ADJUSTING TUNER SETTING V's SEATING DEPTH

[pgcpty]

Ever since purchasing a Browning BOSS 270WIN caliber rifle over 30 year ago and achieving exceptional accuracy results tuning both factory ammo and hand loads I've been an avid Tuner enthusiast fitting tuners to all my target rifles.

Ive had a modicum of success in shooting F Standard over a good number of years and have never adjusted seating depth, only adjusting tuner setting for shot convergence having first established a low ES load through round robin load testing.

My hypothesis is that adjusting seating depth or tuner setting achieves the same outcome in slightly different ways.

Adjusting seating depth incrementally changes projectile velocity, hence barrel time enabling projectile position to be matched to barrel vibration rotational position such that high velocity shots exit lower than low velocity shots, whereas
adjusting tuner position incrementally changes the barrel resonant frequency such that the barrel vibration rotational position is changed instead of the incremental projectile velocity.

I'm not surprised that tuner position setting is as sensitive as seating depth setting however I note that many top F Class shooters both here and overseas who have tuners fitted having once set them, never adjust them?

My question is to other F Class Tuner users, do you as I do, having found a low ES load flex tuner setting only for shot convergence.
Does anyone have evidence to the contrary that adjusting tuner setting only (after establishing a low ES load) doesn't achieve optimum results?

Peter

[GSells]

Hi Peter , there is a lot to unpack here and a lot of theory behind it ! I don’t always put in fancy words as I have no formal engineering background. I’ll get back to u soon when I have time to respond in a proper fashion ! Maybe Willadia or someone else who is a lot more qualified than me may chime in till then ?
Regards Sellsy.

[pgcpty]

Hi Sellsy,
Thanks,very interested in getting feedback re others experience on tuner setting as an alternative to adjusting seating depth. Its all I ever do after finding a low ES powder node and get great results. I occasionally run into shooters on the range who have tuners fitted but don't have an adjustment method that instills them with confidence. I've shown a few Target shooters that use factory 308W ammo how fitting a Tuner and correctly adjusting it can tighten up their groups.
Hoping to get more feedback.
Peter

[Weairy]

We've played with tuners a bit with 308s and now 7SAUM.

I know with the 308s, generally we will load three charges in 0.1gn difference, pick the best, then try 10 Jam - 20 Jump depths in 5thou increments, pick the best again and tune in to firm it right up, then lock the tuner off and leave it alone. Might not be the most economical way, but it definitely works.

But we do have the advantage of a 300yd range at home and, having had a bunch of barrels chambered the same over the past few years, using the same barrel/brass/projectile/powder/primer combo, we nearly know what's going to work straight off the bat. Being able to go and quickly test a load and say "I wonder if .1gn or 5thou more jump will tighten this up?", duck back up and load a handful of rounds and test them again 5min later is pretty helpful though.

Would be interested to see the different responses here. See quite a few people with tuners screwing them in and out all day, depending on weather etc. but I'm personally not sold on it. I don't like extra variables myself, but the old man swears by his tuner barrels and the results speak for themselves there.

[pgcpty]

For interest I've included a table from the Browning Boss Patent US5698810 showing group size improvement for a range of ammunition brands/calibers/projectile weights which clearly shows the benefits of using a tuner to optimize factory ammunition performance.

BROWNING BOS ACCURACY TEST (from patent paper).jpg

[wsftr]

anyone adjust the tuner to dial it in at each yardage?

[pgcpty]

Hi wsftr,
Use to carry 20 rounds, 10 ea. of
+/- 2% of tuned load powder weight to check virticle at various ranges. Surprisingly didnt find sufficient virtical misconvergence to justify making changes. This correlates with current practice of most Target shooters, in not varying loads for different ranges.

[GSells]

So Peter , is your question “ set and forget tuner once tuned ?” So let’s look at the theory a little ! The tuner is essentially acting bit like a guitar with one finger on the fret board . Turning the tuner in or out modifies the frequency or timing of the vibrations through steel , to achieve obt ( optimal barrel timing ). My opinion is, that if it’s just a couple of thin knurled washers ( such as , I think it was shade tree tuner?) threaded on your barrel . Makes it a lot less user friendly, than some of the locally made forward of the muzzle heavy tuners that are used on the mounds here in Australia.

https://varmintal.com/amode.htm

Ok so !! Why is that ? Ok back to basics ! Seat depth adjusts bullet exit timing to hopefully exits the bullet A : slightly on the up on mode 1 ( positive compensation)
B: similar exit times in mode 2 ,3 ( reflected vibrations )
C : bullet exits ahead of “ the donut “ ( lesser reflected vibrations)
Ok enough for tonight . Where’s Willadia lol ! He’s the real expert on this ! I’m just a lackey lol!

