The H&K MP5SD submachine guns are an innovative expansion of H&K's MP5 series. The SD line has a sound suppressor built-in, and it's very effective. The barrel is ported to lower the velocity of the bullets, so standard velocity ammo can be used effectively. About the only noise from an SD being fired is the action going back and forth, and even this noise is buffered somewhat. The end result is about as loud as a light hand clap, or a rapid series of them if fired on full-auto. It almost sounds sort of like a playing card stuck in the spokes of a bicycle wheel, but a little louder. It may even be quieter than the Airsoft version, but that's hard to tell without a side-by-side comparison. If you've got a real SD and want to compare it to the Airsoft, email me. Tokyo Marui, being ambitious as they are, sought to add the SD to their wide product line, and as always, they've done a good job of it.
Appearance
I should just cut and paste the following line for every Marui review I do: Tokyo Marui, as usual, has done an excellent job on the outward appearances of this model. Like the MP5A4/A5, it's well proportioned and everything looks great down to the proofmarks and weld marks. The suppressor assembly is well done, with a removable front piece (so you can substitute the tracer unit), and the corrugated rubber of the handguard is perfect. The cocking tube is longer than a standard MP5 cocking tube, but that's how an SD is designed. For more specifics on the MP5 series in general refer to my review of the MP5A4/A5.
Function
As with the MP5A4/A5, the SD5/6 feels great and is a joy to fire. For this review, I will mostly talk about the SD5 - I originally purchased the SD6 but substituted the fixed stock for the collapsible one, and rewired the battery cable when I did the metal body conversion. Normally on the SD6 the battery goes in a compartment inside the removable handguard, but now it goes in the stock, which is nice because I can use larger batteries (1300 and 2000 mAh rather than the standard 600 mAh battery pack). The SD works just as reliably and is just as easy to use as the regular MP5 series.
Update
One thing I forgot to mention with any of TM's MP5s that I've tested is that if you're firing full auto with a standard capacity magazine, it will empty the magazine no problem. However, if you fire your last shots on semi-auto, it won't even feed the last two or three BBs and when you remove the magazine they will come tumbling out of the gun in a potentially noisy manner. It's hard enough to reload silently as is without having a few BBs rattling out of the gun's magazine well and clattering to the floor (or dry leaves or any other surface that BBs will make noise on).
It has also come to my attention that somebody is selling "silent" upgrades for the MP5 series, with the SD in mind I think. The upgrade kits have a quieter motor, piston, gears, etc. and if I can figure out how much these kits are and where I can get one I may pick one up and install it.
Accuracy update - I finally tried the SD outdoors against a paper silhouette target. Unfortunately there were extreme gusting winds, which affected accuracy, but even so, with cheap .15g pellets I was able to put most of my rounds on the upper body and head of the silhouette at fifteen yards on full auto. Under more favorable weather circumstances (or indoors) and with .25g heavyweight pellets, I would expect that one could successfully engage a human-sized target out to between 25 and 50 yards, possibly farther.
End of Update
Accuracy
The SD is a bit more accurate than the standard MP5. This can be attributed to several things - the sight radius is longer because of the longer cocking tube, the barrel is a little longer, the suppressor adds weight and therefore stability to the barrel, and my battery pack is in the stock as opposed to being under the foregrip where it can press against the barrel and adversely affect accuracy. The Hop-up is adjustable for vertical changes in point of impact, and the rear sight is adjustable for left-to-right variations. This gun shoots a nice small group (for a submachine gun) at ten yards, as is evidenced by the targets below.
Overall Impressions
The SD is just plain nice. It handles well, and is reliable and accurate. It's not as compact as a regular MP5, but I can live with that. On top of all its practical abilities, it just looks cool, too.
7.5x11" target fired at ten yards, 50 rounds semi-auto .2g sighting in
7.5x11" target fired at ten yards, 50 rounds full-auto .2g
8.5x11" target fired at ten yards, 50 rounds semi-auto .25g
- Infrared
