Dirty bore telling me something?

[ptf18]

A general question pertaining to reloading and results.

I pick a powder from any of the manufactures for a given cartridge and bullet weight and I use the listed manufactures charge weight.

I fire say 5-10 rounds of a given reload and find that the bore is noticeably dirty (black), is that telling me something?

IMHO it does but Im not sure what. I would say that the given load (powder charge) is not burning completely. Regardless of what the manufactures suggestion may be using that powder or charge of powder for that bullet weight I should be looking for something (dont know what) that produces a "clean(er)" bore.

Perhaps a "faster" powder? Perhaps an increase in charge? Perhaps crimping the bullet? perhaps "jamming" the bullet? Perhaps a longer barrel?

Thoughts please. I think we all have seen this AND we also have seen loads that leave the bore almost spotless.

 

[Webster]

I think carbon in the barrel is normal up to a point. I use popular powders in my 6BR and they all give black cleaning patches. I get flyers after about 20 shoots if I don't clean the barrel. I never heard of a powder that leaves a bore clean.

 

[gotcha]

Have to agree with Webster for the most part. Your "perhaps" choices might also include primer switch. Some barrels come together quickly. Some take longer.............. Patience is a virtue as there are no magic answers should you run across a finicky barrel. Just my .02

 

[jonbearman]

Could you tell us alittle about your gun and be specific about the reloads,powder,bullet,case,and primer charge weight.

 

[stool]

most powders burn better, cleaner at the higher end of their operating pressure.

you said "manufactures" load.....starting load is often way to low just to be safe, low pressure means dirty bbl...
i seldom see 'A LOAD" BUT STARTING AND STOPPING POINTS.

so be more specific as others have asked.....

 

[artbosco]

A general question pertaining to reloading and results.

I pick a powder from any of the manufactures for a given cartridge and bullet weight and I use the listed manufactures charge weight.

I fire say 5-10 rounds of a given reload and find that the bore is noticeably dirty (black), is that telling me something?

IMHO it does but I'm not sure what.

The general answer is that it now needs to be cleaned.

 

[ptf18]

Thanks Fellows. To be specific. Ive got a seldom shot 6mm250. Ive had it for 7-8 years and have 700 rounds or so thru it. My original plan was to use it in NRA Mid-Course events.

Ive never been real happy with the performance of the gun. Its built on a Single shot Savage action with a Pac-Nor 30", 1/8 twist (I think) S/S barrel.

I've always used SMK 107gn bullets. Most of my load work has used 4350 powders. The cases were W-W 22-250s necked up to 6mm. I think I've used Wolf primers most of the time. Most of my cases have been fired 4-5 times and the pockets are abit loose for Rem 9 1/2 but the Wolf primers are still "snug". Ive got a couple hundred new WW 22-250 cases on hand.

I've seated the bullets 10 off the leade and 20 off the lead. 10 off seems to produce better "grouping . I do my "test" work at 250 yards, the farthest at my clubs range.

I dont shot the gun much as I became somewhat disillusioned with it after the 1st 600 yard match I shot with it even though I felt I had a good load for it at the time. So the gun ended up as a safe queen although I take it out once in awhile.

Anyways.... I've got some loads assembled for it and plan on getting to the range in the AM to see how they work. I'll be shooting off the bench from a rest.... something that Im not real up to as most of my shooting is "slung up".

The gun is NON scoped but I dont have issues seeing sights,targets,etc.....

Reviewing some notes I had the last time I had the gun out but also if I remember correctly was that the loads I shot were producing filthy,black bores with 10 or so rounds. Last time I shot the gun I was using both IMR 4350 and Varget. I cleaned the bore prior to switching loads.

So thats why I was asking about dirty bores... in general... is it telling me something.

Im using the charge weights listed by the powder manufactures but even those close to their max is giving me "dirty" bores. I dont remember getting "signs" of excessive pressures at the max charges listed by the powder manufactures ie, very flat primers, hard extraction, etc.

Ive tried H and IMR 4350, Varget and just loaded some rounds with H4895.

Thanks. All and all I'ld like to quit screwing around with load developement, get a accurate load and start using the gun in Mid-Range Matches.

 

[nastynatesfish]

To me a dirty bore means to slow. Powder or to low a charge. I didn't read all through this but I would scrub the barrel. Do a good defoul. Recheck the powder selection and do another load work up.

 

[dkhunt14]

To me a dirty bore means to slow. Powder or to low a charge. I didn't read all through this but I would scrub the barrel. Do a good defoul. Recheck the powder selection and do another load work up.

I agree with this. Matt

 

[Shynloco]

Ptf,
IMHO and experiences, barrels tell you several things, both about your loads and the powder you use. Powders alone have characteristics wherein some burn "clean" and some are inherently "dirty." By that I mean if you were to compare say a Vhita Vuori powder to say Varget, they to me are polar opposites when you run a patch down your barrel after say 15 rds. I find a mild blackened deposit with the VV powder versus a much more blackened patch with Varget after shooting the same number of rounds. But even then, I've found and developed my own barrel patching/cleaning regiment for each rifle and powder I use wherein over time, I've learned what patching does for me in terms of accuracy and group tightness on the target downrange. You might also note, that many competitors clean their barrels after each and every target they shoot which they believe, gives them their best scoring downrange. Overall for me, its a matter of learning and getting comfortable with whatever method you feel gives you the best results downrange in relationship to the powder/load you are shooting. Just my thoughts.

