benchedsighted
Member
- Joined
- May 28, 2010
- Messages
- 4
The Ode to Marlin 39A. Here are the real reasons for your newer 39A to Fail-To-Fire (FTF) and Fail-To-Extract (FTE) and the options to “tune” your rifle or have it “tuned” for you. My 39A is now 2 years old and out of the box its performance was dismal with any brand and level of ammo. As I do not intend to use this in any high end competition, I would prefer it to do well with bulk ammo. Here were the stats with the top 3 bulk ammo sellers for each 18 rd load of LRs. For Winchester bulk I had an average of 10 FTF and 7 FTE. Remington was 7 FTF and 7 FTE. Federal was the best with 5 FTF and 3 FTE. The problem is both FTF and FTE should be 0. Through surfing the internet and trial-and-failure of most of the suggestions I have found the two most common causes and fixes.
My first try was to shorten the bottom of the “Hammer Rebound Strut”. If you have done any searching and fixing, I’m sure you know what I am talking about. With the first two fixes I am going to suggest you will not need to do this. I am now using a new unaltered strut and every round fires with no annoying spring ping after the shot.
You can do these fixes yourself if you are handy with tools and are really careful. I always make small changes and test in order to find the stopping point. I alter the cheapest parts to replace first in any attempt to tune things. You can have a qualified gunsmith read what the problem is along with their assessment and fix, or you can send the 39A back to Marlin (Remington) with an explanation of the problem. I found that it’s a real gamble sending it back to Marlin and getting a working rifle back.
1. The first thing to check and fix is the “Cartridge Guide Spring”. This is a small spring that is on the inside top of the receiver that helps guide the next round into the chamber. The problem with the spring is that it sticks down too far. The first problem caused is that it blocks a spent cartridge from extracting. The second problem, one I have not seen on the internet, is that it interferes with the firing pin. This is the cause of the many FTF’s and not the “Hammer Rebound Strut”. I have read where some owners have fooled around with the mounting screw that holds this in place or have bent the spring. These fixes may help with FTE, but not with FTF. I experience two things when trying them. First the screw holding the spring is only long enough to catch 2 or 3 threads in the spring on a part of the spring that is a lip created by the hole being stamped. The lip breaks and the screw won’t hold the spring in place. Second, the spring is small and brittle…it breaks. The real problem with the spring is that the slot where it is mounted in the receiver is not deep enough. I used a Dremel tool to carefully ground a deeper channel. This fixed the FTF’s down to 0 even for the Winchester bulk.
2. The next major problem causing FTE was that the bolt was not closing completely. I had about .01” gap after closing the bolt. When the round was fired this gap allowed the cartridge to bulge just above the rim, jamming it in the chamber. You can fix this by either: 1. Cold hammer the end of the finger lever were it locks the bolt or 2. Heat up the end of the finger lever were it locks the bold and hammer it slightly to extrude the metal out. After extruding you will probably have to use needle files to adjust it so it is not too tight. If it is too tight the “Finger Lever Screw” will break.
These two fixes will probably solve all the FTF’s and FTE’s. I had one more that I did that seems to assure extraction of the most stubborn of brass. I filed the end of the ramp on the barrel were the extractor sits when the bolt is in lock position. This created a slight notch in the chamber that allows the extractor to get all the way into the rim. I then filed the ramp itself to make a smooth transition for the extractor. A result of the 3 fixes above…0 FTF’s and FTE’s using any type and length of ammo.
My first try was to shorten the bottom of the “Hammer Rebound Strut”. If you have done any searching and fixing, I’m sure you know what I am talking about. With the first two fixes I am going to suggest you will not need to do this. I am now using a new unaltered strut and every round fires with no annoying spring ping after the shot.
You can do these fixes yourself if you are handy with tools and are really careful. I always make small changes and test in order to find the stopping point. I alter the cheapest parts to replace first in any attempt to tune things. You can have a qualified gunsmith read what the problem is along with their assessment and fix, or you can send the 39A back to Marlin (Remington) with an explanation of the problem. I found that it’s a real gamble sending it back to Marlin and getting a working rifle back.
1. The first thing to check and fix is the “Cartridge Guide Spring”. This is a small spring that is on the inside top of the receiver that helps guide the next round into the chamber. The problem with the spring is that it sticks down too far. The first problem caused is that it blocks a spent cartridge from extracting. The second problem, one I have not seen on the internet, is that it interferes with the firing pin. This is the cause of the many FTF’s and not the “Hammer Rebound Strut”. I have read where some owners have fooled around with the mounting screw that holds this in place or have bent the spring. These fixes may help with FTE, but not with FTF. I experience two things when trying them. First the screw holding the spring is only long enough to catch 2 or 3 threads in the spring on a part of the spring that is a lip created by the hole being stamped. The lip breaks and the screw won’t hold the spring in place. Second, the spring is small and brittle…it breaks. The real problem with the spring is that the slot where it is mounted in the receiver is not deep enough. I used a Dremel tool to carefully ground a deeper channel. This fixed the FTF’s down to 0 even for the Winchester bulk.
2. The next major problem causing FTE was that the bolt was not closing completely. I had about .01” gap after closing the bolt. When the round was fired this gap allowed the cartridge to bulge just above the rim, jamming it in the chamber. You can fix this by either: 1. Cold hammer the end of the finger lever were it locks the bolt or 2. Heat up the end of the finger lever were it locks the bold and hammer it slightly to extrude the metal out. After extruding you will probably have to use needle files to adjust it so it is not too tight. If it is too tight the “Finger Lever Screw” will break.
These two fixes will probably solve all the FTF’s and FTE’s. I had one more that I did that seems to assure extraction of the most stubborn of brass. I filed the end of the ramp on the barrel were the extractor sits when the bolt is in lock position. This created a slight notch in the chamber that allows the extractor to get all the way into the rim. I then filed the ramp itself to make a smooth transition for the extractor. A result of the 3 fixes above…0 FTF’s and FTE’s using any type and length of ammo.
