I’m working on a little something to test that theory. I’m not sure how it will come out yet.
- Thread starter Goofster
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For the group shooters at distance, yes. I wouldn’t say the 16 is more forgiving of imperfect bullets, as what you put in is what you get out, regardless of twist. But what was most notable is, the nine was more concisely repeatable than the 16 twist, especially in the wind.
MB
You heading back over to SFGA this week at all? I've got today and tomorrow off through the weekend.
May be headed up to camp this weekend. If not I’ll let you know. Maybe you can shoot the control group from your vudoo?
One thing you must keep in mind CRPS the radar sees a image a bullet running in a tighter rotation about its axis of a given weight, is computed as a higher BC. if I'm correct, then one that has less stability of the same weight , which would be computed as a lesser BC.
So possibly even a unbalanced bullet spun fast would be a good thing as the spiral around center of flight should be smaller?
That’s not correct. The way that BC is measured by radar is by measuring the decay of bullet speed and fitting that to a curve to estimate the BC. The radar has no way to measure “tighter rotation” directly.
Yes in a sense, any projectile in a atmospheric presence looses its ballistic capabilities the further it travels. We cant change atmosphere, we have days that are better and some that are worse. If we cant alter the projectile shape we can only enhance it by , veloicty or a combination of added rotation or reduced rotation with veloicty variables.
But does the smaller spiral create less drag? Or is there another reason for less drag?
Bullet decay is a result of instability and no it would not be seen as a image ,but mathematical computation and analogs with analysis could generate a image path of its flight break down.
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Translated it dont take much BC. to hit something close REPEATEDLY , but you better have all you can get if your going long for any type of repeated accuracy.
I haven't heard of anything like this before, do you have a source for more detailed information?
Most guns and ammo shoot well at 50 yards. A mix of some guns and some ammo shoot well at 100 yards. Some guns and good ammo shoot well at 150 yards. Good guns with good ammo shoot well at 200 yards. At 250 yards a gremlin comes out, laughs at your gun and ammo selection, and smacks the crap out of your bullets. To me the question is if the fast twist barrels kill the gremlin? Does it take that “what the fudge” out of the 300 yard shooting?
Wow! This could be a long answere I'll try to compact it. Data is very sparse in the rimfire realm. 29 years ago I set upon a journey , I've never been one to look for information I've always tried to find the answeres instead of going with the norm. Money was sparser then , but I was determined. Using the same action and different barrels over multiple chronographs I concluded one thing. Rotational veloicty changed the POI dispersion at 300 yds. Wolf match extra was used the old Greman manfacture , it was the most consistent for the money at the time. FPS was measured at muzzle + 10 feet and at target 50,100,150,200,250 and 300 yds. The worst part of this lengthy test was I started with to short a barrel in 16T and had to start over , I settled on 28" in a 16T the alternate barrels were 15t,14t and 12t up to the year 2008 these barrels were cut back to match the veloicty of the 16t at the muzzle . I didnt have a program to plug the data into other then physical observation and all barrels were zeroed at 50 yds and the same MOA was dialed up for each yardage for every barrel. The further out I went and the tighter twist the projectile climbed more right Of my point of aim. I didnt record any scathing veloicty variables till 250 yards. And it wasnt enough to justify since I didnt have a program to weed out humidity differences , I can say the 12t and 14t showed tighter grouping at 200,250 and 300 yds by measurements. The only difference that was applied other then small variables in veloicty and humidity , was the bullet was turning more rpms at the same or close to FPS. I've started this data research again, unfortunately I no longer have any of the Wolf ammo left and I have to get another chronograph.
Well I have a 1-16 that keeps the gremlin hovering between 300-350 with a few different ammo. But I'd like more.... testing a lot of different barrels is more fuss up here in canada then for you guys I think. Especially if you ordering 1 offs. Looking to get it narrowed down to best return on investment testing.
That didn’t really address my question, which was how you can generate an image of the bullet flight path including yaw from radar velocity data, as you asserted above.
