Silencer Saturday #345: A Weird Sig SG550 Silencer From B&T

Daniel Y
by Daniel Y

Welcome back to another installment of Silencer Saturday. Last week we looked at some of the results from the 2024 Thunderbeast Arms Silencer Summit. This week we have a closer look at a very unique silencer that will probably never be tested at that kind of event.


Silencer Saturday @ TFB:



The SG55X As A Host


Switezerland as a nation has a very strong shooting culture. 300-meter ranges litter the country, despite the fact that the country is not very large. I passed through Switzerland some years ago and stopped to take some pictures of classically-Swiss cows with cattlebells in an idyllic valley. It wasn’t until I was out of the car and walking around that I spotted the target pits on one side of the valley and firing points on the other side, with cattle and a barn down below. That setup would never fly here in the United States!


The Sig SG550 aka STGW90, and the rest of the SG55x family, is to Switzerland as the AR-15 and M-16 family are to the United States. I have a major soft spot for the SG55X series of guns. They are a fascinating combination of utter reliability with precision and attention to detail. About the only area where they do not shine is with suppressors. The standad gas regulators for these rifles have two positions, regular and adverse. Short barrel models can have 4-position regulators which add a suppressed setting and an off setting.


The other major suppression issue is the barrel design itself. Many SG55X models have a flash hider machined into the barrel. There are no threads involved; the flash hider is part of the same piece of steel that makes up the barrel. Here is a close-up of my SG551 (the US 16-inch model) showing the flash hider:


SG551 with US-market 16-inch barrel with integral flash hider

This design is not unique to the US-market SG551, but is also seen on the SG551 SB, SG551 LB, SG550, and some models of the SG553. The lack of muzzle threads is an issue, because almost all silencers use that attachment method. Despite those issues, finding a way to reduce firing noise would be a useful thing to do when shooting these rifles in close proximity to people’s homes and farms. But how?


B&T’s Solution


In 1992 B&T created a batch of very unique silencers to address these issues. This silencer came to my attention on Instagram. @waffenteile.ch collaborated with B&T on the following post:

“Very early @bt_swiss silencer for the Swiss stgw90. Only 60 units got built and have been proposed to the Swiss army...... They unfortunately rather spent more money on shooting tunnels 😂🫣🇨🇭”

This suppressor was so outlandish that I thought it was some kind of joke or prank, and I asked if it was real. B&T responded and said “yes it’s real. Or rather it was. It was purely for 300m static shooting.” That design intent makes a lot of sense for a silencer this massive. The SG550 is not a small or light gun, it has a 20.8-inch barrel. This B&T silencer looks almost as long as the barrel! Shooting it purely from a fixed firing point at a shooting range is about the only way it would work. It is obviously too big for any other use case.


The guys at @waffenteile.ch were kind enough to take more pictures and measurements for me to share with you all.


Specifications

Outer Tube Length: 450mm (17.7 inches)

Overall Length: 510mm (20.0 inches)

Tube Diameter: 50mm (1.97 inches)


And here are some pictures of it on a scale:


It comes in at 45.8 ounces
Here is the weight in grams and kilograms for our non-American readers

45.8 ounces is anything but a light silencer. That is heaver than a 1911 with a steel frame! Silencer weight is also more pronounced the further it reaches from the muzzle, and one can only imagine how unwieldy a setup like this would be while firing offhand. But with the included bipod on the SG550, and shooting from a prone position, the balance may be better.


The mounting mechanism is one of the most interesting parts of this setup. Because there is no way to thread it onto the barrel B&T had to come up with a different method. There are two clamping screws, one that interfaces with the bayonet mount and one that tightens on the grenade ring.


The baffle design is much more traditional. The baffle stack is made up of cups and washers in the standard method, with a threaded section a the muzzle to hold the baffles in place. The baffles can be removed for cleaning.


A More Modern Option


B&T makes a huge range of silencers, including some models that are specific to the SG55X series. Here are some pictures of the B&T Rotex-V with SG550 mount, alongside the STGW90 silencer and on a scale, showing the difference in size and weight. It is half the weight, and somewhere around a third of the length. B&T's new Print-X options are even lighter.

In conclusion, suppressing the SG55X is possible but takes a specialized silencer. The STGW 90 silencer is an interesting design built for a specific task, and though it never entered full-scale production it is still fascinating. Also, a massive thank you is in order to @waffenteile.ch for sharing a closer look at, and so many pictures of, a truly unique suppressor. This article would not have been possible without them.

SILENCER SHOP –   HANSOHN BROTHERS –   DEADEYE GUNS

MAC TACTICAL

ALL YHM PRODUCTS AT BROWNELLS

DEALERS: If you want your link to buy YHM suppressors included in future Silencer Saturday posts, email:   silencers@thefirearmblog.com


Daniel Y
Daniel Y

AKA @fromtheguncounter on Instagram. Gun nerd, reloader, attorney, and mediocre hunter. Daniel can still be found on occasion behind the counter at a local gun store. When he is not shooting, he enjoys hiking, camping, and rappelling around Utah.

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