AR ammo question


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DustyVermonter
February 21, 2011, 11:53 PM
Is Hornady TAP 75gr .223 a suitable HD ammo option for an AR? I was told by one guy that it would be great for HD in an AR as long as your effective range doesn't exceed 50yrds or so, but a different guy told me something about the headspacing and that the 75gr was too big for an AR. I don't know, I'm new to the game and am inclined to concur with the vast majority so please chime in.

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Tim the student
February 22, 2011, 12:02 AM
According to Hornady, it is specifically designed for HD. It should be fine in any AR. I could see a problem with it fitting in the mags, but I sincerely doubt that it won't fit in standard mags. I doubt he was really talking about headspace, even if that is what he said.

Give Hornady a call in the morning and get it right from the horse's mouth.

TonyAngel
February 22, 2011, 12:04 AM
I don't know about home defense, but if I recall, the Hornady 75 gr TAP is loaded with there boat tail hollow point. It's the 75gr A-Max that is too long to fit into the magazine of an AR when loaded to spec.

FYI, as far as I know, there is no headspace issue with the 75gr A-Max. It's just that the bullet is so long that a loaded round will not fit into a magazine. You can shoot them, but have to load them one at a time.

TeamPrecisionIT
February 22, 2011, 12:08 AM
It'll fit in the mag, cycle the gun, headspace properly and shoot great. Its just not cheap.

Damian

DustyVermonter
February 22, 2011, 12:14 AM
Well I just loaded 10 into a usgi mag with no problems at all, but definitely, if that bullet was a fraction of a measurement longer, there would be an issue.

So do you think it would be a safe bet to load a mag or two to keep on hand for wcs(worst case scenario)

BushyGuy
February 22, 2011, 12:16 AM
55gr FMJ or 50gr JHP are best for SD and home defense. thr 75-77 gr might have a little bit overpenetration, while the M193 or 50 gr JHP will fragment sooner at short range then the heavier bullets.

the heavier bullets are suitable for longer range SD . TAP bullets are great for barrier penetration is why police use those bullets in their AR's

Tim the student
February 22, 2011, 12:16 AM
http://www.larrywillis.com/headspace.html

DustyVermonter
February 22, 2011, 12:38 AM
@ Tim the student: Thanks for clearing that up for me. I've had a pretty cloudy perception of that term for some time now, pretty simple actually.

JustinJ
February 22, 2011, 08:37 AM
77 grain is the longest that will fit in an ar mag. Whoever told you 75 grain tap is good only up to 50 yards is plain wrong.

madcratebuilder
February 22, 2011, 09:10 AM
The barrel twist well determine the ammo your AR likes.

http://i32.photobucket.com/albums/d37/madcratebuilder/50923489.jpg

68wj
February 22, 2011, 09:35 AM
TAP was created for LE applications. Aside from sniper use, the round is primarily for the AR platform so that shouldn't be an issue. 50 yds???? Don't take any more advice from him.

http://www.hornadyle.com/

TonyAngel
February 22, 2011, 09:43 AM
Not to get off on a tangent here, but a couple of generalized references have been made to weight of bullets and the ability to run them in an AR.

It isn't about the weight. It's about the length. Any round that is over 2.260" overall length (sometimes shorter) won't fit into an AR magazine and this applies to the 75gr A-Max.

Steve in PA
February 22, 2011, 09:52 AM
I work in law enforcement, and my personal AR at home is stuffed with Hornady 75gr TAP ammo.

Bartholomew Roberts
February 22, 2011, 09:53 AM
madcratebuilder, interesting Venn diagram; but my own experience has been that 1:7 twist will handle all they way down to 45gr just fine. It may go lower than that; but that is the lightest I've fired out of it.

As for what makes the best self-defense ammo for an AR15, this is a good link on the subject:
http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm

Note that training and ability to place rounds accurately is going to be much, much, more important than the ammo used.

M1key
February 22, 2011, 02:08 PM
50 yards?

