Tuner/Snubber/Muzzle Brake......pictures

[jackie schmidt]

My 284 600 yard Light Gun shoots quite well, with one problem. Even at 17 pounds, the recoil gets a tad aggravating with the 180 Berger bullet at 2850.

So I decided to add a muzzle brake. But I needed to incorporate a tuner with my "snubber".

Here is what I came up with. Since the barrel was already threaded .900 inch 32tpi, the main tuner/brake is threaded to fit that. Just behind is a .950 inch 20tpi for a jam nut.

The hard rubber "snubber" is pressed on, with addition of epoxy to hold it in place. (This is my usual practice).

The tuner and jam nut are machined from a Unlimited Barrel drop.

I guess the big test will come when I see if it still shoots, while reducing the recoil to a comfortable level.

http://benchrest.com/attachment.php?attachmentid=20403&stc=1&d=1512225613

http://benchrest.com/attachment.php?attachmentid=20404&stc=1&d=1512225679

http://benchrest.com/attachment.php?attachmentid=20405&stc=1&d=1512225751

http://benchrest.com/attachment.php?attachmentid=20406&stc=1&d=1512225817

 

[Steelhead1]

Jackie,
Great Idea, where do you source the rubber from? Is the rubber portion solid and you drill it slightly under size before press it on? Minus the Brake part would something larger work on a rail gun? Sure like the entire device.

 

[jackie schmidt]

The rubber is a piece froma bumper on a tugboat. It's a fairly hard compound.

I use a 1 1/8 hole saw to core a hole in the rubber, which is 2 inches thick. I then make the tuner body .030 over this. I press it on with a layer of clear epoxy. I then machine it round with the tuner body on the barrel.
K
http://benchrest.com/attachment.php?attachmentid=20409&stc=1&d=1512239725

http://benchrest.com/attachment.php?attachmentid=20410&stc=1&d=1512240297

http://benchrest.com/attachment.php?attachmentid=20411&stc=1&d=1512240522

 

[jackie schmidt]

I took the Rifle to the range yesterday at Tomball to shoot it at 200 yards.

The muzzle brake/tuner worked great. If it wasn't for the blast, you would think you were shooting a HV 6BR with 108's.

It lost no accuracy.

One thing I did notice. When I turned the tuner, The point of impact changed more than I woul have thought. Even though I was careful to machine the tuner and ream the center hole on the same all on the same setup. But even with that, the true alignment might vary enough so when the muzzle blast and bullet both are within the brake, it might push it off ever so slightly. The group and point of impact simply move over.

It's no big deal. Just something to be aware of.

After I got it sighted dead on in a gental left to right, I shot this 5 shot Group. 55 grns of Hodgdon 4831 SC, 180 Berger Hybrid, Federal 210 large Rifle. This is your around 2850 put of the 28 inch barrel.

It was a light drizzle, (in between downpours yesterday), this will get it done.

http://benchrest.com/attachment.php?attachmentid=20420&stc=1&d=1512399386

http://benchrest.com/attachment.php?attachmentid=20421&stc=1&d=1512401301

It's actually six shots. When the 4th shot popped up, and the 5th went in, I told Ed I would put a 6th in to see if it would hit the other four. It did.

 

[alinwa]

...........
One thing I did notice. When I turned the tuner, The point of impact changed more than I woul have thought. Even though I was careful to machine the tuner and ream the center hole on the same all on the same setup. But even with that, the true alignment might vary enough so when the muzzle blast and bullet both are within the brake, it might push it off ever so slightly. The group and point of impact simply move over.

I think you will find this effect to be there whether or not you port the device as a brake, and even if you open it clear up or put it on the outside of the barrel so there can be no chance of gas effects.

I believe it's a vibration thing.... and for me it just proves the tuner is "doing something" whether it actually shoots better or not.

 

[Louis.J]

The picture of the rifle on the prop is priceless.

JLouis

 

[jackie schmidt]

I think you will find this effect to be there whether or not you port the device as a brake, and even if you open it clear up or put it on the outside of the barrel so there can be no chance of gas effects.

I believe it's a vibration thing.... and for me it just proves the tuner is "doing something" whether it actually shoots better or not.

Al, it just kind of shocked me how much the POI moved. On my 6PPC or 30BR, I can move the POI across the mothball with a 1/8 turn if the thing isn't close. This went about 4 inches at 200 yards. Down and to the left.

Since this is a new thing for me, I need to spend more time with it, playing with different settings, trying to get a pattern.

