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Everything posted by brown dog
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
π Royal Mail .. nothing else will do -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
My instinct is that a liquid silicone gasket at the same point, but between barrel and stock, will be a game changer..... just a feeling ππ -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
π k.i.s.s -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Well, I realise this is statistically valid as a feeling in my water, and I'm afraid I stopped just after I started due to it starting to snow.... I wanted to see what, if anything a 'tight rubber band' deresonator might do. Group on the right is 'without bands'... then did one on left 'with bands' ( and then, annoyingly, I packed in) ..... the left group is typical of the better groups (25%) I get with the rifle.. it was just felt odd that it happened straight after I put the bands on, and despite the weather deterioration...I know, chance... but interesting if it turns out to be repeatable 45m/49yds bipod, back bag -
Do you have to have 'good reason' type justification, or is it just a 'right'?
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I've never bought a pistol, so I'm not price-calibrated - but Β£4k and higher- blimey! That's some serious retail therapy! π
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Yeah, horizontal, but left to right, not right to left!π . -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Not seem that 6 x 5 thread before... that's some serious reality! ("All under a thumbnail at 80m" - bolloqs!) -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
You an Arab? Interesting choice on the direction of the x axis! π Interesting that SK is flattest -
Aware of the change, but not really had a chance to understand the what and why, which don't seem obvious at a quick look. The colour change may be a clever anticipatory move, given the change of US leadership?
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
https://forum.accurateshooter.com/threads/latest-test-on-1-cut-on-barrel-length.3946283/ -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
How interesting.... one the things I was going to suggest as a solution to 'the resonant doughnut' (or 'vibrating ring'?! π€π) I'd hazard a guess that these target-grade mfrs have known for a long time that a cure for a vibrating ring... sorry, unstable muzzle, is a choked bore. Pre-compressing the muzzle outer surface is almost a reverse-autofrettage. Makes total sense. -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
π yup; but we've also shown it ain't 5.56NATO rimfire either ππ Right, I need to do some work ... -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
π yup. We now have your Kolbe of 1.75mS Your drawn answer of 1.79 Your redrawn answer (to fit your preconception?ππ) 1.57 And my calculated of 1.88 .... three data points 'group' with one outlier. Squad avg without outlier : 1.8mS Squad avg with outlier: 1.74mS ....which is the Kolbe value, give or takeπ€ To my mind, we've just idiot-checked the Kolby figure and validated it. -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
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Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Damn. Was it 16.25, not 16... standby -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Right, well, here's a 4-step calculation for 16" using one of the step MVs Allan gave earlier. Spoiler: The answer is 1.84mS -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
I said interpolated to linear in first 16... not the whole way ..ππ As regards a baseline commonsense check; I mentioned earlier, even if there was no acceleration, and the bullet did the whole barrel at 324m/s ...it would take 1.28mS to transit a 16" barrel.... so, we know any value below or near 1.28mS is patently nonsense. π ...so I don't think QL looks to be producing anything 'likely to be right' for us in rimfire Allan's cut barrel data will allow a 3-step iteration calculation... I'll do it in a mo (for a break! π) I also note the barrel times shown on the X axis of the Varmint Al graph - which chime with my calculation -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
I'm a bit horse-not-zebras.... if any of those things definitely always had and effect, that's how all guns would now be made.... most of them are voodoo and feelings in people's water rather than supported by hard repeatable data. Have to say, the resonant-doughnut idea chimes with me, as I've often wondered why big guns - 105mm+ are so very much more accurate than small arms.... and it could go some way to explaining that... too much to type! -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
That's bloomin useful data - I've got a mad day, but later, that can be used to calculate a slightly finer-grain representative acceleration/ barrel time to 16" -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
My two earlier eg graphs compare plotting against time vs plotting against distance. Against time, acceleration is an S Shape that interpolates to show linear acceleration ... I'm pretty comfy that linear acceleration to 16" followed by constant vel is 'about right' for a .22match round I think you're being distracted by the shape of the 'against distance' graphs? Im still struck that your barrel times so far haven't been significantly different to rounds giving mvs 3 times higher...., and the latest, I can't follow, but it still doesn't seem intuitively right... We're into tale chasing without an 'actual' number. My ancient pirate copy of QL is long gone with the laptop it was on; so I can't play with approximation tuning, I'm afraid. -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
? Plot one showing velocity against time, not distance. I've got a pretty strong audit trail to my calculation; you seem to be plucking numbersπ€π -
Moderator as barrel tuner
brown dog replied to Mark II's topic in Target Shooting & Informal Long Range Shooting Practice
Thinking on.... even if a 22lr instantaneously accelerated from 0m/s to 324m/s in the first 0.0001mm of barrel; and did all 16 inches at 324m/s...which, clearly it doesn't.. .... it'd take 1.28mS to do 16" ...so 1.5mS fails a commonsense check to my mind. (PS edit: Note in the 6br graph how S-shaped the acceleration curve is - interpolating to a broadly linear acceleration... this is because the X axis on the graph is 'time'. Similar QL graphs, appearing to show faster initial acceleration have the X axis as distance (rather than time) which shows 'where' the acceleration happens, not 'when' it happens - which gives a subtly, but significantly different visual: )