5.56 fired through short barrels

[koz]

I wouldn't use M855 for anything self defense related (unless that's the only ammo I had available). The 1:12" twist isn't great for heavier bullets. I've shot some Coyotes with the military contract Black Hills Barnes TSX 50gr. They have released it for commercial sale. It works well killing things. That seems like a light bullet but it does the job it's designed for. But expect some sticker shock.. $70 for 50rds.

http://www.ammunitiontogo.com/produc...acturers_id/66

[frostfire]

Originally Posted by koz

I wouldn't use M855 for anything self defense related

aw shoot, I was slinging that green tip from a Beretta ARX160 today with Leupold CQT. Once I figured out the hold-off, it touched half E-type silhouette consistently at 200m....from a 12 inch barrel. For something concealable, that's not bad at all. So I guess at 200m, the lethality is questionable? Inadequate muzzle velocity from a 12inch?

[The Reaper]

Originally Posted by frostfire

aw shoot, I was slinging that green tip from a Beretta ARX160 today with Leupold CQT. Once I figured out the hold-off, it touched half E-type silhouette consistently at 200m....from a 12 inch barrel. For something concealable, that's not bad at all. So I guess at 200m, the lethality is questionable? Inadequate muzzle velocity from a 12inch?

Not for punching paper.

IRT the OP, I think that issue type M193 will be just fine for social work at 100 yards or less.

If you have to penetrate vehicles or such, try the bonded as Air.177 recommended.

A 1:12 WILL NOT stabilize a heavy bullet and will it most likely start yawing till it stabilizes base first. I doubt that you will be able to hit anything with it at 50 yards, much less 100.

The M193 and M855 will work fine and will fragment, causing significant damage if they hit the target going 2700 fps or better. Sometimes down to 2500fps , but not reliably. This is discussed in detail elsewhere on this forum.

TR

[WholeManin2010]

Originally Posted by Brush Okie

I am looking for recommendations on ammo for self defense out of an 16" bbl AR with a 1-12 twist. I was looking at the Hornady Vmax 55 gr but not sure if it would expand to fast especially after looking at the shooting link posted in another thread where the 55 gr TAP was ineffective. The rifle would be carried in the mountains and range would be 100 yards or less. Hard to articulate a threat that is 500 M away.

Aside from M193, I would suggest RBCD's Total Fragmenting Soft Point round. I haven't killed anything with it, but I have fired a respectable number of their 90 gr .45acp TFSP round through an HK45c while testing for functionality and relative accuracy. No complaints aside from a hellacious muzzle flash. The 37 gr .223 ammo boasts 3880 fps and 1337 ft lbs -- should be plenty hot for PD, and light (and short) enough for your 1/12 twist.

[The_Mentalist]

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world. Although, as previously posted, a VSBR or SBR may be appropriate for vehicular operations with close proximity targets, typically, anything below a 16" barrel will cause performance degradation. Lower velocity due to incomplete burning of the powder, excessive flash and greater stress on the operating system due to gas pressures in a shorter system.

The round (cartridge) is designed to give the best performance when all powder is burned and gas expansion is maximized as the bullet reaches the muzzle. Designing a round for 5 grains of powder when the barrel is only long enough to have burned 4 grains before the bullet exits the barrel would be fruitless. You would have to go to a faster burning powder in order to reach proper pressures at the muzzle. But, then you face the issue of excessive chamber pressures. Over pressurize the chamber and you have problems ranging from case separation to blown primers to outright explosions. Also, driving the bullet too fast from the chamber can cause excessive skipping of the round before the rifling can catch. This reduces accuracy by imparting inadequate spin to stabilize the bullet.

We see/hear a lot about ballistics. Too many people only know about external ballistics which is what the bullet does in the air. But, we must also consider internal ballistics which is what happens between the primer strike and the bullet leaving the muzzle. Also, and IMHO the most important is terminal ballistics. What happens upon impact. Does it have enough velocity to allow for full expansion at the vitals of the specific target or does it have too little or too much? Would you use a round designed for a 200lb man to kill rabbits? Would you use a varmint round on a man? Although with proper placement, either of these rounds could be made effective, they are not interchangeable.

