Resealing the Beeman P17 air pistol: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
Today’s report is written by reader 45Bravo. It is Part 2 of his report on resealing the Beeman P17 air pistol. This is the part of the report I have been waiting for, because I want to go deeper inside my P17.
This report will go differently than some in the past. We will first learn how to reseal the pistol, which ends today, then I will test one for you. But while this story has been unfolding I have bought a Beeman P3 pistol to test alongside the P17. We will find out how the two airguns really compare in all ways. I hope you are as excited as I am!
If you’d like to write a guest post for this blog, please email me.
And now, over to you, 45Bravo.
Resealing the Beeman P17 air pistol: Part 2
This report covers:
- Step 2.
- Step 3.
- Just remember:
Now it’s time to go beyond the simple fix we did in Part 1. Thankfully that is the biggest problem people have with the Beeman P17 and it is so easy to fix. Today, however, we are going past that to something else that sometimes happens.
If your pistol is dumping the air when you get to the end of the pump stroke, or if you can hear air escaping as fast as you pump the gun and you feel absolutely no resistance while pumping, then we need to dig deeper.
This requires disassembling the pistol, so we will start by removing the piston like we did in part 1. Then the right grip comes off by removing the screw in the right grip with a 2.5mm Allen wrench.
As you slowly pry the grip halves apart, an L shaped spring that connects to the sear will pop out of the rear of the grip, but don’t worry, it is wrapped around a pin, and will not go anywhere. [Editor’s note: Some of our readers have discussed this spring already. Apparently it gives problems if not installed correctly.]
The 2 pins SHOULD stay in the left grip with all the parts in place.
It looks very complicated under the grip, but in actuality, there are only 11 parts, and they are assembled in 3 groups.
Group 1. The sear and L-shaped spring and pivot pin.
Group 2. The hammer, the larger L-shaped main hammer spring, the smaller internal P-shaped spring inside the hammer, lever, coil spring, and pivot pin.
Group 3. The trigger and pivot pin.
Tip: Take photos before you remove the parts as you go.
Using needle-nosed pliers lift the tail (on the left) of the lower L-shaped hammer spring out of the grip frame to relieve the spring tension.
Lift the left-most pivot pin just enough so it clears the plastic hole, and pull the sear, and spring rearward and out.
Unhook the lower spring from the hammer. That’s the part that looks like a big number 7. You do not have to take the trigger out for this repair, but if you do, it is only the trigger and the pivot pin.
Unhook the lower end of the coil spring by the trigger, and remove the spring.
Pull the hammer pivot pin out slightly, then lift the right side up to rotate it around the valve stem, and the whole assembly will lift out.
Inside the hammer (the number 7-looking piece) is another spring, shaped like a P, that the pivot pin goes through, please pay attention to its orientation.
Now we need to remove the compression chamber.
On the left rear of the compression chamber is a 2mm grub screw, loosen it and, using a punch, knock out the pin holding the compression chamber in the frame.
Tip: Support the plastic frame of the pistol while you drive out the pin.
A simple way is to take a scrap piece of 2×4 and drill a 1/4-inch diameter hole through it, as you punch the pin through, it will go down the hole you drilled.
If you don’t have a 2×4, you can support the pistol on a roll of electrical tape and the pin will go into the center of the roll of tape as you drift out the pin.
The compression chamber now lifts straight out the top of the pistol.
There are 3 metal “fingers” at the rear of the compression chamber, they are held in place by a small cross pin, the center “finger” is different than the others at the base. This center “finger” engages the sear during the cocking process. Drive the pin out and remove the three fingers.
The breech o-ring at the top of the compression tube can be can be replaced easily, it is one of the 2 #009 o-rings.
A 13mm wrench is used to unscrew the brass valve nut on the lower part of the compression tube.
After it is unscrewed the valve just pulls straight out.
Clean the valve, and inspect the 2 o-rings.
On the gun I’m resealing, the smallest o-ring at the top of the valve in the picture above was split. Replace it with the #006 o-ring, and lube it with your choice of lube.
Replace the lower (larger) o-ring with the second #009 o-ring.
Tip: Wrap Teflon plumbers tape around the brass threads on the valve to give an extra layer of sealing. (it may not help, but it doesn’t hurt either.)
Screw the valve back in to the compression chamber.
Tip: Hold the valve stem nut while you tighten the brass valve nut in place to prevent the top o-ring from spinning in its seat, and possibly being damaged.
Put the 3 “fingers” back in in the correct orientation, with the different one in the middle.
Put the compression chamber back in the frame, and tap the cross pin in (supporting the frame as this is done) to secure it to the frame, and tighten the set screw at the left rear of the compression tube with the 2mm Allen wrench.
Take the hammer assembly, put the left side of the number 7 looking piece over the valve stem nut, then rotate it to the right, just the opposite of taking it out.
Tip: There is a small groove in the frame where the pivoting lever part of the hammer assembly will fit up into. If the lever doesn’t go up into there, the trigger will not contact the piece to fire the gun.
Put the larger of the 2 springs back on the lower screw shaft, and put it back in place on the hammer (the thing that looks like a number 7) but do not put it under tension yet.
Slide the sear and spring and pin back in place, but don’t put it under tension yet.
Using the needle-nose pliers, hook the small coil spring back into the pivoting lever piece of the hammer assembly behind the trigger.
Now, using the needle-nose pliers, put the left tail of the lower spring up into the left side of the frame.
Start the right grip panel on the pivot pins, and just before it closes completely, push the tail of the smaller sear spring up into the frame. Make sure it goes UP into the right side of the grip.
Tip: If the tail of the sear spring goes into the left side of the grip, it puts pressure on the sear in such a way that it doesn’t catch the hammer consistently, causing the gun to sometimes dump the air on cocking, but not every time.
Tighten the right grip with the 2.5mm Allen wrench.
Put the piston back in as in part 1, and function test the pistol.
This addresses the 2 major reliability issues with this pistol. There are many threads online about how to mod it for more power and many other things.
The one last thing that is a nuisance is when pumping, you accidentally press down on the rear sight assembly, when you do, it relieves spring tension on the elevation screw, and allows it to rotate, thereby slowly raising your point of aim with every shot.
To solve this problem open the action, and unscrew the rear sight elevation screw, be careful, as there is a spring under the rear sight that can go flying if not careful.
Also there is a nut under the sight inside the “slide” that will fall out when the screw is removed.
Tip: Put a piece of tape over the inside nut, so it doesn’t fall out when you remove the elevation screw. Just remember to remove the tape when done.
I put a small piece of the same fuel tubing we used for the transport seal in the S&W 78G reseal on the elevation screw, it now keeps the screw in place, and doesn’t rotate when you press on the rear sight assembly during cocking.
Just put the tubing on the screw, put the spring in place, and tighten the elevation screw.
There you have it, it sounds harder than it is, but for a $30 investment, you get a accurate pistol that is a great value for the money.
When it stops shooting, you have an opportunity to repair the gun with little or no investment.
Be Curious enough to take it apart.
Be Skilled enough to put it back together.
Be Clever enough to hide the extra parts when you’re done.