Huntsman Tuner Load Development

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GSells
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Joined: Sun Aug 13, 2017 11:04 pm
Location: Qld

Re: Huntsman Tuner Load Development

#16 Postby GSells » Thu Jan 31, 2019 8:46 pm

williada wrote:Alex, no need to fire 5 shot groups as the load development should have satisfied the statistical confidence. With the tuner in place you only need two to three shot groups because you are using a load of statistical significance. The essence of what I said was to keep you close to or return you to the best node you saw in load development. Notice how tight the first group is in the picture below? To do that requires you to sneak up in .002"-.003" movements either way of a base mark starting near the muzzle. We are only trying to mimic a small change in say seating depth to keep you on the node when temperature changes. The key is selecting the best node in the load development to also enhance it with the tuner.

Finding another node is something different and more advanced, as you can select nodes for purpose.g. least wind sensitivity, a long distance one that throws slow shots higher etc. These may require larger movements which you can track on another sine wave test such as one "Ecomeat" did for me several years ago when I was trying to convince him of the merits of a tuner. The responsiveness of the tuner depends on the barrel lift profile and as a general rule you might take .005" movements to find them or more. Larger movements might be required on whippier barrels with a lower vibration frequency. Taking a look at Ecomeat's groups you can see the groups open up with movements of the tuner and it is because they are in no man's land in the compensation points of both trough and peak and the harmonics. Also notice how the groups rotate. Some are tight and round, others least wind sensitive. If the tuner is designed properly the sine wave should be rhythmic in which case the movement distance should correspond pretty much with the distance you traveled after finding the second node. Now "GMan" should be able to tell us which nodes are used where? I did post the full reply on that a while back now that I gave to Ecomeat.

Now Ecomeat don't tell 'em, let them figure it out.

Ecomeat's Tuner Test.jpg

I will just add, the best tuners are custom made to accommodate the barrel in use.


No pressure ! After the crash I had on the weekend.... ( rear plate instability issue on Belmont grass ) dunno if I should comment lol!
Ok short to mid range , group 1

600 yds plus , group 5 ?????

“ G Man !” :lol: 8)

AlexE
Posts: 218
Joined: Fri Feb 16, 2018 9:18 am

Re: Huntsman Tuner Load Development

#17 Postby AlexE » Fri Feb 01, 2019 11:34 am

David - typical academic, you won't give us an answer unless we work for it! Teach a man to fish, I suppose..

I'll go out on a limb and say that group 3 would be the long range pick. The increased elevation along with tightening of the group would suggest that the barrel is on the upswing and positively compensating to my uneducated mind. if I'm reading it correctly, the full period of the sinewave is between groups one and five, so they would be the same state of tune.

These are guesses at best - I'd need to head back to uni to get my head completely around this.

GSells
Posts: 798
Joined: Sun Aug 13, 2017 11:04 pm
Location: Qld

Re: Huntsman Tuner Load Development

#18 Postby GSells » Fri Feb 01, 2019 8:04 pm

David the suspense is killing me lol!
Ok Alex I’ll go out on a limb and say group three the timing looks retarted and rotating left . David , would I be right to say the tuner needs turning in a fly spec ?? .
It could still shoot ok but be slightly wind sensitive . All of the groups rhythmically are rotating in this case from the left to the right by the looks to me . It is also more on the top of the upswing . This could cause problems in Tune eg negative compensation, but unlikely though ??

Group 1 could be an x eater across the corse 300 - 1000 as long as the SD and extreme spreads are kept in check .

On 2 of my barrels I’ve seen 30 FPS spread at 1000 and near flat waterline ( although this didn’t happen on the weekend. That was shooter error not gun . Some bad habits from years ago has crept back into my shooting ! That’s another story I want to analyse and fix myself ) .

It’s a beautiful thing to see when PC ( positive compensation) happens and the SD’s are not brilliant .
Mind you that load up close would be no good . This is why I’ve started changing cals for shorts to mids and longs . And have short range loads and long range loads .