Excluding FMJ milspec rounds due to their lack of expansion (thank you Geneva and Hague conventions for taking common sense out of munitions) I would personally recommend a 55 to 62 grain ballistic tip (Barnes X for example) fired from a 16 to 20" barrel with a 1 in 7 to a 1 in 9 twist rate.

I personally use a 16" American Spirit Arms barrel with a 1 in 7 twist and get sub MOA accuracy with a 62 grain Barnes X tipped round. I do use milspec for plinking, but for defense it is the Barnes. I also use the equivalent 155 grain round in my .308 fudd gun. For my handguns, I like the Hornady critical defense which is the pistol caliber equivalent.

I am old school when it comes to weapons. Specific round for specific purpose for specific weapon. Fudd gun for extreme range, AR to 300 yards (but will go further for varmint hunting) and 45ACP for carry. Of course it is a 1911.

[Team Sergeant]

Originally Posted by The_Mentalist

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world. Although, as previously posted, a VSBR or SBR may be appropriate for vehicular operations with close proximity targets, typically, anything below a 16" barrel will cause performance degradation. Lower velocity due to incomplete burning of the powder, excessive flash and greater stress on the operating system due to gas pressures in a shorter system.

The round (cartridge) is designed to give the best performance when all powder is burned and gas expansion is maximized as the bullet reaches the muzzle. Designing a round for 5 grains of powder when the barrel is only long enough to have burned 4 grains before the bullet exits the barrel would be fruitless. You would have to go to a faster burning powder in order to reach proper pressures at the muzzle. But, then you face the issue of excessive chamber pressures. Over pressurize the chamber and you have problems ranging from case separation to blown primers to outright explosions. Also, driving the bullet too fast from the chamber can cause excessive skipping of the round before the rifling can catch. This reduces accuracy by imparting inadequate spin to stabilize the bullet.

We see/hear a lot about ballistics. Too many people only know about external ballistics which is what the bullet does in the air. But, we must also consider internal ballistics which is what happens between the primer strike and the bullet leaving the muzzle. Also, and IMHO the most important is terminal ballistics. What happens upon impact. Does it have enough velocity to allow for full expansion at the vitals of the specific target or does it have too little or too much? Would you use a round designed for a 200lb man to kill rabbits? Would you use a varmint round on a man? Although with proper placement, either of these rounds could be made effective, they are not interchangeable.

Excluding FMJ milspec rounds due to their lack of expansion (thank you Geneva and Hague conventions for taking common sense out of munitions) I would personally recommend a 55 to 62 grain ballistic tip (Barnes X for example) fired from a 16 to 20" barrel with a 1 in 7 to a 1 in 9 twist rate.

I personally use a 16" American Spirit Arms barrel with a 1 in 7 twist and get sub MOA accuracy with a 62 grain Barnes X tipped round. I do use milspec for plinking, but for defense it is the Barnes. I also use the equivalent 155 grain round in my .308 fudd gun. For my handguns, I like the Hornady critical defense which is the pistol caliber equivalent.

I am old school when it comes to weapons. Specific round for specific purpose for specific weapon. Fudd gun for extreme range, AR to 300 yards (but will go further for varmint hunting) and 45ACP for carry. Of course it is a 1911.

What "real world" do you live in? One that thinks a 100+ year old design is state of the art?

[11Ber]

Originally Posted by The_Mentalist

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world.

You might know more about weapons than I do since I am a medic. I will also admit that "shorties" have their disadvantages but this quote is just silly. I will personally attest to their usefulness.

[koz]

Originally Posted by The_Mentalist

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world. Although, as previously posted, a VSBR or SBR may be appropriate for vehicular operations with close proximity targets, typically, anything below a 16" barrel will cause performance degradation. Lower velocity due to incomplete burning of the powder, excessive flash and greater stress on the operating system due to gas pressures in a shorter system.

The round (cartridge) is designed to give the best performance when all powder is burned and gas expansion is maximized as the bullet reaches the muzzle. Designing a round for 5 grains of powder when the barrel is only long enough to have burned 4 grains before the bullet exits the barrel would be fruitless. You would have to go to a faster burning powder in order to reach proper pressures at the muzzle. But, then you face the issue of excessive chamber pressures. Over pressurize the chamber and you have problems ranging from case separation to blown primers to outright explosions. Also, driving the bullet too fast from the chamber can cause excessive skipping of the round before the rifling can catch. This reduces accuracy by imparting inadequate spin to stabilize the bullet.

