Barrel tuners or other muzzle devices effect on velocity and velocity stats

[darkangel_r2]

This is a question for people who have chronographed the same load with and without a muzzle device (not a suppressor I know those can effect velocity) or people who have shot over a chrono while changing a barrel tuners settings.

Does adding a muzzle device or changing the setting on a barrel tuner effect muzzle velocity or velocity statistics of a load?

If I shoot a load with an example ES of 15 for 20 shots will adding a muzzle device or making significant changes to a barrel tuner setting change my velocity or its ES/SD stats?

I am trying to see if velocity stats are separable from the barrel (as long as the barrel is long enough to achieve a complete burn with the load).

Does anyone have chronograph data shooting the same load while changing barrel tuner settings or adding a break?

 

[Bill Norris]

YES, Switching settings (even minimal) on an E C Tuner/Brake will change your E S /S D numbers. I have not payed attention to change in shooting the rifle without the tuner/brake installed vs. installed however I'm certain it will affect the numbers by some degree.

 

[darkangel_r2]

YES, Switching settings (even minimal) on an E C Tuner/Brake will change your E S /S D numbers. I have not payed attention to change in shooting the rifle without the tuner/brake installed vs. installed however I'm certain it will affect the numbers by some degree.

Any raw data to share? I'm curious to the magnitude of this effect.

 

[222Jim]

A muzzle break works by diverting some of the combustion gas to the side, hence the "breaking action", which is really just reducing the rearward thrust of the barrel and rifle when the gas exists. Thus in theory (and immediately I'll lose credibility......), a muzzle break will change how much combustion gas is available to "push" the bullet once it exits the barrel. But in practice I'm not sure if the change would even be measurable.

So as darkangel_r2 asked, anybody have any data?

 

[JimSC]

I will be in a good position to answer this by next week. I am starting load development on a .308 Win tomorrow., I will be doing initial sight in with no attachments, initial velocity testing with a muzzle break, then fine tuning the load with a Ezell tuner. I'll bookmark the thread and post results

 

[darkangel_r2]

I will be in a good position to answer this by next week. I am starting load development on a .308 Win tomorrow., I will be doing initial sight in with no attachments, initial velocity testing with a muzzle break, then fine tuning the load with a Ezell tuner. I'll bookmark the thread and post results

Looking forward to it, thanks.

 

[JimSC]

common sense tells me that once the bullet is out of the bore then the gas has no effect but we shall see

 

[darkangel_r2]

common sense tells me that once the bullet is out of the bore then the gas has no effect but we shall see

That's what I think as well. Once the bullet is out of the barrel unless the gasses are trapped like in a suppressor I doubt we will see much in terms of average velocity change.

My main concern in this post though is with how the different barrel harmonics effect velocity stats. If i have a great 5 SD load will changing a barrel tuner setting or adding a break change my velocity stats? That's what I want to know.

 

[JimSC]

That's what I think as well. Once the bullet is out of the barrel unless the gasses are trapped like in a suppressor I doubt we will see much in terms of average velocity change.

My main concern in this post though is with how the different barrel harmonics effect velocity stats. If i have a great 5 SD load will changing a barrel tuner setting or adding a break change my velocity stats? That's what I want to know.

if it is not affecting the velocity how could it affect the stats? I would be more concerned about how it would affect the POI, but that is just me. You shoot in low SD contests maybe?

 

[Steve Blair]

Just for the record: They are muzzle brakes, not breaks. They "brake" recoil. Homophonic confusion is common, but as people interested in firearms enough to frequent this site, we should try to get this stuff right.

 

[garandman]

I'll check back, but I'd be very surprised if its more than 20 fps for any load north of 2500 fps.

 

[Lefty Trigger]

The last little bit of push on the bullet is right at the muzzle so anything there will effect the bullet. Not to even mention hanging the weight on the end of the barrel. I learned this the hard way when I got my suppressor. I have also noticed that my brake does not change my ES/SD numbers but my suppressor does, a lot. We have all kinds of weird things screwed on barrels at our club from little tiny flash hiders to HUGE brakes that belong on a howitzer, kinda silly really and they swear it makes them shoot awesome... LOL

 

[!Peter!]

