Nails keep jamming in the gun. how do you fix that and not sure about the correct air pressure.

You can check a few things to identify the problem if your Senco FramePro 602 nail gun is not shooting at angles:

Make sure the depth adjustment is adjusted appropriately for the material you are dealing with and the nail size by checking it.
The cannon may not be able to fire at an angle if the depth adjustment is set too high.

Verify the air pressure: Ensure that the nail gun's air pressure is set properly.
For the FramePro 602, a pressure range of 70 to 120 PSI is advised.
The nail gun may stop working if the air pressure is too low.

Examine the magazine for any jammed nails that might be stopping the rifle from shooting properly. If you find any, remove them.
Make sure the magazine is free of any debris and unblock any nails that are stuck.

Verify the angle adjustment: Ensure that the nail gun's angle adjustment is correctly set for the angle you intend to utilize.
The FramePro 602 is capable of firing at 21-degree and 28-degree angles, so make sure that the angle adjustment is set to the appropriate level.

If your using refills that have wire holding the nails together.
Check to see if bits of wire, debris is collecting in around the striking hammer. I switched to paper and never looked back. Must have gone through 5k worth of nails and rarely jams. Other things to check,
1. Check the striking hammer, make sure it is not bent or damaged.
2. Check air pressure, Low pressure can cause jamming, misfires.
3. If the tool needs pneumatic oil, 2-3 drops before you start good rule of thumb.
4. Check spring return. Sufficient pressure must be maintained or the nails will not feed properly. Misfires, incorrect feed, jamming etc.
I had a Hitachi brad nailer and it was horrible. Fire 1 brad nail would jam or misfire. Did everything I could think of nothing worked. Put it up, got a Rigid brad nailer and never looked at the Hitachi again. :)
Sometimes you just get a lemon! (PS I understand you have a framing nail gun. Brad nail gun above is used for an example)
Hope this helps

make sure nails are loaded into the gun straight and correctly

tip of your piston may be damaged... or the feeder system is not bringing the nail fully into position. You may have to file the rail to correct any damage that a jam may have caused

Assuming that the gun will not jam with nails removed and the driver returns to top of cylinder when fired without nails. If the driver is bent the nailer will jam without nails. Jamming is usualy caused by bent driver, driver tip worn (not square), or wrong nails. If the driver is not bent and the tip is square, suspect wrong nails. Easy test. Place a strip of nails on outside of rails with the nail heads aligned with top of rail. Move the strip of nails toward the nose if gun. With the heads aligned with the top of the rail, the first nail should align with the path of the driver. If the first nail does not align with the path of the driver and the head is angled slightly away from the path of the driver, the driver may strike the shaft of the first nail pushing the nails back into the rails. If the head of the first nail is forward with the nail shaft angled back away, the nail will flip causing jam. The first nail should align with the path of the driver to prevent jam. It is difficult to find perfectly made nails that align correctly. But certainly check the nails with test mentioned above with every new box for accuracy. You might find that you will need to change brands to get a good fit. Good luck.

if safety is jamming, its either bent or the pin that keeps it in place is missing/broken, you can find the pin right in front of the trigger. now as far as the nails jamming could be a few things. 1. wrong nails 2.right nail but may have gotten a defective batch 3. bucket that holds nails is adjusted to wrong size. 4.nails have been dropped/ squished and coil is not round anymore 5. nose is very worn and two nails are trying to come out at a time 6. driver is worn/broken and is trying to push out two nails at one time

Most likely just needs piston oring. Remove nails from the gun and point nose of gun up then down again. If the piston travels up and down in the cylinder, replace the oring. The piston returns to top with air pressure and needs good snug piston oring and good lower bumper (if bumper is cracked or missing pieces ~ replace ). Be sure to lube the orings in the headvalve with silicone paste or white grease. Part # ORK11 oring kit will reseal the gun. Good luck with your repair.

This can happen for a number of reasons.

1) Insufficient air pressure (should be set to around 100PSI)

2) Hitting another nail or other extremely hard surface (old roofs are known for this)

3) Defect in the gun or lack of lubrication.

Since this is a reconditioned unit, I think that the gun is probably fine. Verify that the compressor has the correct pressure and that the hose is large enough in diameter to deliver sufficient air to the gun. Check the CFM (Cubic Feet per Minute) rating of the compressor/tank combo against the requirements of the gun.

Keep us posted,

Dan

several things could cause this need more info..... be sure your
firing correct nails #1, check air pressure #2,make sure spring clip
is pushing nails forward #3, make sure ram is moving in the head #4
if this does not help we can go deeper.... good luck

Not sure exactly what Bostitch framer model you have, but if it is powered by compressed air, as long as you remove the air hose from the nail gun, there should be no risk of the nail gun firing while you remove the jammed nail. There should be a way to access the driver area from the top of the nail gun, even via a latch or a couple screws. Remove the top part of the driver area and that should give you access to the jammed nail, which you can remove. Use long nose pliers or something similar if the nails are really stuck.