Teflon Tape Mod for the Sail O-ring on the Threshold and G3 marker.
This mod is for anyone that is having problems with bolt cycling issues with EITHER the Threshold and G3 due to the Sail O-ring
I got fed up with replacing the none standard O-ring (#3 Sail O-ring) on the bolt of my Threshold. First I was going to try and find my own source online, to the none standard O-ring. Rottensquad was kind enough to give me the size that DP uses for the Sail O-ring. Unfortunately I found out that this none standard O-ring to be difficult to locate. I was about to replace it with a 2 x 16mm O-ring as that's just slightly bigger than the stock and would be a usable substitute.
I tried a 2 x 16mm O-ring, I just so happen to have, and wal la. Fixed my bolt cycling problem. The problem was, that the bolt had tons of friction when cycling it. This would decrease the efficiency and possibly increase the heat created when cycling do to excessive friction. I didn't like the feel at all when cycling it by hand.
SO I tried what I'm going to give you directions to. Seals better than the stock oring with less friction than the 2 x 16mm oring. IMO it's the best of both worlds using what most people have readily available to them in there toolboxes.
First here's the O-rings side by side.
Left is 2 x 16mm
Center is Stock DP O-ring (old worn one)
Right is tank buna 70 duro
Here's how the bolts would look with the orings on them.
Stock (used and worn)
Tank without Teflon tape
Here's what you need. I didn't include the pic of the Tank O-ring, but that is what you will be using to put on the bolt after.
Wrap the Teflon tape so that the width of it goes completely into the slot. Helps to turn it sideways as in the pic.
Wrap only 2x and cut it.
This is what it should look like.
Put the Tank O-ring back on.
You can see how much the tank O-ring has stretched and protrudes.
Lube and your done. Doesn't matter what lube you use. Just use what you have.
You can do this with the stock O-ring in a pinch at the field. Just wrap the Teflon 1x instead of 2x.
The oring will hold the Teflon Tape in place. I have tried the mod and shot about 2 cases through it with no problems at all. Teflon Tape was still in the same place with no signs of coming out.
If you cycle your bolt by hand you will feel slightly more resistance than the stock O-ring, but not a lot. If there is too much friction, take some of the Teflon off of the bolt and then recheck how it feels when cycling.
EDIT: After much more paint I've only had to redo this mod 1 time. After letting my friend blast out the 25bps for fun and him fiddling with the velocity, the teflon started to unravel a bit. He over pressurized it and I had to fix a few things besides the #3 sail Teflon tape mod. After everything was put together, it's back to working great. For someone that's sceptical about this mod, I would suggest as xluben said, do it as a quick fix at the field if you don't have a replacement oring. The 2 x 16mm oring Oring Monkey uses would be a more dependable substitute than the stock sail oring. Since I haven't had any problems, besides what I just stated, it will be how I keep my Threshold. If the teflon does unravel it could be because you over pressurized it a bit. Redo the mod or replace the oring with the stock or 2 x 16mm oring. Don't continue to play with it. I'm not sure what, if anything, it'll do. I don't think it'll do any damage but I'm still testing so let me know if you encounter problems with it and I'll update this post.