Dirty barrel experiments.

  • @kanemiker

    Great info. After you shoot your initial 50 “break in” loads, do you clean?

  • 879rnds since cleaned

    Two 5-shot groups @ 100yds.


  • Not even so much as a bore snake run through?

  • @martino1 said in Dirty barrel experiments.:

    Not even so much as a bore snake run through?

    Nothing. Nothing but bullets has gone down this bore for 909 rounds now. I fired 30 more rounds just a while ago.

  • I just remember reading about how stubborn the carbon rings were to get out sometimes after a long run of rounds.BTW is this a Benchmark barrel that is doing this?

  • @pizfiz no it is a normal breakin routine some last 10 some last up to 50 I go through this until I see no copper fouling and once it is gone I don't clean it.

  • Got another batch of rounds on this rifle. Shot 134 rounds over the weekend, shot 50 more today. Including 30rnds back to back, quickly. 1093rnds since last cleaned. This barrel has 2013rnds on it now. Definitely more shots coming out than I've seen previously. Barrel might be on its way. It will still put together a good group... but it doesn't seem as easy.


  • @orkan
    Wouldn’t just over 2k rounds be a pretty low round count for a 6 br?

  • @bull81 said in Dirty barrel experiments.:

    Wouldn’t just over 2k rounds be a pretty low round count for a 6 br?

    It can be. ... but there's a lot of guys that will rip them off after 1500rnds. This barrel wasn't that good to begin with. Just hasn't been many groups in the zero's with it. It's always been a solid 1/3moa performer... but that's starting to open up as well with more flyers. As you can see, it CAN produce some nice groups. Though the number of times 1 or 2 shots come out of the group is steadily increasing. A bit more scatter to things.

  • If you decide to pull it, I’d be interested to see what it would do if you cleaned it down to bare metal again and ran a few rounds of the original load through it to see what it would do before pulling it off and replacing it.

  • @bull81 said in Dirty barrel experiments.:

    If you decide to pull it, I’d be interested to see what it would do if you cleaned it down to bare metal again and ran a few rounds of the original load through it to see what it would do before pulling it off and replacing it.

    I plan on doing that. Thought it would go without saying. :)

  • @orkan
    I figured you would, but I wouldn’t be able to ask after the fact. Like my dad always says you can’t complain if you never speak up.

  • I need to load up another batch of 6BR for some prairie dog blasting... so I decided to use up the remaining 95gr VLD's I had on the shelf. These friggin bullets are so ridiculously seating depth sensitive. Worst I've ever worked with by far.

    Here's where I started:

    Here's where I ended up:

    Good enough for some pdog zapping. 1244rnds since cleaned.

  • 1105rnds since cleaned. A page full of 5-shot groups from my 6 Dasher. I shot the top two rows, @brittel shot the bottom two rows. He injured his trigger finger, so he was doing it Tom Berenger style. hehe.


  • @orkan 1244rnds to 1105rnds? Are you tracking 2 separate rifles or type error? Just wondering, not being a dink. I've stopped cleaning my rifles and they are tracking right along where you and @kanemiker indicate certain changes will occur. I had to drop .4gr powder with my 300 wsm cause pressure was climbing and groups started opening up right at 200rnds. I actually had to increase powder charge .3gr with my 308 at 250-270rnds to get back in the node, but I was only loading 43.2 gr charge to begin with. The 300wsm fouls a lot quicker than the 308 so it made sense that I would see the spikes in velocity and pressure sooner.
    Another question, are you guys cleaning the crown regularly or leaving it fouled as well? I think a lot of the buildup on my crown is due to the muzzle brake. I was wiping it off and scrubbing with a tooth brush, but now am leaving it. If my 300wsm opens up again, I'm going to scrub the crown clean to see if groups shrink before revisiting load development.

  • @donnie one is a 6BR & the other 6 Dasher

  • @gash that's what I missed. Thanks.

  • @donnie said in Dirty barrel experiments.:

    Another question, are you guys cleaning the crown regularly or leaving it fouled as well?

    Not cleaning crown. I shoot suppressed so the crown is absolutely filthy. No ill effect experienced.

  • Ok, I am at 1070 rds down range thru the REM700.308(22) I brought to the class back in May. I have not cleaned it yet. As part of the "dirty" experiment, it is about time to clean it and see if the groups tighten up? I'm thinking, "no" because the groups seem to be getting tighter as the months go by and the primary variable ( MOI) operates within tighter tolerances. But it does seem like a proper "experiment" would include at least one cleaning sometime before the barrel dies?

