WE M92 & M9A1 PDI Raven inner barrel installation guide

[Chris_B]

This guide is for anyone that wishes to fit an aftermarket TBB to their WE-Tech M9A1 or M92

 

I bought a PdI Raven barrel for TM M9A1 which is advertised as 115mm total length, but actually more like 114.5mm when measured with calipers.

 

I installed it, along with a PdI W hold VSR bucking and when it was all put back together I saw that the PdI inner barrel was sitting further inside the outer barrel when looking down the bore about 2.75mm (measured with calipers).

 

Turns out the flat notches on either side of the PdI barrel is located farther forward than the stock WE barrel. So when it's clamped into to hop unit, it sits slightly shorter. Something to keep in mind about. Even though a barrel is advertised as the same or slightly longer than you stock doesn't mean it'll fit well, it's determined by the overall length AND the location of the notches for the hop unit clamp.

 

Anyway, so the PdI barrel has a grove around the circumference about 3/4 down the barrel and I thought that if I install the correct size O-ring onto the grove, it may work...

 

Take a look at the below images. There is ever so slight wobble from the inner to outer barrel, less than 0.3mm going by my feel of gear shimming experience, the entire outer barrel wobbles a heck more in comparison, but it's the closest O-ring size I could get to to fit snugly but so that the inner barrel slides perfectly inside the outer barrel. It's a 6.0×2.5mm O-ring.

 

It functions as it should. I fired a few mags and inspected the wear on the end of the PdI inner barrel and there is ever so slight chafing. So I lubed both the O-ring generously and a wee bit on the end of the PdI barrel (being careful not to get inside it) and it works great.

 

Only test fired it in the dark, approx 20m against a 28cm frying pan and I could hear it pinging on target every time, much much better than the stock WE barrel, that could probably hit it 25-30% of the time. (0.20g)

 

Hope this post helps anyone.

 

I will do some more accuracy and durability testing in the daylight with heavier weight BB's and report back.

 

Chris

 

[Chris_B]

Below images;

 

Picture 1: note the ramp on the inside of the outer barrel that guides the inner barrel forward when the top slide recoils to the rearward position.

 

Picture 2: without O-ring fitted, the barrel was off centre in relation to the outer barrel, if a BB would be fired, it would have clipped the outer barrel.