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Topic: 6mm CM Barrel Replacement (Read 867 times) previous topic - next topic

Re: 6mm CM Barrel Replacement

Reply #45
Bob, don't know anything about your racing.
What class is that?
I see an assortment of different cars there.

Re: 6mm CM Barrel Replacement

Reply #46
Bob, don't know anything about your racing.
What class is that?
I see an assortment of different cars there.
 
 What I do is Autocross or Solo and is part of SCCA (Sports Car Club of America).  You find a large area to setup a course based on pylons that is like a small road course.  Each car runs the course and competes on best time.  There are a lot of difference classes from street cars to fully prepped (ie Modified) cars.  They may run at the same time but each class is scored separately.  Top speeds are in the 80 mph range with car control/handling being the key factor.  It is a sport that brings a lot of different people together to share in they love of driving well.  There is a Nationals event each year in the midwest that draws 1300 competitors over 4 days of competition.   It is a way to keep the budget down but still enjoy some on the limit driving.

Here is a link to the SCCA home page.  https://www.scca.com/pages/what-is-autocross

Here is a link to some in car footage of me from a few years ago of me running an event on an abandoned air field here in CA.
https://www.youtube.com/watch?v=WdRL0p-M2Sk
Bob
If everything seems under control......you're just not going fast enough

Re: 6mm CM Barrel Replacement

Reply #47
.  I did my normal cleaning and there were signs of build up so I think I'll definitely need to keep an eye on it


Bob its my opinion that even with a brand new barrel from the very first shots the hard carbon build up starts.. we clean them with solvents the best we can but theres some left behind.. then we shoot some more.. and clean it again and again theirs a little more stacked on top of what was there.. this cycle continues over and over to the point we have to change are load a little to compensate for the build up we dont really realize is in there.. gun still shooting good but changes to the load are having to be made to keep up with it and finally the hard carbon builds up so much you cant keep up with it.. its toast.. well probably not as you have seen now.. now that you cleaned it like you did it doesnt suprise me a bit that the load you had early in its life shot well.. with mine im going to continue doing my normal cleaning for 3 or 400 rounds and then im going to strip it back down again to bare metal.. after seeing that all that fire cracking can come out of there and how well the barrel looks after a 1000+ rounds im not sure that carbon doesnt act as a protectant to the steel.. but as we know their comes a time it has to come out or screw a new pipe on.. all my opinion.. but i firmly believe it.. lol
Grant

Re: 6mm CM Barrel Replacement

Reply #48
.  I did my normal cleaning and there were signs of build up so I think I'll definitely need to keep an eye on it


Bob its my opinion that even with a brand new barrel from the very first shots the hard carbon build up starts.. we clean them with solvents the best we can but theres some left behind.. then we shoot some more.. and clean it again and again theirs a little more stacked on top of what was there.. this cycle continues over and over to the point we have to change are load a little to compensate for the build up we dont really realize is in there.. gun still shooting good but changes to the load are having to be made to keep up with it and finally the hard carbon builds up so much you cant keep up with it.. its toast.. well probably not as you have seen now.. now that you cleaned it like you did it doesnt suprise me a bit that the load you had early in its life shot well.. with mine im going to continue doing my normal cleaning for 3 or 400 rounds and then im going to strip it back down again to bare metal.. after seeing that all that fire cracking can come out of there and how well the barrel looks after a 1000+ rounds im not sure that carbon doesnt act as a protectant to the steel.. but as we know their comes a time it has to come out or screw a new pipe on.. all my opinion.. but i firmly believe it.. lol
 
I agree with your line of thinking.  I am trying to adjust my cleaning regiment to see if I can maintain a level of carbon versus needing to take back to bare metal.  But if that doesn't work out, I'm in line with you in terms of periodic  deep cleanings. 
Bob
If everything seems under control......you're just not going fast enough

Re: 6mm CM Barrel Replacement

Reply #49

.........  I am trying to adjust my cleaning regiment to see if I can maintain a level of carbon versus needing to take back to bare metal. 

