High Power Video Preview

[jeff59]

Here's a preview of the long awaited High Power high speed video. The turkey segments give the best view of the bullet trail. Pay close attention on the rams. There is a solid hit, several ringers, and a bullet passing through the hole between the head and the horn. The last hit shown on each of the rams is the one that took it down. The last chicken is Bob's 30-06 180 grain elk load.

Enjoy!

Jeff

High Power Video - High Def.

High Power Video - Std Def.

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[Trent]

Were you guys shooting a .223 at the rams or something?? They weren't even wiggling! Also, was there a shot through the ram horn hole? Nice capture! They certainly aren't as acrobatic as the Smallbore animals are they!

[Bob Mc Alice]

Trent, all of the rams fell with one shot except for three. The one at 1:28 was hit with a 150 MK by me. Must have been ice on the pads, yeah. I followed up on it with 175 Hornady Interlocks and yes, one went right through the hole. Jeff had one stand with two low chest shots with I believe Hornady GMX solids, it fell with the second hit. Not enough powder. The ram with three rapid showing hits were with 130 MK's fired by Jeff. The third one did the trick. Jeff cut out the actual falling due to it would take forever to view in slow motion. He has MUCH more video to review and will post more as he processes it. The ram that got hit in the center with that big splash was set at 300 meters and hit with a 180 Hornady Interlock pushed by 57.0grs. I4350. in that M 70 '06 stainless I have.

[DanDeMan]

Jeff,

Thanks for posting your videos, way cool. I'm sure you noticed the bullets' coning motion, also known as gyroscopic precession, in your videos. I'm interested in knowing what bullet was used and what the barrel's twist-rate is.

[Bob Mc Alice]

Dan, I had only two rifles with me. A 7-08 with a 26" Douglas #6 , nine twist. I fired only 150 MK and 175 Interlocks with it. The .30-06 was a stock M70 24" ten twist firing 180 Interlocks. Jeffs two 7-08's were stock 700's with 9.25 twist firing 139 Hornady spt. and GMX's.

Notice the absence of a gray dust cloud using GMX's on the ram hit twice at 1:42-45.

[jeff59]

Dan,

Bob's correct on my rifles, all stock Remington 700's with 9.25 twist. I had a grab bag of ammo along so there's no way he could keep track of what I was shooting at any moment. I do know that the nose hit on the pig at 0:45 was a 139 Hornady BTSP with 37.5 gr. Varget.

All of the ram hits starting at 1:39 were my regular CPT load, 130 MK's with 37.5 gr. Varget. The breeze came up while I was on the rams and I had 5 minutes left dialed in and was 17.5 minutes above my chicken zero. The combination of light bullet and the wind quartering from behind the target gave me 3 ringers on 5 hits.

Later, shooting offhand, I had two consecutive ringers on a ram using my old ram load of a 175 Hornady SP with 37.5 gr Varget. The third hit took it down but we figured it must have been frozen to the rail. The temp was something below 20 degrees and the gloves I wore setting targets had gotten wet and froze stiff when I took them off at the firing line to shoot.

Later when we weren't filming I fired several 139 GMX's out of my hunting gun and Bob remarked about the lack of a dust cloud on my hits. He said it was a bright flash instead of the normal dust cloud.

I think the "coning motion" you're seeing is distortion caused by either a shock wave or heat trail from the passage of the bullet through the air. When we started out I was filming from about 18" directly over the barrel and the distortion caused by the heat of the muzzle blast and the bullet trail almost obscured the target on several shots. I'll include a few examples in when I create the next set of videos. After resetting the targets we moved the camera about three feet to the side to minimize the distortion.

Jeff

[kevinbear]

Great video, I've always assumed that the reason the targets are so difficult to topple here in the winter is because of the reduced velocity from poor ignition in the case and the bullet haveing to travel through the colder much denser air.
BTW you guys are out of your minds shooting that day, brrrr........ what was it 17degrees with about the same wind speed.

[Bob Mc Alice]

17...nope. More like 12-14 but no wind, perfect shooting conditions. I was born in a snowbank and Jeff is from Minnesota, nuff said. I was out there again yesterday putting new belts in the Blue Mule, busted one Wed. Again nice but cold conditions. Fired another 100 rds. when I was done with the truck. A few of us are going out for some practice and more video on Monday. Come on out, and wear that camo abominable snowman suit Trent loves so much.

Oh yeah, when I put the animals back on the rail there was just enough snow melting on them from the sun hitting the black paint. They immediately froze in place to the rail, all of them. I lost numerous rams that ordinarily would have fallen.

[kevinbear]

Sounds good, I'll bring my 223.