We see/hear a lot about ballistics. Too many people only know about external ballistics which is what the bullet does in the air. But, we must also consider internal ballistics which is what happens between the primer strike and the bullet leaving the muzzle. Also, and IMHO the most important is terminal ballistics. What happens upon impact. Does it have enough velocity to allow for full expansion at the vitals of the specific target or does it have too little or too much? Would you use a round designed for a 200lb man to kill rabbits? Would you use a varmint round on a man? Although with proper placement, either of these rounds could be made effective, they are not interchangeable.

Excluding FMJ milspec rounds due to their lack of expansion (thank you Geneva and Hague conventions for taking common sense out of munitions) I would personally recommend a 55 to 62 grain ballistic tip (Barnes X for example) fired from a 16 to 20" barrel with a 1 in 7 to a 1 in 9 twist rate.

I personally use a 16" American Spirit Arms barrel with a 1 in 7 twist and get sub MOA accuracy with a 62 grain Barnes X tipped round. I do use milspec for plinking, but for defense it is the Barnes. I also use the equivalent 155 grain round in my .308 fudd gun. For my handguns, I like the Hornady critical defense which is the pistol caliber equivalent.

I am old school when it comes to weapons. Specific round for specific purpose for specific weapon. Fudd gun for extreme range, AR to 300 yards (but will go further for varmint hunting) and 45ACP for carry. Of course it is a 1911.

Much of bullet performance isn't just velocity and mass, it's bullet design. You choose well with the Barnes bullet (one of the better choices). Being able to penetrate deep enough with the maximum amount of weight retention is critical to effective fatal shots.

The Geneva convention has nothing to do with hollow points. It's the Hague Convention. There are ways around it for SOF troops but will not discuss that here.

My chronograph shows I get right @ 2500'fps at the muzzle with my 11" SBR. That gives me equal performance @310 meters as the same round in an 18" barrel @ 400m. Not really that much difference. Effective kills have been made @400m with the 5.56 platform. If I used some of the powders that we can't buy on the street, I'd get about 100 more fps.

So if I can carry an 11" gun (vs a 16" gun), put a suppressor or it and gain fps and have minimal sound/muzzle signature, I'll take the SBR any day.

[The Reaper]

Originally Posted by The_Mentalist

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world. Although, as previously posted, a VSBR or SBR may be appropriate for vehicular operations with close proximity targets, typically, anything below a 16" barrel will cause performance degradation. Lower velocity due to incomplete burning of the powder, excessive flash and greater stress on the operating system due to gas pressures in a shorter system.

The round (cartridge) is designed to give the best performance when all powder is burned and gas expansion is maximized as the bullet reaches the muzzle. Designing a round for 5 grains of powder when the barrel is only long enough to have burned 4 grains before the bullet exits the barrel would be fruitless. You would have to go to a faster burning powder in order to reach proper pressures at the muzzle. But, then you face the issue of excessive chamber pressures. Over pressurize the chamber and you have problems ranging from case separation to blown primers to outright explosions. Also, driving the bullet too fast from the chamber can cause excessive skipping of the round before the rifling can catch. This reduces accuracy by imparting inadequate spin to stabilize the bullet.

We see/hear a lot about ballistics. Too many people only know about external ballistics which is what the bullet does in the air. But, we must also consider internal ballistics which is what happens between the primer strike and the bullet leaving the muzzle. Also, and IMHO the most important is terminal ballistics. What happens upon impact. Does it have enough velocity to allow for full expansion at the vitals of the specific target or does it have too little or too much? Would you use a round designed for a 200lb man to kill rabbits? Would you use a varmint round on a man? Although with proper placement, either of these rounds could be made effective, they are not interchangeable.

Excluding FMJ milspec rounds due to their lack of expansion (thank you Geneva and Hague conventions for taking common sense out of munitions) I would personally recommend a 55 to 62 grain ballistic tip (Barnes X for example) fired from a 16 to 20" barrel with a 1 in 7 to a 1 in 9 twist rate.

I personally use a 16" American Spirit Arms barrel with a 1 in 7 twist and get sub MOA accuracy with a 62 grain Barnes X tipped round. I do use milspec for plinking, but for defense it is the Barnes. I also use the equivalent 155 grain round in my .308 fudd gun. For my handguns, I like the Hornady critical defense which is the pistol caliber equivalent.

