Certainly not all-inclusive but I figured some would find the info useful. I measured in about the most accurate way possible for anybody without a million dollar underground range and I'm confident in the results. Of course I wasn't shooting 10 shot strings which would have upped the confidence level (some bullets were more consistent than others) but that'll have to wait until somebody else is buying me barrels. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> Anyway, for what it's worth:



Calibrating the Oehlers:



The 206 yd target/205 yd chronograph, with spotter target to the lower left:



The view:

Interesting Information. Thanks for sharing it.

HBB

What is the difference between Standard ICAO and Standard Metro BC's?

Doug~RR

Regardless of if the calculations are "correct" or not, this is the way its supposed to be, real world data, same set of conditions, same gun, same day etc.... This means you can tell which bullet has the best coefficient, regardless of if that number is off .050 or not.

Very nicely done. I've always wanted to do the same since I have a private range with permanent benches at 100,200,300 and 600. Though I'd be scared to shoot to 600 without a trap to protect the works... Soon to be almost 1000 if things work right.

Jeff

Jon, Thanks for sharing the results of your work. Very useful to me. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

Very interesting data. You will no doubt be deluged with requests to test further bullets.

One thing I am interested in. Notice the crooked meplat on your 210 Sierra MatchKing photo. They now sell meplat uniforming devices, which should make the BCs more uniform but, I suspect, reduce them a little. I wonder if this in fact occurs.

Doug, they're just two different set of "Standard Conditions" at sea level that you should use as in ballistics calculations. ICAO is 29.92 pressure, 59 degrees F, 0% Humidity while Metro is 29.53, 59 degrees and 78%. There isn't much difference, Sierra uses Metro, Nosler uses ICAO, etc. So if you were using Sierra's Infinity program you'd want to use the Metro numbers because that's what it expects you to use.... Hopefully I didn't confuse too many people by listing both. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Thanks for the comments, Jeff. I agree that's the best part of a test like this--same day, rifle, chrony setup, etc. Sort of like a "bullet drag race." <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" /> Of course I do try my best to set everything up correctly and do the environmental corrections as accurately as possible so the results are repeatable (and meaningful for others) so I don't have to test the same bullets over and over again. Of the four I tested before, the biggest difference between the tests was .016 with the others being .011, .004 and .001. So I figure I don't need to test them again except for control purposes to validate future tests.

Five of the eight tested to within about 5% of their manufacturer's rating which I figure is pretty good with differing barrels, test velocities, etc. Of the other three, two don't have a current manufacturer's rating so there's nothing to compare with.

Indy, yes that isn't uncommon with Matchkings--though they did test out pretty consistently anyway. I haven't tested uniforming but others have and it generally does reduce the BC slightly but improve its consistency. Of course there are other sources of inconsistency that are harder to see with the naked eye.

Jon,
Thanks for the explanation, and posting your results which I saved. I had done a quick google search and looked in an old Sierra reloading manual about the BC's ,and came up empty.

Doug~RR

That was quite the effort! Thanks for the information. Don't suppose you want to share which company's BC matched your data?

I remembere Rick Jamison did this BC test years ago. The most amazing thing to me was the BC would change based on different muzzle velocities. If I remember correctly he showed that individual rifles showed a BC starting low building up to a peak and then tapering off as the velocity was increased. Unfortunately we cannot try to figure out which velocity is best for each rifle. My personal conclusions after reading that article was that it is amazing we manage to hit animals at long range. The more I know the more I am humbled by the facts.

Sure. The XLC is still advertised at .552 by Barnes but they've since admitted their old methods of measuring/rating BCs left much to be desired. So I don't feel it's fair to hold them to that anymore. If they keep making it very long they'll probably re-test it as they have the TSX.

The GS Custom used to be rated at .650 (God only knows where that number came from <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" /> ) but a recent check shows Gerard has taken all the BC data down from the page with the note:

So it's only fair to consider that bullet unrated at the moment. Maybe Gerard will put out some realistic accurate BC's the way Barnes has the second time around.

Of the remaining six, the TSX and MRX were a bit low but not too far off from Barnes' rating (I don't know if their advertised ratings are ICAO or Metro). "Close enough" for most purposes anyway.

The Scirocco beat its advertised number by a bit as it always does. That's one sleek bullet.

The AccuBond was a bit lower than advertised, but pretty close.

The 210 SMK was a bit higher than advertised. That isn't too surprising since their own data shows BC going up with velocity and I measured at a higher velocity than I expect they did.

