5.7 X 28 FN

[unspellable]

It has long been a desire on my part to have an accurate, flat shooting, low recoil handgun for varmints and such. The other day I picked up an Accelerator pistol in 5.7 X 28 for a pretty reasonable price. But I should have done a little home work. The 5.7 X 28 doesn’t appear to be much better than a 22 Mag.

Given that it has more case capacity than a 22 Mag and runs almost twice the max pressure, why is the performance rather lack luster? What am I missing?

 

[ClickClickD'oh]

The 5.7 X 28 doesn’t appear to be much better than a 22 Mag.

Oh no... not this again.

What am I missing?

The only time .22 mag performance is close to 5.7x28 is if you compare .22 mag rifle performance to 5.7x28 pistol performance.

 

[ironworkerwill]

It's much higher velocity and higher capacity makes the difference.

On paper its energy isn't all that impressive and it could be viewed as a bandwagon cartridge. However in the proper platform, such as P90 with a selector switch, it is amazing. It has a higher degree of controllability and can defeat some armor.

The 5.7 is probably going
*800-1000fps faster than the .22wmr in a pistol.

*WAEG

 

[unspellable]

The Accelerator has a longer barrel than the FN pistol which should help. Since I have it for small varmints or tin cans, the kinetic energy is sort of "Who cares?". I have just looked up some claims of around 1950 fps over a chronograph from the FN which sounds better than earlier numbers I found. (FN claims north of 2000 fps, it always amazes me how a chronograph will slow a bullet down.) On the other hand I have clocked 17 HMRs out of a six inch revolver at 1950 fps.

 

[ClickClickD'oh]

I have just looked up some claims of around 1950 fps over a chronograph from the FN which sounds better than earlier numbers I found. (FN claims north of 2000 fps, it always amazes me how a chronograph will slow a bullet down.)

50 fps variance in different chrony tests isn't something to write home about. Ambient temperatures during testing can easily account for that. 5.7x28mm isn't all the same though. The commonly commercial available blue tips have been slowed down from the original load. The American Eagle stuff is even slower. The 27gr stuff gets up near 2200 fps and there's some custom loads out there that get above 2400 fps.

 

[Rock185]

The 5.7 performance is not lackluster as compared to 22 Mag IMHO. I've chronographed some 5.7X28 from the pistol, and quite a bit of 22 mag from both rifles and handguns. The only way to get performance of the 22 mag to approximate the performance of the 5.7 pistol, is to shoot the 22 mag in a rifle. I had the use of a 5,7 pistol for several months for T&E, along with as much SS192 ammo as I cared to shoot. From the pistol, the SS192 averaged 2025 FPS. I have found no 22 mag ammunition that approximates this velocity in a handgun with similar barrel length. Another characteristic of the 5.7 was that velocity spreads were tighter and standard deviation much smaller than any .22 mag I've ever chronographed in a handgun.....ymmv