[Trent]

Come on out, and wear that camo abominable snowman suit Trent loves so much. .

[DanDeMan]

Jeff,

The 139 GMX's should take rams quite well, no? I've wanted to try some solids with my 6BR, but have been concerned about ram damage. Did you notice any on the ram(s) you hit?

Once again, thanks much for doing the legwork and sharing your video's, they've been reviewed numerous times so far. I'm thinking there's a Casio camera in my future, what a great way to study bullets in flight. Do you think the Casio like yours it the best low-cost option for high-speed video?

Over the years I done a considerable amount of bullet stability testing using yaw cards as well as shooting though heavy, corrugated cardboard at distances from 10-to-1,000 yards to study bullet-hole shapes and estimate yaw angle at impact with the cardboard. I formulated a simple method to estimate yaw by measuring the minor and major axes of the oblong holes and then apply some high school trig, along with a caliper and bullet sample to estimate the bullet's yaw angle at impact. Another method used for HP rounds is to shoot through 60lb cardstock that is stapled to corrugated cardboard. When the cardstock is removed and the back of holes through the cardstock pressed back to the surface, one can often see that the small hole made by the bullet's meplat is not centered in the bullet hole. Again, a bit of trig, a caliper and bullet sample allows one to estimate yaw angle. A yaw angle over 2 degrees will substantially lower BC according to the American Ballistics Guru, the late Dr. Robert McCoy. Dr. McCoy was the chief ballistition at the US Army's Aberdeen Proving Grounds. His posthumously published book, Modern Exterior Ballistics, is the best book out there if wanting to get a handle on the subject.

http://www.amazon.com/Modern-Exterior-B ... 0764307207

Brian Litz, chief ballistition at Berger Bullets, has also done quite a bit of exterior ballistics testing as well as written numerous articles. Here's a link to an article on his web site that gets to the heart of what I think I see as your and Bob's bullets fly downrange. Watch the YouTube video at the bottom of the short article, it's quite interesting. There are a number of great articles on his site for those with the time and interest.

http://appliedballisticsllc.com/epswerve.html

I'm looking forward to your future videos.

[Bob Mc Alice]

I just knew you would post that again, Trent.

Now back on topic with questions. We were shooting RH twist barrels with approximately 2600 FPS bullet speeds. Using the formula to measure bullet RPM based on speed and twist the average bullet RPM was 208,000 (208K) for its entire flight. I read that average bullet temperatures reach 515 degrees F infrared measured 10 feet from the muzzle. The turkey shot at 1:16 clearly shows the "mirage trace" ?? corkscrewing in a RH motion. It even seems to show the bullet yawing but this is not happening at all. The air temp was around 15 F, the humidity was high by CO standards, about 30%. So what is this visual phenomena actually called? We see it frequently year around when spotting for shooters.

Crap..Dan, you were typing faster than I was thinking! I will post my thoughts anyway.

[kevinbear]

I think that might be vapor condensing around the bullet, not enough to actually form a trail but there none the less.

[DanDeMan]

Gents,

Years ago I was spotting for a friend at the Swiss Rifle Club just south of Gonzalez, CA. The HP rams are way up on the side of a mountain, the highest rams I've ever shot at. My buddy was shooting 190 SMK's at rams out of a 308, don't know the barrel's rate-of-twist. It was bright sunshine that day with no clouds. The sun was shinning from about 4 o'clock which allowed me to see the bullet in flight due to the glint off the back of the bullet. The most astonishing observations ever, when watching bullets fly downrange through a spotting scope, were made that day. As the bullets approached their trajectory apex, they started to corkscrew around the trajectory path with increasing and then decreasing amplitude. The bullets went back to "sleep" as the bullets descended from their apex into the rams. That totally blew my mind. Since the only forces acting on the bullets, while in flight, are angular momentum (spin induced momentum,) gravity and aerodynamic drag, that is some mighty strange goings on, no?


Below is a link to some pics of the Swiss Rifle Club. Click on Gallery to see the pics. You can see the HP rams way up on the side of the mountain from the firing line. Their Mother's Day and Father's Day HP silhouette matches are awesome. There is a huge feast that goes on after the match with several hundred members and friends in attendance. And, for you gambles they have dice and card games going on as well as an open bar.

http://www.theswissrifleclub.com/

[DanDeMan]

I think that might be vapor condensing around the bullet, not enough to actually form a trail but there none the less.

KB,

It's the shock wave created by air compression from nose drag, just like the bow wake of a boat. Since the air in the shock wave is compressed and therefore denser than the surrounding air, it refracts the sunlight differently so we can see it.