5.7x28 fanboys are irritating

[WS6]

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).

2300fps out of a 16" PS90 barrel with 55gr ammo is old news. It is sold commercially if you want it. Not in TBBC, but in FMJ, however, I don't see why you couldnt run up a load using TBBC or call the company and have them do it for you. They are known to make some interesting rounds. As far as I know the brass and gun are fine. The company selling it is very reputable, fully insured, has no problems/complaints I am aware of, and possesses a huge support-base of happy customers.

Yes you lose your "low recoil" somewhat but you still have 50 rounds in a mag and a very compact weapon that is now capable of punching through autos very nicely. You can't have EVERYTHING ya know. The question wasn't about recoil but terminal effectiveness. The 5.7 isn't going to kill an elephant with a shot to the rump, but it's not the pip-squeek everyone likes to talk about it being any more than the 5.56 is just because the 7.62 guys like to down it. THey all have their purpose, and they all serve it wonderfully. You would not use a 5.7 for a 200 yard shot, and you would not use a 5.56 for a 800 yard shot. Not unless you had no choice. The right tool, for the right job.

I do not own a 5.7 so I really have no emotional attatchment or investment to defend. I simply was interested in it at one time, and listened to both sides of the argument. In the end, I concluded that both sides had exaggerated their views a tad and the truth lay somewhere in the middle.

[Molon]

Originally posted by WS6:

Think about a 55gr TBBC at about 2300fps.

Originally posted by WS6:

2300fps out of a 16" PS90 barrel with 55gr ammo is old news.It is sold commercially if you want it. Not in TBBC, but in FMJ . . .

So in other words, you’re basing your argument on a load that doesn’t even exist, let alone has been tested to see how it actually performs. Not to mention that the 16" barreled PS90 is a complete abortion of the original concept of the P90 being a "compact" firearm. The 55 grain TBBC actually exists in a 223 Remington load and out of a 16" barreled AR-15 runs 500 fps faster than your fantasy load.

[TiroFijo]

So in other words, you’re basing your argument on a load that doesn’t even exist, let alone has been tested to see how it actually performs.

...not only that , but also out of a 16" barrel, that IMO defeats the "compact" appeal of a PDW.

[Marcus L.]

Even if such a load did exist, its effects would be weak in comparison to a 5.56 carbine and its safety threshold would be borderline dangerous. If it takes a dangerous loading from a full rifle length barrel to make the 5.7mm somewhat viable, then it is a very poor choice from a combat/defensive PDW/pistol cartridge. A large safety threshold is needed in any cartridge considered for serious defensive use as peak pressures can change from a number of factors. When a cartridge gets heated up from being in a vehicle in the summer time, or when it stays chambered in a hot barrel the peak pressure of the load increases. Commercial/military manufacturers take such issues into account when they determine the safe operating pressure ammunition. One thing many handloaders don't take into account is environmental pressures that may make their hot loads quite dangerous to the shooter. The net is full of handloaded KBs from experienced loaders who have ignored this margin of safety.

Anyhow, greatness needs no spokesman. The 5.7mm has been in service around the world since the early 1990s and its actual combat performance with military and LE units has been mediocre. Comparing a 5.7mm loading of 55gr at 2300fps out of a 16" barrel to a 5.56 and calling it equal, is like loading a .380acp with a 105gr bullet at 1000fps and calling it a 9mm.

[Molon]

Originally posted by WS6:

2300fps out of a 16" PS90 barrel with 55gr ammo is old news. It is sold commercially if you want it. Not in TBBC, but in FMJ, however, I don't see why you couldnt run up a load using TBBC or call the company and have them do it for you.

The above statement is ignorant conjecture with no data to support it. The Trophy Bonded Bear Claws have longer bearing surfaces than FMJ bullets of the same weight. A bullet with a longer bearing surface generally cannot safely be loaded to the same maximum charge as a bullet of the same weight with a shorter bearing surface do to the increase in pressure caused by the longer bearing surface.

Also, Speer’s own data states that the “Trophy Bonded Bear Claw . . . bullets have unique ballistic behavior compared to conventional bullets. Loads for TBBC . . . bullets may not “track” with data for conventional bullets.”