All of my 1:9 ARs (16in and 20in ) will shoot the 75gr Hornady just fine out to 200yds, with accuracy. No keyholes, just nice consistent-sized groups hitting center of mass. They shoot them so well, the 1:7 Colt sits in the safe. :cool:


M

HOLY DIVER
February 22, 2011, 10:17 PM
saw a very interesting show the other day. they tested common rds used for HD 2 see if they would go through several walls and exit your house and possibly harm a innocent person and not the bad guy...i may be forgetting a few but here goes these went through 4 walls and kept trucking,9mm,357 mag,12ga 00buckshot. the 45acp went through 3 walls......here is the very interesting part .223 FMJ went through 1 wall and completely fragmented and just peppered the 2nd so yea u could use the 75gr TAP but i think it will over penetrate i recommend 55grain hollow points

Motega
February 22, 2011, 11:16 PM
Why on Earth would anyone choose a rifle for home defense?!! Shotgun with 00 buck please. Even if I lived alone on 100 acres I wouldn't consider a rifle for HD... having shot deer etc at under 30 yards with a hollow point 30-06 I can tell you that it makes pencil sized holes that allow for LOTS of response time from the target.
The only argument I can see is lots of rounds to fire- which translates into a swiss-cheese house. I hitch my wagon to 4 rounds of 00 law enforcement buck shot in a tac-modded SG (just a light and adjustable stock).
Being startled awake by some meth-crazed puke I'll take a nice cone of buckshot TYVM.

mljdeckard
February 22, 2011, 11:27 PM
Because a lot of people can handle a rifle a lot better, and deliver more metal on target. There are a lot of options, what might be right for you won't work for everyone.

My primary is a shotgun loaded with #4 buck. My wife's primary is an M-1 carbine.

arizona98tj
February 23, 2011, 12:19 AM
Why on Earth would anyone choose a rifle for home defense?!!

Just curious.....have you taken a good 3 or 4 day carbine course? If you have, I can't believe you would ask that question. If you haven't, you need to.

Steve in PA
February 23, 2011, 10:18 AM
He's the same guy that doesn't know how to use the charging handle of his rifle.

A human being is NOT a deer. What a deer would shrug off would kill a human. A rifle round carries a lot more energy that a handgun round, a rifle round (especially in .223 and depending on bullet) penetrates a lot less in things like interior walls than a handgun round, a long gun tends to be able to be handled better than a handgun, etc. Also, where in the case of a rifle, I am firing one projectile when I pull the trigger. In the case of 00 buckshot, you are firing multiple projectiles. Need I go on??


Like the other person said, go take a carbine course then come back and gives us your thoughts.

Friendly, Don't Fire!
February 23, 2011, 10:36 AM
Barrel TWIST -- one revolution in so many inches of projectile moving down the barrel, i.e., 1 revolution in 9 inches, or 1:9 -- is a major determining factor in projectile weight.

If you try to push too heavy a projectile down a barrel with a slow spin rate, the bullet is likely to shoot large groups, that is, if the bullet even reaches the target without tumbling (causing key-holes at, say, 100 yards or more).

A 1:9 twist rate will accept 55 grain up to about 62 grain. Heavier than 62 grain and you most likely will need a faster twist -- more like 1:8 or even 1:7.

One problem with the faster twist rates (say, 1:7) is that they tend to wear the barrel out more quickly than a slower twist rate. Typically, you don't get a "free-ride" as, for every "pro" that we can come up with, there are usually "cons."

Friendly, Don't Fire!
February 23, 2011, 10:47 AM
A human being is NOT a deer. What a deer would shrug off would kill a human.
Not necessarily so, please cite your source(s).

A rifle round carries a lot more energy that a handgun round, a rifle round...

I must disagree, not all rifle rounds carry a lot more energy than handgun rounds.

...(especially in .223 and depending on bullet) penetrates a lot less in things like interior walls than a handgun round...

