Mid barrel tuners

J

James n TN

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Can someone educate me on how a mid barrel tuner works? I just installed one on my Turbo rimfire and set it up as instructed by another shooter and began tuning. But I'm lost at what it actually does and how it works. I know before usng it the rifle would shootin in the mid .1's for five shots at 50 yards and after nearly 2 boxes of ammo tuning it it will litterly shoot one hole.

Here's a couple groups shot at fifty without it. Each 5 shots

2CA8D1E3-C73C-468B-854F-897AA8E72D91_zpszdq6rpjc.jpg


506027B2-5EA3-4BDD-BC0A-40DE4C7C0E6E_zps2vlo1n4r.jpg


Now here's a group after tuning and it's actually 10 shots.

FC119BD9-3544-4735-93D9-CA6ACCD9C2D2_zpszeertvcz.jpg
 
I would suggest not touching anything. Your end result was exactly what you were looking for: 10 shots into one hole and right dead-center!

I can't help you on how it works. But after seeing your results, what does it matter so long as it's doing what you wanted.

Now the fun begins.
 
Placement

Where did you place the Mid-Barrel Tuner? ie: Distance behind the Tuner. I've tried several types and each one requires a different location. Just trying to compare.
 
Placement

Fred J said:
Where did you place the Mid-Barrel Tuner? ie: Distance behind the Tuner. I've tried several types and each one requires a different location. Just trying to compare.
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Fred J,

I'm not the OP. But on my two ARA class RFBR rifles which have 26.500" long barrels the lead edge of the Scott mid barrel tuner is positioned 9.250" back from the H/H tuner. This location appears to be stable on both rifles which have Muller 4 MI .900" barrels. John
 
John, how did you arrive at that placement? And how do you tune it? Seems like the mid-barrel tuner works, but I've not seen any in-depth explanation of how. Any input on this would be appreciated.

Dennis
 
Fred J said:
Where did you place the Mid-Barrel Tuner? ie: Distance behind the Tuner. I've tried several types and each one requires a different location. Just trying to compare.
Click to expand...


I placed the tuner at 1.750 from the end of the stock. Never measured the distance between it and the Hoen tuner.
 
DeltaBravo said:
John, how did you arrive at that placement? And how do you tune it? Seems like the mid-barrel tuner works, but I've not seen any in-depth explanation of how. Any input on this would be appreciated.

Dennis
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Dennis, I did not follow the instructions that Charlie Scott includes with his MBT.

My rifles were already tuned quite well with a shaved (lathe cut outer cylinder) on the H/H tuner, which reduced the tuner weight a little more than 1 ounce. Too that, I added total of 4 ounces of stainless steel weights which screw on to the front of the H/H tuner. In addition, I made a small 2" long aluminum bloop tube that screws on to the inner threads. The complete setup weighs a total of 11.2 ounces on my postal scale. This rifle, with the tuner set @ 206 shot competitively in local matches, but had a tendency to throw a flipper (an 8 on USBR target) now an then. I noticed that a very good competitor at the Barn, had a Scott MBT installed on his Muller barrel and was killing it. Figured I purchase a couple and give them a try.

Without messing with anything ... I installed the Scott M.B.T. about an inch from the tuner and started shooting five shot groups. Moved it back about a 1/2" at a time toward the receiver and shot addition groups. My most stable groups were in the 9" to 9 1/2" range. So, I settled for the 9 1/4" distance from the H/H tuner. My occasional flipper problem appears to have been corrected. When I installed another M.B.T. on my second rifle (which is almost identical exception for being two and 3 lug actions) I just placed it at the same distance. Nothing scientific here ... but I feel that both rifles are more competitive now, than before I installed the mid barrel tuners. The second rifle has the H/H tuner set @ 229. John
 
Thanks John and James!

Is it safe to assume (yeah, I know) that now that you've found the best location, you just leave the MBT alone and do all the tuning with the Harrell's?

Dennis
 
center22 said:
Yes, I would agree.
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When you were testing your MBT did you tweak with the torque on the screws each time you moved the tuner?
I set mine 1.750 in front of the stock and snugged it up, then shot a group and from there I'd turn each screw 1/4 turn and shoot another group. I kept doing that and when I'd get 2 in one hole I'd keep shooting and by the 3rd or fourth shot I'd get a flyer so I just kept tightening the screws and when it looked like it was going to shoot I'd try for a group and of course I'd get a flyer. So this went on until I thought it was getting too tight. So I began backing the screws off in 1/8 turns and after like the 3rd adjustment is when I shot the small group above. After I had shot the 10th shot I debated to keep going or stop. Well not wanting to push my luck I packed it all up and called it a day. Dang it's tough enough to get 5 into one hole but the pressure was on putting five more there.

I wanna put a torque wrench to it to find the torque but then again I really don't want to touch it either as I'm afraid I'll never hit that magic spot again.
 
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James n TN said:
When you were testing your MBT did you tweak with the torque on the screws each time you moved the tuner?
I set mine 1.750 in front of the stock and snugged it up, then shot a group and from there I'd turn each screw 1/4 turn and shoot another group. I kept doing that and when I'd get 2 in one hole I'd keep shooting and by the 3rd or fourth shot I'd get a flyer so I just kept tightening the screws and when it looked like it was going to shoot I'd try for a group and of course I'd get a flyer. So this went on until I thought it was getting too tight. So I began backing the screws off in 1/8 turns and after like the 3rd adjustment is when I shot the small group above. After I had shot the 10th shot I debated to keep going or stop. Well not wanting to push my luck I packed it all up and called it a day. Dang it's tough enough to get 5 into one hole but the pressure was on putting five more there.

I wanna put a torque wrench to it to find the torque but then again I really don't want to touch it either as I'm afraid I'll never hit that magic spot again.
Click to expand...

My two Lidgard stocks have aluminum pillars and are bedded using Devcon w/steel. My 10X Actions (XIII & X3L) are tapped for three action screws. I torque each screw to 24 inch pounds and don't mess with them. Occasionally, I will re-torque the screws just to be sure nothing has changed. I normally do not move my tuner setting either.

PS: Sorry James, I misread your post. The Scott MBT uses a soft black rubber material which is somewhat sticky, and is secured with only two screws. I believe the Pappas MBT is longer in length and uses 4 screws to secure it to the barrel. When installing the Scott MBT I make an effort to apply even pressure to both screws ... which is probably only around 5 inch pounds. I do check the pressure on those screws before each match, but never use torque to influence tuning. Since I shoot mainly in a very warm climate and sometimes keep the rifle in a hot vehicle, I have noticed that the soft vibration dampening rubber has a tendency to move/walk on occasion. If this occurs, one must remove the MBT and re-position the vibration dampening material.
 
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