Carbon Ring Update (clean VS fouled)

[lawrence97]

I figured I would do some testing with a fouled VS a clean barrel and here are my findings:

I shot a match and had about 80 rounds thru the barrel. I started on a clean barrel (just wet/dry patches). I shot 15 or so sighters at 800 and it finally stabilized and started hammering the X and 10 ring and finished up the match with no issues and vertical held tight the whole time. At about the 50 round mark, I noticed a slight resistance when closing the bolt due to carbon forward of the neck but it did not affect seating depths or anything else other than a few scratches on the bullet (link to carbon ring post: http://forum.accurateshooter.com/index.php?topic=3825268.0).

On 9/25 I decided to shoot my last batch of reloads so I shot 7 rounds thru my chronograph at a match pace. After that, I cleaned the barrel as best as I could without a borescope using wet patches (TM solution) until they came out clean. Next, I used a .30 cal brush with a little JB and I rotated it a few times in the throat area that was scratching my bullets upon chambering. After the brush I used a tight fitting patch with JB in the same area using strokes. After the JB I used a few dry patches to push out the JB and then I used more wet patches with TM solution to clear all the gunk out until clean. Everything looks nice in shiny to the naked eye!

On 9/26 I shot 7 more rounds out of a squeaky clean barrel. I shot at the same time of the day, same temp and same pace as I did with the fouled barrel and here are the results:

Those of you that shoot the 284 or variants of it, how many rounds are you going between cleanings, do you show up to matches with a clean barrel, how many rounds does it take for the barrel to settle after a cleaning ??? And are my results out of the ordinary, what should I modify?

Thanks.

 

[lawrence97]

Anyone ???

 

[Jay Christopherson]

I showed up to a recent 2-day with a squeaky clean barrel on my 284. On the first string, it took 8 shots for the barrel to settle in and I dropped 4 points in the first 4 shots. It looked like a shotgun on the target and I was frankly resigned to a long day, thinking I had not done a good enough job load testing. But, it settled in and shot quite well for the remainder of the day. For day 2, I decided to not clean it at all, and just shoot it fouled (65 shots worth). After those first four shots, I shot 116 shots and dropped 3 points total.

I've always shown up at matches with squeaky clean barrels. My Dasher can show up and be settled in after two shots, every time. However, after the disaster of that first string (which proved some oddities I'd been seeing practice, so I should have known), I'll never show up to a match again with a squeaky clean barrel on my 284. It's a pain, but it's clear that it will have to be fouled before matches if I want things to go well.

 

[lawrence97]

I guess my finding are similar. The scraping on the bullet had me worried but I guess for cleaning I can just focus on the throat and not touch the rest.

I will fire some more rounds thru it to see how many more rounds it takes to get the same poi I had on a fouled barrel because right now its low left by a lot!

 

[Jay Christopherson]

Yeah, that might work. I'm still cleaning thoroughly between matches, but for shorter matches (2 day), I'm not gonna touch it. In longer matches, I might do what you are thinking and just clean the chamber/throat area and leave the rest of it.

 

[FergusBailey]

... but I guess for cleaning I can just focus on the throat and not touch the rest...

I wonder if this is possible? I mean carbon fouling is hard, abrasive stuff. If you are dislodging it out of the throat/bore area, its got to go somewhere, and that will most likely be further down the bore. I guess you could try a few dry patches down the bore after cleaning the throat.

I usually clean the throat with a brush as part of my cleaning regimen, and then immediately follow the throat cleaning with several soaked patches. That way I am fairly sure I have removed most of the carbon, and the soaked patches help to lubricate the process of removing that carbon.

Having said that, I am using mainly 6mm & 6.5mm cartridges, and have the option of more sighters to settle the bore than you do (short and LR benchrest). So it may be that you have less choices to manage this fouling than I do.