Drastic POI shift

M

Machineguntony

New member
Usually when shooting my MP5s, I don't semi fire much. It's way too fun to just blast the target.

But last night, I decided to semi auto shoot my MP5A2 using a silencer. At first I thought either my aim was bad or the sights were off. The point of impact (POI) was low by about four inches from the point aim, and far right by about three inches. This was from 20 yards.

I fired 30 shots, all with the same results.

I then took off the silencer, and I started hitting nearly dead center (I sight in at 25 yards)

A classic case of a POI shift.

What is causing such a dramatic shift? Is it possible that there is a slight and nondamaging baffle strike or contact? It's a Liberty Mystic.

Does anyone else experience a drastic POI shift when using a silencer?
 
That's not an unusual amount of POI shift for a pistol silencer paired with a locked-breech pistol. But on a fixed-barrel MP5 that seems excessive, though my experience with suppressed MP5s is limited to a few mags, and I never tested them for POI shift.

I have a friend who has a Mystic and he recently had an issue with the can causing bullet stabilization issues. He knows it's the Mystic causing the issue because when he shoots the same host with his Osprey there's no issue. And without the can on it's fine. He even had an endcap baffle strike on his Mystic because of this.

I don't know if the monocore baffle stack of the Mystic causes stability issues with bullets that are already borderline too long, or if it has something to do with the Mystic's mount. Or maybe there's something else going on that we're missing.

Tony, I remember you made a post a while back about an endcap strike you had with your Mystic. Did you ever figure out what caused it?
 
I will tell you my point of shift findings tomorrow. Gonna sight in my new 5.56 Muzzle Brakes on two ARs and new Omega suppressor. I'm interested to see how mine does tomorrow now. Interesting read. I would had never suspected that much point of shift in such a short distance.
 
Hey Tony....

I get a POI shift on all my suppressed guns, can vs. no can. I dont find it to be anywhere near that bad at pistol distance.

My 308 boltgun shifts about 3" down and 2" left at 100 yds.

If it were my MP5, i would zero it with the can on and just dedicate it to that
 
I find it strange that at such a short distance, on a non tilt barrel gun, that there is that much POI shift.

I don't really like shooting the MP5 with a silencer. The amount of gas blowback is just too much, especially since I am left handed. Also, the added length of the silencer causes the MP5 to be somewhat unwieldy.

Theo,

The answer is yes. When I sent the silencer back for repairs, they told me that several internal parts had been melted and deformed. The deformation is then what caused the baffle strike.

No joke...it melted (their words). They advised me against shooting it too hot, as the same thing would happen again. Even though Liberty rates the can as being full auto rated, it just means that the full auto pressure won't blow it up. It's just not as sturdy as something like the Saker, which is a true F/A silencer. I have pictures of my Saker on this site, and if you look closely, you'll notice the coloration of the silencer is off. That's because I shoot it so hot that it now has discoloration. It's one tough son of a gun; the Mystic...not so much.
 
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