Calculation of Bullet Drop/ Various Models

[dellet]

Quick side question. I've had several people ask about a 5.56 aerospike. I have designs for one but I need a 1:7 bolt action to test it. I've had serval mishaps with AR style and it is just safer to develop prototypes with a bolt action. The only one I can find is a Savage precision for like $2,500. Does anyone else make a 1:7 bolt action or single shot 5.56/.223 for cheaper?

I didn't know that people even reloaded them.

This actually a bit scary. It more or less confirms all the jokes about engineers and designers being out of touch with the actual use of the product. Probably on the top 3 of market share.

The CZ 600 series offers a 1/7 twist and are available under $600

CZ 600 Alpha - CZ-USA

The Alpha was designed as the rifle that can do it all. Versatile, durable, and reliable, the Alpha is guaranteed to get it done in sub-MOA style.

cz-usa.com

 

[HappyHellfire]

I have plenty of H4895, but I don’t have any IMR4895; I know they are not the same but the are very close on the burn chart. Also, the two powders you selected are quite far apart on the burn chart (IMR4895 and Win 760), there are lots of more common long range powders between those two that you may want to explore (RL15, 15.5, Varget, 203B, N140, N150, and H380).
Dave

Holy crap. It's Win 748! Typo. I'll change it immediately.

 

[Dave M.]

Holy crap. It's Win 748! Typo. I'll change it

Holy crap. It's Win 748! Typo. I'll change it immediately.

I plan to use either RL-15, varget, N140 or H4895. H4895 is the fastest of the bunch and might be more suitable for your light weight 107g bullets.
Dave

 

[HappyHellfire]

I plan to use either RL-15, varget, N140 or H4895. H4895 is the fastest of the bunch and might be more suitable for your light weight 107g bullets.
Dave

I just picked up a box of sierra 107 6.5 mm for a comparison test. Maybe have some data by Wednesday. It'll all be short range radar data.

 

[WSnyder]

Hornady 4dof sounds like a good idea

It’ll work fine with their bullets but will lead you astray with other manufacturers.

 

[Thauglor]

Quick side question. I've had several people ask about a 5.56 aerospike. I have designs for one but I need a 1:7 bolt action to test it. I've had serval mishaps with AR style and it is just safer to develop prototypes with a bolt action. The only one I can find is a Savage precision for like $2,500. Does anyone else make a 1:7 bolt action or single shot 5.56/.223 for cheaper?

I didn't know that people even reloaded them.

The cz600 alpha is a 1 in 7 twist with s $500 to 600 price tag

 

[WSnyder]

Knowing the method your calculator uses will help you know the approximations that it is making.

Even though I can be the most technical and anal guy in the group I have learned to spend my time a bit more wisely worrying about things that might matter more. I for one do not care what method my solver is using as long as it is accurate and provides good numbers in the field I just don’t care.

I mainly use Shooter in the field. It’s simple. I leave coriolis compensation off. I’ll input density altitude as conditions change.

I also use Ballistic AE but have gravitated to Shooter more because of the simpler interface and simpler is better out in the field.

I also have GeoBallistics but haven’t done much with it.

Btw The Shooter app uses Applied Ballistics as the ballistic engine.

 

[Thauglor]

Is this chart on your data sheet for your load??
View attachment 1566454

Just putting a lapua scenar 108 with Dr. Litz's bc, it is ending up at 1160 fps and 329 ft-lbs at 1000 yards, disproving that 40% improvement in range happyhellfire claimed in his other thread. Just proves that his claims are BS

 

[WSnyder]

I've never read anything about the impact use of an ( example ) 20moa scope base has on the amount of scope clicks needed to adjust elevation for the desired zero.

When using such a base, scope' centerline is a certain height @ one end of the scope; and a different height @ the other end. In such instances... what scope height input would / should be made to a external ballistics calculator ?

Is there some sort of compensating equation, or special algorithm et al that needs to be applied in such cases ?

It strikes me that one might apply too many clicks of elevation when using an ( example )
20moa scope base; across certain distances....if / when applying calculated amount of elevation based on use of a constant scope centerline-derived data ?

No, in the practical world it’s not needed. Input the average dimension at the center of the turrets and you’ll be fine. To prove this out change the dimension from min to max for your rail and look at the outputs. The drop distance change at say 1K yds is minuscule even with a .050” change in sight height. In the real world you couldn’t shoot the difference let alone even see it.

