Win 308 Aerospike Data

[HappyHellfire]

I really don't want to limit aerospike bullets to only new rifles with faster twist rates. I've been working on a Win 308 design for years and I think I finally got it. Here is the data from the range today. I included the current 30 caliber aerospike that is only stable from a 300 Blackout with a high twist. The Blackout design with a more aggressive aerospike tail has lower drag but the Win 308 aerospike is still pretty stinking good. Remember, unlike BC, lower drag (Cd) is better.



I'm still waiting on some feedback from the accuracy testing but I can't help playing with these things. Assuming that this same drag curve would be similar to a 30-06, 243, 270, and other older rifles, would y'all be interested in this design?

 

[Jerry Wick]

With all due respect, regarding your info, you always refer to Mach for bullet velocity. You'll find that everyone on this forum, and in the firearms industry in general, uses feet per second(FPS). Your info would be much more easily understood for us common folk if you adopted this unit of measure.

 

[Evan]

I’m curious what the drop or retained velocity looks like at a distance. If you post a sample trajectory with velocities, that’s going to mean a lot more to me, and I suspect many others too.

The 168 SMK is a really old design that doesn’t compare well to modern bullets, so that makes it hard to compare as well.

 

[B y r o n]

You state; "It has taken over 20 years since the first concept to finally translate the Aerospike Bullet idea into a proven, tested product." Can you point me and everyone else to where this is actually proven?

 

[HappyHellfire]

With all due respect, regarding your info, you always refer to Mach for bullet velocity. You'll find that everyone on this forum, and in the firearms industry in general, uses feet per second(FPS). Your info would be much more easily understood for us common folk if you adopted this unit of measure.

That's the aerospace engineer in me. I have been playing with drag curves so long it looks weird not to have them in Mach. Just multiply the Mach by 1125 to put it into fps.

 

[HappyHellfire]

I’m curious what the drop or retained velocity looks like at a distance. If you post a sample trajectory with velocities, that’s going to mean a lot more to me, and I suspect many others too.

The 168 SMK is a really old design that doesn’t compare well to modern bullets, so that makes it hard to compare as well.

I'll drop the drag curve into a simulation tomorrow and post those results.

I know the Sierra 168 BTHP is an older bullet but it is also the most studied bullet in the world and the aero data for it is published. If other bullet makers would post their drag curves I would use those.

 

[HappyHellfire]

You state; "It has taken over 20 years since the first concept to finally translate the Aerospike Bullet idea into a proven, tested product." Can you point me and everyone else to where this is actually proven?

I am publishing the results in "Defense Technology" and will be presenting them at the next International Ballistic Symposium next May.

I caught a bunch of crap for claiming testing on this forum. I have done what we call "projectile characterization" testing to find out how they fly. What y'all do is mostly "accuracy testing" which includes the gun, the load, and the shooter. I do have a few guys doing some accuracy testing for me. I think they will post the results on this forum.

 

[B y r o n]

I am publishing the results in "Defense Technology" and will be presenting them at the next International Ballistic Symposium next May.

I caught a bunch of crap for claiming testing on this forum. I have done what we call "projectile characterization" testing to find out how they fly. What y'all do is mostly "accuracy testing" which includes the gun, the load, and the shooter. I do have a few guys doing some accuracy testing for me. I think they will post the results on this forum.

So what you are saying is that the data supporting your claims will not be made public until next May. Guess I'll check back then.

 

[HappyHellfire]

So what you are saying is that the data supporting your claims will not be made public until next May. Guess I'll check back then.

No worries. I'm literally showing the data as I collect it. More data than you have probably ever seen from another bullet company.

Hopefully I'll have lead core in a couple of years and plenty of word of mouth. You can jump on board then. For the adventurous, I dropped the prices to try to attract more people to experiment with them.

 

[762willdo]

“A better mouse trap”……….

 

[HappyHellfire]

“A better mouse trap”……….

I prefer to think of it as "developing the math to design a bullet base for maximum performance" but sure, we'll call it a better mouse trap.

 

[HappyHellfire]

I’m curious what the drop or retained velocity looks like at a distance. If you post a sample trajectory with velocities, that’s going to mean a lot more to me, and I suspect many others too.

The 168 SMK is a really old design that doesn’t compare well to modern bullets, so that makes it hard to compare as well.

Here is the rough range table that I calculated using that drag curve. Notice it stays supersonic till 1000 yards. I think I like this design. The bullet is 149 grains.