[pgcpty]

Sellsy, re your comments, regarding the standing wave phenomenon in a barrel, the speed of sound in the barrel is a constant and the timng of reflections off the muzzle are determined by the barrel length. That is why Chris Longs paper and it's subsequent use with Quickload uses barrel length only with no regard for profile diameter, weight etc. What I do using QL is determine a load centred around a Chris Long node then with 5ea x5 loads spaced 0.2 gr apart around the centre seek out a low ES load (under 20) at 100yds.. Then adjust the tuner for best group convergence. I don't run my tuners forward of the muzzle so the reflections time isn't effected.
So back to my main point of interest that tuner adjustment has the same effect as seating depth adjustment.
Regarding your point about set and forget as it turns out I haven't found the need however there are some who are very familiar with their tuner can and do dial in a touch of virtical for some wind conditions. Braver than I!

[wsftr]

Hi wsftr,
Use to carry 20 rounds, 10 ea. of
+/- 2% of tuned load powder weight to check virticle at various ranges. Surprisingly didnt find sufficient virtical misconvergence to justify making changes. This correlates with current practice of most Target shooters, in not varying loads for different ranges.

question - if you have ES/sd above 0 and very small 1 hole groups at 100 yards....would there be optimal tuner settings at different yardages?
if you look at this link it implies that at 25 yards the optimal setting is different to 50 yards
I wondered if anyone had applied this in F-class using a tuner or seating depth.
https://varmintal.com/a22lr.htm

[GSells]

Hi wsftr,
Use to carry 20 rounds, 10 ea. of
+/- 2% of tuned load powder weight to check virticle at various ranges. Surprisingly didnt find sufficient virtical misconvergence to justify making changes. This correlates with current practice of most Target shooters, in not varying loads for different ranges.

question - if you have ES/sd above 0 and very small 1 hole groups at 100 yards....would there be optimal tuner settings at different yardages?
if you look at this link it implies that at 25 yards the optimal setting is different to 50 yards
I wondered if anyone had applied this in F-class using a tuner or seating depth.
https://varmintal.com/a22lr.htm

Ok I’m no expert , but my experience is from the range . So in my opinion group shapes at 140 yds are extremely important tied in with Es . What u see at 140 yds ( I use 100yds not proper but it works for me )is what you get at 1000 yds . However dynamic stability is another thing ! Belmont and other ranges are notorious for vertical and and wind vector changes .
There’s lot happening in that phenomenon Eg wind shear , variable Bc , wind vector Magnus effect 10-4 slope.

[GSells]

Ok , where were we ??? Just to simplify things can we just have barrel whip and reflected vibrations?
This will make it easier for me as I’m not anyone’s engineer lol!

Ok so my opinion on specific tunes for different ranges ! I would say absolutely that’s true !
As for my 280 ai slow load, I have a slow load with less harmonics good to up to 600 yds . Then go full swing for the longs . That barrel has just a fixed weight and of course orings and silicone tape over the orings to arrest reflected vibrations. And the fixed weight to tame the beast on barrel whip !!

I have short and long range loads for my 284 w barrels . Both with Aussie tuners . One barrel likes different setttings for the short range load to the long range load . The other Batlien doesn’t care between long and short loads .

That brings me to another issue is the stock ? What is the best material for arresting reflected vibrations in the stock ? Ultimately you want as little reflected vibrations as possible! Wood seems to be a good candidate for absorbing vibrations.
My stock is a Mac f class. And anyone who’s seen it should have seen closely I’ve got vibration absorption material up the fore stock and silicone tape around the pistol grip and also silicone tape around the scope front and rear . Also orings and silicone tape middle of the barrel and near the muzzle about 4-6” short.

Oring thoery and as well as tuners came from rim fire bench rest . Many people are skeptics , in that orings and tuners ( especially orings and silicone tape ) can’t work as it’s just too simple !

About a month ago my Son’s mate had a $600 howa .223 using factory out back ammo with 55 gr blitz kings . Naked barrel it’s shot well at 100 yds the usual 1” group 3 shots.

I then pulled out the silicone tape , with the boys looking at me as “ That’s weird ! What’s that going to do ?”
Tapped the barrel with my knuckle. It was already harmonically quiet , could only feel the vibrations through the stock . Wound the tape around about halfway . Tapped the barrel again and was remarkably less vibrations through the stock again .
So the young fella laid down prone behind the factory special on a Harris bipod and rear bag .Then shot
a 3 shot group . We could only see one shot on paper but 3” to the right . So where did the other 2 shots go ? Shooter error?
We all went down to have a look at the target and low and behold a ragged one hole group !! Some barrels respond unbelievably to modified reflected harmonics and other barrels do bigger all !
By far with a factory rifle the most improvement from such a simple fix I’ve ever seen !
The young fella couldn’t believe it either and was quite amazed as I was too!

So what group shapes should you look for at 100 m’s for short range and for long range . Well rule of thumb for me , up to 600 yds round groups with good Es . Long range groups, that are more vertical egg shaped slightly hopefully showing positive compensation .

