Can someone explain how this is done please? I have a build it the shop now and was just curious as to what it take to accomplish this.
Thanks,
Thanks,
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Gunsmithing Timing a muzzle brake?
- Thread starter platapus
- Start date
Re: Timing a muzzle brake?
They thread the barrel until the break is correctly timed. On a Vais break it really doesn't matter because the break has holes all the way around and there is to "sides". If you have a break that needs to look a certain way, kinda like holes on the left and right, instead of up and down, well you want those holes perfectly threaded to each side. So the process is just little by little, threading the barrel so the break ends up being perfectly aligned with the barrel...
They thread the barrel until the break is correctly timed. On a Vais break it really doesn't matter because the break has holes all the way around and there is to "sides". If you have a break that needs to look a certain way, kinda like holes on the left and right, instead of up and down, well you want those holes perfectly threaded to each side. So the process is just little by little, threading the barrel so the break ends up being perfectly aligned with the barrel...
Re: Timing a muzzle brake?
Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too.
Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too.
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: StanwoodSpartan</div><div class="ubbcode-body">They thread the barrel until the break is correctly timed. On a Vais break it really doesn't matter because the break has holes all the way around and there is to "sides". If you have a break that needs to look a certain way, kinda like holes on the left and right, instead of up and down, well you want those holes perfectly threaded to each side. So the process is just little by little, threading the barrel so the break ends up being perfectly aligned with the barrel... </div></div>
I'm not sure you worded that quite right. Generally speaking, flash hiders and muzzle brakes time off of the shoulders, not the threads themselves. Facing either the thread shoulder or rear of the brake (depending on the application) allows the brake/FH to rotate more.
There's a series of equations used to determine how much needs to be faced off of the surface to time the item being installed.
1/TPI = P (thread pitch, or distance crest to crest on threads. A full 360° rotation on this thread)
For example, the pitch of a 28 TPI thread is .03571
The pitch can then be multiplied by the fraction of a turn needed to time (measured or approximate), and will give you an approximate number to face off of the shoulder.
For example, with this 28 TPI thread, if the brake needed to be rotated an additional 3/8 of a turn to time properly, the amount faced off of the shoulder would need to be .01339.
Now, these numbers can and will change depending on how much torque is being applied when tightening the brake before and after facing. It's usually a good idea to face slightly less than you think you need to take off and check the exact timing when torqued down.
With a non-directional specific brake like a Vais, the timing becomes even easier. You have 8 points you can to time to, instead of a single point. If, say, you miss your timing mark to get one row TDC (or wherever you decide to time it to) by a few thousandths, you can just move onto the next one, provided you have the material left to do so.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: StanwoodSpartan</div><div class="ubbcode-body">They thread the barrel until the break is correctly timed. On a Vais break it really doesn't matter because the break has holes all the way around and there is to "sides". If you have a break that needs to look a certain way, kinda like holes on the left and right, instead of up and down, well you want those holes perfectly threaded to each side. So the process is just little by little, threading the barrel so the break ends up being perfectly aligned with the barrel... </div></div>
I'm not sure you worded that quite right. Generally speaking, flash hiders and muzzle brakes time off of the shoulders, not the threads themselves. Facing either the thread shoulder or rear of the brake (depending on the application) allows the brake/FH to rotate more.
There's a series of equations used to determine how much needs to be faced off of the surface to time the item being installed.
1/TPI = P (thread pitch, or distance crest to crest on threads. A full 360° rotation on this thread)
For example, the pitch of a 28 TPI thread is .03571
The pitch can then be multiplied by the fraction of a turn needed to time (measured or approximate), and will give you an approximate number to face off of the shoulder.
For example, with this 28 TPI thread, if the brake needed to be rotated an additional 3/8 of a turn to time properly, the amount faced off of the shoulder would need to be .01339.
