Finally replaced the valve in my 392.
Late last year my Benjamin 392 started leaking down. I pulled it apart last year and found a heavily corroded aluminum valve body. I ordered the replacement but never put it in until today. I trimmed the the check valve down to 5/16" before reinstalling. Now the gun will stay pumped up all day without leaking down. I already used it to dispatch a garden ravaging squirrel today.