The only one that was off "significantly" was the 240 SMK. That was disappointing to me since I like that bullet so much, but the Oehlers don't lie. I wasn't all that surprised since that's about exactly what I had measured it at last time but I was hoping the 1:9 twist barrel would show an improvement this time. It didn't, it's just not there. The story my test doesn't tell however, is that its less efficient more pudgy shape is supposed to hold onto its BC better as velocity drops compared with the 210. Even so, if I didn't already have bigger and better things on the way, I may look at switching to the 210. I have no idea how its terminal performance would be though, I'd have to test. I know the 240 flat kills stuff.

Thanks for mentioning the company names. I talked with TY at Barnes yesterday. He said they are retesting their bullet's BC using Ohler equipment. They are shooting at 300 yds.

Thanks to JonA for a nice experiment presented well.

It has galled me for years that we calculate exterior ballistics to four digits of precision using a drag funtion that might fit an individual bullet to within five or ten percent and BCs measured over short distances.

We use the G1 drag function for most references because of a "gentlemen's agreement" that it is better to have only one drag function as standard instead of using many different yardsticks. These same gentlemen agree that G1 doesn't fit all bullets, and that in fact that it doesn't fit any bullet exactly. Their sane philosophy is that BCs based on G1 are close enough for rough comparisons, but actual downrange performance must be determined by actual firing.

The apparent change in BC as velocity changes is simply an indication that the bullet's actual drag function does not fit the the accepted G1 model. Sierra has chosen the logical expedient of quoting different BC's at different velocities; this may well be the most practical solution.

The measurement of BCs is not easy. For years we have told folks that getting BC measurements is at least ten times as hard a getting velocity measurements. For BC, we must measure the velocity lost, and to measure the velocity lost we must accurately measure the velocity at each end. Any time you are looking at the difference between large and independently measured numbers, the large numbers must be measured very accurately, or the accuracy of the difference is questionable. Actual measurement of BCs to an accuracy of better than five percent requires good equipment and a lot of work. Speer's old numbers that quoted a BC of 0.29 instead of the modern convention of 0.291 were a true admission to reality.

For many years, the military has avoided this problem by not using the BC concept except for very coarse estimates. They measure the individual drag characteristics of each projectile as the basis of their "firing tables". This is simply beyond the means of individual shooters or even bullet makers.

The best we can do is to actually measure drop, velocity, or time-of-flight at several ranges that would preferably include the maximum range of interest. If we "fudge" any good exterior ballistics program to fit our firing data from the longest range, the program outputs will closely fit the actual data from the intermediate ranges. The secret is that we're using the program to "interpolate" between our measured data instead of using the program to "extrapolate" short-range data to longer ranges.

We're working on it.

KenO

Jon,

Thanks for the effort, it is good info.

Sierra measures it's bullets BCs over 4 or 5 different velocity boundries. Bullets BCs often decrease as they slow. The 210 Sierra is an excellent example. It's BC falls off rapidly and at around 2000 fps it's BC drops to something like .375. This makes the 210 Sierra a dog, and drifts about 10" more at 1000 yds than the 190, 200, and 220 grainers when fired from the same case at best velocities. I have about 400 I need to get rid of.

It would be a lot of work, but it would also be interesting to see what the Bcs will measure at the lower velocities, say what you get at 1000 yds.

Thanks for the kind words, Dr. Oehler.

I agree on the G1 thing--especially for all the VLD-style bullets out there these days. In Sierra's defense, they have stated in the past that most of theirs fit the G1 curve the best and their BC data backs this up somewhat (G1 BC's not changing much over the velocity range listed). But that was before they made the 210 which is quite a departure for them and naturally should be closer to the G5 or G7. But that's another story--I hope they're scratching their heads as much as I am about their results for that thing (I'd hate to be the only one <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> ). I sure would love bullets to come with their own measured drag curves...but I'd like to win the lottery too. <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />

Blaine,

If I used the 210's for hunting, the most likely ranges for me would keep them at a pretty decent velocity (high altitude and I can launch them fast) so performance should be pretty good over my desired range even if Sierra's ratings are accurate.

On that subject, I wouldn't say the 210 is a good example of how a bullet's G1 BC changes with velocity. I'd say it's a horrible example. It's so far off from being representative of how most pointed boattails act it's more like an aberration. Sierra's numbers for this thing are so far in left field I don't know what to make of them.

