There is also a downloadble PDF version of the Ammo Oracle for those who would like to save a copy or read it off-line.
90+% of the time, the answers to your questions can be found in the Ammo Oracle or the FAQ entries below, and folks have worked hard to compile this information for you. Also, scan the topics on the first couple of pages, because someone else might have had the same question recently, and the answer to your question may be in that earlier thread. If you've made an attempt to find the information but can't, then post away....
Even if someone posts a question which might seem redundant to you, we will not tolerate people "stomping newbies." If you see someone who hasn't followed the guidelines and are tempted to respond with a personal attack, then just don't. Leave it be. You're going to attract negative attention from the moderators by doing so. If you feel compelled to respond, let it be a simple "This information is already covered in the FAQ/whatever. Please read the tack at the top of the page" and provide a link to the topic.
NO FOR SALE/WANT TO BUY ADS, OR RELOADING QUESTIONS IN THIS FORUM! There are dedicated forums for reloading and selling ammo. Posting topics of this nature will probably cause your post to be moved or locked without warning.
If you discover a common question that isn't answered by this FAQ, please contact myself or the other authors so that we can get that information added.
 | IM brouhaha |
| IM Zhukov |
| IM Troy |
One of the most common questions is "What ammo is OK to shoot shoot in my XYZ AR-15?" Well, the answer is, we don't know. What do you want the ammo to do exactly? How much are you willing to pay for it? There are too many variables to take into consideration, and there's no way to answer that question without more info. In general, your Colt won't have any different ammo requirements than a Bushmaster or whatever; brand doesn't really matter.
I suggest the following guidelines for looking at ammo:
| Good - the ammo generally works well across many rifles |
| Marginal - the ammo usually works, but has some problems with feeding/extracting (Wolf, for example) |
| Dangerous - this ammo could damage my rifle (AMERC, for example) |
Use the Ammunition Review and Reference post to see a comparative ranking of many different kinds of ammunition. Clink on each link for ammo you're interested in to read people's comments. You may decide that you'd like to have "good" ammo, but you've decided that you're willing to take a chance with the occasional stoppage by buying "marginal" ammo and save money. If in doubt, buy a small amount of ammo and run it in your rifle to make sure it works before buying a whole case.
Next you'll have to ask yourself about the intended use. Plinking? I'd suggest the cheapest ammo that runs reliably in your rifle. Informal target shooting? Maybe something a little more expensive. Nothing but the best accuracy? Federal Gold Medal Match or similar high-quality (and expensive) ammo. Self defense? Refer to Best Choices for Self Defense Ammo. Then you have to take into consideration the price of the ammo involved. You may have started out wanting premium match ammo, but decided that $0.50/round is too much. Every person is different.
If you feel like this doesn't answer your question, feel free to post in the ammo forum, but BE SPECIFIC about explaining your requirements.
This is undoubtedly one of the questions that is asked the most. The answer depends on many things, but here are some rough guidelines for those that don't care about the details:
| 1-in-14" | 55gr or less |
| 1-in-12" | 35gr up to 55-60gr |
| 1-in-9" | 45gr-75gr, possibly up to 77 if you're lucky |
| 1-in-8", 1-in-7" | 45gr - 80+gr |
To find out for sure if your bullet will stabilize a given bullet which is on the fringe, you'll have to try it out in YOUR rifle. Some people's 1/9 can't stabilize 75gr bullets, while others can get away with 77gr bullets in theirs. Technically, it isn't about the WEIGHT, but the LENGTH of the bullet, as well as air density and velocity. A simplified method for determining the minimum rifling twist rate for a given length of bullet is given by the Greenhill formula. A Google search will show many sources for those interested in a more in-depth discussion. If you have the length of your bullet, and just want a look-up table to see what twist rate you need, refer to this page. If you really enjoy the in-depth mathematical treatment of the subject, check out these pages.
Not to be cheeky, but the answer is "it depends". Are you looking for a hyper-accurate round, or just something off the shelf that shoots well? People's definition of "accurate" varies quite a bit. Some people would call a 1.5" round at 100 yards accurate, while others wouldn't be happy with anything larger than 0.5" at the same distance. To obtain the absolute best in accuracy, you'll have to try it in your rifle and experiment. If you're just interested in some loads that others have been happy with, then here's some recommendations. The list is not all-inclusive by any stretch of the imagination, but should give you a starting point:
| TWIST RATE | RIFLE | AMMO | RESULTS |
| 1:7 | Bushmaster M4A3 (EOTech 511) | Mk262 Mod1 | 1.25" |
| CMMG 20", scoped | XM193 | 1" | |
| LMT M4 14.5 1/7 twist Aimpoint ML2 | Black Hill Blue box 77gr | ||
| Global Tactical Recon bbl | Mk262, Federal GMM 77gr, BHBB 75gr, TAP 5.56 75gr | All 4 loads will go sub MOA anyday. The Gold Metal Match has the tightest groups at around .7" at 100 yards | |
| WOA 18" SPR barrel | Mk262 | 1.65" at 200 yards | |
| 1:8 | RRA 16in SS mid-length | Hand-loaded 77gr Nosler | < 1/2MOA |
| RRA Predator Pursuit | Black Hills Red Box 77 grain HP, CorBon 69 grain HP, and Hornady 5.56mm 75 grain TAP | All shot 1/2" groups at 100 yards | |
| MSTN Recce Mod1 16" Lilja SS, Mid gas, 3 groove, 1:8 twist | Mk262 Mod1 (Black Hills 5.56 77gr Seconds) | 1/2 MOA | |
| 1:9 | Bushmaster varminter, 24" barrel | Winchester white box 45gr JHP | Several 1/2 or less 3hot groups @ 100 yards |
| Stag 16in carbine | Federal 50gr JHP sold @ Wal Mart | Consistently less than 1 MOA | |
| Bushmaster XM15 16", ACOG TA-33R-8 | Federal Gold Medal Match, 69gr SMK | 1.15" | |
| RRA A4 Midlength, chrome lined, non free float on Stag Lower | Black Hills Blue Box 52gr match | 1/2" 5 shot group at 100 yards | |
| RRA A4 Midlength, chrome lined, non free float on Stag Lower | Black Hills Factory Seconds 75 gr Match | 0.65" 5 shot group at 100 yards | |
| Bushmaster 16inch | Federal American Eagle 62gr FMJ | 1" @ 100 yards |
As you can see, there are a lot of different ammo types that people have good results with. To reiterate: To find the absolute best, you have to experiment to find out what works best for you. If you're a reloader, you should already know that. One additional note: While 1:9 barrels usually can shoot 75gr bullets, they're only marginally stable and you will probably find that they won't shoot very accurately out of these barrels.
