Here is a look at the HK USP Expert which was recently re-introduced to the US market in mid 2012. These pistols were very scarce as they only imported a few hundred in 2012 and I was lucky enough to find one. Recently, the 2013 and 2014 9mm models have flooded the market and can be found for as low as $1100

I am often asked if police can tell if a suppressor was used in a crime. The answer is generally no, but there are some things to consider. Crimes involving bullets are investigated using various aspects of ballistics. Some or all may be used depending on what evidence is available.

Depending on the crime and gun used there may or may not be shell casings for inspection. Generally bullets or bullet fragments are often recovered and under a microscope can yield a "fingerprint" determined by the striations. Depending on the gun, striations are usually found on the shell case as well.

Striations are formed as the bullet is pushed down the barrel due to the spiral (rifling) found on the inside of a gun barrel. Fired bullets can be matched using these striations to identify the gun it was fired from with a very high certainty. Here is where the concept of using a suppressor comes into play.

Modern suppressors using a baffle-type design never make contact with the bullet once it leaves the barrel. As the bullet passes through a suppressor, the gasses are trapped in order to suppress the sound and muzzle flash. This process has no effect on the original striations left on the bullet once it exits the barrel. Therefore, the bullet itself would not show any differences between guns shot suppressed or unsuppressed.

However, due to the design of suppressors, there is an inherit amount of "blow back" which occurs as the suppressor baffles trap the excess gases. Since these gases do not exit the suppressor they are forced back down the breech of the gun. Once the shell case is ejected from a semi-automatic gun it is considerably more dirty than when a gun is fired unsuppressed.


So while a modern suppressor will not leave evidence of use on the actual bullet, the shell casings will leave clues as to the use of some device which added significant blow back or fouling to the shell cases.

For most recreation shooters, the use of a Nickel Boron bolt carrier isn't really needed as the traditional phosphate carrier is pretty darn good. But it is cool. The gun runs a little better with it and the charging handle is noticeably easier to operate because there is less friction. With a little elbow grease the NiB cleans up nicely.

How much better is NiB over a traditional bolt carrier group? The answer depends on what you are doing with your gun. If you are shooting for extended periods of time or simply don't like cleaning your gun at all, then it might be worth the money. You can dump your old bolt carrier on gunbroker or a AR-15.com for about $100. Chances are the Nickel Boron carrier will outlive you.

I've had mixed results using an ultra-sonic cleaner but with wire brush and some flitz polish it looks good as new.