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F T/R Competition 1000 yards w/ 20" barrel?
- Thread starter CGGunnersm8
- Start date
I thought my chrono velocities were wrong, too. So I checked my drops at 300, 500, and 800 and back calculated velocities approximately the same as what my chrony was reading. Could be Litz's BC's are off for the 185gr Hybrids because even correcting velocity with my drops, it doesn't match up just right, but it is close enough.
The point I was trying to convey is that for these super long Berger bullets, velocities need to be well outside of the transonic region to remain stable. With a short barrel, you don't have much room for forgiveness. Even now, I would say that I am on the bleeding edge.
If I am currently at 2590 fps, my bullets must have a greater-than-book BC or my scope must be broken because my drops are 9.3 - 9.6 Mils where I am shooting (about 180 feet above sea level). JBM says my drops should be 10.2 Mils at 2590 fps and 1,000 yards. I am definitely not over 10 mils. Reloading book values are great, but between my CED M2 and ballistic calculations, I trust what I need to input into the program to get me there, and that is what I get. 1,000 yards is laser verified and the atmospherics come from Kestrel, so the only thing that could really be wrong is my BC. If that is off, then you're right, my velocities are off.
But again, the bigger point is that you need to get not just close to Mach 1.2 (1.18 rounds up, right?), but sufficiently above it to hit consistently at 1,000 yards. And that is before you can even think about wind effects.
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I think what you are trying to say is that the Berger bullets lost stability at Mach 1.18, way before going transonic. I have a hard time believing that this is the case. As you know, the longer a bullet flies (supersonically) the more stable it becomes because its spin rate does not slow down while the overturning forces acting on the bullet diminish as the forward velocity decreases. It is my understanding that it is the actual transonic passage that may create a disturbance important enough to actually cause the bullet to tumble. The inherent stability of the bullet is a function of the distribution of the weight in the bullet, rather than its length alone. For instance, the 168SMK is very heavy in the back compared to the front (ogive) whereas the 175SMK's weight is much better distributed along the whole bullet. The 168SMK is the poster child for tumbling through the transonic passage, whereas the 175SMK will remain point on after going subsonic.
So, my point is that I believe your bullets were going subsonic way before 1000 yards, regardless of what the calculators say. If bullets tumble when they get below Mach 1.2 there would be a lot more reports of keyholing and I have yet to hear of one with the Berger Hybrids at 1000 yards in F-class competition. Did the pit crew ever complain about not hearing your bullets come in at 1000 yards?
So, my point is that I believe your bullets were going subsonic way before 1000 yards, regardless of what the calculators say. If bullets tumble when they get below Mach 1.2 there would be a lot more reports of keyholing and I have yet to hear of one with the Berger Hybrids at 1000 yards in F-class competition. Did the pit crew ever complain about not hearing your bullets come in at 1000 yards?
I am guessing that you saw the thread title in the right hand console and replied without realizing that you were posting in the F-class section? We are discussing F-TR, which is .308 at 1,000. I think there is a disconnect here as managing to finish a 20 round match with all shots inside a 10" circle is extremely difficult to do. Even with a couple of sighters. So when you bring up your .3 MOA GAP 10, and we are talking about 1,000 yards, the conversation gets crossways. I am sure your GAP 10 is .3 MOA at 100 yards. At 1,000 yards, that .3 MOA just doesn't translate. XTR wasn't just creating some artificial constraints for shooting that you can't live up to, he was describing the rules of F-class, F-TR division. Hence the confusion.
Our handicaps in golf are based on our best 10 rounds out of the last 20, the worst 10 are thrown out (Equitable stroke control also stipulates the maximum score you can record on any hole when posting your round for handicap purposes). In F-Class you have to count all 20...no equitable shot control either...
Clmayfield
Youre right man. My bad. Mouth shut and on I linger. Cheers mate
Lawman
You just took me on a roller coaster ride through your brain and spit me out. Im a nug. Sorry man... Have a good one bud
Youre right man. My bad. Mouth shut and on I linger. Cheers mate
Lawman
You just took me on a roller coaster ride through your brain and spit me out. Im a nug. Sorry man... Have a good one bud
The problem is that transonic is a region, not just a single point. There is a great graphic on this page: The Rifleman's Journal: Cartridges: 1000 Yard .308 Load Development. Even above Mach, the flow pattern does not look the same as well above Mach.
As to me being at Mach 1.18, yeah, I might be off a bit on that. That was what I calculated before I hit the range. But I guarantee I was above the speed of sound. Being above the speed of sound is not that same thing as being outside of the transonic region, though. I didn't do this with a pit crew... this was load development at my range... and it is frustrating as all get out as I have to load up my cartridges, drive to our ranch, 2 hours away, sneak away from the family for a couple of hours, and then not hit paper. I choke up to 700 yards, make sure my velocities is on, make corrections to my velocity based on what was happening at 700, go back to 1,000 yards, and have magically disappearing bullets. Of course, as you get into the transonic region, ballistic calculators no longer work well, so I had to up my drops. I add some extra drop, find paper. Shots are erratic. Vertical (not to mention horizontal) is all over the place. And then I saw keyholing and realized my time with this load is better spent at shorter distances.
