Hi Guys
I have been reading the forums and have gleaned heaps of information that has been very helpful.
Haven't posted before as I had nothing to contribute.
So thought it about time that I shared my info now that I have something to share.
Is was plinking away at my spinner targets at 50m when I started to miss.
I never miss like this, knew something was amiss.
Checked where I was on paper, shooting way low, hmmmm.
Got out the FX Chronograph, sure enough only 720 fps instead of usual 930 fps (Exact Kings 25.39)
So must be C3 bumper (after about 3000 pellets).
I have the Power Plenum on order so I rang Herman's Guns (the Australian distributor) to see where they were at.
They said, in Australia but at Customs, should arrive soon.
OK, let them know about the C3 bumper as it is a warranty issue.
The procedure for warranty work in Australia is you have to use your local gun shop to ship the gun back to Herman's.
Now my local gun shop is Suffolk Sports in Lismore (70 km from where I live) and Herman's is in Mirboo North, Victoria hundreds of km away.
With the Covid 19 situation I was unprepared to take the risk of sending the gun for repair.
I decided talking with Herman's that I would wait for the Power Plenums to arrive and fix the C3 bumper by installing the power plenum myself.
That was Friday 20 March.
Over the weekend the poop hit the fan in Australia and we were facing all sorts of extra quarantine measures.
There was now a real possibility that the power plenums would be later rather than sooner, with a shut down could be ages.
Being unprepared to be without my Impact, especially with social distancing and lockdowns, I decided to act.
On Sunday I sent an email to Herman's requesting a couple of C3 bumpers (BS006 2.9 mm x 1.78 mm PUR90 oring) be mailed to me.
I couldn't get a Delrin bumper in Australia and anyway the power plenum has a new set up.
So figured I would replace the C3 bumper with the originally designed one as above.
Due to the very fluid situation with the epidemic I was not sure that I could get the orings from Hermans.
To cover all options I found Seal Innovations, an Australian supplier of orings .
https://www.sealinnovations.com.au/Product/info/BS006BUPT
The closest branch to me was in Brisbane.
Rang first thing Monday( 23 March) morning to order the oring only 60 cents, problem, they had a minimum sale of $10 with $10 shipping ( 200 km too far to go to pick one up)
Had to make up the value of the order so ordered as many of the Impact orings off the parts list that they had in stock to make up the required value.
The parcel arrived the next day Tuesday (24 March) (lunch time), each oring individually in a zip lock bag with details of what the oring was, brilliant service.
On Monday, Hermans emailed that they were sending me a couple of C3 bumpers free of charge, great customer service.
Spares if the epidemic continues for a long time and I can't get the power plenum in time.
Like I said I wanted to make sure I would get the bumpers from somewhere soon as, the orings from Hermans have not arrived yet, further to come.
Right, got the orings, now to install, Tuesday after lunch.
This is where I get to share my procedure.
Made the gun safe.
I removed the bottle, turned to min and dry fired until air release (thanks Uncle Hodge)
In Australia we don't have moderators (illegal) so have a shroud on the barrel.
Unscrewed the shroud and pulled it forward enough so that I could unscrew the valve adjuster.
Then I was able to use the 11 mm spanner to remove the other bit to expose the hammer seat.
I was able to pull the valve rod forward and clamp it with a pair of pliers with a bit of leather padding.
I then heated the hammer seat with a small butane torch to release the thread locker (thanks Krale)
I was then able to unscrew the hammer seat and remove the green C3 bumper.
Here again I can share some info.
In my discussions with Hermans about C3 bumpers and the green colour of the oring a theory emerged.
The C3 bumpers I received where white and Herman's reckons that the green colour comes from the thread locker used in assembly.
That is the oring is stained by excessive thread locker and that is why they fail as they are affected by the thread locker.
I tend to agree with this theory as there was a poop load of thread locker that I had to remove to be able to screw the hammer seat back on.
Seems to me that the original design choice of PUR 90 oring was based on the specs of the hardness of the oring.
However if the thread locker has an adverse effect on the PUR then it will not act as designed.
That is a manufacturing error rather than a design error.
My old C3 bumper was green and you could see the start of the damage that causes the inner part of the oring to separate and the oring was swollen compared to the new one.
Well after changing orings I reassembled the Gun, didn't take long at all.
Tried it over the Chronograph, back to 930 fps, interestingly it was shooting low.
Adjusted the elevation and back to prior accuracy.
Thus, you can change the C3 bumper without removing the barrel, scope and picatinny rail, it is tight but doable.
