Wildcat predator. Some modifications..

[Czhowa]

I thought I'd share a couple of ideas that have worked for me. These are merely suggestions (so calm yourselves oh self-righteous SD police) and food for thought.

Firstly I've had issues with the rear tube on my predator 12 leaking gas. Cleaning, new o-rings and even a new outer tube didn't solve the problem. Given that this part of the moderator doesn't really get particularly dirty I've come up with an idea that has cured all leaks and it is still possible to dismantle if necessary, with a bit of persuasion. Normally I just leave the rear section intact and pop it on the radiator for half an hour to dry any condensation inside.
OK, so to the semi permanent seal. I strip the rear tube set and clean the o-ring contact points. Then I apply a thin coating of sealey air and brake line sealant. This stuff takes 60 hours to fully cure but after 500 rounds there's not gas blow by at all.

My second and probably more controversial modification is to shorten the rear tube by a maximum of roughly 10 mm. This was necessary to allow the moderator to be fitted to my new chassis without interfering with the forend.

The process is
1. Strip the mod.
2. Cut the desired length from the outer tube (max 10mm). I used an angle grinder.
3. File the cut completely flat and deburr inside and outside.
4. Remove rear plastic bush (this won't be going back on.
5. Using a die grinder or dremel carefully remove the thread that the back bush screws into, keeping it level with the highest point of the inner thread.
6. Working from the inside (inner tube threaded side) screw in an M34 x 1.5mm tap. Clamp the back nut in a soft vise and apply generous amounts of cutting lube. Work the tap gently, maybe an 1/8 of a turn at a time and gradually cut the thread all the way through.
This allows the inner tube to travel further, taking up the 10mm gap that you have made by trimming the outer tube.
7. Clean up any swarf and cutting fluid and trial assemble the mod.
8. If happy with the fit apply the air and brake sealant and alloy to dry.

Having done this the back bush can no longer be used, I find no detriment in this whatsoever and from an engineering point of view I see something that (sort of) touches the barrel as an unknown variable.
Anyway once again this is just my own experience, I'm putting it out there incase anyone else is having the same issues and is looking for a suggestion on how to remedy them

 

[Making holes in things]

Hello Czhowa,

I have a Wildcat Evolution so we do not have the same, but there are many similarities that is why I am wondering about when you say "had issues with the rear tube on my predator 12 leaking gas".

I am curious, how did you see it was leaking gas, was there a carbon buildup on the outside ? Was the leak from new, or only after you stripped it for cleaning . . . OK part of this question is, do you strip yours for cleaning and did you reuse the O-rings ?

I have had no leaks or issues with my Evolution. The only time I had it apart, was when it was still new (unused). I stripped it and lightly greased all the rubber O rings with silicone grease, and all the metal threads with copper grease. My reason for doing this was; At the time of taking delivery of my rifle and the moderator in the dealers shop, we were in his workshop around the back where he was drilling out the plastic part of the moderator to fit over the barrel. He showed me a moderator which someone handed in to him to fix because it could not come apart, after long usage and no cleaning at all. If was stuck, he up to that point, had not been able to open it.

I knew I did not have the time or patience to clean my moderator after every shoot (unlike my rifles, they get the Rolls-Royce treatment), so I did some research into it. That is why I decided to grease all the threads on my suppressor. Yesterday was the first time I opened my suppressor to have a look inside and to clean it, after roughly 300 to 400 .308 rounds over many years. It came apart easy, no issues at all and all looks OK. I was going to reuse the same O-rings but then noticed the one big one, is squashed (formed to fit) where the outer thin tube bumps up to the bracket. I only then went on the internet to get a O-ring service kit and to my shock , saw Wildcat charge £15 for a couple of O-rings !?!?!?!?! To me that is a rip-off.

However, now having read your post, I think I may have made a mistake in taking my moderator apart to clean, that is if the 'cleaning' may cause it to leak gas. FYI. Once I have put it together again, I will not be opening it up again for a longer period, maybe never . . . . see it as an expensive consumable. Cleaning a moderator is a messy business but my biggest reason for skipping its cleaning, lack of time.

 

[trickie]

Czhowa,

I’ve a Preditor 12, had a very similar issue about 2/3 years ago sorted it in a similar manner, 6/700 rounds later I have still no leaks

 

[Czhowa]

With regard to the evo mine has never leaked at all, my usual cleaning method is to only strip the diffuser 9 times out of 10, every once in a while I strip the whole thing. O-rings are readily available if youve got a digital caliper .
I first noticed the gas leak on the predator when I took the praesidia cover off and noticed a chalky stain around the back nut. Got a new tube from wildcat and it leaked immediately, not calling wildcat here because their engineering is spot on. Maybe my fault getting the mod hot, whatever it was the problem has gone, still got the mod and wouldn't swap it

 

[Making holes in things]

Oooooh so that is what that chalky mark was, I did not know. I can't remember where it was on my Evo, but it was somewhere on the inside and was so small and it wiped off no problem, that I did not think anything of it. Unless someone can tell me if/why it is a problem and what can be done about it, I think since I was not aware of it (ignorance is bliss . . . I will play ostrich) and can't see any damage, I will live with it.

Thanks for the caliper suggestion, I should have gone down that rout without someone else having to point it out to me.

 

[Making holes in things]

FYI. I also removed the back plastic bush from my Evo early on for the same reason, but also because of the risk of scratching my barrel when I screw it on and off. I in place, use a LimbSaver Barrel De-resonator to fill that gap. I have it so that the Evo is just off it, it does not touch. I can not say if it (the one LimbSaver) affects my accuracy or not, my eyes are not good enough to put more then one bullet into the same hole. I shoot at County level, I spread my bullets all over it.