GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Fred J on May 30, 2017, 11:51:38 PM

Title: My Marauder .177 barrel keeps leading up
Post by: Fred J on May 30, 2017, 11:51:38 PM
I have a Marauder in .177 cal that I want to use in Hunter Field Target matches, as well as general plinking. After changing out the barrel with a Mac1 refurbished barrel, tuning the hammer tension, stroke and PV, and removing the baffles and the "Lawyer" trigger spring, the rifle is starting to shoot pretty accurately. I am having one problem with the rifle: The barrel is "leading up" and need to be cleaned every 250 shots or so. I think there are still some rough areas in the barrel. I am currently shooting JSB 10.3gr pellets at 860 fps. I need some advice on how to correct this problem:

- Should I take the barrel out and run a brass brush through the breach end of the barrel, or should I polish the barrel with JB Non-embedding cleaner, or both?

- Should I lube my pellets with something like Ballistol. Currently I am using Lemon Pledge, but I don't think the Pledge is keeping the barrel from 'leading up'

-Should I just resign myself to cleaning the barrel every 250 shots? I have tried using either Ballistol or Hoppes bore cleaner on the first couple of patches, then I run about 8 dry patches through until they come out white.

Thank you for your help.
Title: Re: My Marauder .177 barrel keeps leading up
Post by: nervoustrigger on May 31, 2017, 12:22:53 AM
I would try polishing the bore with J-B, first with the standard compound and then with Bore Brite.  However I would first push a few different types of pellets through and try to assess any roughness or hangups and to get sense of how tight the choke is.  Frankly I don't think cleaning every 250 shots is that bad for a choked barrel, particularly if it is providing good accuracy.

Pushing the velocity over roughly 900fps will accelerate leading quite a bit.  Of course that's not a sharp cutoff that applies in all situations but the fact yours is tuned to 860fps simply suggests to me it's not likely to be a major contributor.
Title: Re: My Marauder .177 barrel keeps leading up
Post by: ackuric on May 31, 2017, 12:37:20 AM
leading up is fairly acceptable IMO and shouldn't be confused for fouling like a powder burner. Lead particles actually provide lubrication, much more so than bare steel, most people advise having a barrel seasoned with lead for best performance. YMMV
Title: Re: My Marauder .177 barrel keeps leading up
Post by: triggertreat on May 31, 2017, 12:42:51 AM

I would try polishing the bore with J-B, first with the standard compound and then with Bore Brite.  However I would first push a few different types of pellets through and try to assess any roughness or hangups and to get sense of how tight the choke is.  Frankly I don't think cleaning every 250 shots is that bad for a choked barrel, particularly if it is providing good accuracy.

Pushing the velocity over roughly 900fps will accelerate leading quite a bit.  Of course that's not a sharp cutoff that applies in all situations but the fact yours is tuned to 860fps simply suggests to me it's not likely to be a major contributor.


What Jason said plus after getting the barrel super clean and polished, I would try lubing a tin of pellets with some FP-10.  Just 10 drops in a Ziploc swished around and then dump the tin in there and carefully move around, then back in the tin.  I deal with a very tight bore on my .22 fitted with a MM HF barrel.  keeps the barrel from fouling so quickly and increases velocity somewhat.  I just pull a bore snake through it periodically and it stays very consistent long-term.
Title: Re: My Marauder .177 barrel keeps leading up
Post by: wahoowad on May 31, 2017, 08:08:10 AM
I would be curious what Tim has to say on the topic. I hate to see 'call the company' as a response but in this case his input would be at least worth considering over most folks here. I'm in the camp that says give it a good polishing. I have a HW98 barrel that does he same thing but have not shot it enough lately to bother experimenting with a polish job.
Title: Re: My Marauder .177 barrel keeps leading up
Post by: strever on May 31, 2017, 11:14:42 AM
i bet Tim will OK the cleaning process you are doing
Title: Re: My Marauder .177 barrel keeps leading up
Post by: Fred J on May 31, 2017, 11:41:51 AM
Thanks for the advice!