TOF	RANGE (yards)	DROP (inches)	Velocity (fps)	Impact Energy (ft-lbs)
0.00	0	0	2900	2783
0.11	102	5	2669	2356
0.23	204	5	2445	1978
0.36	305	-1	2233	1649
0.50	405	-14	2036	1371
0.65	502	-34	1857	1140
0.82	602	-66	1685	940
1.01	704	-110	1524	768
1.21	800	-166	1381	631
1.44	901	-243	1249	516
1.69	1000	-342	1142	431

 

[Evan]

Here is the rough range table that I calculated using that drag curve. Notice it stays supersonic till 1000 yards. I think I like this design.

TOF	RANGE (yards)	DROP (inches)	Velocity (fps)	Impact Energy (ft-lbs)
0.00	0	0	2900	2783
0.11	102	5	2669	2356
0.23	204	5	2445	1978
0.36	305	-1	2233	1649
0.50	405	-14	2036	1371
0.65	502	-34	1857	1140
0.82	602	-66	1685	940
1.01	704	-110	1524	768
1.21	800	-166	1381	631
1.44	901	-243	1249	516
1.69	1000	-342	1142	431

How do you think this bullet design will handle the transition through the mach 1 region? It would be a real advantage if your bullet could pass through the transonic region and remain stable and predictable after.

 

[HappyHellfire]

How do you think this bullet design will handle the transition through the mach 1 region? It would be a real advantage if your bullet could pass through the transonic region and remain stable and predictable after.

I think it will remain stable. The drag is directly related to the overturning moment that causes instability. The spike in drag at transonic causes most bullets to go unstable. The aerospike drastically lowers the transonic drag.

That being said, the only way to know is to test.

 

[D-4297]

Twenty-eight and a half feet in drop at 1,000 yards ? And just barely still supersonic ? Where is the improvement over bullets we are shooting now . And where did you find any 168's that would stay stable enough to reach the Target at a Grand ? We sure as Hell didn't have any in Nam !

 

[Evan]

Here is the rough range table that I calculated using that drag curve. Notice it stays supersonic till 1000 yards. I think I like this design. The bullet is 149 grains.

TOF	RANGE (yards)	DROP (inches)	Velocity (fps)	Impact Energy (ft-lbs)
0.00	0	0	2900	2783
0.11	102	5	2669	2356
0.23	204	5	2445	1978
0.36	305	-1	2233	1649
0.50	405	-14	2036	1371
0.65	502	-34	1857	1140
0.82	602	-66	1685	940
1.01	704	-110	1524	768
1.21	800	-166	1381	631
1.44	901	-243	1249	516
1.69	1000	-342	1142	431

I wanted to circle back around to this now that I've thought about it some. Your bullet weight is probably best suited to go after Palma shooters, which are limited to 155gn 30 cal bullets. Pretty much every bullet maker has a 155gn match bullet to scoop up some of this admittedly small and niche market. Using the JBM calculator, with sea level std. atmosphere conditions, your drop, speed, and TOF are all pretty much right on a 155gn Sierra Matchking shot at the same speed. The 155 Lapua Scenar manages only -333 inches of drop and the Berger 155 Hybrid is flatter still with only -321 inches of drop. So the question becomes: can your bullet be driven harder without unmanageable pressure spikes? If your bullet, with largely similar 1000yd performance at the same speed, can be driven 100fps faster without poor accuracy, spikey pressure, or other uncontrollable aspects, then it might get some traction with Palma shooters in it's current configuration.

Other forms of competition like Benchrest or F-Class will put you in comparison with bullets that have far less drag and far more weight than your 149gn bullet. The FTR competition "standard" Berger 200.20X, for example, shot at only 2650fps from a 308, gets to 1000yds with only -331 inches of drop. A Berger 210VLD, shot at 2950fps from a 300 WSM in Benchrest, gets to 1000 yards only dropping -260 inches. I just don't think your current bullet will compete in these arenas without showing significantly more performance than you are claiming, or unusual consistency and accuracy for shooters to afford it the reduced ballistic performance.

 

[WSnyder]

Here is the rough range table that I calculated using that drag curve. Notice it stays supersonic till 1000 yards. I think I like this design. The bullet is 149 grains.

Can you add some wind numbers?

BTW if I see your chart correctly it is zeroed at 0yds and does not take into account a sight height so sight height would be zero as well? Your chart is just bullet drop looking straight down the bore and looks at the drop from there? FWIW most of us are used to looking at charts with a 100yd zero and some sort of elevated sight height like 1.5” above the bore. 1.5” is a close default for optically sighted rifles and moving off of that slightly doesn’t change things much.

A Berger 30 cal 155 VLD at 2900mv has a drop of 354” @ 1K yds with a wind deflection of 87” @ 1Kyds and a 10 mph wind with a 1yd zero and a 0” sight height. I think that’s comparing to your bullet (chart) close to the same, correct??? Shooter doesn’t like a 0yd sight in range and nulls out the wind when doing that so this is a 1yd zero. The 155 VLD is still 1330fps @ 1K.