One wouldn't expect this bullet to follow the G1 curve as closely as most of their others do, but this thing doesn't come close to any of the curves--at least the way Sierra rates it. G5, G7, etc, it's way, way off from all of them. Not plus or minus a few percent throughout the velocity range as you would expect any bullet to be, but off 40%, 50%, 60%....! Somethin' just ain't right here.

I roughly sketched in what the portion of the drag curve, based upon their ratings, for that bullet would look like:



So either Sierra has invented a bullet that flies like no other projectile known to man (which would be amazing since it looks virtually identical to other 210s which are proven performers at long range) or their testing/rating of the BCs at various velocities was flawed.

I won't claim to know what the deal is. There may be something about its shape which escapes my eye that makes it so unique. I have a few theories on what could have gone wrong in testing, but I'd want to know more details on how they tested it before I put my money on that. If derived from Doppler data, well OK, nevermind then. If not.... If I wanted to use these at 1000 and beyond, I'd do quite a bit of my own testing before discounting them out of hand based upon those published BC's.

Anyway, while quite interesting to me, I'm not worried enough about it that I'll likely do much further testing to unravel the mystery since I won't be using any of these bullets for much longer. But I will love to hear results of anybody testing them at an extreme range where it should be pretty clear if they're working better than advertised or not.

Jon,

Really cool, thanks for sharing.

I am starting to look at BCs differently. Given Sierra is the only company that actually measures BCs over multipe velocity boundaries, my take is their numbers have just shown us what VLDs really do at long range. Based on how the Berger 210s shot in my rifle, I'd say Sierra is hitting closer to the mark with their BCs for their 210 than Berger is with the BCs for his 210. Obviously I'd need to do more testing at 1K to verify my "take", but I am becoming suspicious of the predictive model used to calc BCs for these VLDs.

I discounted the 210 SMKs them because they shot like crap in my rifle.

Unfortunately, I am no longer motivated to fuss with any VLDs because the 220 SMK is posting ES of 11 fps, is shooting the small group of matches (4.000" best), and is winning matches overall. Further, it has an excellent BC which has been reflected at the 1K target.

If it wasn't going so well with the 220 SMK I'd be trying 210 JLKs. It would be fun to set up a chrono at the muzzle AND at 1000 yds.

That could be Blaine. I'm just thinking out loud here, I don't know all the answers.

I would be more inclined to believe that if Sierra was the first to actually test a VLD style bullet. But of course, they are not. Even disregarding the Military, companies like LRB, SOE, etc have been doing the doppler thing with bullets of "VLD-ULD type shapes" for quite some time. If bullets shaped like that opened up parachutes (picture little parachutes like those on the back of really fast drag racing cars) progressively as they lost velocity as Sierra's data would indicate for this bullet, I think it would be pretty well known by now. And I don't think these guys would choose bullets shaped like that for rounds they expect to perform well beyond 1000 yds--even more than twice that distance, where the differences would become very clear.

Frankly I think it more likely to be exposing shortcomings in Sierra's testing methods. Measuring via doppler at actual ranges is going to be so much more accurate than reduced loads fired over 150 yds from a marginal twist (they had to recommend an 11 twist since that's what the competition recommends, so maybe they felt they had to use that twist while testing?) where yaw, coning effect, etc could greatly influence the results that I'm going to say I'll need to test for myself before I put that much faith in Sierra's data for this bullet. Then again, maybe it really is correct for this particular bullet. Maybe there's just something "wrong" with the design I don't see.

Like I said, I'm just thinking outloud and welcome more thinking out loud on the subject to point out anything I've missed. That's how I learn. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

A 1000 yd chronograph test like I did above would give some insight. While the difference in trajectory from a "somewhat" constant BC and Sierra's data wouldn't be much, even at 1000 yds from my rifle, the velocity at the far end would tell an interesting story. I'd need to make some sort of sheild for the chronograph though, or I have the feeling I'd be calling up Dr. O. yet again for more replacement parts..... <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

JonA,
I would be interested in what you think after reading this.
http://www.pejsa.com/articles.htm
Thanks for the great test.
dave <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

I ain't JonA but that fella Pejsa makes my head hurt. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Jon, a very well presented piece, and thanks for that.<img src="/ubbthreads/images/graemlins/cool.gif" alt="" /> <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />

