30 cal. bolt probe blow by
Sent this email to Tony.
Received My 30 cal. Edgun today and it is a impressive piece. Unfortunately there is a lot of blow back by the bolt probe, something I have seen some others mention.
In fact it sounds like a 22 rim fire going off by my ear when I shoot. Hearing protection a must.
So I pulled my bolt and took off the existing O-rings.
I have a metric and SAE set.
1/4″ I.D. x 1/16″ seems to be the exact size and there was none in my metric set that were close.
I installed the mentioned O-rings. They fit the same but were new.
Upon firing a couple shots the noise was reduced some. I could still feel a pretty good puff of air on my cheek.
I am thinking the grooves that hold the O-ting are cut too deep in the bolt.
Perhaps the probe’s diameter is too small.
This will have to be addressed in some way.
I would appreciate it if you would run it by Ed.
Best Regards
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Ed told me that the probe O rings are 5.5 mm X 1.5 mm. I had some 5.5 X 1.5 Viton O rings and they were too “tall” when installed in the probe’s 2 grooves. The probe wouldn’t close all of the way with the 5.5 X 1.5s installed.
Ed sends a spare set of probe O rings with each gun, mine measured 5.0 mm X 1.5 mm and they fit and worked fine.
I ordered these:
http://www.theoringstore.com/index.php?main_page=product_info&cPath=368_52_1002&products_id=24524
I wanted some 90 duro Buna N O rings for the probe. When I called last Wednesday, they had 180 some in stock. I ordered 100 of them and I will post in my topic when I get them and have a chance to try them.
Interesting. I don’t notice much air but the noise is loud with your ear next to it. You think Ed is using SAE orings? I have a divers set of both standards and will see if there any close metric sizes.
Viewing 3 replies - 1 through 3 (of 3 total)
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Good to hear your is working fine old Goat.
There must be a tolerance off either in the barrel or the probe on mine.
I put a few thin wraps of Teflon tape in the groove of my bolt to expand the O-rings a bit.
It is quite a bit quieter.
Not as quiet as it should be. I can still feel a burst of air on my cheek.
On the positive side the gun is beautiful and well balanced.
The trigger is very good. Definitely impressed with the trigger out of the box.
8 degrees and a foot of snow in the making here right now.
I hope to get her sighted in spite of it.
Gun shoots hard and I’m sure once I get this straightened out I be very glad to have this rifle.