When to replace firing pin spring?

[vonb]

I have a Remington 700 that's on it's second .308 barrel. It probably has b/t 2-3K rounds on the bolt. After installing the new barrel, I get erratic fliers here and there with no rhyme or reason. I've rebedded the gun, changed the scope. Short of calling it a bad barrel, I'm wondering if it's just the firing pin spring.

With that said, it's cheap to replace. When does someone normally replace a firing pin spring? How long do they normally last? I was going to put a 28lb. spring back in the gun.

 

[LHSmith]

I change the springs every 2 years on a competition gun. On hunting rifles almost never. I always keep the firing pin in the uncocked position when not in use. I replace springs with the OEM spring weight.

 

[FNSafari]

Kelbly's recommends every year. Of course they are in the biz of selling accessories, but their advice is cheap insurance imo.

 

[Gb300wm]

I replace them when I rebarrel.....

 

[jdh47]

You can find someone that can check the spring weight. If it's within limits I'd look a other things.

 

[drover]

Short of calling it a bad barrel, I'm wondering if it's just the firing pin spring.

With that said, it's cheap to replace.

A weak spring can certainly cause flyers and as you mention they are cheap to replace. Replace it and see if it makes any difference, if not then start having barrel concerns.

drover

 

[K22]

You didn't state your shooting discipline so I'll defer to the competitive guys on this issue if that's your game.

However, if hunting, even high volume hunting such as varmint hunting is your game then I'll share my experience. The only time I ever replaced a rifle spring is on a Rem 700, 22 -250, 90 circa, that had that convoluted curled spring to accommodate the lock on the bolt cap. What a terrible design - I replaced the entire firing pin assembly with a conventional Rem firing pin assembly and spring.

Between range practice and hunting I shoot between 1,000 and 1,500 rounds a year spread over several rifles and I never had a problem with springs. Some of my rifles are over 30 years old.

It's no big deal to replace them so if you want to try it go for it but I would strongly suspect that your precision problems are due to something else, not the spring.

 

[Uthink Uknow]

It’s not so much a question of so many rounds but of time for me. Every other year is the norm for me. Daddy always said start with the cheapest and easiest fix first.

 

[Bill Rodolph]

Every new barrel, cheap insurance.

 

[Straightshooter1]

Hmmm, I have an RPR .308 with it's second barrel at 5,500 rounds and the first barrel with over 3700 rounds. I never thought about the firing pin spring being the problem when I see an occasional flyer out of nowhere. I figured it's the barrel getting worn out and/or something going on with one of the cartridges I loaded. The firing pin makes a good impression on the primers, even for those cases that thru a flyer.

Does the firing pin really make that big a difference that way? If so, can it be seen on inspection of the primers?

 

[D-4297]

I went through this ; unexpected fliers , and weird unexplained shot patterns , and a highly knowledgeable shooter shot ten rounds with my rifle . Got up ; looked at me and said , "When did you change your firing pin spring last" ? I had owned the rifle for two years , and never had . Over 6,000 Comp rounds , and on the second barrel in F class . I changed it that week , and the fliers mysteriously went away . Every year , or every barrel . Whichever comes first .

 

[vonb]

This rifle was an original Rem LTR purchased new in 2005. It now has a Krieger 4 groove .308 20" barrel. It sits in the original HS stock which was surface modeled and machined to negate the need for epoxy. It still had some crazy fliers....It would shoot a good group and then a flier. I bedded it and thought it would help but had similar issues. The crazy idea of replacing the spring came to mind. I should have started there first.

 

[Bill Rodolph]

Springs take a "set" over time. Even if you release your firing pin when you close the bolt, the spring is still under compression. It is interesting to compare a springs length side by side, with new and used. They are different which will reduce the power and consistency that the pin strikes the primer. And it won't show up visually on the primer, just on the target. I shot a 600 yard match a few years ago and was quite disappointed in my score. Friend asked about my firing pin spring, I hadn't changed it in quite a few years. Went home and changed it, shot another 600 yard match the next morning and went clean. A big difference in the way the rifle shot.

 

[dkhunt14]

Hmmm, I have an RPR .308 with it's second barrel at 5,500 rounds and the first barrel with over 3700 rounds. I never thought about the firing pin spring being the problem when I see an occasional flyer out of nowhere. I figured it's the barrel getting worn out and/or something going on with one of the cartridges I loaded. The firing pin makes a good impression on the primers, even for those cases that thru a flyer.

Does the firing pin really make that big a difference that way? If so, can it be seen on inspection of the primers?

The firing pin spring can make all the difference in the world. I don't think you will see it on the primers. I think it has to do with consistent hits on the primers that makes the vibrations the same. Just because the dents look good, doesn't mean that some are not hitting them with lighter force. I have seen many 1000 yard BR rifles come alive when new springs were put in. Ignition is very important, especially on long range shooting. I also think it isn't due to number of shots but the compression over time. I have seen springs that after a year or two lose as much as 1/2 to one inch of length. Matt

 

[Straightshooter1]

The firing pin spring can make all the difference in the world. I don't think you will see it on the primers. I think it has to do with consistent hits on the primers that makes the vibrations the same. Just because the dents look good, doesn't mean that some are not hitting them with lighter force. I have seen many 1000 yard BR rifles come alive when new springs were put in. Ignition is very important, especially on long range shooting. I akso think it isn't due to number of shots but the compression over time. I have seen springs that after a year or two lose as much as 1/2 to one inch of length. Matt

For sure, the firing pin spring's ability to hit a primer with sufficient force to initiate ignition is important. And besides spring tension as a factor, variations in primer's cup thickness and primer mixture must also play a roll with consistency. . . especially if this issue about aging springs is that significant.

Apparently, there's a lot of anecdotal evidence in support for aging firing pin springs to cause this issue brought up in the OP. . . even though it may not be evident by inspecting the dimples in the primers. I wonder if anyone has runs tests to quantify this phenomenon??? In any case, I'm convinced (not easily done to an old fart like me) it's worth replacing my original spring since it has well over 10,000 cycles. Of course, I'll have to report back as to whether I experience any improvement or not.

 

[Gb300wm]

I’m a competitive shooter. When I replace a barrel, I always change out this very inexpensive part. The used spring is usually 1/4”-3/8” shorter than a new one. It fired just fine. I find though when you over use one, you start experiencing unexplained flyers which really hurts in a match. When I started replacing springs with every barrel, these things went away. Consistent primer contact with the firing pin is extremely important. I’m a believer that there are a thousand factors in consistent low extreme spreads, and we can only control very few of these. And this is one of them.