Let’s Field Strip The SIG Rattler BB Gun

Today, we’ll field strip the SIG Rattler BB Gun. HAM reviewed this CO2-powered airgun recently when it earned a Gold Award for its performance on test.

The Rattler is SIG Air’s first field-strippable long gun. The Rattler itself is based on the SIG MCX platform, so you’ll find that there are some similarities with AR15s – if you’re familiar with them.

First, shoot the gun until it stops to ensure there’s no BBs in the barrel, then drop the magazine. SAFETY FIRST!

Next stepis to rack the charging handle to cock the action.

Next, push out the takedown and pivot pins from the left side using a punch. The pins should then project from the right side of the gun as shown in the photograph below.

Note that both pins are of the “captive” variety. You push them through until they stop, however they cannot be pushed right out of the lower receiver.

It’s important to push through BOTH of these pins! Do not try to push out the takedown pin only and attempt to rotate around the pivot pin (as with an AR). This will not work and may cause damage!

Let's Field Strip The SIG Rattler BB Gun

At this point you can push the upper receiver up and forward, away from the lower. You’ll see the recoil spring sticking out of the back of the upper, make sure that this does not fly out and become lost.

Let's Field Strip The SIG Rattler BB Gun

Below we see the lower receiver open, with the trigger, fire selector/safety and bolt release exposed.

Let's Field Strip The SIG Rattler BB Gun

Below is a close-up of the trigger assembly. That steel “plate” sticking up in the left of this photograph is the fire selector/safety mechanism.

You can see from the photographs as we field strip the SIG Rattler BB Gun that it’s completely dry. No lubrication was used at all when the gun was put together.

SIG Air’s technical specialists suggest that there’s no need to lubricate the gun and that it was designed to operate “dry”. They also confirmed that they have tried lubricating the action themselves but that it seemed to make no difference.

Below we see the upper receiver with the recoil spring and guide sticking out to the left.

After removing the recoil spring and its guide, the bolt can be pushed back out of the receiver. The separate parts are shown below.

Let's Field Strip The SIG Rattler BB Gun

Now for a word of caution! I suggest that this is as far as you field strip the SIG Rattler BB Gun!

Yes, it’s possible to strip the bolt, but there’s no good reason to do so and it’s VERY easy to loose the small spring and plunger that are incorporated in one side of the assembly. You can probably guess how I know this…

Re-assembly is simple the reverse of stripping. However, I found that the takedown and pivot pins required a little “wriggling” to re-engage correctly.

Note that if the recoil spring guide rod is not seated correctly in the back of the receiver during re-assembly, the bolt will jam and the charging handle not rack correctly. In this case, disassemble again and re-install with the recoil spring and guide correctly located.

Finally, if you happen to look through the barrel while your Rattler BB gun is stripped, you will notice that the barrel seems to have a partial obstruction at the breech end.

Don’t worry! That is actually part of the hop up mechanism, so don’t try to remove it. It’s not generally realized, but the Rattler BB gun includes this hop up capability to reduce BB drop (and hence improve accuracy) at longer ranges.

Let's Field Strip The SIG Rattler BB Gun


SIG Sauer MCX Rattler CO2 BB Rifle 0.177