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Need pressure schooling !

FWIW I've got the same barrel, same powder and bullet, and same brass. My particular barrel likes 29.0 of Varget. 30.0 starts to show signs of pressure and groups open up considerably. This at .010 off.

I believe what you're experiencing is carbon in the throat. Easily cleaned with a bronze brush spun by a cordless drill. Be careful not to shove it in too far. If you aren't in the market for a bore scope, at least get an endoscope camera. It's quite sufficient for inspecting chamber, throat, lands and muzzle for copper, carbon etc. Cost is about $35 and it'll confirm that your cleaning methods are doing what you think they are, or NOT.
 
Sure, I'm 3 1/2 hrs. south of you. Let me know when to expect you as my schedule is some what flexible.
Williamsport is probably a little closer and I would bet money someone there has one when there is a shoot. Not a bunch of better guys than there..
Great idea mrmajestic . mark if you would like bring that baby to Williamsport this weekend , I will be there . you could shoot a match if you want ,going to be a great weather ,wind we be twisted as normal . we always have fun come join the fun. dave
 
Have we all read this thread and listenned to the very real stories a well respected employee of a barrel maker told?

Please, for the love of your barrel and money, do not spin a bronze brush in the barrel with a drill.

I was taught that the brush should always be allowed to spin freely with the rifling as you push it down the bore. If the rod's bearings are bad and don't allow that, or the brush is not a good snug fit, you replace them. A drill has no place in cleaning a rifle!
 
Endoscope camera?
Got a link ?

Take your pick.

The one I recently bought wi-fi's to my smart phone so I can take pics and send. Many have an approximately 1 inch focal distance, but some are much closer (and they cost more), but all are adequate to see throat, lands, chamber, copper in the muzzle end, etc. I use mine every time I pick up a cleaning rod, start to do a measurement of distance to lands (to check that throat is clean), check for carbon in the neck area of the chamber, etc.

Very useful and inexpensive.
 
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FWIW I've got the same barrel

Not necessarily.....even from the same maker...you don’t know if the same chamber reamer was used. Could’ve been made at a different time and a different reamer used.

Also unless you know if the barrels bore measurements to the .0000” (4th decimal place) and or if his barrel is actually undersize on the bore and or groove or both.....the difference in bore size from one barrel to the next you can have a barrel that creates pressure differently.

Unless you know the numbers on both you cannot compare apples and apples.
 
Ok !

Quick update . Been working on ring with nylon brush (no drill) and C4 . Good news ! Ring is only on half of the bullet now . So yes you guys were right it’s a carbon ring . Tomorrow I’ll pick up a bronze brush (still no drill , lol) and hopefully I’ll have it gone by Saturday morning so the wife and I can hit the range . Thx for everyone’s help . It’s much appreciated !
 
Never anything on a brush but solvent. Use a pierce style jag. For a 6mm i use a 22cal jag with a 1 3/4” square proshot patch.

I understand but right now all I have are nylon brushes and cloth patches . Picking up bronze brushes tomorrow . This is all I have for right now and I have to get this done by tomorrow night .
 
Never anything on a brush but solvent. Use a pierce style jag. For a 6mm i use a 22cal jag with a 1 3/4” square proshot patch.

Now I’m confused !

I got in there with a bronze brush and cleaned it out real good . No black is coming out with the C4 . Here’s the strange part . I went to chamber a round and it felt like I was jamming into the lands .005 or .01 . Took cartridge out and it looks like rifling marks on bullet . I’ll send u a pic in a little bit . WTF ?
Chambered another round that was seated .02 deeper and no marks whatsoever and no seating pressure .
 
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Now I’m confused !

I got in there with a bronze brush and cleaned it out real good . No black is coming out with the C4 . Here’s the strange part . I went to chamber a round and it felt like I was jamming into the lands .005 or .01 . Took cartridge out and it looks like rifling marks on bullet . I’ll send u a pic in a little bit . WTF ?
Chambered another round that was seated .02 deeper and no marks whatsoever and no seating pressure .

Sounds like youre exactly on the lands now instead of the carbon ring. Thats good news
 
If you have carbon on the lands your grooves, the bore diameter, is probably a black ceramic-like carbon deposit. That primer blanking you show is common when carbon deposits get in the bore. Just seems the 6BR variants are the worst for that. C4 is useful but not the real answer.

The real answer is a borescope to see where you are. Then it may be decision time to scrub the mess repeatedly. Even the serious chemical I use does not work on that ceramic groove deposit. It takes horrible scrubbing with abrasives and then just maybe - give up and get a new barrel.
 
If you have carbon on the lands your grooves, the bore diameter, is probably a black ceramic-like carbon deposit. That primer blanking you show is common when carbon deposits get in the bore. Just seems the 6BR variants are the worst for that. C4 is useful but not the real answer.

The real answer is a borescope to see where you are. Then it may be decision time to scrub the mess repeatedly. Even the serious chemical I use does not work on that ceramic groove deposit. It takes horrible scrubbing with abrasives and then just maybe - give up and get a new barrel.

So you’re saying only some barrels show this mess ???? If that’s true I’ll send it back to Shilen .
 

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