What topics in ballistics would you like to see explored?

[Bryan Litz Ballistics]

I'm taking suggestions for research topics that we can explore and publish. Primarily the intent is to identify some content for the next volume of the 'Modern Advancements in Long Range Shooting' series. Any suggestions can be considered even beyond the scope of that series though.

Here's some content that's planned for the next volume, to give you an idea of what we're doing:
Exploring dispersion: 1 MOA groups at 100 yards and 1/2 MOA groups at 200...?
Rimfire ballistics: MV and BC test results for many common rimfire types out of various length and twist barrels
Pointing and trimming bullets: Effects on uniformity and magnitude of BC
...

If you have an idea for a test that you'd always like to see done, please reply to this thread with ideas. We always try to do relevant work meaning topics shooters are most interested in, no better way to do that than taking input directly from the shooters.

Thanks!

-Bryan

 

[Cochran]

Hornady bullet tips melting. Should I trust them or sell them ?

 

[Bryan Litz Ballistics]

I've got a box of each on order from Midway right now.

 

[jrm850]

I always wondered if different rifling profiles affected drag.

 

[Bryan Litz Ballistics]

I always wondered if different rifling profiles affected drag.

jrm,

This topic is covered in the first volume of Modern Advancements: https://store.appliedballisticsllc.com/ProductDetails.asp?ProductCode=0004

The short answer is that; thru supersonic speed, rifling profile has very little affect on drag/BC. However, different rifling profiles can affect the rate of RPM (spin rate) decay the bullet experiences. When the bullet slows to transonic speed where stability is challenged, the retained RPM's affects the bullets stability, and alter the bullets 'effective' drag/BC indirectly thru stability. The topic is fleshed out in several chapters in the book that's linked above if you're interested in greater detail.

-Bryan

 

[Nvreloader]

Bryan

The Rimfire ballistics testing would be very interesting and helpful,
as the LR shooting out to 5-600yds is quite challenging, I am finding out,
and which twist would work the best etc.

Thank you,
Don

 

[Roslyn]

Barrel tuning might be of interest. How to assess the harmonics of a barrel relative to load and bullet. This may be of more interest to rimfire than high power shooting, but evidently F Class shooters have improved their groups using tuners even for hand loads.

 

[chkunz]

I am not sure if this topic fits what you had in mind but I would like to see more on using statistical analysis to evaluate data (is load A better than load B? or I made this change and it appears to be an improvement but is it statistically significant?). There was a time when folks like Creighton Audette and Bill Davis helped us with this type of analysis but I do not see much on this subject these days. I do see a lot of folks that appear to be making decisions on data that would have a low statistical confidence level if it were analyzed properly.

 

[broncman]

Bullet ogive angles vs throat/lead angles!
Idea lead angle for each ogive design and how or if it effects accuracy.

 

[Gabe22BR]

I hope the 1-9 twist barrel (for the 60SSgr.) is used in there as well for all the different wt. bullets.
Seems a 1-14" twist was the standard for the 223, back when, now it's a 1-9 to 1-7" twist.
Would be nice to see if a 1-9" twist would be to the old standard 1-16" twist....

 

[JPeelen]

There is a definite lack of measured drift data due to bullet spin, as far as I can tell.

My proposal is to revive the old, proven testing method: using 2 barrels with right and left hand rifling. Choose a caliber for which a lot of different bullet types are available.

Test as many bullet types as possible, so we learn more about the interdependence of bullet stability and drift.
Some believe that straight base bullet are actually more stable than Miller's stability formula suggests. Perhaps we can get some insight into this also.

 

[m500]

More on how plastic tips effect or don't effect SG.

 

[CH Luke]

+1 on tipping and trimming.
Would also like to see you take your scientific approach to the topic of handloading for F-class (specifically 308 from an entirely selfish perspective) from soup to nuts. What works and what not so much.
Some of your posts here have been very influential in my loading strategies, plans, purchases and budgeting. Recent examples include your recommendation on the 200 Hybrid or pointing out typical free bore ranges and expected velocities for 185 Juggs.
Now I may be in the minority here but frankly I have no problem with paying for this kind of work put in to book form. Probably many here that agree with that thinking. After all, not many of us here do this for a living and we need to support those that contribute like this.
From there I could even see you working with Clare and his friends on a curriculum (since you're in their neighborhood so much). Could help them bring in more Fclass enthusiast members so I don't have to bring my own pullers all the way up there.

 

[ShaunBrady]

+2 on tipping and trimming. Beyond is it good or bad, when and where to do it. Maybe some simple equations, typical values, and boundary's so the reader could judge for themselves whether it was worth it for their specific application and box of bullets.

More on transitioning would also be appreciated. Maybe more specifics and diagnostics. Shooters are attempting longer and longer distances with better and better equipment. The end game is going to require making it to the other side of the transonic.

Anything on extended long range shooting. Even just a case study or two with optic travel as the limiting factor, similar to the magazine length discussions in your books.

 

[X-Caveman]

How about some facts about hummer barrel & load? How do some seem to cheat the wind, not only better than others, but better than the external ballistics suggest they should? It doesn't make much sense to me, but I'm 95% sure I've seen it.

 

[6BRinNZ]

Bullet sorting - probably the most argued about piece of reloading, but not a single mv or set of groups to substantiate. What steps, are the largest influencers - weight, tipping, base to ogive sorting etc. The most asked question (IMO) is what tolerance to use.

 

[savagedasher]

I would like to see what effect if any does true in internal case volume have when shooting both short and long range. Thanks Larry

 

[Bryan Litz Ballistics]

Thanks for all the input guys!

I'll turn some focus to these internal ballistics/handloading topics. Barrel harmonics is something I've never given much thought to beyond: use heavy barrels for accurate rifles. I'm aware of some high level analysis that's been done on the topic by Varmint Al: http://www.varmintal.com/amode.htm
I'll have to re-read his work and see if there's anything I can add or elaborate on.

As for bullet treatments, there's a very thorough test being conducted right now which aims to quantify the effects of pointing, trimming, and pointing-and-trimming bullet tips on BC uniformity and magnitude. This work will be published in Volume 2.

Another test that's been suggested on this thread is real world wind deflection. It's difficult to determine wind deflection as a function of actual wind speed because it's difficult to measure true wind speed all along the trajectory with reliable accuracy. However it is much more do-able to measure relative wind deflection by firing multiple rifles at the same time and comparing their relative wind deflection to each other. This is a very practical (and fun!) test which is only limited by the number of shooters and target pullers available (rifles are not a limiting factor ). I'll get this going for the next volume for sure. Thanks.

JPeelen; we have conducted live 'drift firings', just as you described, to determine spin drift for several bullets. This work was published in Volume 1 of "Modern Advancements in Long Range Shooting".

Thanks to everyone for their suggestions. Your input will help guide our future research projects.

-Bryan

 

[aussiepowderburner]

Hi Bryan
1. Gain twist rifling ? Benefit or not? Amount of gain twist required with regard to BC and velocity?
2. Barrel harmonics / accuracy possible compared with various barrel length?
EG 28" v 30" v 32"?
Cheers
APB

 

[SHootSTraight22]

I would like to see a book dedicated to terminal ballistics.. I'm sure many hunters and others would as well.. Have plenty of wound tracks from different bullet makes and models.. (VLD vs. Standard,, Bonded vs non,, 100% lead vs lead alloy,, brand x vs. brand y..) The best write up I've ever seen is the "Shooting Holes in Wounded Theory", search "The Mechanics of Terminal Ballistics" for examples of wound tracks... Thanks