Ballistics by the inch (*WOW*)

[strangenh]

Chronograph data for 16 calibers out of barrel lengths from 2" to 18" all performed by one test team. They even use multiple commercial loads for the tests and also a few commercial firearms per test.

Just amazing data.

http://www.ballisticsbytheinch.com/

 

[EddieCoyle]

Awesome! Great find. Rep points inbound.

 

[bpm990d]

Interesting. There is nothing like hard data.
Thanks for posting.

B

 

[Admin]

This shirt is awesome...

 

[KMM696]

This shirt is awesome...

And still available.....

XKCD Store

 

[strangenh]

The recent discussions on here about higher-power pistol-cal carbines sent me looking for data on the benefit of barrel length for various cartridges (esp. the 357Sig) and, bam (after an hour of searching... ), there it was. That site is just a big pile of awesome.

It's really interesting to note where some rounds stop benefiting from more barrel length - and where some start to SLOW from too much barrel. For example, it's interesting that some of the commercial 357Sig loads seemed to have a hiccup going from 5" to a 6" barrel, then start to speed up again. Obviously very load-dependent as I've read competitive 357Sig shooters report speed increases in DoubleTap and also in their own custom loads when going from 5 to 6" bbl.

Really, so much data there...

 

[richc]

As I shoot a lot of 9mm I was interested in where you get the biggest bang for the buck. Here's a chart of the 9mm data. Looks like the chart starts leveling off at around a 5" barrel.

Cheers,

Rich

 

[terraformer]

My only issue is they didn't test Federal HSTs. But other than that, interesting info. It would be the balls to see a rifle cartridge version of these tests from 16" to 24".

 

[NHAtHeart]

My only issue is they didn't test Federal HSTs. But other than that, interesting info. It would be the balls to see a rifle cartridge version of these tests from 16" to 24".

Yeah I was thinking that too, from some of the .22 cals up to the .338's at least would be pretty neat, some hard data to help select barrel length for your .308 or .223 AR

 

[Jim Downey]

Hi guys - saw we got a sudden upsurge from this site, so I thought I would register and say howdy. I'm the guy holding the T-shirt there (we got 'em for all the guys on the team).

Glad you like the site - our project has had a good first year, and if you'd like some glimpse of what we are planning for the future, take a look here: http://ballisticsbytheinch.wordpress.com/2009/11/27/what-a-long-strange-year-its-been/

Anyway, I won't clog up your forum - just wanted to drop in and be neighborly.

Cheers to one and all -

Jim D.

 

[Admin]

Good to see you join up Jim, welcome.

 

[Jim Downey]

Thank you, sir! Looks like a nice place y'all have here. One of the fun things about doing our project has been getting some exposure to some of the regional forums, getting a sense of what more local issues are on people's minds (you don't always get that in the bigger global forums).

Anyway, I probably won't be around a whole lot, but I am always happy to answer questions if someone wants to drop me an email, and I'll definitely drop in from time to time.

Jim D.

[email protected]

 

[kingfisher]

Welcome to NES, Jim, and thanks a lot for sharing your data. I did some chrono testing a couple of weeks ago, and in one combination of ammo and barrel length there’s a good basis for comparison with what you did. As I’d expect, our results are very similar.

I’ll keep an eye on your blog for results of your upcoming Cylinder Gap Test, and I’m also very interested in the results of any muzzle flash and “felt recoil” testing you do. Keep up the good work!

 

[Monadnock]

Yes ...as mentioned, great data.

And thank you for taking the time to handle the details, like actively linking the firearms to a "real-world firearms" page, and then a-linking those individual firearms to manufacturer's pages (when possible).

It's details like that that make a site easy and enjoyable to navigate.

 

[matt]

would that the climatologists espousing global warming were so thorough and open with their data!

 

[bpm990d]

Yeah I was thinking that too, from some of the .22 cals up to the .338's at least would be pretty neat, some hard data to help select barrel length for your .308 or .223 AR

This has been done. For 7.62 and 5.56 use ~25 fps/inch.

For example a M4 has a 14.5 inch barrel and a M-16A4 has a 20 inch. The difference in published velocity (FM 3-22.9) is 130 fps. It works out to 23.6 fps/inch.

B

 

[terraformer]

This has been done. For 7.62 and 5.56 use ~25 fps/inch.

For example a M4 has a 14.5 inch barrel and a M-16A4 has a 20 inch. The difference in published velocity (FM 3-22.9) is 130 fps. It works out to 23.6 fps/inch.

B

The data at that site clearly shows there is not a linear relationship to length and velocity so no, I suspect that those rules of thumb don't relate well over the range of sizes in between.

 

[bpm990d]

I didn't say it was linear. the "~" means approximately.

B

 

[Jim Downey]

Hey, thanks for the good wishes, everyone. Kingfisher, I'm glad to hear that you came up with similar values in your test. That's one thing that was our goal: setting it up so that the data could be tested and reproduced by anyone following similar protocols. Science, baby, science!

terraformer, that's one of the myths we pretty clearly debunked with our tests, as well - *where* you are in barrel length makes a very big difference. But still, I constantly hear from people "oh, the rule of thumb is . . ."

Jim D.

 

[bpm990d]

From Mike Lau's The Military and Police Sniper for the 7.62 with barrel lengths from 16" to 26".

 

[MassMark]

Jim - Welcome aboard

Trust me - you're not clogging up the site in the least. We have car starter threads for that... Anything you post will be welcome and appreciated...