I am old school when it comes to weapons. Specific round for specific purpose for specific weapon. Fudd gun for extreme range, AR to 300 yards (but will go further for varmint hunting) and 45ACP for carry. Of course it is a 1911.

Mental:

This has been pretty well flogged here before, if you want to do some searching and reading.

TR

[The_Mentalist]

Originally Posted by koz

Much of bullet performance isn't just velocity and mass, it's bullet design. You choose well with the Barnes bullet (one of the better choices). Being able to penetrate deep enough with the maximum amount of weight retention is critical to effective fatal shots.

The Geneva convention has nothing to do with hollow points. It's the Hague Convention. There are ways around it for SOF troops but will not discuss that here.

My chronograph shows I get right @ 2500'fps at the muzzle with my 11" SBR. That gives me equal performance @310 meters as the same round in an 18" barrel @ 400m. Not really that much difference. Effective kills have been made @400m with the 5.56 platform. If I used some of the powders that we can't buy on the street, I'd get about 100 more fps.

So if I can carry an 11" gun (vs a 16" gun), put a suppressor or it and gain fps and have minimal sound/muzzle signature, I'll take the SBR any day.

Which gas system are you using? A carbine length system could increase MV over one set for a VSBR by extending the point at which the gasses are vented to cycle the bcg. Then again, there are so many different mods coming out that a great part of my data is out of date.

Also, I did include The Hague conventions in the munitions issue. Not arguing just saying.

Reaper, my apologies if I mentioned something previously mentioned but was just trying to follow along in this particular thread and had no intention of rehashing things. I did "browse" quite a bit and primarily in this section before I made my first post. Sorry if I missed it. Trying hard to comply with policies here.

[Sinister]

Short Colt Commandos (both modern and the XM-177 family), the Mark 18, and the Para-Commando SAW are all the rage because they're short. They almost scream, "Look at me -- I'm special!"

As discussed, they have a place if that's your mission or the mission calls for them.

It doesn't hurt if you're surrounded by guys with longer-reach and heavier weapons, tasked to watch your back and flanks.

M193 and M855 aren't perfect and both have their faults and limits. They're issued and generally available.

While there's been LOTS of talk about how a projo MUST fragment to create wounds to kill people (especially on peripheral hits), if you hit someone in the Central Nervous System (center of the grape or through the spine) you can knock the knucklehead down and make him floppy faster than waiting for the air and blood to leak out slowly.

Hit the bad guy, hit him a lot, in the center, early and often. Simple. Does it really matter what gun it is, and what's bolted on the rails?

I've never been issued the ideal weapon. At one time I had a dozen individual weapons cards for stuff I COULD use if the mission called for it.

[JMonty]

Originally Posted by Sinister

Hit the bad guy, hit him a lot, in the center, early and often. Simple. Does it really matter what gun it is, and what's bolted on the rails?

That's an idea.

[kgoerz]

Can't remember the exact velocity. But when I was a fed we Chronographed a bunch of different stuff thru our 10" barrels. The winner was Federal 77 grain HP. I remember when the Army first issued the M4 to the Infantry in mass. My first thought was did they change the Ammo. Answer was no. It was right around Faluija. Reg Army guys were begging SF for Ammo. Marines went back to their 21" AR'S.

[Max_Tab]

Originally Posted by The_Mentalist

Some of the issues with short barrel rifles (or AR pistols) make them pretty much useless in the real world. Although, as previously posted, a VSBR or SBR may be appropriate for vehicular operations with close proximity targets, typically, anything below a 16" barrel will cause performance degradation. Lower velocity due to incomplete burning of the powder, excessive flash and greater stress on the operating system due to gas pressures in a shorter system.

This is why I'm contemplating the .300 Blackout. It was designed to burn all the powder in the cartridge, at 9 inches.

I saw some old post's talking about the .300, anyone got some experience with it yet? (if I missed a thread talking about it, sorry)

[The Reaper]

Originally Posted by Max_Tab

This is why I'm contemplating the .300 Blackout. It was designed to burn all the powder in the cartridge, at 9 inches.

I saw some old post's talking about the .300, anyone got some experience with it yet? (if I missed a thread talking about it, sorry)

I like it.

TR