  • I clean my barrels usually after every match or around the 200 round mark. I clean using the method @orkan suggest with CLR and brushes. I’ve never had an issue with carbon build up using this method until now. My 6br had hard carbon built up horribly for the first 2 inches of the barrel. No amount of scrubbing and soaking would even knock a dent in it. I was unaware of the carbon and had to switch bullet lots as well as powder lots and contributed the poor accuracy and need to rework a load up to the bullets and powder but was never able to get it back to shooting as well as it had previously. The carbon build up had a lot of copper imbedded in it so I am pretty sure it was damaging the bullets causing accuracy issues. I ordered some Iosso Bore Paste and was able to remove the build up last night and hopefully accuracy will return to what it was before. The only difference between my cleaning procedure on the 6br from my other rifles is I wasn’t using VFG pellets with it cause either they weren’t in stock or I’d forget to order them with other orders. I did get some pellets with the Iosso so I’ll be using them from this point forward in the BR as well.
    Couple questions

    1. why did this particular rifle develop an issue when cleaned regularly using the same procedure as my others?
    2. with the ones of you not cleaning do you see copper imbedded in the carbon
    3. are you able to get the same level of accuracy after the carbon develops as you had previously.

    This 6br is bar far the most accurate rifle I’ve had and I’ve had some good ones. It routinely shoots in the mid .1’s with several low 0’s from a bipod and rear squeeze bag. It shot a 20 round group at 1000 that was 6.9 inches 19 of which came in at around 4 inches. I hope now that the carbon has been removed that level of accuracy returns.

  • Were you using wipeout patchout with the clr as I specify? Strange that you'd have copper buildup if you were using CLR first, and then finishing up with wipe out.

  • @orkan
    No I don’t use whipeout I use KG 1. CLR is the first thing I use, and this is the only rifle that I’ve had this happen too. I just finished shooting it now that the carbon is gone and the accuracy has returned after the first two fouling shots. I’ll pick up some whipeout though to try out and see how it does

    First five

    Next five

  • @bull81 Nice to see it is working. Just curious to make of barrel.

  • @tpk936
    26 in bartlien heavy Palma

  • Well I finally ran into some problems with the original "dirty" 6BR. For those that haven't been following along, this rifle has been one of two rifles which were the basis of an experiment I have been running on the behavior of barrels which are not cleaned. Load workups were done after 250-300 rounds had been fired on each, to get the bore heavily fouled and then get a very tuned node established... and then see how long it takes to come out of it.


    I had 1530 rounds since it was last cleaned, and it pressured up bad, and quick. The barrel has just over 2500 rounds total now. I had 100 rounds loaded up all in the same batch, and pressure started about 30 rounds into it, so it presented a nice opportunity. In the name of science, I sacrificed a few pieces of brass to the cause. Once it pressured, I tried some things to make double sure it was the bore condition that was causing it and not some other variable. I had been able to run the same loads during the entire "fouled" condition of this barrel, so after about 300rnds to foul in, my loads have not needed to change across multiple bullet types.

    When I say it started to pressure, I mean it was violently demolishing brass. From the onset of pressure on the left, to where it ended up when I stopped on the right. The things I do in the name of science... :rolleyes:

    The following was done, with no positive effect:
    Removed the suppressor.
    Cleaned the chamber.
    Cleaned the brake.
    Seated bullets deeper 5 thousandths (making sure no cold weld)
    Full inspection of bolt, trigger, and action components.
    Pushed a dry patch down the barrel.

    Rounds were fired after each step to check each variable independently. No change was observed, as pressure signs on the brass were equally high at each step. Final step was to clean the bore!

    When it first started pressuring up, I put it on paper at 100yds and fired two 5-shot groups. The top group was first, then it started hitting pressure bad, and the second group is on the bottom. Obviously went fully haywire.

    Here's a short video showing the bore condition at the time of cleaning, with roughly 1564 rounds since the previous cleaning.

    I went at the barrel with wipe-out patch-out and accelerator, and after a few cycles with heavy brushing... I went to Flitz polish and used some aggressive pellets and viciously polished the bore. I could have kept at that for an hour and still not got it all the way clean I think.
    Here's a video of where I ended up.

    After cleaning I fired 5 rounds on steel, just to settle it in a bit. Then I fired a couple 5 shot groups at 100yds. First one was a bit wild... as I suspect the bore wasn't quite settled in yet. Second one started to look much better.


    While I understand none of this will be a huge revelation... its still nice to have some quantifiable and observable results with a rifle that has had a good barrel log. The same load that has always run well in this rifle, ran well after I cleaned it up. At 2500rnds, the barrel is still performing acceptably. It's also noteworthy that the rifle went right back to its previous zero once cleaned. The remaining 20 rounds which were fired after cleaning, exhibited no adverse pressure. This Benchmark barrel has certainly exhibited some excellent stability. It will be interesting to see how it behaves going forward.