I with this school of thought and have changed my regimen so far this season.

It can be done IMO and I have no desire to take one back to bare metal, I still patch it outwith solvent to get it loosened up then hit it with a bronze brush. 10 - 20 strokes then patch that out and run a JB patch on a jag about 30 strokes. 10 or so in the throat, 10 or so at the muzzle and 10 or so full strokes then patch it out with solvent.
I do this after every match or every 2 - 3 ladders. Last year the barrels I was running had me convinced they liked to be fouled in good and dirty. This years barrels seem to like staying on the clean side. So far it seems.
It's been working for me.
Dave

Re: 6mm CM Barrel Replacement

Reply #50
The past week has been busy but wanted to get the 6mm CM back out and see how it shot after the cleaning regiment that Grant proposed.  I was at the first race of the season over the weekend, got home Sunday night and then headed to the Benchrest practice sessions that we have on Monday morning.  This week was going to 600  yards, which I thought would be a good test.

I shot 30 rounds total.  The first 10 were sighters/foulers.  I then started shooting 5 shot groups.  I finished with a few extra sighters to check on some wind changes.  The first 5 shot group was 4.5".  The second group was 2" and the last group was 1 7/8"  For the practices, the pit just uses a ruler....so 1/16 is the most resolution they will provide.   I used a load that I had good results early in the barrel's like which was RL-23 and Bart's Infinity 105g bullets.  It appears that the barrel will still shoot well.  I did my normal cleaning and there were signs of build up so I think I'll definitely need to keep an eye on it.

I attached a photo from the race.....my little beast ran well....set fast time of day for both days.
glad things went well for you bob do they ever televise autocross?
11X Grandfather
Part time Savagesmith

Re: 6mm CM Barrel Replacement

Reply #51
Randy, it is not much of a spectator sport....so I have not seen one televised.  That being said, they do stream the Nationals from the SCCA website which is run the week after Labor Day weekend.  Also, there are some other events that you might find on-line such as the Good-Guys series and the Optima Challenge series.  Both are gaining a higher level of visibility....but not on any broadcast stations.
Bob
If everything seems under control......you're just not going fast enough

Re: 6mm CM Barrel Replacement

Reply #52
Randy, it is not much of a spectator sport....so I have not seen one televised.  That being said, they do stream the Nationals from the SCCA website which is run the week after Labor Day weekend.  Also, there are some other events that you might find on-line such as the Good-Guys series and the Optima Challenge series.  Both are gaining a higher level of visibility....but not on any broadcast stations.
i just watched a youtube vid of some nice classic cars giving it a go, a cherry 55 chev post and a nice A body chevelle (68-72) also 70s camero and firebird. Intetesting to watch looks like fun never ends. Some "rat rods" also in the mix.
11X Grandfather
Part time Savagesmith

Re: 6mm CM Barrel Replacement

Reply #53
I've been looking for a way to keep a barrel from getting as carboned up as what I did to my 6mm CM barrel.   It was demonstrated by Grant that the use of J-B Bore Cleaner had the ability to take the barrel pretty much back to bare metal.  After using this, I then tried something in addition.  I have put over 100 rounds down the barrel and it has been easier to clean and the signs of heavy carbon don't seem to be coming back.  Still a bit early for sure but so far I've been pleased.    What id tried after the Bore Clean was to use the J-B Bore Bright.  It seems to be more of a polish versus a remover.  So I followed the directions and so far the barrel is shooting well and the clean up is much easier.  I guess time will tell.
Bob
If everything seems under control......you're just not going fast enough

Re: 6mm CM Barrel Replacement

Reply #54
 thank you for posting this information bob... i will have to get a tub of that...
Grant

 

Re: 6mm CM Barrel Replacement

Reply #55
thank you for posting this information bob... i will have to get a tub of that...
 
For sure.  Also, follow the directions...they warn about inadvertently  polishing the chamber...not a good idea since the case does need to have something it can grab onto.  Would be good to get more test cases.....
Bob
If everything seems under control......you're just not going fast enough