Author: Sourav Chowdhury

This isn’t a terribly common occurrence but it does happen from time to time. All of a sudden for no apparent reason you can’t pull the trigger or move the safety on your AR15. The hammer is stuck in the cocked position and will not move no matter how hard you try to pull the trigger.

Nine times out of ten this is because a primer blew out of a case as it was fired and fell into the lower. The primer rolls under the trigger and jams underneath the back of the trigger. If this happens clear the rifle and remove the lower from the upper receiver by pushing out the takedown and pivot pins.

First try shaking the lower upside down while trying to move the hammer, trigger and safety. Sometimes you can jar the blown primer loose and shake it out of the lower. If this doesn’t work than it is a fairly simple matter of removing the hammer and the trigger and removing the blown primer.

First look into the lower and note how the parts fit into the lower receiver to make it easier when you reassemble. Note how the legs of the hammer spring are on top of the trigger pin. To remove the hammer and trigger pins use a punch that is about 1/8″. Punch the hammer pin out of the lower. The hammer will probably be stuck to the rear still. Keep in mind that the hammer is under tension and is going to come flying out of the lower when it is released. So have the lower pointed in a safe direction and also where the hammer can’t get lost when it comes out of the lower. You may have to pull the trigger to get the hammer to release from the lower.
Once the hammer is out you may see the primer inside. You may be able to get it unstuck without removing the trigger at this point by using a small pick or punch.

If not just drive out the trigger pin and remove the trigger. The disconnector will also come out with the trigger. Note its orientation.
ou will see the primer in the lower at this point. Also make sure there isn’t any other debris in the lower that might interfere with the proper operation of the rifle.

Reassemble the trigger and disconnector and push them back into the lower. Line up the hole in the disconnector with the holes in the hammer and push the trigger pin back in. Then reinstall the hammer making sure the legs of the spring rest on top of the trigger pin and push the hammer pin back in.

Blown primers do happen from time to time with reloads or factory ammunition so when you find a blown primer it doesn’t mean there is anything wrong with your rifle. However, if you are experiencing blown primers commonly with factory ammunition this does indicate that there may be a chamber problem with the rifle.

1. Verify your weapon is safe
2. Remove Bolt Carrier Group
3. Remove Firing Pin Retaining Pin
4. Remove Bolt Cam Pin
5. Remove Bolt
6. Carefully remove the 3 gas rings. They are not needed
7. Install existing Bolt into the New Bolt Carrier
8. Align Bolt and install Bolt Cam Pin
9. Insert Firing Pin and Firing Pin Retaining Pin
10. Remove existing handguards. You will not need them
11. Using a 1/16″ punch, remove the Gas Tube Spring Pin. You will not need it
12. Remove Gas Tube from Front Sight and Upper Receiver
13. Install Bushing into Upper Receiver using a military style cleaning rod
14. Install Piston Chamber into the Gas Port of Front Sight
15. Using a 1/16″ punch, verify the holes are aligned
16. Install the solid Pin included with the kit into the Front Sight
17. DO NOT USE OLD GAS TUBE SPRING PIN
18. Make sure it is flush with the Front Sight
19. Take note of orientation of the Operation Rod flat part, it needs to be facing up
20. Install Operation Rod into Upper Receiver
21. Insert Piston into Piston Chamber
22. With flat part facing up, assembly both parts together
23. Install Operation Rod Clip into hole
24. Use a flat head screwdriver to secure the rod clip around the Operation Rod
25. Make sure the assembly moves freely
26. Install new handguards. DO NOT USE OLD ONES. They are different
27. Verify you can see the Operation Rod inside the Upper Receiver
28. Install Bolt Carrier Group
29. You are done!

First make sure the rifle is unloaded. Then remove the upper from the lower by pushing out the takedown and pivot pins. Put the lower receiver on an AR15 lower receiver vice block and remove the upper rear stock screw with a flat screwdriver. Remove stock body.

Remove takedown pin detent spring from lower and set aside.

Remove buffer and spring by pushing down on buffer retainer and releasing the buffer and spring.
Remove both completely from the lower and set aside.


With the cutout portion of the tele stock wrench loosen the buffer tube but don’t unscrew it all the way. (If you are not using this style of tele stock wrench simply use an end wrench)
Before doing so make sure you put a thumb over the buffer detent to keep it from shooting out of the lower when you turn the buffer tube all the way off. Release the buffer detent and spring slowly and leave them in the lower.



Screw the tele stock buffer tube all the way in while holding the buffer retainer down with your thumb. Turn the stock in until it stops against the retainer, then back it off until it holds the retainer in, but isn’t rubbing on it hard. The buffer retainer should move up and down freely when you press on it.

Stock should be straight with the pistol grip

Reinstall takedown pin detent spring. Make sure it is square against the tele stock endplate and push the spring in then screw the castle nut up against it.