I could have done more yesterday, but most of the time, it was raining. That, and I spent all day on a new 7 1/2 twist 6BR trying to get it to shoot inside of one inch at 200 yards. That barrel has a future of being a tomato stake.

 

[Steelhead1]

I’’’m with Louis J I would have that picture framed! Awesome way to show off a rifle.

 

[alinwa]

Since this is a new thing for me, I need to spend more time with it, playing with different settings, trying to get a pattern.

I'm looking forward to this!

IME it's several steps beyond chasing my tail, more like chasing a bucket of snakes.

I envy these guys who casually "turned it a few degrees to bring 'er back into the window'.....it has never been like that for me.

 

[alinwa]

BTW, kudos on the prop

(see what I did there, eh )

 

[Boyd Allen]

I'm looking forward to this!

IME it's several steps beyond chasing my tail, more like chasing a bucket of snakes.

I envy these guys who casually "turned it a few degrees to bring 'er back into the window'.....it has never been like that for me.

A while back, at the Visalia range there was a two day HB (unlimited)match. In the Saturday AM 100 yd. agg. Jim Nicolas shot couple of decent groups in matches four and five, a .040, and a .041, this after moving his tuner, a 1# double disk Stewart, a little less than 8 degrees. His third match group was a .196. Evidently the trick is to make very small moves. Ococks third match group in the same agg. was an .039 without a tuner.

 

[alinwa]

A while back, at the Visalia range there was a two day HB (unlimited)match. In the Saturday AM 100 yd. agg. Jim Nicolas shot couple of decent groups in matches four and five, a .040, and a .041, this after moving his tuner, a 1# double disk Stewart, a little less than 8 degrees. His third match group was a .196. Evidently the trick is to make very small moves. Ococks third match group in the same agg. was an .039 without a tuner.

I went for a while there where I would just POP THE DISCS LOOSE and tighten them back up trying not to move them a'tall.........

As I said, I'm excited to see Jackie try his quantification magick because he KNOWS how to analyze and backcheck. IME setting up the procedure can be the biggest problem to deal with. I never really got to "the procedure part" just spent many years flailing around in the dark hoping to catch a live one.

I can make powder tuning stand up and bark. even guess right first at least 50% of the time....but my experience with tuners leads me to believe that those vibberations are really small.

 

[Greyfox]

A while back, at the Visalia range there was a two day HB (unlimited)match. In the Saturday AM 100 yd. agg. Jim Nicolas shot couple of decent groups in matches four and five, a .040, and a .041, this after moving his tuner, a 1# double disk Stewart, a little less than 8 degrees. His third match group was a .196. Evidently the trick is to make very small moves. Ococks third match group in the same agg. was an .039 without a tuner.

My limited experience with tuners tells me that the heavier the tuner, the smaller the move. Most of my barrels have Ezell tuners which are on the heavy side. My moves are usually 1/16" or so. I have also use Beggs tuners which are very light. They needed to be move quite a bit more to have an effect. Jackie's tuner looks like it would be pretty weighty. I would think it would be a challenge to move it small enough. It takes such a tiny amount to change things.

YMMV,
Rick

 

[mwezell]

My limited experience with tuners tells me that the heavier the tuner, the smaller the move. Most of my barrels have Ezell tuners which are on the heavy side. My moves are usually 1/16" or so. I have also use Beggs tuners which are very light. They needed to be move quite a bit more to have an effect. Jackie's tuner looks like it would be pretty weighty. I would think it would be a challenge to move it small enough. It takes such a tiny amount to change things.

YMMV,
Rick

FWIW, my tuners are weight adjustable from 7 ounces, as shipped, down to 4 ounces. That said, I like them to be as close to the 7 oz weight, as weight limits and gun handling will allow.
The weight is adjusted by removing some of the tungsten dampening media. I want as much damping as possible but I also prefer a tuner that is well marked and does it's job within a small range of adjustment. It just makes things much simpler IMO.
More weight lowers the frequency and widens the tune window as well as making state of tune more apparent on the target by creating more muzzle deflection than a lighter tuner. They all work on the same basic principles. That being, a mass on the end of the barrel that adjusts muzzle position in time, so that it can be timed with bullet exit.

 

[zippy06]

I took the Rifle to the range yesterday at Tomball to shoot it at 200 yards.

The muzzle brake/tuner worked great. If it wasn't for the blast, you would think you were shooting a HV 6BR with 108's.

It lost no accuracy.

