Velocity drop after barrel cleaning?

Forums PCP Airguns Velocity drop after barrel cleaning?

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    james.dean
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    Hi guys,

    Well, it’s all in the title.. Have you ever experienced a 10-15 fps drop after you’ve cleaned (deep cleaning) your barrel??
    That’s what I’m experiencing on my regulared AA S510 xtra FAC .22…
    MY guess is that the barrel needs to be “lubed” by the “grease” of lead, so, I hope, the velocity will come back as normal after few tenths of pellets.. What do you think about it?
    Thanks for your income !! =)

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    jking
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    I’ve seen this before JD. I cant remember which gun or guns did it. I posted about it and I think everyone thought I was nuts. There was a couple of conclusions, one maybe I had switched tins of pellets just after cleaning or two, maybe a dirty barrel helped seal the skirt some resulting in higher velocities. You’d think a nice shiny barrel would be the opposite. How long ago was it that you checked the previous faster velocity? Another thing to consider is the temps are getting cooler fast and I’m a believer that warm guns shoot faster than cold. So I’m not sure in your case. Keep us posted.
    Jimmy

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    Dartagnan
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    Could you discribe how you cleaned your barrel? Did you put cleaning solvent (lube, etc)? 

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    james.dean
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    Jking: Last time I checked velocities was the Day before ^^ using the same pellets with the exact same set up and temps =/

    Dartagnan: I cleaned it using a pull through (homemade: microfiber), beginning from where the pellet exits.. I had to pull quite hard though as it would not pass the choke (by hard I don’t mean like a complete retard but for a few seconds, I thought it was gonna stay stuck before entering the choke)
    Totally dry no lube or anything..

    Now, I lubed 10 pellets with nappier gun oil Just for testing (I normally never lube my pellets) and the velocities came back to normal (maybe 3-5 fps less)..

    Any ideas ? =$

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    Dartagnan
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    Possibly, something got stuck in the transfer port during cleaning, plus the reduction of velocity due to cooler temperatures. 

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    james.dean
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    Not when you have a regulated rifle shooting 895 fps over 55 shots for months which drops to 880 right after you’ve cleaned it mate..

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    Dairyboy
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    Wait you cleaned from the muzzle end towards the breech end?

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    james.dean
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    Yes.. Thought about it afterwards.
    As I only use micro fiber, I don’t think it has any kind of importance, still, I don’t like it.
    Just me being tired and dumb –“

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    Bullfrog
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    Actually it can happen. Very thick lead deposits can act like a lube. When the rifling is cleaned out, the rifling will contact the pellet properly and create more drag. 

    I’ve seen this happen on both a .25 Marauder. The kind if fouling I’m talking about though is the kind that is so severe that when you push a pellet thru before cleaning, you barely get rifling marks on the pellet, and when you push one thru afterwards, you get well-defined rifle marks. 

    I’ve also seen cleanings do the opposite and add some fps.

    And if you removed you barrel to clean (as you often must for a deep cleaning), its possible to ever so slightly misalign or unknowingly correct a misaligned barrel transfer port. 

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    jking
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    JD, I’m assuming your S510 is not regulated. Maybe the higher velocities were up on the high portion of the curve and the lower velocities were on one end or the other. Did you by chance refill just after cleaning the barrel. I’d just shoot it for a while and see if the velocity doesn’t come back..

    Oh, I’ve done this before with my AA’s too,, accidentally bumped the power adjuster and ended up short on speed.
    JK

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    james.dean
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    Nope mate !! My s510 is regged and by now, it came back to normal velocities (890 – 895 fps).. After few tens of pellets through it, I think the lead lubed it and pellets don’t have as much drag as a non lubed barrel.

    I guess what you Said bullfrog and Totally agree with you, as the rifling gets deeper by cleaning the lead déposit, there more drag hence the diminuated velocities.
    I didn’t remove the barrel though.
    And I’m worrying a bit about how I cleaned it: using a microfiber pull through but starting from the muzzle and going to the breach end.. Hope it doesn’t mess with the barrel quality / finish or anything..

    I also Wonder whether the accuracy is better with a pellet well “gripped” by the rifling or with a lubed barrel in which rifling will not grip the pellet as much..

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    Dartagnan
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    Cleaning the barrel starting at the muzzle could possibly drop deposits collected in the barrel to drop into your transfer port.  More reason not to start at the muzzle

    Removing the moderator to fit a long enough straw past the baffles, in this case the Benjamin Marauder, can help thread the fishing line through the barrel

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    I found pulling an 80lb fishing line thick enough to pull a cleaning patch through comfortably. 
     
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    And can be tucked away in an empty pellet tin for transport.

    Here’s how I think of a pellet leaving a dirty barrel. Say your house fan (pellet) with 4 blades (rifling) happen to break off 1 blade (debris or collection of leading in the rifling), how would the fan spin or in our case, how would the pellet react once it leaves the barrel with only 3 out of the 4 rifling it should have?

     

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    Bullfrog
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    “james.dean”Nope mate !! My s510 is regged and by now, it came back to normal velocities (890 – 895 fps).. After few tens of pellets through it, I think the lead lubed it and pellets don’t have as much drag as a non lubed barrel.

    I guess what you Said bullfrog and Totally agree with you, as the rifling gets deeper by cleaning the lead déposit, there more drag hence the diminuated velocities.
    I didn’t remove the barrel though.
    And I’m worrying a bit about how I cleaned it: using a microfiber pull through but starting from the muzzle and going to the breach end.. Hope it doesn’t mess with the barrel quality / finish or anything..

    I also Wonder whether the accuracy is better with a pellet well “gripped” by the rifling or with a lubed barrel in which rifling will not grip the pellet as much..

    
Don’t fret over how you cleaned it. I’m not familiar with your gun, but most quality airgun barrels these days are made of various steels. So long as you don’t stick anything in the barrel that is as hard as or harder than the steel the inside of your barrel is made out of, you’ll be fine. I clean my Flex from the muzzle whenever it needs a light cleaning and I don’t  want to pop the barrel off and rezero my gun afterward. 

    I am convinced that much of the lore on the internet concerning the “proper” way to clean a rifle barrel, that of both airguns or powder-burners, is a mythology that arose from the influence of competition shooters and some gun smiths and started validating itself thru social media. Sure, use common sense when you stick something down your gun barrel. But don’t fret too much over it either. Just give your gun a good scrub whenever groups open up, and not before.

    Concerning lube, that really seems to depend on the barrel. My .25 Marauder love lubed pellets and bullets and various power levels. My Flex seems to prefer dry pellets. The Flex will actually shoot 44 grain JSBs wet or dry, but when it comes to the 50 grain JSBs and the Polymags, the gun noticeably groups those pellets tighter when they are absolutely dry. 

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