Now I have a question for you or Dr. Oehler regarding variations of BC due to nonconformity to the G1 Function, and the apparent reduction of BC as velocity increases. Robert McCoy's book "Modern Exterior Ballistics" is quite explicit that for numerous forms, to include Boat Tail Spitzers, Cd diminishes as Mach increases. There are some specific drag curve examples of this up to velocities as high as Mach 6 IIRC. I'm not saying anybody is wrong one way or another but it seems my mind is short circuted on the matter...I'm seeing this as a conflict...mebbe not? Can somebody shed some light on the matter? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

One additional question: ISA...did the specs on that change within the last 30 years? Seem to recall that humidity was once part of the standard though nobody references that from what Google shows... <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

<img src="/ubbthreads/images/graemlins/confused.gif" alt="" /> <img src="/ubbthreads/images/graemlins/confused.gif" alt="" /> <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

DD,
"I ain't JonA but that fella Pejsa makes my head hurt. "
Ya I know.But his discription of what his math can do to the slop of the curve.Fits what JonA is looking for.I think.
From what I can read comming up with a curve based on drag for the bullet your usuing is much more accurate than say Sierras multiple BCs.
His math goes over my had real quick.
dave

Jon,

There is a very interesting article in this month's Precision Shooting about VLD vs non VLD bullets. The author's take is the way the a bullet engages the rifle is critical and can make a big difference in how true the bullet flies. He points out that once a bullet is deformed in the initial firing process, it stays that way. VLDs seem to be especially fussy about how the contact the rifling. The answer to making VLDs fly like they are supposed to is to cut the leade specifically for the VLDs. The article in next month's PS is going to explain more.

dave, you may be on to something there...will take a second look. Pejsa's math doesn't bother me so much as his prose....it seems like he's yelling or something...and we're on the Group W bench a jumpin' up and down yellin'.... <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />

Dave,

The only catch is Sierra multiple BCs seem to be spot on. I can chrono a Sierra bullet, plug the numbers in Infinity, crank up the scope the requisite clicks as per the program, then hit within a foot vertically at 1000 yds with the first shot. Then again, maybe it IS all just chance............... <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Thanks for the heads up on the VLD article, Blaine. Sounds interesting, I'll check it out.

On the Sierra BC front, within a foot at 1000 just doesn't tell me much. For example, from my rifle at my Montana altitude, the difference between Sierra's published BCs in stepped form for the 210 and using a constant .647 as I measured (which is a pretty big difference) only makes about 3" difference in trajectory at 1000 yds. With a relatively accurate starting point with a high BC bullet from a decently sized round, things aren't going to get really interesting trajectory-wise until beyond 1000. Running the comparison at 2800 MV it's about 10" difference. Starting to become significant, but still within a foot for such a huge BC/drag curve difference.

I'm working on getting locations worked out for 1300, 1500 and 1 mile targets. That's going to be interesting. Curve differences that are so small they get lost in the noise of other variables at 1000 will become quite apparent.

Thanks for bringing that up, Dave. I had seen that before, I even found I had a spreadsheet on my computer using Pejsa's method. I must have gotten distracted before I could dive into it and forgot about it. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

I was wanting to have a better handle on the math before I commented, but I've been busy (testing even higher BC bullets! <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" /> ) but I'll give you my thoughts on second glance:

I think it has the potential to provide very accurate data, in many cases more accurate than using standard drag curves. Just using the software and/or the math without good data collection I don't see much of an advantage though. Where I see the possible advantage is if you have a 3rd piece of data from far downrange. Say I repeated my above but put the second chronograph at 1000 yds or so. Or I get really accurate drop data at 1500.

I could just adjust the BC to reflect the average over that distance for whatever standard curve I thought my bullet would fly close to. This would put me exactly on at that distance, under those conditions. But depending upon how differently shaped the bullet's actual curve is from the one I'm using for the calculations, it could be off significantly in the midrange and way, way off at distances much farther than the distance at which I collected the last piece of data. The bullet might fly really close to one of the standard curves, it might not. Or I might guess the wrong curve.

You're basically taking two differently shaped curves and matching them up at two points, ensuring they'll be off everywhere in between. How much depends upon how different they are. So with a data point at 1000 yds, I'd be dead on at 1000 but I could be way off at 1500. At 2000 yds I could be missing the target by several feet, even with all the other variables taken care of accurately.