Now, these numbers can and will change depending on how much torque is being applied when tightening the brake before and after facing. It's usually a good idea to face slightly less than you think you need to take off and check the exact timing when torqued down.
With a non-directional specific brake like a Vais, the timing becomes even easier. You have 8 points you can to time to, instead of a single point. If, say, you miss your timing mark to get one row TDC (or wherever you decide to time it to) by a few thousandths, you can just move onto the next one, provided you have the material left to do so.
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Csf45</div><div class="ubbcode-body">Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too. </div></div>
or you could do a bit of math so you only have to make one correction, not the guess and check method.
say you have a 24 tpi thread, that means there are 24 threads in an inch. if you divide that one inch by 24 you get .041667". this means that the threads are .041667" apart and every full turn moves the device that same amount. one full turn is 360 degrees so we can divide that .041667" by 360 degrees and get .000116" of movement per degree of rotation. now you need to multiply the amount of rotation degrees you need to make by the .000116" to figure out how much material to remove from the shoulder. say you need 90 degrees of rotation, multiply 90 degrees by .000116" and come up with .010417" of material to remove from the shoulder.
i think there is a simplified way of doing this but this is the way i figured it out and it's fast enough for me to use so i stick with it.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Csf45</div><div class="ubbcode-body">Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too. </div></div>
or you could do a bit of math so you only have to make one correction, not the guess and check method.
say you have a 24 tpi thread, that means there are 24 threads in an inch. if you divide that one inch by 24 you get .041667". this means that the threads are .041667" apart and every full turn moves the device that same amount. one full turn is 360 degrees so we can divide that .041667" by 360 degrees and get .000116" of movement per degree of rotation. now you need to multiply the amount of rotation degrees you need to make by the .000116" to figure out how much material to remove from the shoulder. say you need 90 degrees of rotation, multiply 90 degrees by .000116" and come up with .010417" of material to remove from the shoulder.
i think there is a simplified way of doing this but this is the way i figured it out and it's fast enough for me to use so i stick with it.
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Csf45</div><div class="ubbcode-body">Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too. </div></div>
or you could do a bit of math so you only have to make one correction, not the guess and check method.
say you have a 24 tpi thread, that means there are 24 threads in an inch. if you divide that one inch by 24 you get .041667". this means that the threads are .041667" apart and every full turn moves the device that same amount. one full turn is 360 degrees so we can divide that .041667" by 360 degrees and get .000116" of movement per degree of rotation. now you need to multiply the amount of rotation degrees you need to make by the .000116" to figure out how much material to remove from the shoulder. say you need 90 degrees of rotation, multiply 90 degrees by .000116" and come up with .010417" of material to remove from the shoulder.
i think there is a simplified way of doing this but this is the way i figured it out and it's fast enough for me to use so i stick with it. </div></div>
That makes sense. It would have been easier to do it that way, but I think I got too giddy about doing some DIY smithing and jumped into it. It only took a second to check it each time though being I had the brake chucked up into a collet and had a lathe tool clamped to the table, so all I had to do was pop the holder out each time I wanted to check.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Csf45</div><div class="ubbcode-body">Take a couple thousandths at a time off the back of the brake checking it in between until it lines up. I did mine manually in a CNC, but it can be done in a lathe too. </div></div>
or you could do a bit of math so you only have to make one correction, not the guess and check method.
say you have a 24 tpi thread, that means there are 24 threads in an inch. if you divide that one inch by 24 you get .041667". this means that the threads are .041667" apart and every full turn moves the device that same amount. one full turn is 360 degrees so we can divide that .041667" by 360 degrees and get .000116" of movement per degree of rotation. now you need to multiply the amount of rotation degrees you need to make by the .000116" to figure out how much material to remove from the shoulder. say you need 90 degrees of rotation, multiply 90 degrees by .000116" and come up with .010417" of material to remove from the shoulder.
i think there is a simplified way of doing this but this is the way i figured it out and it's fast enough for me to use so i stick with it. </div></div>
That makes sense. It would have been easier to do it that way, but I think I got too giddy about doing some DIY smithing and jumped into it. It only took a second to check it each time though being I had the brake chucked up into a collet and had a lathe tool clamped to the table, so all I had to do was pop the holder out each time I wanted to check.
