HOW OFTEN TO CLEAN A PCP BARREL????

[30-06]

Hi all you good folks!! I recently aquired a Bam 50 tuned to about 20fpe. It shoots JSB Exact\ AA fields into 5-8mm groupings at 10m. I also get very good results with Gamo Prohuntes 6-9mm at 10m. Out to 20m the groups open up to about 9-12mm(latter half inch) I have tried CP heavies, H&N Barracudas(Kodiaks) ,Gamo Ts10 (awfull!!!!) etc. If i move to 30 and 40m the groups open up to about 3/4 -1.25 iches and at40m anything between 1 and 2 inches(ouch!!!). The guys on our local forum suggested cleaning the barrel and trying JSb Heavies. I could only get about 100 JSb Heavies to test but havent had the time yet to get to it.

Now the Main Question??? How often to clean a PCP barrel??? I know with springers its about once every 1000-2000 shots depending on accuracy variations, but does the same apply to a PCP rifle?? One guy suggested cleaning a PCP rifle every 250 shots. I would greatly appreciate your input. Thanks again for the replies to my last post regarding the charging of a pcp rifle, got that under the belt now!!!

The "pullthrough" method seems to be the one used buy the most guys.

Thanks so long!!

Johan

[Crimson Sky]

Time between cleanings depends a lot on your choice of pellets and also on frequency of use. Cros. Premiers tend to dirty up a barrel quicker than say, Kodiaks--it's just softer(or 'dirty' as some folks call it)  lead. Lubing your pellets will also increase time between cleanings.

[HNT5]

Was the gun brand new or used when you received it? I ask because if it was previously owned and shot alot, the barrel may have a fair amount of lead build up. That may be contributing to your less than ideal and expected accuracy. If 1 brand of pellet shot poorly and others didn't, then it would be a pellet issue. But since none of the pelleys you try seem to do any better than the others, I say it's a barrel issue. I would give it a thorough cleaning. I (just my opinion) would even consider using a brush and rod to really give it a cleaning. That way you would all but eliminate leading as a contributing factor to your accuracy issues. I would not use the JSB Heavies you have until you have cleaned the barrel. That way you don't squander the limited supply on a "dirty" barrel. I use felt cleaing pellets with a little oil on my PCP's probably one a month. More so to put a light coat before I put them away than to clean them. To clean the barrel on my Logun MKII would require me to remove the barrel so I use felt pellets only. Not the case with the AA 410 ERB, but I choose the felt there too. Just my thoughts, suggestions and opinions.
HTH some. Good luck sorting things out and let us know what you come up with.
Regards
Nathan

[30-06]

It is a used rifle Nathan, so the barrel might be dirty. Will give it a thorough cleaning and retest. Locally everybody is out of stock on the JSb Heavies, they are only expecting the new shipment in 2weeks time. So i don't want to waste the few i have on "bad test results" with a dirty barrel.

Thanks again!!

[London177]

Hello Johan,
After you've cleaned your barrel and have it nice and clean I think it unlikely that it would need a clean every 250 pellets. I thought a little lead in the barrel helped? I might be wrong but isn't less cleaning a little a better than too much?
good luck,
Alan

[DanoInTx]

I clean my barrels once when I first get the gun, then shoot until accuracy starts to suffer....2000-3000 pellets?  I usually don't see tight groups after a cleaning until a couple hundred shots are through it, lead is actually a lubricant and will also fill in any surface blemishes in the rifling.  I am also shooting a B51 and it is a one holer out to 20 yards or so with Crosman Heavies.  The biggest accuracy flaw with most B50/51's is poor muzzle crowns.  If your B50 is really having accuracy issues I'd look at the crown.  Mine was recrowned on a lathe and the groups are pretty spectacular.  I owned another B50 prior to the one I have now and it was bone stock,...did group real well at all at first.  That one ended up liking Kodiaks pretty well, this one likes Crosman Heavies, and I have been told most of them like JSB Heavies.  At 20FPE I am guessing you are shooting a .22?  What do your chrony strings look like, pretty tight?

[30-06]

Dano she is actualy a .177!! We need a firearm license for anything bigger than a .20 caliber airrifle ie: .22 etc She does not like Kodiaks(Barracudas( at all) and the CP Heavies do okay to about 20m, thereafter acuracy starts to suffer. I gave it a thorough barrel cleaning this past Friday evening and "Pledge Lubed" some JSB Exacts (8.44gr) and some CP Heavies. I Also tested the JSB Heavies. The JSB HEavies grouped 8-10mm @ 20meters. The Groups @ 30m was about 12-15mm. So far the JSB Heavies seem to group the best in this rifle.

Strange thing i found though,  was that the JSB Exacts that did not group too bad before barrel cleaning and lubing suddenly became worse. Groups opened up to about2 inches at 30m.... This was my fist try and the guys on the local forum suggested "leading in" the barrel again and then see what the groups are like. I have a limited supply of heavies as our local suppliers are out off stock at the moment. I will do some further testing and see  if the groups improve.

I havent had a good look at the barrel crown yet. in this regard i am a litle stupid. What does a good and bad crown look like??? ANy pics to show the difference?

I dont have a chrony but the guy that did the "tuning" on her tested with JSB Exact (8.44) and she gave +-20FPE. He said the power will go up slightly to about 23 FPE if i use the JSB Heavies. One thing i know for sure is that she is avery hard hitter. At 30m she penetrates a 22mm pine board fully and dents a 1mm steel plate fastened to the back off the pineboard as a back stop, and you can hear the hard hits she gives on the steel plate. I have tried 21gr piledrivers in her as well...WOW...sledgehammer.... groupnigs about 3/4  inch at 20m. They seem lik they don't want to stop once they hit the steel sheet.

This is the go-to gun if i want to have lots of killing power. Wish we had stuff like G\Hogs and P-Dogs to shoot locally

Thanks for your input also Londen177 !!

[DanoInTx]

20FPE with a 8.4gr. pellet?  No wonder your groups open up with lighter pellets, that's 1030+ FPS!!!  Much over about 950fps with a diablo shaped pellet and they start losing accuracy because they get near or break the sound barrier.  With that gun I'd shoot the heavy stuff, which it sounds like groups better for you anyways.  Heavy pellet = less FPS = subsonic = better accuracy.  I actually have mine detuned to shoot in the high 800's with heavy pellets and it groups excellent.  My Career 707 can spit out heavies well past the sound barrier, but I can't hit anything with them, I think you've found your problem:)

Good luck!

[London177]

You are dead right Dan. I've been told by several tuners that anything over 1000fps for .177 and you'll lose accuracy especially for a light pellet. My Brocock Enigma has the potential for nearly 30ft/lb but as it's a .177 job better to stay around 18-19ft/lb.
regards,
Alan