I own a 22” 1:16 Bartlien and a 24” 1:9 Bartlien Vudoos. I’m actually getting around 20 fps less out of the faster twist which I assumed was from the slightly longer barrel but I’m also seeing lower ES/SD’s from the 24”.
Ordered the blank directly from Bartlien last year sometime
It might be worth cutting it back to 22” to see the difference, but I wouldn’t do it prior to measuring time-of-flight.
MB
Why cut it shorter for 20 fps if the ES is consistently better?
It’s shooting really well so far with a couple lots of sk but the only lot of center x I had was so so, that lot wasn’t good out of my 1:16 either. It’s going to the test center next week and hopefully comes back with good results.
A doppler radar imparts thousands of pings across the flight path of the bullet , it denotes its exact time of flight from beginning to end. It creates a drag model, know as a ballistic curve. It can also measure and determine a bullets stability or its beginning of instability.
Could you measure MV and then time report of the hit on steel at a known distance and atmospherics and back calculate the BC? Or is that just not sensitive enough to divine the BC from?
Yes this was an old format of calculating BC. mics would be placed at the target and gun to record flight time , but this did not analyze its total flight. It would tell you if your profile was more or less effective based on time. The doppler can detect abrupt changes during the flight path , showing if it's a stability issue or lack of.
It would be best if you send it in, but we're not ready to start doing more nine twist builds just yet. The barrel has to be made very specifically and there's a lot more to educate end users on as it relates to what to expect in performance and why. We'll communicate accordingly as we stand up vendors to make barrels to my specs so the variables are under control.
MB
That statement makes me feel like I was a little premature getting a 9 twist put together
No sir, you weren't. To unpack what I'm saying above, I've been pouring over data all day and comparing results from various twists. The nine twist outshined 10, 12 and 16 twists, so standby for more details....nothing premature about your decision.
MB
I look forward to the details and the continuing education. I have not had the opportunity to shoot it further than 100 yards but it is hammering. So much so I’m taking the fast twist 360 to a PRS match tomorrow instead of my tried and true gen 2.
I'm looking forward to that day too.
I've avoided 60 degree throw center fire actions for a while now, and decided the V360 would be the best first step!
It might not surprise you but it tickles the shit out of me!
Thanks I appreciate the info and all the help you give on here.
I haven't limited faster twist rate testing to just 22LR. I'm pasting text here from an IG post I made earlier today at vudoo_labs.
As I completed the load out this morning for my trip to NY, I remembered that I forgot something. My approach to this trip as it equates to @michaelrshea new book, Rimfire Revolution, was to take with me what I consider to be milestones for @vudoogunworks; so, another Sunday on the range. What I forgot was my favorite fast twist 22WMR. After the first few minutes on the range, it wasn’t hard to remember why 22WMR is my go-to magnum rimfire using @hornadymfg 30 grain V-Max ammunition. My zero is at 50, but my nearly 20 year old @nightforce_opticsNXS 3.5-15 won’t parallax that closely, so I was balancing magnification and parallax to shoot the best groups I could. I generally take small game much further out, so I’m not too worried about this scope on this rifle. @krg_ops @timneytriggersusa@wiebadgear @btindllc #defti#wordsmatter #toldyaso
MB
As I completed the load out this morning for my trip to NY, I remembered that I forgot something. My approach to this trip as it equates to @michaelrshea new book, Rimfire Revolution, was to take with me what I consider to be milestones for @vudoogunworks; so, another Sunday on the range. What I forgot was my favorite fast twist 22WMR. After the first few minutes on the range, it wasn’t hard to remember why 22WMR is my go-to magnum rimfire using @hornadymfg 30 grain V-Max ammunition. My zero is at 50, but my nearly 20 year old @nightforce_opticsNXS 3.5-15 won’t parallax that closely, so I was balancing magnification and parallax to shoot the best groups I could. I generally take small game much further out, so I’m not too worried about this scope on this rifle. @krg_ops @timneytriggersusa@wiebadgear @btindllc #defti#wordsmatter #toldyaso
MB
Thanks! I recently picked up some CCI 40gr TMJ that I am hoping to try out over the 4th and see how that does.
