Top Ten Maintenance Issues
by Bob Londrigan, published in Front Sight Magazine, March 2007
If you want to shoot your best, your gun must also be at its best. That’s why preventive maintenance on a regular basis is important. After all, it can take a lot of practice and good shooting to make up for one malfunction caused by improper or negligent gun care. To that end, I present my list of the top ten maintenance issues. This list covers about 90% of what can cause you mechanical problems at a match. These are mainly items that can cause reliability problems if left uncorrected or can lead to bigger problems if not fixed early on. I have purposely not included cleaning and lubrication of your gun because I am assuming you are taking care of this on a regular basis. If you focus on these top ten issues and make sure they are taken care of, there is a good chance your gun will provide you with many years of trouble-free service.
Number 10 - Trigger adjustments
Your trigger system requires periodic maintenance, especially if you dry fire a lot. Check your over travel to make sure it has not changed. If the trigger becomes very hard to pull, too little overtravel could be the culprit. From time to time also check the weight of your trigger pull with a trigger pull gauge to make sure that has not changed. Whenever you check your trigger adjustment, also make sure that your firing pin spring has not broken (common with lots of dry firing). If you find you need to make some trigger adjustments, check your back issues of Front Sight for articles on related topics or click here to go to the list of articles.
Number 9 – Damaged barrel crown or bullets hitting the comp
Inspect the crown of your barrel from time to time to make sure there are no nicks or gouges. If you have a compensator, also check the baffles for evidence of bullet strike. You will see copper marks in the bore of the comp. Anytime you see a sudden decrease in accuracy out of your gun or notice bullets tumbling, check out the crown and the comp first. If you have damage to your barrel crown you will have to make a trip to the gunsmith so he can clean up the barrel. The same goes for bullets hitting the comp baffles – your gunsmith should have a special reamer to clean up the comp.
Number 8 – Cracked grip
On STI/SV guns, check your grip often especially if the magazines you are loading into the gun have little or no play in the bullets. Cracks usually start around the magazine release area and at the top of the grip at the front edge of the checkering. Cracks can cause all sorts of mystery jams, hammer following, and magazines to stick. If you do notice such cracks, it’s time to replace the grip.
Number 7 – Loose screws
Screws that commonly come loose include scope mounting screws, scope adjustment screws, grip screws, and the rear sight set screws. Check your scopemount screws often especially the one furthest to the rear on the scopemount. This is the one that usually comes loose first. On a C-more, locktite the set screws, tighten the windage set screw down snugly, and then never touch it again. You can still adjust the windage without loosening the set screw. If you repeatedly loosen and tighten this screw, you will eventually crack the body on the C-More. Put some locktite on the elevation set screw and sight-in with the set screw tight. If you tighten it after sighting in, it will change your point of impact. Check the set screw on your rear sight – loctite and keep it tightened down. Also locktite your grips screws. Loose grip screws in the STI/SV platform can cause hammer follow and other problems similar to having a cracked grip.
Number 6 – Worn Springs
Replace your recoil spring every three to four thousand rounds. Replace the firing pin spring at the same time, making sure to clean out the firing pin tunnel when you do. If you have an Aftec extractor, replace the springs every five to ten thousand rounds or when you start to see erratic ejection. The mainspring should not need to be replaced but it doesn’t hurt to take a look at it every once in a while to make sure it does not have any broken coils.
Number 5 – Cracked firing pin stop
A cracked firing pin stop is an extremely common problem, especially if you dry fire on a regular basis, so check it often. The crack will usually start at the inside corner closest to the firing pin hole. If you see a crack, replace the firing pin stop as soon as possible. It may not cause a problem right away but it will eventually crack through to the other side and then you will have a catastrophic failure.
Number 4 – Ejector problems
Ejectors do break on occasion, so inspect yours on a regular basis to make sure it is intact. Although it is common for your ejection pattern to change as your gun wears in, a significant change can lead to jams. If it gets to this point, you will need to adjust the ejector/extractor to get your gun back to cleanly ejecting empty cases.
Number 3 – Extractor problems
Your extractor may also need to be tuned at some point. If your ejection pattern changes, check to see if it is the ejector or the extractor that is causing the problem. Once you have narrowed down which one it is, you will need to make adjustments accordingly. If you have an Aftec, try changing the springs first. Again, check previous Front Sight articles for information on adjusting your extraction/ejection pattern.
Number 2 – Magazines
For your gun to be reliable, you must have a good set of magazines. Make sure you keep your magazines clean and be sure to change the springs in them on a regular basis. Jams where there is a round lodged at the bottom of the feed ramp are almost always caused by the magazine. If you get this type of jam, check the dimension of the feed lips against some of the magazines that work well and make sure they match. If they do not, adjust the feed lips. If the dimension is good and your magazines are clean, then it might be time to replace your magazine springs. I usually replace all my magazine springs at the same time so I know how long they have been used. It is also a good idea to mark or number your magazines somehow so that you can tell them apart. This helps in diagnosing gun problems as you will be able to narrow down which magazine is causing the problem.
Number 1 – Reloads
You have to feed your gun good ammo for it to work up to its potential. Consistency is extremely important when loading ammo. Case check your match ammo. Decide on an overall length that works well in your gun and then check it often to make sure your loads are consistently that length. Also chrono your loads to make sure they are consistent. Check your dies on a regular basis to make sure they are clean and adjusted properly. For matches, use either new brass or at least brass that is of the same headstamp.
If you keep up with all ten of these issues, you will be well on your way to having a gun that you can count on to serve you well on match day.