Not necessarily so. Please cite.

...a long gun tends to be able to be handled better than a handgun, etc.

Again, please cite your source(s). I disagree that, in close quarters, i.e., inside a typical house, a handgun is much easier to handle and is much less awkward to handle than their long counterparts!

...Also, where in the case of a rifle, I am firing one projectile when I pull the trigger. In the case of 00 buckshot, you are firing multiple projectiles. Need I go on??

A .410 rifled slug is a single projectile that could have very similar penetration as certain pistol ammunition! There are, of course, others that I could list, but I do not have the time right now to do so.

Like the other person said, go take a carbine course then come back and gives us your thoughts.

No, take a Pistol Course AND a Rifle Course so you can compare the two!

bpl
February 23, 2011, 11:06 AM
I'm sure that the 75gr TAP will work fine, but my understanding is the lighter 5.56x45mm loads at higher velocity will fragment well and have less wall penetration. I have 55gr TAP and 55gr XM-193 FMJ loaded up for mine.

Ithaca37
February 23, 2011, 03:39 PM
u could use the 75gr TAP but i think it will over penetrate i recommend 55grain hollow points

Over penetration is not nearly the issue that under-penetration or lack of fragmentation is. 75gr TAP is a fine round, but I prefer barrier rounds like MK318.

All of my 1:9 ARs (16in and 20in ) will shoot the 75gr Hornady just fine out to 200yds, with accuracy. No keyholes, just nice consistent-sized groups hitting center of mass. They shoot them so well, the 1:7 Colt sits in the safe.

The issue is not accuracy, it is fragmentation. Reliable fragmentation (and terminal performance) relies on a minimum velocity (2250fps for the hornady 75gr OTM I believe). What limits the effective range is the velocity it can achieve coming out of your barrel and how far it can travel before it drops below 2250fps.

Hornady TAP FPD 75gr OTM will retain fragmentation performance to about 115 yards when fired from a 16" barrel. This is based on chrono data obtained by Molon over at AR15.com.


I'm sure that the 75gr TAP will work fine, but my understanding is the lighter 5.56x45mm loads at higher velocity will fragment well and have less wall penetration. I have 55gr TAP and 55gr XM-193 FMJ loaded up for mine.

XM193 shows inconsistent fragmentation. There is a great deal of variation in the bullet yaw during flight. This causes the angle of attack when it hits the target to vary which leads to inconsistent results (no fragmentation results in a wound not terribly different from 22lr).

Hornady TAP 55gr is a varmint round and will not provide adequate penetration to guarantee results. I do not understand why hornady markets it as defensive ammo.

TonyAngel
February 23, 2011, 04:16 PM
Barrel TWIST -- one revolution in so many inches of projectile moving down the barrel, i.e., 1 revolution in 9 inches, or 1:9 -- is a major determining factor in projectile weight.

This is wrong.

The major determining factor of the required twist to stabilize a projectile is its length, NOT its weight. This is why many rifles with slower (not slow) twist rates do OK with most 75 and 77gr bullets, but won't shoot the A-Maxes well at all. The A-Max is a very long bullet.

I have a 14.5" Bushmaster barrel with a 1:9 twist. It shoots 77gr SMKS alright. I also have a Remington 700 in .223 with a 1:9 twist and it does OK with 77gr projectiles as well. It just does better with 69s and under.

FC
February 23, 2011, 07:40 PM
A human being is NOT a deer. What a deer would shrug off would kill a human. A rifle round carries a lot more energy that a handgun round, a rifle round (especially in .223 and depending on bullet) penetrates a lot less in things like interior walls than a handgun round,

Where do you get this stuff? Here is a test you might want to read.

http://www.theboxotruth.com/docs/bot1.htm

HOLY DIVER
February 23, 2011, 08:03 PM
i might buy a sheet of Sheetrock and do some tests this weekend i'm curious. if someone is trying 2 kill u by all means use what u have 2 defend yourself imo.

mljdeckard
February 24, 2011, 12:02 AM
Even if it sounds counterintuitive, it's true. Defensive loads for 5.56 will not penetrate through people or sheetrock as far as most pistol rounds will.

