Juls are tight in my barrel too but so far the oring is OK even at 70J. I did have one or two Juls that had a bigger seam on them - I needed to sand those ones because they did not fit well in the barrel. Anyway your refit seemed to have worked ok, glad its working again.
@@airgunsanonymouslesslethal1904 I guess the pressure gets to hi and this causes backpressure forcing the O-ring out. I found it in the bed, so it had shot out the barrel
@@runerebel8441 oh ok. I hope that doesn't happen to my 7.5 J version as I am not able to take apart the metal clam shell without ruining it. removing the valve block is as far as i go. So.. I guess i will only use light, undersized ammo and keep my fingers crossed.
Your hypothesis seems plausible. Too tight on the bore size and the pressure has to go out somewhere. O-rings are a fail-safe for overpressure for safety purposes. Glad that's all that broke.
Hey so another Tuber is lubing his Juls prior to going into the magazine and that seems to make it work with the tighter fit of the Jul with 850 HPA or 88 gram CO2 for 405 fps down to 372 on an 88. 1100 HPA blows the heat core O ring. He is in Canada for sure. Ehh? Umarex T4E Home Defense. His method I am not too sure about but the result is good. That being said a smaller diameter ball. I think the Jul is .686 so a Canadian Riot ball at .683? But it's 10 grams and that damn spring can feed the heavier round. I see the 8 gram round in this beast but need a smaller diameter than the Jul. Suggestions? I am running HPA no block and don't want to use the wrong oil? Thoughts? Thanks RR! Cheers from Nor Cal.
Hi. Thanks for the info. I have seen his videos too. He had to change the O-rings to a harder material. If I get hold of that type of O-ring I will change it and try for more power. But for now I keep it on CO2 and use balls that dont fit to tight in the barrel. Cheers my friend 😃
I also have problems with the o-ring in my hdx. I replaced it and it blew out after the first shot. So I tried a slightly larger o-ring which was a much tighter fit. This seemed to fix the problem at first but after 10 shots, it blew out again. Now I am getting frustrated and was wondering if you know of a better solution.
Hmmm. I have blown two of the heat core O-rings. I put lot of silicone grease on them when I put them back in, and afther I did this they have stayed in place. These guns like a lot of oil and lube. Also dont use a heavy thightfitting ball/slug. Its when I used this ammo that the O-ring popped out. I guess it makes a back-pressure when you use the heavy and tight fitting ammo, and this popps the O-ring. So try some silicone grease and lighter ammo. It might fix the problem 🤔
So the trick for longlasting fun with this gun and 12g co2, not too heavy ammo but still up to 40J is just removing the valveblock? With no tuning restrictor or tuning valve? Sorry if this might be a dumb question but I am new to this. Is there a vid somewhere which shows how to do remove the valveblock? Thanks!
Yes my friend. Remove the valveblock and restrictor and you will have max power. Check out my video here for how to do so. Watch the hole video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-KR-7wM1hTCU.html
Thanks my friend. I put the restrictor back in, but not the valveblock. I lubed all the seals with silicone grease and not it seems to work great, anso if I use it with an open valve :) Cheers my friend
@@runerebel8441, yea, you say so, if I open it. all of a sudden, I will have 10 extra screws. question any recommendations on any Umarex plinkers?....I'm collecting Umarexs.
@@bostonswift I was quite nervous the first time I worked on guns also. But we all have to learn and its always a risk when opening something up that we cant fix the problems, plus not getting the stuff back as it should be. I have ruined a few airguns over the years too... I dont like opening them up unless I feel I have to. If it works it works 😉👍