As an example, the Speer Reloading Manual lists a maximum charge of 26.0 grains of AA 2230 for the Speer 55 grain FMJ for a velocity of 3233 fps. The maximum charge of AA 2230 for the 55 grain TBBC is only 24.0 grains for a velocity of 3077 fps. That’s 156 fps less for the TBBC.

[WS6]

The above statement is ignorant conjecture with no data to support it. The Trophy Bonded Bear Claws have longer bearing surfaces than FMJ bullets of the same weight. A bullet with a longer bearing surface generally cannot safely be loaded to the same maximum charge as a bullet of the same weight with a shorter bearing surface do to the increase in pressure caused by the longer bearing surface.

Also, Speer’s own data states that the “Trophy Bonded Bear Claw . . . bullets have unique ballistic behavior compared to conventional bullets. Loads for TBBC . . . bullets may not “track” with data for conventional bullets.”

As an example, the Speer Reloading Manual lists a maximum charge of 26.0 grains of AA 2230 for the Speer 55 grain FMJ for a velocity of 3233 fps. The maximum charge of AA 2230 for the 55 grain TBBC is only 24.0 grains for a velocity of 3077 fps. That’s 156 fps less for the TBBC.

Obviously you are more up-to-date on your information of the TBBC. I was incorrect in light of that. No, that load does not exist, and based on your information WILL NOT exist.

Also, I say use the thing for what it was meant. With better than factory ammo, it does better than the poor round everyone says it is. I feel that it does have it's place.

On another note, one could load the 53gr DPX, no? I would think the reduced bearing area would make this a good choice, but again am no expert.

I still feel that any round that fragments violently and penetrates to 10"+ is doing the exact same thing as the 60gr .223 TAP. The 40gr VMAX at 2400fps from a 5.7 pistol does just this (and exists). From an P90 I would bet it does 2500+ish. Really not that bad if you aren't going through cars with hit. No it isn't as powerful as a .223, but it does the job in a compact, hi-capacity platform.

[WS6]

Even if such a load did exist, its effects would be weak in comparison to a 5.56 carbine and its safety threshold would be borderline dangerous. If it takes a dangerous loading from a full rifle length barrel to make the 5.7mm somewhat viable, then it is a very poor choice from a combat/defensive PDW/pistol cartridge. A large safety threshold is needed in any cartridge considered for serious defensive use as peak pressures can change from a number of factors. When a cartridge gets heated up from being in a vehicle in the summer time, or when it stays chambered in a hot barrel the peak pressure of the load increases. Commercial/military manufacturers take such issues into account when they determine the safe operating pressure ammunition. One thing many handloaders don't take into account is environmental pressures that may make their hot loads quite dangerous to the shooter. The net is full of handloaded KBs from experienced loaders who have ignored this margin of safety.

Anyhow, greatness needs no spokesman. The 5.7mm has been in service around the world since the early 1990s and its actual combat performance with military and LE units has been mediocre. Comparing a 5.7mm loading of 55gr at 2300fps out of a 16" barrel to a 5.56 and calling it equal, is like loading a .380acp with a 105gr bullet at 1000fps and calling it a 9mm.

It seems that the 5.7 and .223 again have something in common. There is a never-ending search to make them more viable combat loads due to the same failures with barriers and supposedly rapid incapacitation.

Also, 5.7 ammo used and 5.56 ammo used by these groups is obviously not cream of the crop. M855 and SS190 are both sub-standard performers in their respective calibers.

[WS6]

...not only that , but also out of a 16" barrel, that IMO defeats the "compact" appeal of a PDW.

Compare the PS90 to an SBR'ed AR for length.

[kal]

Why is there an argument being made for the P90's capacity when compared to a 5.56mm platform, when there are or is possible to produce a 45-50 round magazine for 5.56mm?

The argument in favor of the P90's capacity becomes moot.

[WS6]

Why is there an argument being made for the P90's capacity when compared to a 5.56mm platform, when there are or is possible to produce a 45-50 round magazine for 5.56mm?

The argument in favor of the P90's capacity becomes moot.

Who makes this 45-50 round reliable magazine?