Re: Timing a muzzle brake?
Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?
Thanks in advance and sorry if this is a dumb question!
Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?
Thanks in advance and sorry if this is a dumb question!
Re: Timing a muzzle brake?
it has been my understanding that brakes require a specific and fairly narrow window of "expansion chamber" between the crown and first baffle. if this is the case, you would have to remove equal amounts off the shoulder where the muzzle brake will seat and the crown once you have determined how long the thread shank needs to be. is this correct?
chuck
it has been my understanding that brakes require a specific and fairly narrow window of "expansion chamber" between the crown and first baffle. if this is the case, you would have to remove equal amounts off the shoulder where the muzzle brake will seat and the crown once you have determined how long the thread shank needs to be. is this correct?
chuck
Re: Timing a muzzle brake?
If buying a prefabbed brake the above is spot on.
If you have the luxury of making your own might I offer this:
I loath installing brakes as the timing is the biggest concern I have. Threading and whatnot is the easy part. Getting the ports clocked "Jonny on the spot" however has historically been a biche for me.
So I solved the problem by flip/flopping the orders of operations. I machine a blank with the threads/center hole done and install it. Knock out the finish contour so it's a seamless transition to the barrel and pull it from the machine.
Then it goes in the 4th axis assembled on the barrel with the action also installed. In my case I use a 5C collet to captivate the end of the brake and support the barrel in a steady rest adapted to fit the table like a tail stock does. Then its easy. You find your center, index the whole assembly off the raceways of the receiver and get busy.
With a manual mill the same is accomplished by using either a rotary table or a simple "spindex" indexer. It'll take a little longer to do, but its pretty simple and goes quickly once you get the hang of it.
The beauty here too is being able to fiddle with port geometry. Once upon a time I was encouraged to play with venturi effects on the ports. Small at the bore, increase in size at the OD.
For now I just rake the whole assy back a few degrees and call it good. Seems to work pretty well.
Directly below is a 9 shot group fired at last weekend at 200 yards from a M700 that I recently blueprinted, barreled (308 Win), and fitted a brake to. The owner/shooter is Chris J. He goes by "Chef Jones" here on the hide.
These are how they come out once finished.
If buying a prefabbed brake the above is spot on.
If you have the luxury of making your own might I offer this:
I loath installing brakes as the timing is the biggest concern I have. Threading and whatnot is the easy part. Getting the ports clocked "Jonny on the spot" however has historically been a biche for me.
So I solved the problem by flip/flopping the orders of operations. I machine a blank with the threads/center hole done and install it. Knock out the finish contour so it's a seamless transition to the barrel and pull it from the machine.
Then it goes in the 4th axis assembled on the barrel with the action also installed. In my case I use a 5C collet to captivate the end of the brake and support the barrel in a steady rest adapted to fit the table like a tail stock does. Then its easy. You find your center, index the whole assembly off the raceways of the receiver and get busy.
With a manual mill the same is accomplished by using either a rotary table or a simple "spindex" indexer. It'll take a little longer to do, but its pretty simple and goes quickly once you get the hang of it.
The beauty here too is being able to fiddle with port geometry. Once upon a time I was encouraged to play with venturi effects on the ports. Small at the bore, increase in size at the OD.
For now I just rake the whole assy back a few degrees and call it good. Seems to work pretty well.
Directly below is a 9 shot group fired at last weekend at 200 yards from a M700 that I recently blueprinted, barreled (308 Win), and fitted a brake to. The owner/shooter is Chris J. He goes by "Chef Jones" here on the hide.
These are how they come out once finished.