No doubt, I was keyholing at velocities above the speed of sound. Whether it was Mach 1.18 or Mach 1.1 or Mach 1.05, I don't know with the precision that I know my current load. The point is that transonic is a region. You don't want to be just above the speed of sound, you need to be well above the speed of sound, like more than 20% over the speed of sound or you will experience erratic behavior in your shot pattern.
That's all I'm saying.
WE ( BROTHER+12+/-5 FRIENDS ) SHOOT MOST WEDS.AT 1k YDS......USUALLY SHOOT AROUND 20 SHOTS.I`VE SHOT THE 2007 NATS.AND THE 2011.....NEVER REMEMBER ANYONE.....IN MATCHES OR PRACTICE.....RUNNING MORE THAN 5-6 "x"`S IN A ROW.....NEW TARGET IS 5" "x" RING AND 10" 10 RING...... SOOOOO...... IF YOU CAN SHOOT 20 X`S IN A ROW CONSISTANTLY @ 1k YDS.....
YOU CAN CLEAN UP ALL WORLD WIDE COMPETITION......
I have no clue. Where does one get to shoot 1,000+ yards on the Internet? Is there a site for that?
One of my shooting partners started a little wager game last match and I am loving it, it makes every shot count .
$5 high X count
$5 high score
$5 for any five 10s in a row
$5 for five Xs in a row
-$5 for the lowest value shot
The last weekend we shot I came out even over the two matches we played.
I believe that there have been a total of three (3) clean 200's shot in F-TR since the target was changed in 2007. Phil Kelly at Butner(200-6 I think), Mid Tompkins at Camp Perry (I believe it was a 200-9, but don't quote me on that one) at Raton last yr. Three, out of all the rounds fired by all the shooters in the US over the last seven yrs, three have held 1MOA for 20 rounds.
I think my personal best run of X-s has never exceeded 3.
Yeah, Clint Cooper shot a 200-7X at Raton last year. I shot a 199-7 on the same relay and I thought I had that one nailed but ended up third in Expert behind Steve Siracusa (199-11) and Laura Perry (199-8). Mid Tompkins, sandbagging as a Sharpshooter took second in that class with 199-9, behind Robby Burton also with a 199-9. In Master/Unclassified class, Jonathan Laitre took first with a 199-12 and Terence McQuaid took second with 199-3. I ended up in seventh place overall with my best ever score; how humbling.
Well, on the internet I can shoot to 1000 all x's all day...but in reality I'm still new to 1000-1200 yards and only have opportunity to practice at those ranges once a month at the most. So, while I can make hits at that range, I'm not an F-class shooter and still am learning.
No harm no foul. I will take your set up for staying alive any day over these game guns we use for 1000 yard comps.
Clay, my comments about chromos had to do with personal experience. I had one that was consistently 200 fps off so I always wonder now.
20 fps is a lot! I always have to end up adjusting my velocities a bit based on results I get on paper. Even a 20 fps differential will make a big difference at 1,000 yards. Being 200 fps off, I would have a difficult time finding paper even at 600 yards!
Anybody have any experience at 1000 and beyond with 178 Hornady Amax bullets from a 20" barrel? If so, how do you find they fly through transonic and beyond?
I shoot them out of my 20" Savage 10fp and do quite well with them out to 800, which is our local range maximum distance, so that's all I know about them for now. I use the Shooter app on my Iphone and I ended up having to punch in a G7 BC of .260 to get my chart to agree with my actual dope for hits on paper at 600 and 800. Brian Litz's G7 BC for the 178 Amax is listed at .240, so it seems that my 178 Amax bullets are flying slicker than that.
My load is Lapua brass, 43.8gr IMR4064, 2.850" (.010" jump), running 2600fps average. My chrono has been crossed checked with other chrono brands and has been found to be in check. Brass life is pretty decent with this load and fired primers look safe.
I shoot them out of my 20" Savage 10fp and do quite well with them out to 800, which is our local range maximum distance, so that's all I know about them for now. I use the Shooter app on my Iphone and I ended up having to punch in a G7 BC of .260 to get my chart to agree with my actual dope for hits on paper at 600 and 800. Brian Litz's G7 BC for the 178 Amax is listed at .240, so it seems that my 178 Amax bullets are flying slicker than that.
My load is Lapua brass, 43.8gr IMR4064, 2.850" (.010" jump), running 2600fps average. My chrono has been crossed checked with other chrono brands and has been found to be in check. Brass life is pretty decent with this load and fired primers look safe.
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