One thing I did notice. When I turned the tuner, The point of impact changed more than I woul have thought. Even though I was careful to machine the tuner and ream the center hole on the same all on the same setup. But even with that, the true alignment might vary enough so when the muzzle blast and bullet both are within the brake, it might push it off ever so slightly. The group and point of impact simply move over.

It's no big deal. Just something to be aware of.

After I got it sighted dead on in a gental left to right, I shot this 5 shot Group. 55 grns of Hodgdon 4831 SC, 180 Berger Hybrid, Federal 210 large Rifle. This is your around 2850 put of the 28 inch barrel.

It was a light drizzle, (in between downpours yesterday), this will get it done.

http://benchrest.com/attachment.php?attachmentid=20420&stc=1&d=1512399386

http://benchrest.com/attachment.php?attachmentid=20421&stc=1&d=1512401301

It's actually six shots. When the 4th shot popped up, and the 5th went in, I told Ed I would put a 6th in to see if it would hit the other four. It did.

2 props and a nice BR rifle pic....Nice...

 

[jackie schmidt]

My limited experience with tuners tells me that the heavier the tuner, the smaller the move. Most of my barrels have Ezell tuners which are on the heavy side. My moves are usually 1/16" or so. I have also use Beggs tuners which are very light. They needed to be move quite a bit more to have an effect. Jackie's tuner looks like it would be pretty weighty. I would think it would be a challenge to move it small enough. It takes such a tiny amount to change things.

YMMV,
Rick

This tuner assy including the lock nut weighs 7 ounces. It's on a 32 pitch thread.

I did not make it out of aluminum because I thought the thin sections between the holes might succumb to the heat and erosion of the blast.

The large shift in impact took place with about 1/4 turn, which is a little over .007 advance. That amount of shift is what lead to my hypothesis in Post #4.

 

[alinwa]

......That amount of shift is what lead to my hypothesis in Post #4.

I'm not trying to argue but I really believe that the last thing that your bullet should feel is the crown...... If you're getting any gas effects beyond the crown I don't believe you can shoot small.

I've played with lots (hundreds??) of muzzle brakes of many designs and those that allow gas effects to affect the bullet are failures IME and don't shot well.....CAN'T shoot well.

I often use tuners to show normal people why they can NEVER sight in with one load or brand and switch over to another for hunting.....that even hyper accurate rigs which easily map effects on the target will walk all over the place as vibrations are varied.

 

[jackie schmidt]

I'm not trying to argue but I really believe that the last thing that your bullet should feel is the crown...... If you're getting any gas effects beyond the crown I don't believe you can shoot small.

I've played with lots (hundreds??) of muzzle brakes of many designs and those that allow gas effects to affect the bullet are failures IME and don't shot well.....CAN'T shoot well.

I often use tuners to show normal people why they can NEVER sight in with one load or brand and switch over to another for hunting.....that even hyper accurate rigs which easily map effects on the target will walk all over the place as vibrations are varied.

Al, I would love to see a ultra high speed camera shot of a Bullet/Muzzle Brake just as the Bullet exits the crown and enters and leaves the Brake.

Physics teaches that the instant a Bullet leaves the muzzle, it starts slowing down. Do the hot gasses pushing it down the bore slow down at the exact same pace?. Do they "catch up" with the bullet during that microsecond that it is encased within the Muzzle Brake, thus influencing it's stability?

I honestly don't know. I do know this. If a Muzzle Brake does reduce recoil at the expense of accuracy, then I would have to live with the recoil.

I am glad to see this particular Rifle still shoots at a competitive level. If it was shooting 1 inch+ groups at 200, this idea would be put into that closet where I keep all of my other ideas that didn't pan out exactly the way I had planned.

 

[Wilbur]

"...normal people...."

I get it as intended but thought it was funny.

 

[mks]

Al, it just kind of shocked me how much the POI moved. On my 6PPC or 30BR, I can move the POI across the mothball with a 1/8 turn if the thing isn't close. This went about 4 inches at 200 yards. Down and to the left.

It might not be the tuner, but something else that isn't quite balanced left/right. The whole system produces a characteristic muzzle angle pattern in time (like in the figure below) that speeds up when the tuner is turned in and slows down when the tuner is turned out. The bullet exits at a different point on the pattern when the tuner is adjusted. If POI shifts laterally, it means the pattern has a sideways component at the point where the bullet exits. The best tune is where muzzle angle is only moving vertically with exactly the right speed. Another way to test for this is a ladder test. If the muzzle angle pattern is vertical when the bullet is exiting, then the ladder test changes with powder charge should have no horizontal component (and zero vertical for perfect compensation).

Keith