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
<span style="color: #FF0000">
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?</span>
Thanks in advance and sorry if this is a dumb question!
</div></div>
I'd like to know as well...
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
<span style="color: #FF0000">
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?</span>
Thanks in advance and sorry if this is a dumb question!
I'd like to know as well...
Re: Timing a muzzle brake?
Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter.
Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter.
Re: Timing a muzzle brake?
Sure, you could do it with a file. Just wouldn't be as precise or pretty if you had used a lathe/mill.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter.</div></div>
Sure, you could do it with a file. Just wouldn't be as precise or pretty if you had used a lathe/mill.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter.</div></div>
Re: Timing a muzzle brake?
Also interested as my crowned and unthreaded FN A2 is soon to be done.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jtb33</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
<span style="color: #FF0000">
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?</span>
Thanks in advance and sorry if this is a dumb question!
</div></div>
I'd like to know as well... </div></div>
Also interested as my crowned and unthreaded FN A2 is soon to be done.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jtb33</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BasraBoy</div><div class="ubbcode-body">Am I right in understanding the method recommended above (i.e. removing metal from the barrel) is for new, unthreaded, uncrowned barrels?
What if the barrel is already crowned and threaded? Does this need a different approach - such as shims?
<span style="color: #FF0000">
What is the best way to ensure correct timing and alignment using shims on an existing threaded barrel?</span>
Thanks in advance and sorry if this is a dumb question!
I'd like to know as well... </div></div>
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Doing this with a file or a flat surface with sand paper is possible, but it will be very difficult for you to keep the rear face of the brake square to the bore axis. I don't know how badly a small amount of non-squareness would affect the rifle's accuracy, but it sure won't help.
I've ever had to do similar tasks, just not specifically on a muzzle brake. If you have a SMALL amount of material to remove, you can use a flat piece of glass, and stick a piece of wet/dry sandpaper to it. Rub the brake on the sandpaper (with water) in a figure 8 fashion. Stop and rotate the brake every 3 or 4 figure 8's. Stop often and measure the length of the brake in several places to see if you're starting to get unsquare. If you develop some unsquareness, it's tough to square it back up. If it does, you'll have to focus more attention on the long side, again, stopping often to check your progress.
Another "DIY" method that can work nicely uses a drill, a dremel, a vise and a little ingenuity. Make an arbor to chuck your brake in a drill, then clamp the drill in a vise. Using some flat-stock, bolt together an articulating "arm" you can hose clamp your dremel (with a grinding wheel) to. The "arm" works as a guide to keep the dremel perpendicular to the workpiece (your brake), and you can now run the dremel back and forth over the face that needs trimming down. Obviously, you'd have the drill running as well. A similar technique can be used on a lathe - hose clamp a dremel to the tool post or a boring bar, and there are a lot of small grinding tasks you can achieve!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Doing this with a file or a flat surface with sand paper is possible, but it will be very difficult for you to keep the rear face of the brake square to the bore axis. I don't know how badly a small amount of non-squareness would affect the rifle's accuracy, but it sure won't help.
I've ever had to do similar tasks, just not specifically on a muzzle brake. If you have a SMALL amount of material to remove, you can use a flat piece of glass, and stick a piece of wet/dry sandpaper to it. Rub the brake on the sandpaper (with water) in a figure 8 fashion. Stop and rotate the brake every 3 or 4 figure 8's. Stop often and measure the length of the brake in several places to see if you're starting to get unsquare. If you develop some unsquareness, it's tough to square it back up. If it does, you'll have to focus more attention on the long side, again, stopping often to check your progress.
Another "DIY" method that can work nicely uses a drill, a dremel, a vise and a little ingenuity. Make an arbor to chuck your brake in a drill, then clamp the drill in a vise. Using some flat-stock, bolt together an articulating "arm" you can hose clamp your dremel (with a grinding wheel) to. The "arm" works as a guide to keep the dremel perpendicular to the workpiece (your brake), and you can now run the dremel back and forth over the face that needs trimming down. Obviously, you'd have the drill running as well. A similar technique can be used on a lathe - hose clamp a dremel to the tool post or a boring bar, and there are a lot of small grinding tasks you can achieve!
