View Full Version : Terminal balistics for a 10.5" barrel
I've been reading the fragmentation articles elsewhere on the site. That article compared fragmentation of various loads out of 20", 16" andd 14.5 " barrels.
Check it out here: http://www.ar15.com/content/page.html?id=173
What about a 10.5" barrel. Is it too short to reliably get frangmentation with commons loads?
Check it out here: http://www.ar15.com/content/page.html?id=173]
:-(
There is your problems right there...
Do a search on this board there is a good thread on just what you are asking about.
edit
I dug it up.
http://m4carbine.net/showthread.php?t=7154
There is your problems right there...
Do a search on this board there is a good thread on just what you are asking about.
edit
I dug it up.
http://m4carbine.net/showthread.php?t=7154
Thanks Colt6920. That thread really doesn't address my question. It was more about killing people at certain distances.
I'm looking for technical data.
If the other thread doesn't answer your question, and the link you posted to the fragmentation chart on TOS doesn't help you, I think you're going to need to restate your question. While neither gives you an exact "fragmentation will happen out to exactly 51.7 yards with M193 ammo", there is enough information at those other links to figure out (A) approximate fragmentation range for each type of ammo and (B) that there isn't much value in knowing an exact fragmentation range.
If the other thread doesn't answer your question, and the link you posted to the fragmentation chart on TOS doesn't help you, I think you're going to need to restate your question. While neither gives you an exact "fragmentation will happen out to exactly 51.7 yards with M193 ammo", there is enough information at those other links to figure out (A) approximate fragmentation range for each type of ammo and (B) that there isn't much value in knowing an exact fragmentation range.
I'm simply wondering if that data is available. If it doesn't exist, then so be it.
I'm unsure why you're giving me flack for asking a question :confused:
So then what you're looking for is the exact distance at which ammo from a 10.5" barrel will reliably fragment? Do you understand that this is an incomplete question? You should have been able to tell from the link you posted that fragmentation range is dependent on bullet type as well as barrel length.
Perhaps your question should have been "do charts exactly like those in this link exist for 105" barrels?"
If I'm giving you "flack", which I don't think I am, it's because you don't sound like you understand the issue of fragmentation well enough to understand the answer even if someone gave it to you, and even if you did I'm not sure what you think that information would be good for.
This may help as well, if you haven't already read it
http://www.ammo-oracle.com/body.htm#sbr
As a very, very, very basic rule of thumb, subtract 150-175 fps from the 14.5" velocity to get the 10.5" velocity.
So then what you're looking for is the exact distance at which ammo from a 10.5" barrel will reliably fragment? Do you understand that this is an incomplete question? You should have been able to tell from the link you posted that fragmentation range is dependent on bullet type as well as barrel length.
Perhaps your question should have been "do charts exactly like those in this link exist for 105" barrels?"
If I'm giving you "flack", which I don't think I am, it's because you don't sound like you understand the issue of fragmentation well enough to understand the answer even if someone gave it to you, and even if you did I'm not sure what you think that information would be good for.
Rob - yes, I am looking for information similar to the data in the linked chart about fragmention of common rounds out of a 10.5" barrel.
Sorry if I didn't ask the question in more precise manner. I am planning on buying a SBR and am interested in this data.
However, the tone of your post is very condescending (e.g. "you don't sound like you understand the issue of fragmentation well enough to understand the answer even if someone gave it to you"). It's a simple and valid question. If you have the information, then please share it. If you don't, then surely have have something better to do then be rude to me.
I gave you a rough way to calculate it, but what you keep ignoring is that the sources you've found tend to agree; using a 10.5" barrel rifle and expecting fragmentation is (depending on ammo) a fruitless endeavor. It's like pissing on the sun and expecting it to go out. With your typical M193 (since you still haven't said what ammo you're interested in) you're not likely to be at fragmentation velocity out of a 10.5" barrel even at the muzzle.
If I was "rude", it is because your question seems to be the equivalent of "how long do I have to piss on the sun in order to put it out?", and everywhere you've looked so far you've found the same answer.
In other words, you're doing it wrong. You don't pick a tool and then ask "what is this good for?", you figure out what you want to do and select the appropriate tool. To continue with the sun analogy, the question would be "what do I need to do in order to put out the sun?"
For example, I wanted a gun that, with a suppressor attached, was shorter than my 16" barrel carbine and only needed an effective fragmentation range with my selected defensive ammo (Black Hills 75 grain) of under 50 yards. So I had a JOB that now I could go out and find the proper TOOL for.
If I was "rude", it is because your question seems to be the equivalent of "how long do I have to piss on the sun in order to put it out?", and everywhere you've looked so far you've found the same answer.
What?? That makes no sense.
All I am saying is that I'm considering buying a SBR. I'm looking for data similar to the linked chart in order to get as much data as I can before I decide to buy or not.
