Thanks Josh, I can see the potential advantages for other disciplines and the twist constraints you had to work within to run these in current barrels. Will be curious to see what you come up with for the 7 twists with a heavier bullet.
Not sure I follow you on flatter trajectory being interplayed with wobble zone to make a smaller or larger "assured impact" zone when dealing with vertical wobble. Maybe it plays out in theoretical math but is it a real world thing? Are you talking about minute fractions of an inch here? I don't know math enough to solve an equation but my gut says it must be incredibly small. If you don't mind, here's a scenario question... If I have a perfectly accurate 2900 fps gun, a 700 yard 2 MOA target, and I break a shot 0.025 degrees above center (1.5 MOA high) due to wobble, how much deviation from the 1.5 MOA "aim point" is there, given the angle of attack of the bullet path? How much better is it if you go to 3200 fps? With such a small angular deviation for the miss, plus what is still a fairly flat trajectory at 700 yards (about the farthest we see wobbly positional targets), I can't picture this being a real thing to consider.
Of course, there are a lot more incorrect ranges given in match books than we'd like, so flat trajectory is a real benefit in that situation.
IMO it's a tough sell on recoil alone. Weight kits have already brought the recoil down to very low levels, and cost/bullet would be significant if you were going to run them the whole match. It would be multiple thousands of dollars a year for me to switch from a traditional 105.
Other question, what does an impact from a copper solid look like vs a lead core bullet on midrange steel? I'm assuming no lead spatter/vapor cloud, so you're relying on target reactivity. Is energy transfer to the plate as good as a lead bullet? Or do they "bounce off" for lack of a better term?
They carry more energy at the plate but there isn't a cloud of lead, they leave a small copper impact mark. It's not hard to see at ranges where we don't have flashers but there is a definite difference in what the impact mark looks like. For the same reasons that matches are required for flashers past a specific distance already the bullets have an issue with being able to see the impact point of a small copper mark vs. a lead splat that is 3x the size. This comes with a silver lining though as there is a distinct advantage on a target which hasn't been painted all day and had its ass whooped by regular bullets. The copper penny looking splats shine clear as day against all the lead marks.
For the drop advantage you need to know the waterline of the load you're comparing it against but here's the easy way to think about it. The "wobble zone" for lack of a better technical term right now is heavily influenced by the waterline of the load being shot. The waterline is the vertical dispersion in a group at a given distance. A tighter vertical dispersion means that targets are statistically larger when held on center to be an assured hit. This is not a new concept and it's one of the oft quoted reasons to go to a Dasher in online discussions... tight waterlines.
The flatlines tighten those waterlines through a few factors, one of them being the consistency from bullet to bullet and the other big factor in this case is the reduced ToF. The lower ToF is a combination of overall performance which we can think of as MV*BC for a normalizing value.
If a given setup shoots a waterline size of X and the new setup shoots a waterline of 0.82*X you have a larger target in many common shapes (diamonds, circles, triangles) because you can tailor where to aim to maximize target size horizontally while being at less risk of dropping a shot high or low out of the target bounds.
The lower the ToF and hence the lower the overall drop value gives a lower dispersion factor because dispersion is based a 3rd order relationship to ToF. This is also a well known behavior: 100yd groups don't translate to 1000yd groups by simply a 10x multipler. It's more like a 25-45x multiplier in actual practice.
So why is that important?
If you can take a 1000yd target and make it look like only say a 925yd target in terms of the ToF then you have an advantage for the effective target impact area. The waterline normally shot at 925 can now be applied to 1000 and the waterline for 600 now applies to 850 and so on. I know when I'm trying to plan a stage I look at target shape as well, it is an important factor on how to shoot them, how to hedge the wind and any concerns over target range.
Same holds true for the application in a wobbly environment. You don't have to steady out quite as much on every shot, you know you have more error margin to work with. Therefore if you have more error margin you can work through the less than optimal position and less than optimal hold while still having the high confidence of a hit in order to execute the shot. This is a time advantage on a wobbly position in a timed stage like a PRS skills barricade.
There isn't enough information in your requested example to give you an idea but the comments should at least explain it to you for the concept.
Thanks for the feedback.
I can get that this design was not really a "NRL / PRS" purpose built bullet.
That being said, I am not getting the "making it work in existing barrels"? IMHO, if anyone is seriously competing, and dropping this kind of money on a bullet, then they are going to buy whatever barrel they need to shoot the optimal bullet. If they need a 7 twist to stabilize a 105 bullet, then that is what they are going to buy and hang off their receiver.
Also per the comments above, if you are shooting in a "NRL / PRS" type match, having that additional bullet weight & size is going to make a difference when it comes to spotting impacts, whether they are hits or misses.
Once again, I can get that this was not intended to be an optimal bullet for everyone, but I sure hope that some key people don't really think that this is somehow going to become the answer for shooters running a 6mm in NRL / PRS.
You would be surprised at the people who won't try something if it means a new barrel, I get the call with it every week. There are a few examples but the most outstanding one is consistently the F-T/R with a 308. The trend for 10 years has been heavier heavier heavier. Get every ounce of BC you can, who cares what the recoil or speed is. Enter the 198 Flatline with a verified BC of almost 0.84 G1 out of 308's but it requires a 9twist or faster.
The phone call:
"The 198's look amazing, are those BC's Warner published real?"
Yes, they're tested via Doppler radar now.
"How about throat? Do I need a different throat"
You can use a standard throat, no problem. (Enter hedging bets so other bullets can be used)
"I really want to shoot the 198's in F class but is the 9 twist really necessary"
Absolutely, unless you're over 7500ft DA the 10tw won't work, you really need a 9tw.
"Are you sure? Because <insert bullet manufacturer's name here> recommends a faster twist but it doesn't need it all the time"
I'm quite sure you can't use a 10 twist for this 9 twist bullet. I tried it just to be sure that there wasn't something missing in the math.
"Too bad, maybe next time"
And that's with a 30c bullet that has a massive advantage in both BC (0.84 G1) adn speed (24" 308 runs them over 2800fps) over any other 30c on the market.
Hence why we chose to make a bullet that can be used by the majority of barrels before making something for the competitor willing to drop the money on a new barrel. Shooters are incredibly cheap... I should know, I'm a cheap shooter. If I can't see an advantage it doesn't happen. It is a big factor of why I went from 6x47 to a Dasher (barrel life) and then from a Dasher to a 6BR (barrel life, lower recoil, longer barrel life, easier brass forming, longer barrel life... did I mention longer barrel life?)
