Are You Listening to Your Gun?
by Bob Londrigan, published in Front Sight Magazine, Sept 2008
The funny thing about guns is that they will tell you when they are not feeling well. Often, long before you have any type of stoppage that might cost you match points. The big question is, are you tuned in and listening?
It is a good idea to get in sync with your gun and know its quirks both good and bad. If you know how your gun feels when it is running right, you will be able to cut down on the number of malfunctions you experience. There are some hard data points, or benchmarks, to establish for your gun that will help you determine if all is well. Anyone who is truly interested in reliability must take the time to establish these benchmarks. There are also some more subtle points to look out for. These may take more experience to deal with. They can be added to your toolbox as you gain expertise.
The hard data points or benchmarks you need to establish for your gun deal with accuracy and velocity. It is important do the testing I recommend here when your gun is running well. A benchmark done on a gun that is not running right wonít do you much good.
To establish a benchmark for accuracy, pick a distance for your testing between 25 and 50 yds. Then shoot groups. I suggest five to ten-shot groups from a rest. Shoot several and take the average. If you know you pulled a shot, throw it out of the group. Your average will give you a starting group size. Log this information as well as your load, OAL length, etc. You want to make sure you have all the info you need to duplicate your testing. This will enable you to re-test the gun later and compare results. For a valid comparison, remember that all factors (loads, etc) must be the same. Anything else is apples to oranges.
Next, test for velocity. You will need a chronograph for this. Test your match loads and get an average. The load you test does not have to be the same as the one you tested for accuracy but I like to do it that way because then I know how accurate my match loads are. (Your match load may or may not be the most accurate load in your gun.) Get a good average and test it over several trips to the range to average out the effects of light, temperature, and humidity, etc.
Once you have these two benchmarks, you can repeat the tests at a later date. If your results vary significantly your gun is trying to tell you something. Pay attention to what your gun is telling you. Donít try to ignore it and hope it will go away.
If your accuracy worsens significantly it could be several things. First make sure your load has not changed or that something has not changed on your reloading machine that would affect the accuracy of your loads. Examples would be a change in OAL, crimp, components, primer depth, or bullet deformation. If all that checks out look your gun over carefully for cracks or broken parts. Check your sight/scope to see if it is loose (loctite everything down.) Make sure the barrel crown has not been damaged. If you have a comp, check it for signs of bullet strike on the baffles. If all that checks out, then give the gun a good cleaning. While cleaning, check closely for bits and pieces of debris that might be caught in the mechanism and especially check in the chamber for foreign material. Then run your test again. If you still have seriously degraded accuracy it is time for a visit to the gunsmith for some diagnosis.
Changes in velocity for your standard load can signal problems also. You have to be careful though Ė chronograph results are notorious for varying wildly at times especially if done in outdoor light. Make sure you have good chrono results before you start changing things. Decreases in velocity are usually related to changes in your load Ė so go back and check your loader first. Different lot numbers of powder can also cause substantial variations in velocity (this is not something to worry about). If everything checks out with your load, then you may have another problem. Some decrease in velocity as the round count on a barrel increases are normal. This is just a sign of barrel wear. The usual solution is to bump up your load by a tenth of a grain or two. If you have to start adding a half grain or more extra and the lot number is the same, your barrel is probably just about worn out. You will probably be seeing accuracy problems at the same time. Again, the solution at this point is a trip to the gunsmith for repairs.
Next we need to cover some of the more subtle things you might notice about the performance of your gun. If you run into any problems with your gun it is always a good policy to make some good notes describing the problem, how you noticed it, and what the final solution was. If you ever have the same problem again you can go back to your notes and get insight on how to resolve it. There are a lot of things that can cause gun malfunctions. I donít have the space to cover everything, but I will cover the top issues that I see.
The biggest reliability issues I see involve ejection and extraction. As your gun ages, parts wear and the gun will cycle slightly differently. The slide and frame rails wear, the barrel unlocks down to a slightly different spot, the spring rates change slightly, and the extractor and ejector wear. This results in the case striking the ejector in a slightly different spot and at a different velocity. This can cause ejection/extraction malfunctions. If your gun is running well right now, you need to dial in on exactly how it is ejecting rounds. Note how far brass travels and the general ejection pattern. If this changes significantly at a later time your gun is telling you it needs attention. If the pattern changes suddenly you need to look for breakage of parts. If the changes are more subtle and occur over a long period of time, you still need to pay attention. However, the problem will likely be related to wear or adjustment issues rather than breakage. Your extraction pattern may need to be adjusted before the problem gets bad enough to cause malfunctions. More info on how to tune your ejection/extraction can be found here: http://www.brazoscustom.com/magart/ejection%20perfection.htm.
Other subtle changes to notice include how ammo is feeding from your magazines, how your magazines feel when loading them (stiffness of spring), how the sights/dot move under recoil, how the trigger feels when it breaks, etc. Youíll also need to pay attention to new vs. old springs, different types of lube, and whether or not your lube has worn off. You can come up with even more things if you really pay close attention.
The key is how your gun feels when it is running 100%. Use this as your benchmark, and then compare that to how the gun is running at todayís practice. This will help you spot most problems before they get bad enough to cause malfunctions and cost you match points.