Anyway, this stuffed has worked for me and I’m very satisfied that for me, I’ve have proven it in competition over the years . Often with a lot of people knocking it . But there is no way I would shoot a naked barrel in competition. Done right , it can make the barrel very user friendly. Cheers. G

[pgcpty]

wsftr,
re your question, years back I was curious about the same question re the same Varmint Al paper and did the exercise with the high and low loads at various ranges to investigate the value of adjustment. It well may be that in theory or even if math were available to show that there is group deterioration over distance as you move away from the tuner setup range I couldn't measure meaningful results, however I do know and have experienced group shape changing from wide to round to vertical with micro setting changes. As I said you need to know your tuner characteristics and rifle well and be brave to go alter the tuner setting during a match, not for me!
I shoot 80gr and 90gr bullets from my 30in 223Rem 6.5T barrel at different muzzle velocities and accordingly the tuner setting is different for each

[wsftr]

wsftr,
re your question, years back I was curious about the same question re the same Varmint Al paper and did the exercise with the high and low loads at various ranges to investigate the value of adjustment. It well may be that in theory or even if math were available to show that there is group deterioration over distance as you move away from the tuner setup range I couldn't measure meaningful results, however I do know and have experienced group shape changing from wide to round to vertical with micro setting changes. As I said you need to know your tuner characteristics and rifle well and be brave to go alter the tuner setting during a match, not for me!
I shoot 80gr and 90gr bullets from my 30in 223Rem 6.5T barrel at different muzzle velocities and accordingly the tuner setting is different for each

yeah I wouldn't alter in the match - POI changes (IME anyways). My thinking is having the specific setting for that distance which you set it to prior to the shoot. You already know what the POI does as you tuned at each yardage.
I do believe that there is an ultimate tune at any specific distance. Long range BR 6mm guys would state what shoots best at 300 won't necessarily shoot best at 1000. the varmint AL article seems to back this up.
Tuners seem to offer the ease of adjustment.
I make no argument that 1 setting for F-class purposes can carry all the way through from 300-1000...but if I look at the varmint AL info it implies we are giving up a bit. I've had rifles absolutely hammer at specific distances and have wondered if this is why.
If I get motivated I might try this theory out - mostly curious to see if others had explored it.
Thanks for your replies

[GSells]

Ok , where were we ??? Just to simplify things can we just have barrel whip and reflected vibrations?
This will make it easier for me as I’m not anyone’s engineer lol!

Ok so my opinion on specific tunes for different ranges ! I would say absolutely that’s true !
As for my 280 ai slow load, I have a slow load with less harmonics good to up to 600 yds . Then go full swing for the longs . That barrel has just a fixed weight and of course orings and silicone tape over the orings to arrest reflected vibrations. And the fixed weight to tame the beast on barrel whip !!

I have short and long range loads for my 284 w barrels . Both with Aussie tuners . One barrel likes different setttings for the short range load to the long range load . The other Batlien doesn’t care between long and short loads .

That brings me to another issue is the stock ? What is the best material for arresting reflected vibrations in the stock ? Ultimately you want as little reflected vibrations as possible! Wood seems to be a good candidate for absorbing vibrations.
My stock is a Mac f class. And anyone who’s seen it should have seen closely I’ve got vibration absorption material up the fore stock and silicone tape around the pistol grip and also silicone tape around the scope front and rear . Also orings and silicone tape middle of the barrel and near the muzzle about 4-6” short.

Oring thoery and as well as tuners came from rim fire bench rest . Many people are skeptics , in that orings and tuners ( especially orings and silicone tape ) can’t work as it’s just too simple !

About a month ago my Son’s mate had a $600 howa .223 using factory out back ammo with 55 gr blitz kings . Naked barrel it’s shot well at 100 yds the usual 1” group 3 shots.

I then pulled out the silicone tape , with the boys looking at me as “ That’s weird ! What’s that going to do ?”
Tapped the barrel with my knuckle. It was already harmonically quiet , could only feel the vibrations through the stock . Wound the tape around about halfway . Tapped the barrel again and was remarkably less vibrations through the stock again .
So the young fella laid down prone behind the factory special on a Harris bipod and rear bag .Then shot
a 3 shot group . We could only see one shot on paper but 3” to the right . So where did the other 2 shots go ? Shooter error?
We all went down to have a look at the target and low and behold a ragged one hole group !! Some barrels respond unbelievably to modified reflected harmonics and other barrels do bigger all !
By far with a factory rifle the most improvement from such a simple fix I’ve ever seen !
The young fella couldn’t believe it either and was quite amazed as I was too!

So what group shapes should you look for at 100 m’s for short range and for long range . Well rule of thumb for me , up to 600 yds round groups with good Es . Long range groups, that are more vertical egg shaped slightly hopefully showing positive compensation .

Anyway, this stuffed has worked for me and I’m very satisfied that for me, I’ve have proven it in competition over the years . Often with a lot of people knocking it . But there is no way I would shoot a naked barrel in competition. Done right , it can make the barrel very user friendly. Cheers. G