I have done a full powder test with 5 shots per charge with and without a tube on the end of my 308 and found SD/ES trends were different.

 

[Bill Norris]

Any raw data to share? I'm curious to the magnitude of this effect.

Sorry, I did not send those groups to my email and did not save them in my App for the chrono.

 

[Bill Norris]

That's what I think as well. Once the bullet is out of the barrel unless the gasses are trapped like in a suppressor I doubt we will see much in terms of average velocity change.

My main concern in this post though is with how the different barrel harmonics effect velocity stats. If i have a great 5 SD load will changing a barrel tuner setting or adding a break change my velocity stats? That's what I want to know.

Changing settings on my brakes on three different rifles changed the S D & E S.

 

[JimSC]

Changing settings on my brakes on three different rifles changed the S D & E S.

you mean changing the tuner settings? I have never seen or heard of a muzzle brake that is adjustable.

I have seen changes in ES/SD just by removing my jacket however. Two groups of ten rounds each all loaded at the same time and randomly pulled from the ammo box, powder measured to .02 gns on a A&D 120. Shot at 300 yards fifteen minutes apart same rifle same conditions etc. Only difference was I removed my jacket

edited for pic and explanation

 

[gunsandgunsmithing]

That's what I think as well. Once the bullet is out of the barrel unless the gasses are trapped like in a suppressor I doubt we will see much in terms of average velocity change.

My main concern in this post though is with how the different barrel harmonics effect velocity stats. If i have a great 5 SD load will changing a barrel tuner setting or adding a break change my velocity stats? That's what I want to know.

With my tuner, I've not seen it change velocities and I'd have to see it to believe it, if it ever could. That said, my tuner doesn't incorporate a brake and I can see a brake changing speeds a tiny bit, but I'd call 47fps more than a tiny bit of change.

I think you might have a combination of small factors at play, assuming the velocity readings are correct..which is another consideration itself.

A couple of things that come to mind are humidity and powder storage. The powder may have taken on a bit of moisture simply due to humidity. That brings how how your charges are measured. I assume by weight.

Another thought is throat wear and barrel condition. It may not take much in this area to make several fps difference. . Primers were already mentioned. Another small factor is air density. Temp can be the same but have more or less density.

Just tossing out a few ideas but I can't begin to imagine moving a tuner a couple of thou changing speed or es numbers..harmonically. I've just never seen it and can't think of a single plausible or physical reason that would explain it.

There is something to physical length that MIGHT play a role due to acoustics but again, that's a really long stretch on a very good day and if the brake extends beyond the tuner,..well, that would make it irrelevant unless the brake moves with the tuner. AFAIK, his doesn't work like that.

Bottom line, I think there is bound to be a more plausible and believable cause that has yet to be determined. I might be sold on the brake doing it but not the tuner adjustment without seeing it with my own eyes. Keep in mind, I've done vibration analysis testing that allowed me to see bullet exit and barrel position while moving the tuner, while reading velocities. So, I don't think it's a harmonically induced thing at all.

If it's really happening and can't be attributed to more plausible causes, I think the brake is the only thing that could possibly affect it. I'd just be surprised if it would be by that much, alone.

 

[Bill Norris]

you mean changing the tuner settings? I have never seen or heard of a muzzle brake that is adjustable. I have seen changes in ES/SD just by removing my jacket however.

The E C Tuner/Brake is two devices in one. Brake & Tuner. See pic below.

 

[gunsandgunsmithing]

The E C Tuner/Brake is two devices in one. Brake & Tuner. See pic below.

Bill, it looks like it could be either way...Do you move the actual brake on that thing, to make tuning adjustments? If so, I can half way get my head around how it would do this but not so much, if the brake is not moveable. Years ago, the military did research on shock waves and muzzle brakes relating to where peak pressure happens with the escaping gasses. I can see where changing the placement of the baffles, mainly the first one, might do this. FWIW.

 

[JimSC]

The E C Tuner/Brake is two devices in one. Brake & Tuner. See pic below.

I am familiar with it, but when you said brake I was thinking of the more common muzzle brake not Erik's combo. Once again I do not se how that would affect muzzle velocity unless you think the muzzle blast blowing on the base of the bullet could push it faster