As you have probably noticed, the supply of ammunition, especially for self defense - has drastically gone down and up in price. Please read this article Troy has written in regards to the current ammunition supply woes.
A note about SURPLUS ammo: While Troy's post mostly discusses the availability of 5.56/223 ammo during the WoT, I thought I should add a mention about the supply of surplus ammo as well. The most famous example of surplus was the South African 5.56 battlepacks. During their day, they were the cheapest stuff around and people did not figure it would ever run out. Well, we all know how that ended. Remember cheap Portugese .308 a couple of years ago? The same thing applies to the current batch of South African .308. When you think about the meaning of SURPLUS, it should be immediately obvious that it's a limited supply. Governments get rid of a finite amount of "stuff" they don't need anymore. There might be some more at an indeterminate amount of time in the future, or there might not. Another country may step up to the plate, or maybe not. The latter is especially difficult to predict, as more countries sign on the UN arms non-proliferation treaties. This warning applies to ALL calibers that you can think of. 7.62x54R (Czech, Hungarian, Polish, etc.), 8mm (Turk, Yugo, etc.), .223 (Radway Green, South African battlepacks, Guatemalan, etc.), and many others. Finally - when talking about the price of ammo - let's not forget that we live in a capitalist society. SUPPLY and DEMAND should be simple enough for everyone to understand. Ammo prices have been going up a lot, and the reasons really aren't important. Supply certainly appears to be part of the equation, and dealers are simply charging what the market will bear.
For more background about wound ballistics in particular, please note that there is some excellent background reading you can do. I strongly suggest you educate yourself on the merits of why bullets work the way they do if you plan on using a firearm in a defensive situation.
A note about file sizes: Some articles had to be scanned grayscale, and the size ballooned up quite a bit. I tried scanning in B&W as much as possible, but some pages needed the detail of grayscale. JPG's would have been smaller, but I would have had individual files for all pages, and that was too much of a hassle for me. The quality of the material varies. Some were original articles, other were copies made by Dr. Fackler before sending them on to me - sorry that they don't look nicer.
For a medical view on the subject you can check out an online version of the textbook Conventional Warfare: Ballistic, Blast and Burn Injuries. It is a textbook of military medicine series on combat casualty, published by the office Department of the Army.
Federal has also published PDFs of several wound ballistics workshops they have run, primarily to show off the HST and Gold Dot handgun rounds. They do show a wealth of data for all FBI protocols:
Fort Collins 6-26-08
Aurora 6-24-08
Los Angeles County - California 7-30-07
Riverside - California 7-12-07
Santa Clara - California 5-8-07
Fresno County - California 5-9-07
Kern County - California 5-10-07
Sacramento County - California 5-24-07
San Angelo - Texas 3-9-06
Pierce County Workshop - Washington 11-19-03
San
Diego County Workshop - California 10-2-03
Portland Police Bureau - Oregon 9-6-02
The following links are experiments performed by brouhaha and tatjana at great cost and lots of time:
An excellent source for data for many other types of bullets, including handgun, rifles, and shotguns can be found at BRASSFETCHER.COM. This person has dedicated a lot of time, effort, and especially money to run a ton of experiments across a lot of different calibers and is sharing them free of charge. I applaud his efforts in making a treasure trove of excellent information available for everyone to peruse.
| 5/7/2008 | Rewrite in HTML. |
| 5/12/2008 | Create dedicated steel case ammo FAQ, adjust links. |
| 6/18/2008 | Added link to Conventional Warfare: Ballistic, Blast and Burn Injuries book |
| 6/26/2008 | Added section for "What ammo is the most accurate?" |
| 6/30/2008 | Added section for ammunition vendors |
| 10/29/2008 | Improved section on "what ammo can I shoot in my rifle?" |
| 11/20/2008 | Added links to Federal's wound ballistics workshops |
| 12/8/2008 | Added link to TBOT website |