Question to Duck re 1300

[Ryan]

Duck,

I couldn't resist the curiosity how the 1300 self-setting valve worked, so I took everything apart. I wanted to redo the internals anyway.

1) Now I note that the hammer spring and the sears spring are almost identical in length and the # of coils. One does seem a bit stronger than the other though. The Crosman part list shows two different part # for them. Are they the same? I got them mixed up before I tagged them.

2) Is the barrel removable from the breech? I want to be sure before I forcibly separate them in a vice.

3) The internals are all gummed up and dried up with whatever that had gone into the pump tube. I recall it has been said a number of times that 1040 motor oil should be used in a pumper. Is Crosman's pell gun oil also 1040?   What is the secret sauce that everybody has been talking about?

4) 1300's linkage roll pin has the same part # as the 13xx's.  Someone was asking a little earlier which way the roll pin should come out and get back in. Here are the measurement of the linkage holes by looking at the pump tube on the top - the one on the left hand side is .0190" and the one on the right is .0188". The roll pin should therefore come out and get back in on the left side.

Thanks in advance,

[mudduck48]

Check you PM. Here is a picture of the springs.
Trigger spring on top.
Hammer spring on bottom.

[Ryan]

10 pumps on a 1300 seems to exert a lot or pressure on the sears making the trigger not smooth at all. You can smooth a 13xx trigger and sears by polishing the contact. I still have to get a better understanding of the interaction between a 1300 trigger and sears. Is it at all possible to smooth out the trigger pull on the 1300?

[Big Bore Bart]

  That's the drawback of the blow-off style valves.   The more you pump the harder the trigger pull.   It's because the trigger is holding the valve closed against the valve pressure.

[BDS]

Thank you Big Bore Bart...

At the heart of all the issues described so far is... the modern 13XX guns are hammer cocking/sear engagement designs, the older multi-pumpers like the 1300 and the 140 carbine, are self cocking on the first pump (sets the hammer and the sear). And yes, the trigger pull or energy to move it gets more difficult with the greater amount of pumps (resistance against the sear and trigger).

Trying to mod these triggers and contact points like a 13XX or 22XX gun can be hazardous to one's health, a little polishing and a good lube is about all that should be done.

[mudduck48]

Trying to mod these triggers and contact points like a 13XX or 22XX gun can be hazardous to one's health, a little polishing and a good lube is about all that should be done.
I totality agree. The hammer is pushed against the front part of the sear. You just want to smooth it up just a little without changing the angle. The front edge of the hammer do the same way. I have my #1, 1300 so smooth that I have to pump it first, then load it. Sometimes it goes off while pumping. I checked the trigger pull with my Lyman trigger pull gauge and at 6 pumps it is 1lb 14oz. At 10 pumps it is 2lbs 7oz. If you screw up the sear you can still buy them from Bryan and Associates. The sear in the new guns will not work, too short. See picture. 1300 on top and new style on the bottom. 

[BDS]

Similar here... my 140 carbine is 1lb-ish at 3-4 pumps, 1lb-12 oz 5-6 pumps and nearly 2 pounds at 8 pumps.

I polished the trigger works to mirror finish (no metal removal) and moly lubed it and it passed a good, hard bump test and has never fired under it's own volition.

I still pump first, load second just to be on the safer side of the equation.

[mudduck48]

Yep, that is the safest what to do the pumpers. When I first got the gun back together and working, I had loaded it, turned around and was pumping it and POP! The pellet went across the garage, hit the cupboard door, ricochet off the door and went back behind me. Nope, pump then load then take safety off pointing down range.

[Ryan]

Thanks for the heads up. I have the 1300 taken apart already, but got tied up with work for the time being. I know you have explained how the self-dump valve worked, but I still have to study the entire set-up to get a good grip of how it works. I was going to polish the trigger sear and hammer contact. Now that knowing the downside of putting a monkey wrench to it, I may just as well leave them alone. In any rate, I always pump first and load before I shoot. I will post pic when I have the gun put back together. Thks,