bore cleaning?

[firefly1957]

I have the 25 Caliber Benjamin Nitro piston gun it shoot great but recently accuracy went south First thought was scope slipped again as this does happen . Ended up bore was all carboned up .

So how often do you clean your air gun bores?

I do need to explain a bit about the issue As soon as I got the gun I bought three pellet weights and also started cutting dies to swage pellets . I found my home swaged 20 grain pellets formed from cast #4 buckshot shot best and had much better weight consistency then any of the three factory brands. ON Here I learned to use the silicone lube for the piston as lube but before that I had tried another lube, I ended up being happiest with lanolin I just spray finished pellets with the case lube mix of alcohol and lanolin shake them and let them dry.

My first batch was lubed with a heavy lube they shoot well but these are the ones that really messed the bore up I should have guessed by the smoke produced when shooting them! The lube was a pond of paraffin slowly heated and mixed with a 15 oz. can of STP motor oil additive and a couple blue crayons for Identification.

By the way if wondering the combustion of this lube adds nothing to the pellet velocity which is a bit low at about 800 f/s for a 20 grain pellet .

Other results I noted ( did not note make of them, tin pellet is from my dies made with plumbing solder)

27.7 grain pellet with hollow base 520 f/s very poor accuracy some missed target. (Home swaged Solid bottom pellets shoot best)

12 grain pellet of tin 900 f/s 4" group shoot high. (This one really made a crack on firing first thought was is was super sonic that was not correct the crack was the piston slamming harder from light weight I believe!

Factory 27.5 grain pellet 630 f/s 4" group if pushed in chamber further with pen 5" group and a loss of 100 f/s!

Factory 34 grain pellets do 580 f/s and about the same accuracy as other pellet they do seem to go further into wood.

Seems I have not written down any data for factory 38 grain pellets?

[GBertolet]

The crack and smoke is from dieseling. The piston acts as a diesel engine does. The high compression generates high heat, which ignites any oils in the chamber, and even sometimes on the pellets. Too much or the wrong kind of oil, will cause severe dieseling, causing accuracy to go to heck, along with extremely high velocities, and is hard on the gun. Small amounts of weak dieseling, often refered to as combustion, aids velocity, and is desirable. The pellets you buy are not lubed, other than a light graphite coating.

Some serious airgunners, wash their pellets, and then spray lemon pledge, furniture polish on them, and let dry. They claim good results. Might be something you can try.

Generally, you seldom have to clean airgun barrels. I use a pull through snake cleaner, once a year, just for the heck of it, when I do a lube tune on my springers. The nature of the combustion, sprays oil residue on the barrel, acting as a protectorate.

[gwrench]

I made note of an article that gave the recommended stuff to clean lead. https://www.pyramydair.com/s/a/J_B_N..._Compound/1086

I have not done it on any of mine yet so I can't advise on it. When there's a problem with accuracy I will give it a try myself.

[firefly1957]

I will note I only have trouble with the one lube in this gun the lanolin works great for me and I have it on hand.

As far as dieseling I do understand that, this gun has a warning not to use anything but silicone oil in chamber or piston seals can go bad so I lube it every couple hundred shots with proper silicone oil.

I have a old Spanish made .177 target pellet gun that only pushes pellets at 540 f/s filling the pellet base with starting fluid bumps them to 950 f/s ! I tried the same in a .177 Chinese pellet gun that does 950 f/s there was no change in velocity at all .

I did not get any cleaner in piston area I used carburetor cleaner then Ed's red and wiped most of it out and fired a pellet as gun was cocked to clean so no cleaner would get in piston area . Since cleaning it has shot well taking out small pests to 20 yards and three coons and a possum in live trap . ( State law prohibits moving them elsewhere ) This pellet gun will cut the wire in the live trap If they are hit it also goes though 3/4" of treated wood at 25 yards . I find chest shots on possums and skunks are lethal however Raccoons need to be head shot.