5.7x28 fanboys are irritating

[Marcus L.]

Vehicle penetration of substances such as windshields is a very important attribute of a firearm now days. Whether you're dealing with Mexican drug cartels, Iraqi insurgents, domestic organized crime, or just the occasional dirtbag that want to shoot at you......vehicles will be the most common barrier you will encounter anywhere in the world today.

The 5.7mm and the H&K 4.6mm obviously do poorly against windshields, but they also make relatively small wound channels in comparison to other alternatives. Dr. Martin Fackler modeled the wound profiles of both and in testing, neither round could produce a wound volume that could beat out a standard 9mm NATO FMJ. Fragmenting bullets in these PDW cartridges do not have the enough mass or velocity to produce the necessary momentum to carry the fragmenting projectile to acceptible penetration depths and the temporary cavity effects are minimal. Expanding bullets in these PDW cartridges still do not reach a recovered diameter greater than that of a 9mm NATO FMJ, and their temporary cavity stretches are also very minimal. Based on wound generation, which is Facklers expertise, he's said that the weapons using the 5.7mm and 4.6mm are more likely to get officers killed due to their lack of quick incapacitation ability on dangerous opponents. Several PD SWAT units that have used the FN P90 have said that it requires a generous burst in order to achieve desirable stopping effects unlike the M4 or even the MP-5. German units in Afghanistan have has mixed results with theirs too. Once again, they require a higher degree of shot precision and a higher volume of fire to get the job done.

The Russians were a lot smarter when it comes to small armor piercing weapon systems. They simply beefed up the 9mm to fire +P+ penetrators which can pretty much do anything the 5.7mm and 4.6mm can to at ranges up to 100yrds and it generates a larger wound channel.

[variablebinary]

I'm having a long drawn out argument with someone who is obviously a fanboy of this cartridge. The arguments on his side have devolved into speculating about when bullet technology might catch up with the awesomeness of the 5.7x28 so that the whole thing becomes useful.

Why are people so desperate about this kind of stuff? They take anything counter to what they believe and make it personal. I encounter the same thing with people defending the HydraShok. No matter how much evidence you provide otherwise, they "feel" like it's a good round and just shut down. I don't care if you "feel" 5.7x28 would be great, the facts are that it's NOT.

Sorry for the rant.

Why do you feel the need to be right and bait people who obviously see value in the 5.7 round. Dont you think that is irritating?

Name a couple of gun products you own, and I promise there are a few people on this forum who would love to tell you your cash was wasted and you should have gotten something else.

I personally dont own any 5.7 products. But I can see the appeal from my time spent with MadDogs 5.7 upper with a suppressor. It's fun, and unique.

[Zhukov]

I still don't see why everyone harps on the little round. It is a good round. Getting almost 3,000fps and 50 rounds in a short, compact carbine, is pretty impressive. 2600fps from a pistol is awesome. Yes this is a 28gr round, but you can bet it will still do some damage. Would I rather have it than a 5.56? Only if the 5.56 was an SBR.

I think the main issue is that people are trying to put the 5.7 in situations it wasn't designed for. It wasn't MEANT to go through windshields. It was meant to go through body armor like cheese cloth and get the deed done from a FA SBR type weapon that was ultra-relaible and very portable. It does that in spades. Yeah, it sucks that us civvies have a hard time getting an FA/SBR'ed P90, but the PS90 is still pretty compact and full-auto is as much a liability as it as (arguably) an asset.

I think that it does what it was meant to do if you use the right ammo. I am surely not going to say it is the ultimate SD round, but I am also loath to dismiss it as ineffective when it mirrors the .223 in so many ways.

There are many issues with your line of thinking. Let me start by saying that in full-auto, a gun like the PS90 could be pretty effective for certain applications. I can't even think of many of those - you already mentioned that it doesn't penetrate windshields well, so what good is it even for a LEO who can be expected to routinely engage vehicles? That being said, it's a moot point for us mortals who can't own post-86 FA guns.

Reading all the stickies in this forum, you should know that worshipping at the altar of high velocity if a fallacy. You can keep jacking bullet weight down to increase the velocity, but all you'll do is end up with a bullet that either fragments severaly and thus horribly underpenetrates, or a non-fragmenting FMJ that may penetrate sufficiently but has a very unimpressive permanent cavity. Unless the 5.7x28 has the ability to redefine the laws of physics, it's stuck with inferior performance.

5.56 SBRs are problem for the same reason - insufficient muzzle velocity and subsequently reduced terminal performance.

[Zhukov]

Why do you feel the need to be right and bait people who obviously see value in the 5.7 round. Dont you think that is irritating?

Name a couple of gun products you own, and I promise there are a few people on this forum who would love to tell you your cash was wasted and you should have gotten something else.

I personally dont own any 5.7 products. But I can see the appeal from my time spent with MadDogs 5.7 upper with a suppressor. It's fun, and unique.

Whether a gun is fun or unique is irrelevant. The argument specifically concerned the terminal performance of 5.7x28, and it doesn't deliver - as specifically pointed out by DocGKR's sticky in this forum. If the argument was merely about the "fun" aspect of shooting 5.7x28 I wouldn't have said anything; baiting had nothing to do with it.

[Jim from Houston]

Agree with Zhukov...this is the Terminal Ballistics forum, not the "fun guns to shoot" forum...on the Terminal Ballistics forum, there's nothing positive to be said about the 5.7

Quite frankly, I've never much seen the point of any of these tiny-caliber PDW weapons (no one has yet been able to explain to me what sort of performance advantage they offer over an MP5K loaded with 9mm AP rounds like the Nammo BNT HP7).

However, IF for some reason the PDW's really float your boat, the 5.7 still ain't too hot...the HK 4.6x30 cartridge has far superior terminal ballistics to the 5.7 in the tests that I'm aware of - of course, arguing about the terminal ballistics of PDW rounds is a bit like the proverbial "privates arguing about rank".

The whole point of the PDW concept is the ability to pierce soft body armor...for civilians who don't have access to the armor piercing rounds that are intended for use in these PDWs, then really what is the point?

If people like plinking with it, fine...who said any different? But this forum is about terminal ballistics...and the 5.7's are a disaster.

If people still want to talk PDWs, the KAC PDW with the 6x35mm round...now THAT is interesting.

[WS6]

There are many issues with your line of thinking. Let me start by saying that in full-auto, a gun like the PS90 could be pretty effective for certain applications. I can't even think of many of those - you already mentioned that it doesn't penetrate windshields well, so what good is it even for a LEO who can be expected to routinely engage vehicles? That being said, it's a moot point for us mortals who can't own post-86 FA guns.

Reading all the stickies in this forum, you should know that worshipping at the altar of high velocity if a fallacy. You can keep jacking bullet weight down to increase the velocity, but all you'll do is end up with a bullet that either fragments severaly and thus horribly underpenetrates, or a non-fragmenting FMJ that may penetrate sufficiently but has a very unimpressive permanent cavity. Unless the 5.7x28 has the ability to redefine the laws of physics, it's stuck with inferior performance.

5.56 SBRs are problem for the same reason - insufficient muzzle velocity and subsequently reduced terminal performance.

I agree with all of your assessments assuming factory ammo. With factory ammo, this thing is dismal. However...

Think about a 55gr TBBC at about 2300fps Those expand reliably down to around 18-1900fps. Would do great through glass. You can tailor the load to anything you want. No it is not going to replace the 5.56 carbine, but I still don't think its as bad as everyone makes it out to be. As far as going through a vest, there are loads out there for it that are far superior to anything commercially available in the 5.56 world except for M995 or possibly SSA's offering.

[Jim from Houston]

As far as going through a vest, there are loads out there for it that are far superior to anything commercially available in the 5.56 world except for M995 or possibly SSA's offering.

Would you mind clarifying what you mean by this? On the face of it, this statement does not make any sense to me...all commonly encountered 5.56/.223 rounds will zip through soft body armor like it was a sheet of paper...and M855/SS109 rounds will penetrate certain types of level III hard armor rifle plates (watch out for the polyethylene and steel ones).

Bringing the M995 round into the discussion goes to an entirely different level...that's a round that will penetrate Level IV hard armor plates...

In other words, I just don't understand your statement...PDW cartridges such as the 5.7 were designed to deal with the problem of pistol bullets having difficulty with soft body armor...the 5.56/.223 has never had such a problem...

[WS6]

Would you mind clarifying what you mean by this? On the face of it, this statement does not make any sense to me...all commonly encountered 5.56/.223 rounds will zip through soft body armor like it was a sheet of paper...and M855/SS109 rounds will penetrate certain types of level III hard armor rifle plates (watch out for the polyethylene and steel ones).

Bringing the M995 round into the discussion goes to an entirely different level...that's a round that will penetrate Level IV hard armor plates...

In other words, I just don't understand your statement...PDW cartridges such as the 5.7 were designed to deal with the problem of pistol bullets having difficulty with soft body armor...the 5.56/.223 has never had such a problem...

M855 only has a small mild-steel 10.5gr core. It is not very effective as the core will slip/shed the jacket and lead base, and continue minimally after penetrating 1 homogenous barrier. This is why M855 sucks on windshields according to gel junkies as well as some of the people who have used it across the pond. Vests, not a problem. Car-doors and windshields, that is why everyone likes the TBBC rounds. 5.56 is just as inadequate as 5.7 without the correct loads when used on glass,ect.

[Zhukov]

I agree with all of your assessments assuming factory ammo. With factory ammo, this thing is dismal. However...

Think about a 55gr TBBC at about 2300fps Those expand reliably down to around 18-1900fps. Would do great through glass. You can tailor the load to anything you want. No it is not going to replace the 5.56 carbine, but I still don't think its as bad as everyone makes it out to be. As far as going through a vest, there are loads out there for it that are far superior to anything commercially available in the 5.56 world except for M995 or possibly SSA's offering.

See - this is the exact issue I had brought up in my original post. I agree that a 55gr TBBC at 2300fps would be a good thing, but do you really get that out of 5.7x28 or is that a "if only at some point in the future" kind of deal? And is that within the SAAMI spec, or is that running pressures close to destroying the brass and gun?

You can get those velocities with a AR carbine already without doing anything crazy to the load and staying well within spec. The low recoil advantage of a 5.7x28 goes out the window with the 2300fps load as well; heck, it'll probably have more recoil based on the gun being lighter (I assume the PS90 would be lighter than an AR).

[Puffy93]

Better than 5.56 for pistol and SBR(especialy the Five-seveN pistol) not so much for rifle length or even longer SBR barrels

It is a bad-ass round for the Five-seveN