Tighten castle nut down snugly with the wrench. It is also okay to use a little blue Loctite on the threads to keep it from loosening. (Or stake the nut on if you want a more permanent installation. I covered castle nut staking in the May 2013 newsletter.)

Push the carbine buffer and spring that came with the tele stock assembly into the buffer tube and you are done.



To remove a tele stock and install a standard stock assembly you basically just reverse these instructions. The only thing to be mindful of is to back the castle nut off enough to remove the takedown pin detent spring completely before turning the tele stock off so you don’t damage it.

The excellent Geissele trigger comes with a set of instructions but I thought it might be helpful to provide a pictorial instruction to make it a little easier.

First make sure rifle is unloaded then push out the takedown and pivot pins and remove the lower from the upper.
Using a 1/8″ or smaller punch, punch out the hammer pin then the trigger pin and remove the stock hammer, trigger, disconnector and pins and put aside.

Lubricate any bearing surface with the provided grease. Hammer/trigger pin holes and sear surfaces

Line up the disconnector hole with the trigger pin hole in the receiver and tap in the trigger pin provided with the Geissele trigger.

Install the hammer pin retainer on the hammer. This is very important. If this is not installed the hammer pin will walk out and may cause serious and potentially dangerous malfunctions.


Put hammer in as shown. Make sure the legs of the hammer spring are on top of the trigger pin. It is the legs of the hammer spring that keep the trigger pin from walking out.


It’s easiest to put the hammer in if the lower is on a lower receiver vise block as the legs of the hammer spring are very stiff. Push the hammer down until the hammer pin hole lines up with the receiver and push a 5/32″ punch into the hole in the receiver to hold the hammer in place. Insert the hammer pin in the other side. You will have to move the punch around a bit to get the holes to line up. Once they are lined up push the pin in with a plastic or wooden hammer far enough so you can remove the punch from the other side. Then move the hammer around until the holes line up on the other side and push the hammer pin the rest of the way in.
Reinstall upper onto lower and function test lower for proper function. Refer to page 6 of the Windham Weaponry Operating and Safety Manual entitled “Range Safety Checks-Before You Fire”. Follow that same procedure to test the trigger group for proper function.

To purchase this fine GEISSELE 2 STAGE (G2S) TRIGGER, click here:

To install rail, first verify that the rifle is unloaded. Then push the takedown and pivot pins out and remove the upper from the lower receiver. Remove handguards per the instruction on page 23 of your operator’s manual.

With a pair of needle nosed pliers remove the inner heat shield from the handguard.

Place rail in the desired location on the handguard. There are three possible locations you can place it.

Place the rail nuts inside the handguard and tighten the screws into them with the Allen wrench provided with the rail kit. There are two lengths of screws. For our stock M4 handguards you will want to use the short screws. You can also use a little blue Loctite on these screws as well to make sure they don’t back out.

You can replace the inner heat shield if desired or leave it out. It is optional. If you put it back in it may be necessary to stake it into place by the plastic tabs or melt the tabs so it stays in place.

Reinstall handguards on rifle.

This rail is an easy and economical way to allow the mounting of a forward pistol grip, flashlight, bipod mount or any other accessory that will mount to a MIL-STD-1913 rail on your rifle.

Midwest Industries 4″ Handguard Rail in our website catalog

Since some AR15 style rifles come with a triangular handguard cap, some users might find it necessary to change the handguard cap to a round style. This is necessary if an aftermarket handguard is purchased that requires the use of a round handguard cap. Currently we sell two rifles that come standard with a triangular handguard cap, our base model .308 SRC and our 20″ gov’t rifle. Many handguards, such as the Magpul MOE handguards for example, will fit either round or triangular. But if you purchased a handguard that is specifically made to fit a round handguard cap and you have a triangular one, here’s how to change it out.

First make sure the rifle is unloaded. Then push the takedown pin and pivot pin out and remove the upper from the lower receiver. Remove the bolt carrier and charging handle (see page 14 of your Windham Weaponry Operating and Safety Manual). Then remove the handguards as shown on page 23 of the manual.

Now remove the flash hider with an open end wrench.
If you have a ban compliant gun that has a welded muzzle brake, stop here as those cannot be removed.
Secure the end of the barrel in a padded set of barrel jaw blocks in a vise and turn the flash hider counter-clockwise (a vise padded with wood will work too, the flash hider only needs about 15-20 foot pounds of torque for removal). Remove flash hider and crush washer and set aside.

Set gas block on a hammer handle or other similar piece of hard wood so that the taper pins can be driven out of both sides. Taper pins must be driven out from left to right as shown (from the small end of the taper pin). Use a wide flat punch to start the taper pin and push it in flush, then use a 1/8″ punch to drive them all the way out.