Again, just because you haven't been correctly TRAINED to use a long gun indoors doesn't mean it's a bad idea.

FC
February 24, 2011, 02:24 AM
Even if it sounds counterintuitive, it's true. Defensive loads for 5.56 will not penetrate through people or sheetrock as far as most pistol rounds will.


You should really check that link a couple posts up! I would be happy to see another series of test results if you have a source to share though.

223 rounds tested were going through 12 sheets of 5/8" sheet-rock without stopping and twelve 3/4" thick pine boards without stopping in another test.

http://www.theboxotruth.com/docs/bot3.htm

By contrast a shotgun is only going through 6-7 sheets of 5/8" sheet-rock until they went to slugs.

Bartholomew Roberts
February 24, 2011, 10:26 AM
You should really check that link a couple posts up! I would be happy to see another series of test results if you have a source to share though.

Here is an entire thread of .223 drywall penetration tests. Pretty much all of them support what mljdeckard and Steve in PA told you.

http://www.thehighroad.org/showthread.php?t=566923

Box O' Truth gets different results because the original, early tests didn't use realistic spacing between the drywall. It takes some amount of time for .223 to yaw and fragment and it is only after it fragments that penetration begins to be reduced. In the original BOT tests, the drywall sheets are spaced so closely together that .223 exits before that can happen - note that the yaw doesn't even start until the 6th of 12 sheets in that test. BOT #1 also doesn't indicate what portion of the bullet exited or how much remaining energy the bullet had, which can lead to erroneous conclusions.

Now take a look at the tests linked above and see what happens when you have a more realistic spacing between interior walls.

FC
February 24, 2011, 04:21 PM
I guess those test results show off particular bullets pretty well when fired (mostly) from a SBR at a range of 21 feet? Some cool tests to be sure and definitely shows that certain projectiles will fragment quickly, they also show that others will not. For the most part it looks like most 223's when fired through a single wall will still give lethal penetration according to Federal's own tests. I use a handgun for home defense myself because it's quick and easy to handle and I have no urge to run around my house like Rambo with my AR, I'm pretty sure my coffee table would break if I tried to do a tacticool roll over it anyway.

I'll admit that certain 223 rounds have been proven by these tests to be safer for bystanders than many pistol rounds while others haven't. I do like how 230grain shoots at closer range making it a much more realistic test. My only complaint with his methodology was using the same pieces of sheet-rock for all testing.

Bartholomew Roberts
February 24, 2011, 05:20 PM
For the most part it looks like most 223's when fired through a single wall will still give lethal penetration according to Federal's own tests.

Yeah, two 5/8" sheets of drywall aren't much of a barrier when it comes to stopping bullets. There is a long list of ammo that has the potential to be lethal after going through a single interior wall.

But let's say you could have a magic round that would stop instantly in a single interior wall; and would still be very effective if it hit an attacker. Would you be willing to use such a round in your house knowing that almost everything in your house was now hard cover for your ammo; but that there was a better than 99% chance that your intruder could shoot through many of those same obstacles?

I use a handgun for home defense myself because it's quick and easy to handle and I have no urge to run around my house like Rambo with my AR

Well, I don't have any urge to run around my house like Rambo - especially if I think I need a firearm seriously; but I do want to hit what I shoot at and fire as few shots as possible and an AR beats a pistol in terms of accuracy and terminal effect.

FC
February 24, 2011, 05:50 PM
I am envisioning a scene from Ace Ventura "Pet Detective" with the soundtrack for Mission Impossible playing in the background...LOL!

mljdeckard
February 24, 2011, 10:37 PM
I said DEFENSIVE loads. No one is saying to take G.I. SS-109 ammo and load it up to shoot in the house.

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