Gotcha, I tend to stick with the V-Max in either the Hornady or Remington boxes. I believe it's all loaded in the same place though.
MB
Im looking forward to said data about the 1/9 twist options.
For a PRS/ELR type build it seems like the ideal configuration
Jumped on a fast twist opportunity.
A couple weeks back, someone posted Lilja had a series of CZ 457 prefits ready. This spurred my memory from several months back, I had called Lilja base on a comment on their website. Indeed, they do periodic runs of 1x9 twist 22LR barrels, so I got on their list. Fast forward to the comments a couple weeks ago, I called again. I was in fact on the list and had a 23” 1x9 twist on the way.
It arrived yesterday, so I went to work. It was very interesting seeing how changes in headspace changed group sizes. It didn’t take long to realize this barrel had potential. Accuracy was incredible with A LCX lot# my Vudoo was not at all fond of.
The .003 barrel shim was the magic number for bug hole accuracy and bolt lift. Not just one, but multiple bug holes followed. The wind and rain put a stop to the testing.
Today, I was able to shoot with no wind at 146 and 208 yards.
Unfortunately, I was a little disappointed. Not necessarily with accuracy, but with the drop. Accuracy at least matched/maybe surpassed my Vudoo (1x16 twist and 20”), but required about .7 more elevation at 146 and 1.3 more at 208 yards. Upon trueing my velocity, it showed 1009 fps.
In a better comparison, the same CZ with a 20” 1x16 barrel averaged 1085 via trued velocity. So somehow, the new Lilja 23” 1x9 barrel is running about 75 FPS slower.
I fully acknowledge the barrel only has a about 150 rounds on it, so the velocity may pick up. I also want to run it through my chronograph to validate the velocity.
I’ve been intrigued with fast twist barrels for a while and look forward to my continued testing and validation.
Reviewing other “fast twist” information, especially that of MB has me on pins and needles for his continued test results, as it seems he did not experience a velocity loss.
Anyone else have input/experience on fast twist velocity?
A couple weeks back, someone posted Lilja had a series of CZ 457 prefits ready. This spurred my memory from several months back, I had called Lilja base on a comment on their website. Indeed, they do periodic runs of 1x9 twist 22LR barrels, so I got on their list. Fast forward to the comments a couple weeks ago, I called again. I was in fact on the list and had a 23” 1x9 twist on the way.
It arrived yesterday, so I went to work. It was very interesting seeing how changes in headspace changed group sizes. It didn’t take long to realize this barrel had potential. Accuracy was incredible with A LCX lot# my Vudoo was not at all fond of.
The .003 barrel shim was the magic number for bug hole accuracy and bolt lift. Not just one, but multiple bug holes followed. The wind and rain put a stop to the testing.
Today, I was able to shoot with no wind at 146 and 208 yards.
Unfortunately, I was a little disappointed. Not necessarily with accuracy, but with the drop. Accuracy at least matched/maybe surpassed my Vudoo (1x16 twist and 20”), but required about .7 more elevation at 146 and 1.3 more at 208 yards. Upon trueing my velocity, it showed 1009 fps.
In a better comparison, the same CZ with a 20” 1x16 barrel averaged 1085 via trued velocity. So somehow, the new Lilja 23” 1x9 barrel is running about 75 FPS slower.
I fully acknowledge the barrel only has a about 150 rounds on it, so the velocity may pick up. I also want to run it through my chronograph to validate the velocity.
I’ve been intrigued with fast twist barrels for a while and look forward to my continued testing and validation.
Reviewing other “fast twist” information, especially that of MB has me on pins and needles for his continued test results, as it seems he did not experience a velocity loss.
Anyone else have input/experience on fast twist velocity?
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