For this, I think Pejsa's method could be much more accurate. Instead of moving a fixed curve to match your actual curve at two points, adjusting the constant adjusts the shape of the curve, letting you simulate the drag curve of your particular bullet. If done properly, I think it has the potential to be much more accurate at ranges farther than your last data point vs. assuming your bullet flies to a standard curve.

I have played with the math a little over the last couple of days. For most BC/velocity combinations you can think of, you can change the constant to fly to the G1 curve within an inch or so out to 2000 yds (or where it goes transonic). A different constant simulates the G7 curve about as accurately (those are the only two I spent time comparing so far). If your bullet falls in between somewhere, I think the Pejsa output that matched your data would likely be more trustworthy at extreme ranges than just picking a curve that might or might not be close. Or say Sierra's data is accurate for the 210--it would be WAY off at 1500 for any curve even if I had it nailed at 1000. Making your own curve would be the only way to even come close.

The above was for really high BC bullets at supersonic ranges. Obviously lower BC bullets fall below that before 2000 and the math in the spreadsheet I was looking at doesn't cover that portion of it. In general, smaller rounds shooting lower BC bullets will have all these different curves show significant trajectory differences at much shorter ranges than my 300. Things won't get too interesting for me until I get well beyond 1000.

One word of warning in general though, like anything else it's only going to be as accurate as your data collection. It's pretty common for people to adjust BC's in software to match actual data via the standard curves and there is nothing wrong with that. But I do feel many people do it way too soon, without eliminating other variables that can cause errors much larger than the differing drag curves will at the ranges most people shoot. Accurately measuring Baro, temp, etc. Using a velocity they got from a cheap chrony last month. Not knowing if their scope clicks are supposed to be 1/4 MOA or 1/4" per 100 yds much less what they really are. Stuff like that can cause errors large enough that all this drag curve talk is just mild noise in the background.

Those are my thoughts, anyway, just at second glance. It ain't no doppler, but it might be pretty good if one goes through the effort of collecting good data to shape it. Maybe a good shot better than most ballistics programs. I'll look at the math more closely in the future and will be putting this stuff to the test at much longer ranges in the future. It'll likely teach me a few things...but it should be fun. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

Dan, Metro is 78% humidity, ICAO is 0%. Is that what you meant?

JonA, do not mean to hi jack your thread, but I have a stock in the classifieds that you may be interested in........Blake

No, I recalled ISA contained a standard humidity factor, somewhere in the 40-50% range. Might have confused that with something else though, I'm reaching back in time awhile. Maybe I've entered a parallel universe... <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> Not important I guess. Thanks for your thoughts on the matter.

Dan

JonA great data! Thanks for sharing! Can you share with us some information on the bullets you plan to be shooting in the near future?

Thanks again,
JonK

Sure.

There won't be anything magic about them--the most difficult thing was just trying to find somebody to make them (Richard Graves of Wildcat Bullets rocks!). They'll be a nice pointy VLD/ULD style shape, just much longer and heavier (higher SD) than 30 cals have been made in the past.

The goal I've had in the back of my mind for ages is a 30 cal bullet that will run with (or even beat) the 338 cal 300 grain SMK ballistically. I won't know for sure until I shoot them over the Oehler lie detectors, but they should have no problem accomplishing that. They'll make all the bullets in my above test look pretty silly BC-wise, that's for sure.

So far I've just played with some initial prototypes to sort of test how long and heavy a bullet my rifle can handle. These have been over 1.80" long and weigh 290 grains. <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" /> My 300 RUM thumps them out there nicely at 2680 fps over a mild load of US869. The final versions will be lighter, probably around 260-270 grains and will go somewhere in the 2800-2900 fps range--longer barreled rifles will likely push 3000.

While super high BC was the primary reason for wanting such a thing, better terminal performance was a close second. These are built on a tapered jacket, bonded core optional--very much a "hunting bullet." If you've tested the 240 SMK, you probably have some idea of the potential such a bullet will have. That'll be fun to test as well.

Of course I know there will be those who point out nobody should "need" such a bullet and that I must be nuts.... But it's sure going to be a lot of fun. That is why I do this stuff, afterall. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

JonA, I am very interested in your resultwith these heavy for caliber Wildccat bullets. After read you sucess with US=869 and the 240SMK. I ordered a 30 Cal. ABS Carbon weapped bareel with a 1 in 9.2 twist to finish at 30" and am planning on building a 300 RUM bulit especialy to shoot the very heavy for caliber high BC bullets.
Thanks, for the insperation.............. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

John, I had a brief email flurry with Wildcat Bullets a short time back, inquiring as to BCs...found it interesting that he would not dicuss BC beyond stating that he didn't care to enter into the fray...would be interested in what you find on that horizon.