Spray a liberal amount of oil on the outside of the barrel and at the gas block area. With a wooden or plastic mallet drive the gas block/gas tube assembly off the barrel. Remove the triangular handguard cap and replace it with the round one. Wipe any grime off the barrel and gas block then re-oil the barrel. Put the assembly back on the barrel and line up the taper pin holes. Drive the taper pins back in the way they came out through the right side. Make sure the holes are lined up well. If they don’t seem to be going back in, drive them out and realign the holes and start again.

Reinstall crush washer and flash hider, install your new handguard and you are done.

Click here for the round handguard cap in our website catalog.

This is a long piece with 19 Photos, WW Technical Paper – POF Drop In Trigger complete instructional article.

First make sure weapon is empty. Push in pivot pin and open rifle. Remove bolt carrier and charging handle from the upper.

You will need a small hammer, 1/16″ punch, 1/16″ roll pin holder, paper clip, wire cutters, a block of wood (soft wood like pine), thumb tack and a wide punch. Wear safety glasses.

The block of wood should have a hole drilled in it to rest the charging handle over for when you drive out the roll pin. This hole will capture the roll pin.

Using the 1/16″ punch, drive out the roll pin from the back side of the charging handle. It’s easier from this side as the roll pin is slightly recessed there.


Now take the thumb tack and drive it all the way into the block of wood. Rotate it around a bit when you take it out to enlarge the hole slightly.

Then with the wire cutters snip off a piece of the paper clip approximately the same length as the pin on the thumbtack. For this I used a coated paperclip with a diameter of about .050″. One even slightly thicker would work even better as the latch roll pin size is about .063″ but this is what I had laying around my bench and it worked fine. You might find some other kind of stock available that will work even better.

Put the piece of paper clip in the hole just far enough so it stands firmly on its own. Not too loose, not too tight.

Insert the tactical latch like so and press it into the latch spring in the charging handle visually lining up the hole in the latch with the holes in the charging handle.

Now place the whole assembly onto the block of wood pushing it down onto the paper clip through the pin holes in the charging handle. The paper clip will now hold the latch in place like so

Now put the roll pin in the roll pin holder and start the roll pin into the hole

Now take a wide punch and drive the roll pin home. This will drive the paper clip out and down into the block of wood.

Most mil-spec AR trigger pulls aren’t really the best they can be right out of the box. With a ceramic stone and a few minutes of time you can greatly improve the trigger pull of your AR15.

Following the instructions below, you should be able to make the trigger pull both smoother and a little lighter. If you are using ammo with hard military type primers you may want to skip the hammer spring bend I mention here. For commercially manufactured ammunition the spring bend shouldn’t affect reliability though. I only recommend the use of a ceramic stone as you can’t really over polish the sear engagement areas with this type of stone if you work slowly and carefully. Do not use any other type of stone or sandpaper.

As stated in the caption below, keep the sear engagement areas flat on the stone and as straight as possible. With a few passes you should be able to remove any minute burrs on the surface.

When you reassemble the hammer and trigger make sure the hammer legs are resting on top of the trigger pin and not underneath it. A little Moly Slide paste on the sear surfaces will make the trigger pull even slicker. Once it’s back together, perform a function test to make sure the safety and all the other parts are working properly.

Make sure weapon is unloaded!  Wear safety glasses!

For those wishing to replace the stock trigger guard with an aftermarket trigger guard, here are instructions for removal of the stock triggerguard without damaging the lower receiver.

Removal of trigger guard roll pin must be done with careful support of the trigger guard ear. If you fail to do this the trigger guard ear will break off and is not repairable.

Here I have simply removed and replaced the stock trigger guard. Most aftermarket trigger guards are installed the same way but follow the instructions that come with whatever replacement you want to install.

Remove upper receiver from lower receiver by pushing in the rear takedown pin and front pivot pin.
Remove Pistol grip with a 3/16″ Allen wrench. Be careful not to lose the safety detent spring or safety detent.


Cut two small blocks of wood that are about 1″ thick and drill a hole in one of them. Position them as shown.

Place lower on the two blocks with the trigger guard roll pin over the hole in the block of wood as shown. Use pistol grip for support under the stock.

With a 1/8″ roll pin punch and a hammer slowly and carefully drive the roll pin out through the ears. Be sure to keep the punch nice and straight. Push it all the way out and into the hole in the block of wood.



Use the punch to push in the detent in the hole on the magwell side of the trigger guard and remove trigger guard. 

To reinstall, push detent in and replace in the magwell side trigger guard ear. Then replace the roll pin in the rear trigger guard ear.  It’s best to use a roll pin holder that holds a .130″ roll pin to start the roll pin into the hole. Be sure to keep the hole in the trigger guard lined up with the hole in the trigger guard ear.

With the 1/8″ punch slowly drive the roll pin in until it is flush with the outside of the trigger guard ear.


Replace pistol grip in reverse order of removal.