Regards
Deafdog
I have been reading the forums and have gleaned heaps of information that has been very helpful.
Haven't posted before as I had nothing to contribute.
So thought it about time that I shared my info now that I have something to share.
Is was plinking away at my spinner targets at 50m when I started to miss.
I never miss like this, knew something was amiss.
Checked where I was on paper, shooting way low, hmmmm.
Got out the FX Chronograph, sure enough only 720 fps instead of usual 930 fps (Exact Kings 25.39)
So must be C3 bumper (after about 3000 pellets).
I have the Power Plenum on order so I rang Herman's Guns (the Australian distributor) to see where they were at.
They said, in Australia but at Customs, should arrive soon.
OK, let them know about the C3 bumper as it is a warranty issue.
The procedure for warranty work in Australia is you have to use your local gun shop to ship the gun back to Herman's.
Now my local gun shop is Suffolk Sports in Lismore (70 km from where I live) and Herman's is in Mirboo North, Victoria hundreds of km away.
With the Covid 19 situation I was unprepared to take the risk of sending the gun for repair.
I decided talking with Herman's that I would wait for the Power Plenums to arrive and fix the C3 bumper by installing the power plenum myself.
That was Friday 20 March.
Over the weekend the poop hit the fan in Australia and we were facing all sorts of extra quarantine measures.
There was now a real possibility that the power plenums would be later rather than sooner, with a shut down could be ages.
Being unprepared to be without my Impact, especially with social distancing and lockdowns, I decided to act.
On Sunday I sent an email to Herman's requesting a couple of C3 bumpers (BS006 2.9 mm x 1.78 mm PUR90 oring) be mailed to me.
I couldn't get a Delrin bumper in Australia and anyway the power plenum has a new set up.
So figured I would replace the C3 bumper with the originally designed one as above.
Due to the very fluid situation with the epidemic I was not sure that I could get the orings from Hermans.
To cover all options I found Seal Innovations, an Australian supplier of orings .
https://www.sealinnovations.com.au/Product/info/BS006BUPT
The closest branch to me was in Brisbane.
Rang first thing Monday( 23 March) morning to order the oring only 60 cents, problem, they had a minimum sale of $10 with $10 shipping ( 200 km too far to go to pick one up)
Had to make up the value of the order so ordered as many of the Impact orings off the parts list that they had in stock to make up the required value.
The parcel arrived the next day Tuesday (24 March) (lunch time), each oring individually in a zip lock bag with details of what the oring was, brilliant service.
On Monday, Hermans emailed that they were sending me a couple of C3 bumpers free of charge, great customer service.
Spares if the epidemic continues for a long time and I can't get the power plenum in time.
Like I said I wanted to make sure I would get the bumpers from somewhere soon as, the orings from Hermans have not arrived yet, further to come.
Right, got the orings, now to install, Tuesday after lunch.
This is where I get to share my procedure.
Made the gun safe.
I removed the bottle, turned to min and dry fired until air release (thanks Uncle Hodge)
In Australia we don't have moderators (illegal) so have a shroud on the barrel.
Unscrewed the shroud and pulled it forward enough so that I could unscrew the valve adjuster.
Then I was able to use the 11 mm spanner to remove the other bit to expose the hammer seat.
I was able to pull the valve rod forward and clamp it with a pair of pliers with a bit of leather padding.
I then heated the hammer seat with a small butane torch to release the thread locker (thanks Krale)
I was then able to unscrew the hammer seat and remove the green C3 bumper.
Here again I can share some info.
In my discussions with Hermans about C3 bumpers and the green colour of the oring a theory emerged.
The C3 bumpers I received where white and Herman's reckons that the green colour comes from the thread locker used in assembly.
That is the oring is stained by excessive thread locker and that is why they fail as they are affected by the thread locker.
I tend to agree with this theory as there was a poop load of thread locker that I had to remove to be able to screw the hammer seat back on.
Seems to me that the original design choice of PUR 90 oring was based on the specs of the hardness of the oring.
However if the thread locker has an adverse effect on the PUR then it will not act as designed.
That is a manufacturing error rather than a design error.
My old C3 bumper was green and you could see the start of the damage that causes the inner part of the oring to separate and the oring was swollen compared to the new one.
Well after changing orings I reassembled the Gun, didn't take long at all.
Tried it over the Chronograph, back to 930 fps, interestingly it was shooting low.
Adjusted the elevation and back to prior accuracy.
Thus, you can change the C3 bumper without removing the barrel, scope and picatinny rail, it is tight but doable.
Regards
Deafdog