DD,
If you looked at some older posts on the LRH forum you would see that there were some heated discussions concerning BC.
That, I believe is main reason why he doesn't want to get into it. If you are interested in the 7mm 200 ULD/RBBT I would be glad to tell you what BC I am using for my BP/Alt/MV on Exbal. I am not making any claims of true BC, but what matches up with my drops.

Ernie, would appreciate that info if you don't mind...here or PM, whatever. Would be willin' to bet that a gross majority of folks discussin' BC don't really know that much about it, a case of knowledge being inverse to testosterone. I'd be tryin' the Wildcat .257s if I was twisted enough...mebbe later for that bore.

Wow, jwp, that should be one fine setup!

Dan, like XP said, Richard got yelled at a while back for providing computer-based estimates. Not because anybody actually tested and found them to be off, but because some people like to yell. So he decided to just stop and let people find out for themselves. My expectations aren't based upon anything he or anybody else has said, but my own experience and understanding of the physics behind it all.

DD,
Right now I am using a multi BC for the 7mm 200 WC, like Sierra does. I use Exbal on my home computer and on a pocket PC.
BC is listed as .825 @ 2700 fps, .8 @ 2300 fps, and .75 @ 0 fps.
My MV is 2706 with the 200 grain ULD RBBT Wildcat bullet. My MV is from 300+ fps slower than many guys using this, since I am shooting this bullet in a 7MM Dakota specialty pistol/Remington XP-100 (Center-grip). Guys using rifles with substantially higher MV's are using higher BC's to match their actual drops.
I have not shot this pistol past 1000 yards to date, but have shot it @ 600 yards on steel and paper the past four weeks.
When I was shooting @ 1k this past May my drops were matching the BC I listed above. It is really nice in the wind, and gives a field shooter (no access to flags) some fudge room @ 600 yards. All of my shooting has been off of a bi-pod and my 3-shot groups hover in the 3"-4" (some a little better some a litlte worse). I know that isn't anything special, but since I have been shooting without a spotter, I have been focusing on wind (watching the Kestrel) since my shooting locally has had some crazy wind lately South Central Kansas, and I have rushed some of my shots and have ended up with more vertical (3-4 inches) than I typically do @ 6. I am going to make sure my bi-pod/bag tension is consistent this week and set-up my Kestrel so I can see it without having to hold it.

Thanks for that, impressive performance indeed.

Jon, I just saw this data. Great info. Thanks for doing the test and sharing the results. I wonder if you have tested any of the Wildcat Bullets made by Richard Graves up in Alberta, Canada? Thanks, Rufous.

I haven't tested any for BC yet. I shot some 290 flat bases only shooting them out to 700 yds and they did well (and boy to they whack that gong hard!). But the 290 RBBT has proven too long for my 1:9 twist. There are several people getting 1:8.x twists as we speak for it...it's a beauty:



From left to right: 200 AB, 210 SMK, 240 SMK, 290 Wildcat RBBT ULD, 300 SMK (338 cal).

I should be testing some shorter 265's that should work in my 1:9 pretty soon. I'll likely be using a bonded version of that for elk next year.

I figured I should update this when I noticed Sierra has changed their ratings for the 210 SMK. They now rate it as:

.645 @ 1800 fps and above (Which means from the muzzle to about 1200 yds for me)

.630 between 1600 and 1800 fps
.600 between 1400 and 1600 fps
.530 @ 1400 fps and below

Compare their old rating (that made for the whacky curve above):

.620 @2500 fps and above
.575 between 2500 and 2200 fps
.490 between 2200 and 1950 fps
.425 between 1950 and 1700 fps
.375 @ 1700 fps and below

As you can see, this is a big improvement and if plotted on the graph above would come much closer to real drag curves (specifically the G5 and G7) than the whacky data they had before did.

So, they ended up a whopping .002 off from my data. And I don't even get paid for this stuff! But it's nice to see the change. I haven't yet tested myself, but have seen enough testimonials of this bullet (as well as the Berger 210 with very similar shape, etc) well beyond 1000 yds that show them doing very, very well.

However, I suspect the 208 A-Max is going to beat it by enough to make me lose interest in it. Maybe it's time for another drag race!

.002 huh? Man, that's really sloppy.