Alex

 

[Webster]

I would think that carbon is the result of complete combustion. You cannot break it down into something smaller. I am retired now but about two years ago I analyzed a carbon deposit on a barrel cross-section. I cannot remember the exact composition but it was about 90-95 % carbon and somewhere around 2-3% copper with trace amounts of other elements from primer chemicals and any coatings or chemicals mixed with the nitrocellulose. I don't know if any of the residue was a carbon containing compound that looked like pure carbon. From everything I have read over the years there is no known solvent that dissolves carbon. I think the bore cleaners kind of break up or loosen the stuff so it can be removed. Ammonia would attack any Cu mixed in the carbon which might help loosen it???

 

[Lapua40X]

I don't believe there is one right answer. There are too many variables. I can tell you that my .223 with H335 shoots nice and clean. My 6BR with Varget is not as clean but still pretty good. My .284 with Alliant RL17 produces patches that are embarrassingly black.

 

[Syncrowave]

I would think that carbon is the result of complete combustion. You cannot break it down into something smaller.

Carbon dioxide?

 

[BoydAllen]

Although this is not directly related, I think that your load development procedure needs a lot of work. Since your action is a single shot, you can load to any length that the chamber will accommodate as long as there is enough bullet shank in the neck to maintain alignment during handling. Why did you choose, .010 and .020 off the lands for your seating depth? What sort of charge weight experimentation did you do? Working up a load is not that hard. Your rifle may like its bullets seated slightly into the rifling. Have you tried that? What about different charge weights? I usually pick a seating depth and load a series of test rounds. That are the same charge weight interval apart. In a case of the size that you are using the interval would be .3 grains. I load one per, with properly (measured shoulder bump from a tight case) FL sized brass, and keep going till I get some pressure signs. I shoot all of these carefully on the same target, and pay close attention to the wind. I look for clusters where changes in charge weight did not have much effect on where the shot impacted, and then load up several a the middle weight of the group for further testing. If things look promising, I make small changes in seating depth to see if I can fine tune the load for more accuracy. I find this much easier to do loading at the range. If I am loading for long range, I do my testing over a chronograph.

 

[jonbearman]

Does the accuracy fall off right away during ,say, 15 rounds or is it just dirty.If it still shoots well after 15 or 20 rounds and is dirty,what difference does it make. I use rel 15 and that is filthy in my 308 but the accuracy is outstanding.

 

[amlevin]

From everything I have read over the years there is no known solvent that dissolves carbon.

True but there are solvents that dissolve the substances that are binding the carbon to the bore surface.

It's a lot like washing your clothes. The laundry detergent doesn't dissolve the dirt, it just dissolves the gums, oils, and other binders that keep it attached to the fabric, and then holds the dirt in suspension so it can be rinsed away.

 

[Webster]

You are correct. I looked up a chemist definition of complete combustion. In complete combustion the carbon combines with oxygen to form CO or CO2. I was thinking that when your burn paper or a small piece of wood it ends up being black carbon. I worked in a R&D lab at a large chemical company but my background is metallurgy related. What happens in a rifle barrel must be very complex. How much carbon you get is probably related to what chemicals are in the powder, temperature, time, pressure and available oxygen. Probably the best we can do is find out what burns clean from our experience or from other people. A search on this website gives a lot of info. I accept the carbon I get in my bore as normal and don’t worry about it as long as the rifle shoots small groups. I don’t shoot in competition.

 

[stool]

i continue to suggest as others have to lite of a charge , too slow..no real pressure to help the burn.

do you have a chronograph ?

what does -.010 and -.020 have in relation to actuall oal ??......

my guess is your longer lengths are giving you a larger combustion chamber and lower pressure, poor burn and dirty bbl...

 

[Webster]

David Tubb's website give his suggested reloading data for the 6XC which is a 6mm250 with a 30 degree shoulder. He has set many records with his setup.

http://www.davidtubb.com/Articles
Look in the article for fire forming. His data is for 107 gr bullets moly coated. His action is probably stronger than your Savage rifle. He uses N150, N160, 4350 and Varget powders.

 

[WyleWD]

A general question pertaining to reloading and results.

I pick a powder from any of the manufactures for a given cartridge and bullet weight and I use the listed manufactures charge weight.

I fire say 5-10 rounds of a given reload and find that the bore is noticeably dirty (black), is that telling me something?

IMHO it does but Im not sure what. I would say that the given load (powder charge) is not burning completely. Regardless of what the manufactures suggestion may be using that powder or charge of powder for that bullet weight I should be looking for something (dont know what) that produces a "clean(er)" bore.

Perhaps a "faster" powder? Perhaps an increase in charge? Perhaps crimping the bullet? perhaps "jamming" the bullet? Perhaps a longer barrel?

Thoughts please. I think we all have seen this AND we also have seen loads that leave the bore almost spotless.

What is your barrel cleaning procedure? WD