the less gas gets out the front of the brake, the looser the bore to bullet fit, the more gas goes out the front of the brake with the bullet.

    This was taken underconsideration when I designed the PK muzzle brakes.

    I had also shot the Armalite AR-50 BMG ALOT previous to me designing my brakes and we also tested the down range sound signature on these rifles. Of the 50 BMGs I have shot this was the loudest at the shooters location but the quietest down range. Obviously the back angle on this brake contributes to lower down range sound signature as well.

    Again, this was taken into account when I designed my PK brakes.

    In testing my medium 3 port PK brake, we found it to be about as quite as you can get a rifle to be as far as down range sound signature without using a suppressor.

    Another witness to this was Shawn Winchester who owns and runs Headhunter Whitetails and Exotics down in Oklahoma where we just went on an exotic big game hunt a few weeks ago. When we were hunting some Exotic sheep, Shawn and his hired hand drove down off the high spot we were positioned at to see if he could locate any rams in the creek bottom. Well, he did and his precence was enough to move the sheep out of the creek bottom where they began feeding on some of the more open food plots. THe shee were roughly 820 yards from my shooting position and Shawn was probably 400-500 yards down range and 200-300 yards to the left of my line of sight to the sheep.

    When I shot one of my rams, he radioed back and said the only thing he heard was the bullets sonic crack at what seemed to be around 600 yards from my muzzle. He said he never did hear the muzzle blast of any kind.

    Now I am sure if he had been ready for it and expecting it he could have heard something from the muzzle but the design of the PK is such that its first job is to reduce recoil as much as possible but also to conceal the shooters location as much as possible as well.

    Now when those pairs and triplets of yotes come wondering down the draw, after that first shot they will have no idea which way to run to avoid danger and I have found they are much more likely to simply stand there or only trot off a short distance before stopping to see what just went on as they did not hear that clear warning crack telling them that a human is in the area.

    It was not a design requirement of the brake but its a hell of a bonus!!!

    Again, all partition style brakes do this pretty darn well, in my testing though, the PK is about as quiet as it gets for down range sound signature short of using a can on your muzzle.
     
  13. ss7mm

    ss7mm Writers Guild

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    One spot where we shoot locally is up a small canyon. It's about 500 yards to the end of the bottom and both sides and the end go up pretty steep.

    We've noticed in shooting and being up in the canyon behind a safe spot that the guns with the QD/baffle type brakes are very quiet as far as muzzle blast goes. You see a puff from the muzzle area and hear the sonic crack but at 500 yards the muzzle blast is very muffled. If we weren't in the canyon it would be even quieter.

    I'm looking forward to trying the PK brake in the canyon as from what little I've experienced so far, I'm betting that it will be very quiet.

    I shot an elk with the AM with QD brake a couple of years back at a range of about 690 yards from me. The other elk in the bunch didn't react as if they heard the sound they just moved off in the direction dictated by the lay of the land.

    We talked to a couple of guys later on that were about 400-500 yards up and behind the elk in a small little draw and they said they never heard the shot at all.

    An efficient brake works by directing gasses in the best possible direction. This means more noise for the shooter, although it may be a more manageable noise. It also means that the noise level down range is a non issue after you get a ways out.

    Use a good brake, muffle the down range sound and hide the bullet impact in the animals body. It just doesn't get any better than that.;);)
     
  14. Buffalobob

    Buffalobob Writers Guild

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    Very interesting report and discussion.