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Old 08-18-2019, 09:12 AM
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Nomercy448
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Join Date: Oct 2009
Location: Kansas
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What was old becomes new again. I remember a wave of “tuner popularity” in the late 90’s, especially among 22LR competitors, but had rarely heard a peep about them in 15 years or so - until recently, it seems they are popping up all over. I’ve had them on 22LR rifles, but never one on a centerfire, with the exception of the similar limbsaver type barrel dampener.

In theory, dampening with a tuner should work much like the OBT, OCW, Ladder, or Satterlee methods, but from the other side of the coin. Instead of matching the charge weight to the barrel harmonic, we’re effectively adjusting the harmonic to match the charge weight. I was apprenticing under a local benchrest gunsmith during the last tuner-era, and he described the same - and proposed this as the reason so many rimfire guys were using tuners, but so few centerfire guys. Centerfire shooters can control the load, so they don’t need the hardware solution, whereas all we did with rimfires back then was buy match ammo in bulk, and sort by rim thickness/headspace. Centerfire guys had access to both avenues, rimfire only one.

In my personal experience hanging different devices from muzzles, and shooting groups, including weighted tuners, and the equivalent limbsaver type dampener weights, has me asking more questions, rather than holding more answers. I have shot multiple rifles with various “system masses,” and really don’t see significant results to tell me I’m affecting group size, but only that I’m affecting POI. I HAVE to think it should also affect group size, but I don’t witness it.

For example - I have fired my current match rifle under the following conditions:

Bare Muzzle
Bare Muzzle + Magnetospeed
Muzzle brake
Muzzle brake + magnetospeed
Suppressor
Suppressor + Magnetospeed
Suppressor + suppressor brake
Suppressor + Suppressor Brake + Magnetospeed
Brake mounted Suppressor
Brake Mounted suppressor + magnetospeed
Brake mounted suppressor + suppressor brake
Brake mounted supp + Supp brake + Magneto

Within this, I have fired 3 different muzzle brakes and 2 different brake mounts for the suppressor. As you might expect, there’s a significant difference in muzzle weight for these different combinations, and even different velocities observed between suppressed and “rude” fire.

In firing all of these, the observable difference is point of impact, but no statistical difference in group size. Very specifically, before every single match I shoot, I fire 3 things, so I’m running side by side groups with and without Magnetospeed and either the suppressor or the brake ~20 times per year, across 4 different rifles. I also use this same method now for my hunting rifles, further iterations each year where I have been doing these side by side exercises, not meant for comparison, but certainly serving as such.

24 round ladder to confirm my node position
10 round velocity check with magnetospeed
10 round zero confirmation (without Magnetospeed)

The 24 round ladder, 3 shots at 8 charge weights at 8 targets. Then I come back with a load in the node, and fire 10 rounds at one target with the Magnetospeed. Followed by 10 rounds at one target confirming zero - could be 1-3 rounds, but I usually fire 10.

When I first bought my match rifles, I played with different brakes side by side to feel the recoil difference. I also switch back and forth between suppressed fire and muzzle brake for rifle matches, depending upon how much positional shooting will be done. My SiCo Omega’s also have optionality for a suppressor mounted brake. I prefer to use the suppressor brake for most matches, but we do shoot some night matches where nobody wears ear pro, so I shoot the flat cap for these to keep the suppressor as quiet as it can be.

Out of all of these permutations, my group sizes don’t statistically change, and my node doesn’t move. The only result is shifting POI.

Very similarly, I question the principles of the Optimal Barrel Time method, and the Positive Compensation/Ladder/OCW/etc manner of thinking that there’s a discreet, exceptionally narrow node where the load is optimized for the harmonics. Maybe a better way to say it is that I believe there is a huge difference between “away from the anti-node” and “centered in the node”. The peak of a sine wave is locally flat, so being “away from the anti-node” is what matters, but being perfectly centered in the node isn’t as critical.

I don’t have a satisfactory explication for my self as to why my groups might shift to 6 different POI’s when shooting bare muzzle, bare + Magnetospeed, brake, brake + Magnetospeed, suppressor, suppressor + magnetospeed - but NOT change in observed group size or resulting charge weight node - even when the velocity changes between the conditions (which violates Optimal Barrel Time principles on multiple aspects).

Equally, I also know the same node will present itself despite considerable shifts in velocity when I shoot a match in January at 17 degrees versus one in July at 104. Which is enough for me to THINK there’s a fundamental flaw in the perception the criticality of alignment of barrel time and harmonic. If perfect alignment barrel time and harmonic position at release were narrowly critical, velocity changes due to powder temperature would change my group size. But it doesn’t. If I have 30fps muzzle velocity change, my dwell time changes considerably, so my alignment between harmonic and barrel time changes - why don’t my nodes change? Why don’t the group sizes change?

There’s a paradigm in communication language training called “TFK,” which is “Think, Feel, Know.” This paradigm is to develop a habit of identifying and communicating information - and equally evaluating information you are given, by judging the TFK spectrum of the person sharing the information. So what I THINK about load development method principles might be at odds with which method I FEEL is the best fit for my application, which might also be different than what I KNOW about the efficacy of these methods. I KNOW a lot of methods work because I have done them and proven them to work. I FEEL like some work better than others for various applications. And I THINK there are many reasons which might explain how and why they work.

What I think - we speculate wildly about bore dilation as a wave function, barrel flex like a coachwhip, wave position relative to bullet dwell time, and a hundred other theories for load development. On the principle level of physics and thermodynamics, there are proven failings in many of these “theories.” However, most of these theories are backwards facing explications for observed results - someone tried a method, it worked, so they started trying to understand why. But “why it works” shouldn’t matter as much as the fact it does work.

So what I do know - 1) if I don’t tune my charge weights to identify a node, and don’t control neck tension to deliver reliable and repeatable velocity results in tuning, I get vertical stringing at long range. 2) OCW, Ladder, and Satterlee methods work to identify a charge weight node, and barrel tuners also work. They might not work for the reasons some of us might THINK, but enough of us have proven that it does work for us to KNOW it works.
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