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Check your fit while still chucked up in the lathe. It makes no sense to me to be so close to a perfectly meshes finish and then go after it with a file.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Check your fit while still chucked up in the lathe. It makes no sense to me to be so close to a perfectly meshes finish and then go after it with a file.
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hero's machine</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Check your fit while still chucked up in the lathe. It makes no sense to me to be so close to a perfectly meshes finish and then go after it with a file. </div></div>
True statement. If you can get a square shoulder on a lathe then the rest is easy. PM me and I will give you a hint. So simple you will kick your own ass for not thinking of it. No long math formula needed, creep up on it. Will look better than any pictures posted anywhere.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hero's machine</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VjjR</div><div class="ubbcode-body">Has anybody done this with a file instead of a lathe? if you only have say .010417" to remove it would seem any inconsistencies from filing would be minimal enough to not matter. </div></div>
Check your fit while still chucked up in the lathe. It makes no sense to me to be so close to a perfectly meshes finish and then go after it with a file. </div></div>
True statement. If you can get a square shoulder on a lathe then the rest is easy. PM me and I will give you a hint. So simple you will kick your own ass for not thinking of it. No long math formula needed, creep up on it. Will look better than any pictures posted anywhere.
Re: Timing a muzzle brake?
My experience with timing brakes is to use the calculation method to get close to the not enough side and then creep up by a .001 or .002 off the brake face. When I am really close, a little extra torque will usually line the holes up and insure a tight fit.
My experience with timing brakes is to use the calculation method to get close to the not enough side and then creep up by a .001 or .002 off the brake face. When I am really close, a little extra torque will usually line the holes up and insure a tight fit.
Re: Timing a muzzle brake?
I realize this thread is somewhat old... But I could use a little help on the subject.
What is the purpose of timing a muzzle brake? Is it for looks? Or is it to serve accuracy?
I ordered a brake from CoreTac Solutions, it threads on and has a screw to clamp it in position.
I realize this thread is somewhat old... But I could use a little help on the subject.
What is the purpose of timing a muzzle brake? Is it for looks? Or is it to serve accuracy?
I ordered a brake from CoreTac Solutions, it threads on and has a screw to clamp it in position.
Re: Timing a muzzle brake?
C.Dixon does it exactly how my buddy makes his brakes. Works out fantastic
C.Dixon does it exactly how my buddy makes his brakes. Works out fantastic
Re: Timing a muzzle brake?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SavageLapua</div><div class="ubbcode-body">What is the purpose of timing a muzzle brake? Is it for looks? Or is it to serve accuracy?
</div></div>
Many brake designs have some "bias" in them to reduce muzzle jump.
You want the "top" side of the brake to generally be facing up so it gives the muzzle a gentle downward push as the bullet exits the barrel.
This helps you stay on target to spot your impacts or take a followup shot if needed...
If there is no bias built into the brake, there is probably no need to index it unless it's a side-to-side balanced design.
Then you would want the two sides facing sideways so as not to increase muzzle blast downward onto the ground when you are in prone.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SavageLapua</div><div class="ubbcode-body">What is the purpose of timing a muzzle brake? Is it for looks? Or is it to serve accuracy?
</div></div>
Many brake designs have some "bias" in them to reduce muzzle jump.
You want the "top" side of the brake to generally be facing up so it gives the muzzle a gentle downward push as the bullet exits the barrel.
This helps you stay on target to spot your impacts or take a followup shot if needed...
If there is no bias built into the brake, there is probably no need to index it unless it's a side-to-side balanced design.
Then you would want the two sides facing sideways so as not to increase muzzle blast downward onto the ground when you are in prone.