 

[Just Say Moe]

Looks like someone else is working on it also. With penetration tests..... still in development...from 2018

Aerospike Ammunition Technology

 

[WSnyder]

Looks like someone else is working on it also. With penetration tests..... still in development...from 2018
Aerospike Ammunition Technology

They’re working on the front end. Now maybe if they got together and combined the tech we could get a “Super Bullet” that’d make everything else obsolete?

Seriously though a mechanical device at the front of the bullet looks like it would be hard to deploy consistently. I wonder what the mechanism is? Edit: The patent is right there on the homepage. If the expansion is what they say then it helps it as a hunting bullet.

 

[Dave M.]

Even though I can be the most technical and anal guy in the group I have learned to spend my time a bit more wisely worrying about things that might matter more. I for one do not care what method my solver is using as long as it is accurate and provides good numbers in the field I just don’t care.

I mainly use Shooter in the field. It’s simple. I leave coriolis compensation off. I’ll input density altitude as conditions change.

I also use Ballistic AE but have gravitated to Shooter more because of the simpler interface and simpler is better out in the field.

I also have GeoBallistics but haven’t done much with it.

Btw The Shooter app uses Applied Ballistics as the ballistic engine.

Is the shooter app available for I phone?

 

[Dave M.]

Just putting a lapua scenar 108 with Dr. Litz's bc, it is ending up at 1160 fps and 329 ft-lbs at 1000 yards, disproving that 40% improvement in range happyhellfire claimed in his other thread. Just proves that his claims are BS

I just compared his drop chart (shown below) to a 6.5CM using the 100g nosler ballistic tip (chart from Ballistic AE shown below) and they seem to compare at almost every distance from 500 yards through 1000 yards, with almost no appreciable difference at any of the distances.

 

[WSnyder]

Is the shooter app available for I phone?

Yes, I use it on Apple/iOS

 

[Dave M.]

Looks like someone else is working on it also. With penetration tests..... still in development...from 2018

Aerospike Ammunition Technology

View attachment 1566479

Dr. John, how did you get left off this patent? And how do you guys both have the same name for your bullets??? AeroSpike???
Dave

 

[HappyHellfire]

Dr. John, how did you get left off this patent? And how do you guys both have the same name for your bullets??? AeroSpike???
Dave

So there are two different things called aerospikes. The oldest is the inverted rocket nozzle. The other is a stick that pops out of a missile nosecone to detach the shockwave. It is a shame that the two will get confused but I am willing to bet (and I have) that the base shape will catch on faster than a bullet with moving parts.

 

[HappyHellfire]

I just compared his drop chart (shown below) to a 6.5CM using the 100g nosler ballistic tip (chart from Ballistic AE shown below) and they seem to compare at almost every distance from 500 yards through 1000 yards, with almost no appreciable difference at any of the distances.
View attachment 1566485
View attachment 1566486

Notice that we have the same velocity at 500 yards but by 1000 yards mine is 1086 ft/sec and the other is 989 ft/sec. The aerospike doesn't engage until it reaches the design point. My current design is to engage at Mach 1.6. Above about Mach 1.8 it flies like a normal bullet. When the aerospike engages at the correct Mach number it dramatically reduces the drag.

Also look at the lag time improvement. The TOF in a vacuum is about 1 second to 1000 yards. The lag time for the nosler is 0.8 sec. Mine is 0.72. That is a 10% reduction in lag time which is equal to a 10% reduction in cross wind error. I would think a competitive shooter would be interested in that.

I have more designs that engage at higher Mach numbers but I wanted to hit the market with a minor improvement that still looks and flies like a regular bullet with just a bit of improvement. If y'all find the bullet of equal accuracy to existing then the minor improvement will be worth it.

 

[WSnyder]

which is equal to a 10% reduction in cross wind error.

That right there would be great for the future if you ever get anything together that works for hunting.

With laser rangefinder’s/known distances I don’t care so much about drop, wind is where it’s at in the field.

 

[Thauglor]

Here is your 100gr bullet and a 108gr scenar. What is the actual BC or your bullet so we can compare wind effects? And how come we dont see the 40% improvement in range you claim?

 

[dellet]

Here is your 100gr bullet and a 108gr scenar. What is the actual BC or your bullet so we can compare wind effects? And how come we dont see the 40% improvement in range you claim?

View attachment 1566570
View attachment 1566571

You might want to change your zero to 300 yards.