Anyway the way I shot on the weekend just gone , I may as well be talking Bla Bla Bla lol! #-o

williada
Posts: 969
Joined: Wed Jul 22, 2009 12:37 am

Re: Huntsman Tuner Load Development

#19 Postby williada » Tue Feb 05, 2019 4:48 pm

Group tunes
Sorry, Alex I have been busy. The details I cut the groups were posted a few years back on the forum when I was working with Tony on development. Such a barrel would perform better across the course on trough nodes. Each of the groups could be formed in .005" increments of the tuner thimble, having been established through development. The tuner increments could roughly equate 0.2 grains in a .308 for the purpose of the exercise if people went that way, rather than equate with seating depth. Competency depends upon studying your load development and knowing which way to move based on group shape in certain conditions, then sneaking around a node as the day warms in small increments. It’s all work, you could do this with competition notes over time if you are worried about wearing out a barrel. Got to learn somewhere and it’s not free.

The most reliable would be, Group 1. It’s nearly a nice round node suggesting shock waves are not distorting the bore on exit. This occurs when the muzzle oscillation both vertical and horizontal are equal or in the same 1:1 ratio. If it was just a tad further forward on the bottom node it may compensate mildly and effectively broaden the node. Graham is correct, if a low SD is generated, it will hold reliably out to 1000 yards. The only risk is if the temperature drops dramatically which happens more in the south, the group may form before the trough and give negative compensation which is exacerbated with distance. In this scenario primer fluctuations can be seen in six o'clock shots.

Group 3 is closer to a peak node and assuming the slow bullets are tossed higher would only really be suited for 1000 yards, but could be refined for distance with a tweak of the tuner. This would shoot ok at 300 yards but distances between the compensating distances, especially mid distance would express more vertical. Unless the tuner was tweaked that top left shot would repeat with distance and should be considered if groups are safe sided. Group shape is not random despite the crap that gets peddled.

I like Group 5, and with a tweak of the tuner the right shot could be brought into more vertical alignment. The group offers two advantages, one being it is the least wind sensitive and the other is that it could offer mild positive compensation which brings all ranges into contention across the course.

The groups clearly demonstrate there is no comfort in waterline shooting at long range when barrels can flick shots there. You need to have the least wind sensitive load possible, then you can say the waterline is correct. However, temperature and bullet slip in the atmosphere affect shock waves. When groups change shape it is a sure sign you are not on the selected test group position whether that it is a node, a positive compensation tune or an OCW tune. It can indicate slipping to a poor node where the ratios of vertical and horizontal maybe 1:2 etc. Still a node but the oscillation pattern is like the ABC logo. One minute you are on the tight intersection of the barrel oscillation path and the next a small temperature change can tip you off. Groups do hold shape with distance but merely get bigger.

So if you guys were shooting at 1000 yards and getting a waterline group like Group 4 what do you suppose would happen during the shoot?

What options would you have in moving the tuner?

Which one would be preferable?

How far would you have to move the tune?

Would you adjust elevation before shooting?

Why?

How much?

If you have a thimble that moves you .005 for every 5 graduations what would 1 graduation equal?

Suppose you had a tuner with 30 divisions you get a group like group 6 a week later, after a good shoot, how far would you move the tuner to get a group like Group 1 for the second shoot?

If the tuner thimble thread was 32 tpi and suppose you moved from group 6 to group 1, would it be more than a full turn of the tuner or less?

If you found a node in the morning and the group shape was starting to change in the afternoon when it was warmer, would you try and find the old node or chase another one? Explain.

Assume the incremental base for charge weight was .2 of a grain for the purpose of the exercise, and you were at Group 6, and your tuner was fixed because you did not know how to use it, how much would you reduce your load to get back to group 1? Mind you, these are extreme scenarios.

Now the big problem with beginners is that they confuse conditions i.e. light, mirage, wind etc with real grouping capability. Load development should take place, not only because the bullet has lost its fast precession (gone to sleep) but you can actually examine true group shape at 140 yards for F Class.

Sorry if it’s over the top, but top competitors know this stuff. If you are a team man, hopefully the coach can do it for you and all you have to do is break the best shot possible. David.

saum2
Posts: 1046
Joined: Fri Jun 13, 2008 12:22 am

Re: Huntsman Tuner Load Development

#20 Postby saum2 » Tue Feb 05, 2019 8:03 pm

David, C U at Rosedale March 2nd & 3rd?
Geoff

williada
Posts: 969
Joined: Wed Jul 22, 2009 12:37 am

Re: Huntsman Tuner Load Development

#21 Postby williada » Wed Feb 06, 2019 12:59 am

Hope to be available one of the days Geoff. Bloody fires down here and floods up North, the climates is erratic. Wish the politicians would could see the obvious.


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