Rusted chokes.

[Rob85]

13 hours ago, DUNKS said:

Just an aside. I have read on a USA forum that a mixture of 75% ATF. "automatic transmission fluid" To 25% paraffin or turps makes  perhaps the best goo for freeing locked nuts and works on chokes. Couple of days soak will free the most stuck choles. Just stand muzzles in a few inches of the fluid.

One of the best things I know for loosening rust and old grease and crud is a good soak in some cheap red diesel. And if you're not afraid of riding the pot into a low earth orbit you can GENTLY warm it up a bit while it soaks

[JohnfromUK]

16 hours ago, DUNKS said:

I have read on a USA forum that a mixture of 75% ATF. "automatic transmission fluid"

I am not surprised; automatic transmissions are expensive, complex and demanding and a lot of work will have gone into making the fluid/oil used high quality to give a reliable and long lasting product.  Motor oils (best modern synthetic) are also very good, but have a whole lot of additives (to cope with things like soot and combustion products) which may not be appropriate on guns.

[DUNKS]

1 hour ago, JohnfromUK said:

I am not surprised; automatic transmissions are expensive, complex and demanding and a lot of work will have gone into making the fluid/oil used high quality to give a reliable and long lasting product.  Motor oils (best modern synthetic) are also very good, but have a whole lot of additives (to cope with things like soot and combustion products) which may not be appropriate on guns.

I am sure that's true. It's also the base of Ed's Red bore cleaner with the addition of Acetone to soften plastic. and Lanolin as a rust proofer.

[figgy]

Ed's red is a great product. I bought some off a member on here years ago. He bought the ingredients as they come in quantities you'll never use yourself, he made up glass spay bottles for sale to spread the costs. Well worth it if you can get some. Many recipes about for the ingredients and quantity of each.