Silver Supporter
- Messages
- 6,072
- Reactions
- 15,023
I have a S&W (Howa) 1500 in .30-06 that I picked up a few years ago used. I've been having a problem with it failing to feed at times since day one, but the problem seemed to come and go. I thought I had this fixed last year after I polished out all the machining marks in the feed ramp. Once I completed that operation I couldn't make it jam. But then last Sunday after I fired one shot and took down my buck I went to jack another round into the chamber and it jammed again.
A really close inspection of the loading ramp revealed a small vertical high spot near the center of the ramp, which might have made it difficult for the bullet nose to migrate toward the centerline of the bore as the cartridge is pushed forward by the bolt. I took a little more metal off to true it up and thought I had it fixed when I cycled it on the bench with a couple of cartridges. However, when I simulated conditions from Sunday by loading 5 cartridges into the magazine, and loading and ejecting the first round, the second round was very difficult to chamber. After the second round all other cartridges seemed to feed smoothly. So what was it about the second round, and only the second round out of this fully loaded 5 round magazine that caused it to hang up?
Then I looked closely at the magazine follower spring and noticed an extra bend in the last segment before the floor plate attachment point. Depressing the follower produced a fairly uniform pressure until I got to the last 1/2" of movement, where the pressure suddenly increased dramatically due to that extra bend. I straightened out that bend enough to reduce the pressure to a more uniform amount and suddenly the second round fed easily. Apparently, the extra bend in the spring was putting enough upward pressure on the second cartridge in a full magazine that it was very difficult for the bolt to push the cartridge forward and roll it out of the retaining/guide rail machined into the receiver. One tip-off was numerous lengthwise scratches appearing on the cartridge cases I was using for testing produced by the cases being forced hard up against the guide rail's sharp edges. So now I'm keeping my fingers crossed that the problem is truly resolved. Has anyone else ever run into something similar?
A really close inspection of the loading ramp revealed a small vertical high spot near the center of the ramp, which might have made it difficult for the bullet nose to migrate toward the centerline of the bore as the cartridge is pushed forward by the bolt. I took a little more metal off to true it up and thought I had it fixed when I cycled it on the bench with a couple of cartridges. However, when I simulated conditions from Sunday by loading 5 cartridges into the magazine, and loading and ejecting the first round, the second round was very difficult to chamber. After the second round all other cartridges seemed to feed smoothly. So what was it about the second round, and only the second round out of this fully loaded 5 round magazine that caused it to hang up?
Then I looked closely at the magazine follower spring and noticed an extra bend in the last segment before the floor plate attachment point. Depressing the follower produced a fairly uniform pressure until I got to the last 1/2" of movement, where the pressure suddenly increased dramatically due to that extra bend. I straightened out that bend enough to reduce the pressure to a more uniform amount and suddenly the second round fed easily. Apparently, the extra bend in the spring was putting enough upward pressure on the second cartridge in a full magazine that it was very difficult for the bolt to push the cartridge forward and roll it out of the retaining/guide rail machined into the receiver. One tip-off was numerous lengthwise scratches appearing on the cartridge cases I was using for testing produced by the cases being forced hard up against the guide rail's sharp edges. So now I'm keeping my fingers crossed that the problem is truly resolved. Has anyone else ever run into something similar?
