The MSR Upper Tension Set Screw hole installation kit is designed for professionals and hobbyist alike. Set screws are designed to place tension on the upper receiver to remove the play found on many AR platforms. This kit contains all the components you will need to begin installing set screws on modern sporting rifles and pistols. If your a gunsmith with a Federal Firearms License, this kit will literally pay for itself on the first job!
This is a great way to add an additional revenue stream into your business or market your new capability to your existing customers. The Alabama Precision Gunworks upper tension set screw hole installation kit includes a high quality extended length drill bit, tap and brass tip set screws. All components are Made in America by Americans for the gun community. The brass head of the set screw is designed to conform to the mating surface on the upper so it will remain set once installed. Many of these set screws contain nylon which can compress over time, requiring continuous adjustment.
Other designs include a cheap insert that will suffer the same fate with time or will provide too tight of an upper/lower fit. Additionally, the AR upper tension set screw is made of alloy steel to prevent bimetallic (galvanic) corrosion. This kit includes:
- 5 ea APG 3/4″ Upper tension set screw
- 1 ea APG set screw tap
- 1 ea APG tap drill bit
- 1 ea APG hole locator blueprints
To install, the process is simple:
1. Insure you have access to proper PPE such as safety glasses and that your firearm is unloaded.
2. Insure your upper has been removed from the lower and the pistol grip. You must also remove the safety, trigger and hammer.
3. Chuck the lower in a vice or use a jig to secure it. The lower must be facing up, just as if it were being held for firing. If you have an eighty % lower milling jig, secure the lower in it, though this is not required.
4. Locate the hole. The schematic for the hole location is the last photo on this item. Additionally, a copy is sent with your kit. Watch the above video so you know how to pull your measurements.
5. For best results, use a starter punch to prevent the drill bit from walking. If you do not have a starter punch, use very light pressure when starting the drill bit to prevent walking.
6. Though a drill press is not required, a properly trammed press will deliver the utmost precision when drilling the hole. Carefully drill the hole. Insure you have enough bottom clearance for the drill bit so it does not break. If using a hand drill, insure you remain level at all times so the hole is concentric.
7. Tap the hole. If you have a drill press, you can chuck the tap in the drill press to insure an even start then finish by hand.
8. (Optional) Using a 3/8” drill bit or countersink, countersink the top hole slightly. The bottom of the pistol grip mount can also be countersunk or counter bored as well with a 5/16″ drill bit to a depth of 1/4″.
9. Clean the hole of all debris and oil. Brake cleaner works great for this. Optionally, you can use Birchwood Casey aluminum black to apply a protective finish to the threads.
10. Apply locktite to the set screw and insert it brass tip up from the too of the receiver.
11. Using an 1/8″ Allen key, run the set screw until it contacts the upper and adjust it until the play is removed.
12. Check the ease in which you can remove the rear takedown pin and adjust screw until you have a healthy balance of upper tension and pressure on the takedown pin when installed.
13. Install pistol grip and wait 24-36 hours before shooting to allow thread locker to fully cure. Installation video here: