Tailgate Wrote:As for cleaning, I did after every round for first 20, then after every 5 rounds for the remaining 48 rounds.
As for the crown, I've not noticed any dings...and just checked it with a flashlight (again, my flash hider is .30, so a bit larger than the muzzle crown edge), looks sharp and clean all around.
UPDATE: Well, after looking at my invoices, there is no indication if either the barrel or the bolt was a "Type 1" or "Type 2," and frankly, now I can't remember. I want to say they were both Type 2, but at this point, I'm not sure.
The "good news" is that the barrel is indeed 1:9 when I tested it with a patch and rod. Right on the money, in fact. So, "now what???"
TG:
That is because there is no such thing as 'Type 1' or 'Type 2'. You can find two types of Grendel chambers because one is cut for a 7.62 X 39 bolt and the other is cut based on a 7.62 X 39 bolt with the bolt face recessed another .011 (?) inches. The only difference is the depth of the chamber, not anything else. And, brass fired out of one, when resized using a decent sizing die, will shoot just fine out of the other. And, if the barrel / bolt combination is called a 'Grendel', it uses the deeper bolt face. The only company I know of that will use a chamber cut for the 7.62 X 39 bolt is Lothar Walther if the customer wants one. And, if such a bolt is used, LW is very clear that he is using a 7.62 X 39 bolt and a chamber cut a bit deeper than for a Grendel bolt.
If you had a true 7.62 X 39 bolt but with a chamber cut for the 'Grendel' (deeper) bolt face, your brass would not chamber. Or if you had a true 'Grendel' bolt, and used a chamber cut for the 7.62 X 39 bolt face, the brass would chamber and shoot but it would be stretched on the shoulder rather dramatically. Enough for you to tell the difference. However, that would have nothing to do with keyholing.
LRP52 may be on to something with his .277 bore hypothesis.
Either way, you won't get it to shoot by cleaning it. If it is keyholing, cleaning it won't do anything but waste your time and money.
Too bad because now you will most likely go through a huge problem.
LR1955