You have no entitlement to be rude.
I'm not being rude, I'm only explaining that your question doesn't make any sense and that you're doing things ass-backwards.
I'm done. This is like trying to pound in a nail with a drill press.
I'm not being rude, I'm only explaining that your question doesn't make any sense and that you're doing things ass-backwards.
Once again, all I'm asking is if there's technical data for a 10.5" barrel similar to the linked chart.
I'm unsure how that's ass-backwards. I guess "Senior" status entitles you to be condensending to people you don't know behind the safety of the internet.
http://www.hunt101.com/img/517604.jpg (http://www.hunt101.com/?p=517604&c=500&z=1)
I realize that you are looking for specific technical information on a technical forum and that you are getting non-technical answers that aren't helping you. Rob is just trying to go deeper into why you might be concerned with the information and obviously you aren't concerned with what he has to say (and he does come off as abrasive, but I think it's just part of his online persona, so don't take it the wrong way).
If you really want the information, here's a quick way to get it:
1: Select your ammo, try several different weights and makes, don't rule out lightweight varmit rounds.
2: Chrono that ammo in YOUR barrel, every barrel is different.
3: Use the chrono data for your ammo to compare the threshold velocities listed in the chart for other barrel lengths.
4: Enter your chrono data into a ballistics calculator and it will tell you at what distance (if any) your selected ammo will fall below the fragmentation threshold.
Realize also that many factors come into play when discussing fragmentation, such as penetration, bullet consistency, ammo consistency, shot placement, target size, etc., so any information that you do get will just be an idea of when the bullet will PROBABLY fragment.
Thanks Shark31. Good info.
BTW - I like your signature lines :-)
The 14.5 M4 gives you frag range of about 40m w/ M855 and maybe another 5m or so with M193.
I chrono'd a 10, a 10.3 and a 10.5" barrel with M855 and Mk262 - but my old laptop crashed and burned while in California last leave.
I got the drive recovered and HH6 is mailing it out to me here.
As well I ordered a Timer/Chrono so we can do some better drills (or get a better idea of relative individual performance) - but its no here -- then I can Chrono several different ammo's from 10.3, 10.5, 14.5, 16, and 18 barrels (heck maybe even dig out a 20" musket to test).
However I will point out that IF I recall correctly that even with Mk262 - a 10.5 will give your frag with Mk262 to about 10-12m - and it will nto frag with M855 or M193 even at the muzzle.
I think DocGKR just may be able to add to this as well.
I'm not being rude, I'm only explaining that your question doesn't make any sense and that you're doing things ass-backwards.
I'm done. This is like trying to pound in a nail with a drill press.
Bob's your uncle.;)
AR15barrels
09-14-07, 13:31
I'm done. This is like trying to pound in a nail with a drill press.
While not productive, sometimes using the wrong tool for the job is more fun.:D
http://files.turbosquid.com/Preview/Content_on_1_5_2003_04_03_27/dynamite_explosion.jpgC4045604-81DA-47AE-BD5787DD792E7D1F.jpgLarge.jpg
People just don't realize that if they don't ask a complete question, they won't get a complete answer.
chp5,
Despite vast quantities of internet poppycock, there are actually very few public web sources that offer accurate, valid terminal performance information.
Your initial question regarding 10.5” barrel terminal ballistics is not precise enough to be able to give you an accurate answer. Specific load being shot, barrel twist, target distance, and target type are all important factors.
If you are concerned about the potential ability of a specific load to incapacitate an opponent with other than CNS hits, then the location and extent of the fragmentation pattern are critical, not just merely knowing whether the projectile has fragmented or not at a given velocity. See: https://www.m4carbine.net/showthread.php?t=34714
We have tested a variety of 5.56 mm ammunition types ranging from 40 gr to 100 gr when fired from 10.5” 1/7 twist barrels at distances from 3m out to 300 m.
In general, in soft tissue, FMJ like M193 and M855 is unlikely to offer much in the way of fragmentation potential even at close ranges; in addition the yaw cycle is often too deep with FMJ. Heavy OTM loads like 75 gr Hornady TAP and 77 gr Black Hills MK262 can continue to fragment down to around 2000 f/s or so (a bit beyond 100 m); unfortunately the 77 gr SMK OTM used in MK262 frequently has a deeper than ideal initial upset point. Lightweight JHP’s have good fragmentation and early upset, however, total penetration is often insufficient. JSP loads like the 55 & 62 gr Trophy Bonded and the 60 gr Nosler Partition demonstrate early upset and good expansion out to 100 m or so, however they have significant weight retention leading to deep penetration with frequent exit.
Some general 5.56 mm recommendations are available at: https://www.m4carbine.net/showthread.php?t=19881
KevinG and DocGKR - thanks for your informative responses ;)
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.