6 Dasher carbon fouling problem

[matorre]

This is a good report, but I wonder if the temp and pressure at the
muzzle , virtually in the atmosphere, mind you, are the same as the throat.

I only mention this, because the throat is damaged by the intense heat. Also the throat is where the toughest carbon is.

I really need a good carbon solvent, and don't have a borescope to see the TRUTH.

Michael

 

[Obtunded]

Carb cleaner is basically the same as laquer thinner, and i have used laquer thinner for scrubbing carbon rings in 6.5-284's with terrific success.

RL15 and Norma 203B are basicallt the same powder and i swear that cra*p is made from old ires. It carbon fouls like white shorts at a prune eating contest.


Varget varget varget.......

 

[queen_stick]

RL15 and Norma 203B are basicallt the same powder and i swear that cra*p is made from old ires. It carbon fouls like white shorts at a prune eating contest....Varget varget varget.......

I agree with your comparison of Varget and RL15, however others claim that Varget is one of the dirtiest powders they've used. (I've read in these forums quite often).

When I switched from Varget to RL15, the first thing I noticed, is that the amount of carbon coming out in cleaning was A LOT worse. It's a night and day difference. People who claim Varget is dirty have either never used RL15, or they've used other powders that burn exceptionally clean compared to Varget.

I've heard that the amount of carbon fouling with RL15 can be reduced by finding a load that burns it at the highest possible efficiency (not sure what the measurement or units for "efficiency" would be here?). Just like getting air-fuel ratios correct in a combustion chamber (using Stoichiometry)...

 

[fdshuster]

Michael: "Also the throat is where the toughest carbon is". Actually what I see with my Hawkeye is virtually no carbon from the case mouth forward for about 6" to 7", then the carbon streaking begins, and continues for another 4" to 6", and from there to the muzzle: no trace of carbon. So, I would have to generalize it as being confined to the approximate center section of the barrel. A ring of carbon will buildup at the case mouth, but only if you have a large gap there between the case mouth and the forward limits of the chamber. One of the reasons I'm so particular about overall chamber lengths when I spec my chambering reamers. I don't want to see more than a .010" gap in front of the case mouth. For those who can't wait to trim ".010" shorter than max case length ( for example: the 223 Rem. max length of 1.760", trimmed to 1.750"), they are only adding to the problem of creating that ring of carbon. With my bench ctgs., like the 6ppc & 6BR's I keep my case's trimmed to .005" shorter than overall chamber length, as spec'd. out on my reamers or verified with the Sinclair chamber O.A.L. gauges, and have yet to find a ring of carbon at that location. But, working that close does require careful monitoring (after sizing) of case lengths. Carbon fouling built up and left unchecked will raise chamber pressures and will result in blown primers. Ask me how I know.

 

[Nomo4me]

Great post Frank. Thanks

Michael: "Also the throat is where the toughest carbon is". Actually what I see with my Hawkeye is virtually no carbon from the case mouth forward for about 6" to 7", then the carbon streaking begins, and continues for another 4" to 6", and from there to the muzzle: no trace of carbon. So, I would have to generalize it as being confined to the approximate center section of the barrel. A ring of carbon will buildup at the case mouth, but only if you have a large gap there between the case mouth and the forward limits of the chamber. One of the reasons I'm so particular about overall chamber lengths when I spec my chambering reamers. I don't want to see more than a .010" gap in front of the case mouth. For those who can't wait to trim ".010" shorter than max case length ( for example: the 223 Rem. max length of 1.760", trimmed to 1.750"), they are only adding to the problem of creating that ring of carbon. With my bench ctgs., like the 6ppc & 6BR's I keep my case's trimmed to .005" shorter than overall chamber length, as spec'd. out on my reamers or verified with the Sinclair chamber O.A.L. gauges, and have yet to find a ring of carbon at that location. But, working that close does require careful monitoring (after sizing) of case lengths. Carbon fouling built up and left unchecked will raise chamber pressures and will result in blown primers. Ask me how I know.

 

[johara1]

Frank, It is very hard to get the new BR brass to work in a 1.570 chamber when the brass is only 1.550 to start with and if you shoot a dasher it's worse. Some very good short range bench rest shooters run any where from .015 - .040 clearance from the end of the case to the end of the chamber. They have had great success with these numbers,so i guess it doesn't really matter, what ever you can make work.
RL=15 seems to be dirty at the low end, high end load are cleaner,I have never had carbon in the throat unless the humidity is really high..........jim

 

[fdshuster]

Jim: yes, and you'll notice I did not include my 6BRX chambering when I said I kept the case mouth within .005" of the front of the chamber. When I fireform the Lapua 6BR to BRX, like your Dasher it too is shorter than I like. And that was one of my screw-ups when I ordered the BRX reamer. I did not account for that, and do have a gap of about .025" in front of the case mouth, requiring frequent inspection with the hawkeye & carbon ring removal when it builds up, although, so far with 585 rds fired, it has been minimal. before cutting another BRX chamber with that reamer I'll have to send it back for a regrind, and I'm thinking from the present 1.570" to 1.550" or maybe even 1.540". I continue to learn.

 

[matorre]

Thanks Frank,
I needed that......... from someone who has been there and seen that.

Now if you can reccomend a no fail carbon melter, that would be great.

Michael

 

[fdshuster]

Michael: You'll get a lot of different recommendations from others about their most effective way to remove carbon, and I'm sure many will work, just as there are many cleaning solvents that work. "Carbon melter" would translate, for me, to mean a liquid that will remove it, and I've yet to find one that is as effective (for me) as JB bore paste ( original blue label can/ not the red label polishing), and using a snug fitting bronze brush. Right there I've probably raised a lot of eyebrows, with those who won't use a bronze brush, and/or believe that JB will damage the bore surface. The many barrels that I've worn out have all been the result of firing bullets down the bore, the intense heat from the burning powder being the biggest destroyer, and not from a bronze brush. I have tried wet & dry patches only, ( did nothing), wet patches with a nylon brush (minimal results & not in the corners where the lands meet the grooves), but my most effective method has always been the scraping of the bronze brush with the JB, ( original blue label, not the red label/polishing). As few as 10 strokes ( chamber to muzzle) or as many as 40, depending on the degree of fouling. IOSSO is said to have the same results as JB, and when my supply runs out, I'm going to give IOSSO a try. As I've mentioned before, I'm not concerned with getting the bore squeeky clean, I just want to keep the carbon under control. I did take a few down to absolute, clean bare metal & they took 15 to 20 rounds fired before they returned to their usual excellent groups. I now leave the bore just a little fouled & no fouler are req'd. I continue to learn with the Hawkeye borescope, the best investment I've made. Without it you really don't know what's going on inside the barrel, and holding it up to a light & looking with the naked eye tells you nothing.

 

[johara1]

Frank, The fastest way to take the carbon build up from the front of the chamber is to make a long case and expand the neck to a tight fit and sharpen it from the inside and close the bolt and the carbon is gone.......jim

 

[fdshuster]

Jim: Good tip. I'll keep it in mind. I've been using a tight fitting brush on a non-rotating short pistol cleaning rod and rotate the brush. Gets the job done, but does take time. Wouldn't it be nice if they could make powder that would not leave carbon fouling. I'll put that on my wish list.

 

[johara1]

Frank, I don't like to use a brush that is turned against the path of the bullet travel, this can harm the throat and cause copper fouling....jim