M70 Firing Pin or Striker Spring Replacement

[RSL]

My circa 1998 New Haven M70 375 H&H was finally released from ATF Delay. I am thinking about replacing the Firing Pin Spring. Just as a matter of preventative maintenance. I have not had a chance to fire it yet. I have had good results using Wolff springs in the past on pistols. And was planning to use a Wolff spring on the M70. My question is should I use standard strength or 25 lb or a 30 lb spring? I am hoping this post does not create as much fuss as my last one. ;-) Thanks, Stan

 

[Wyatt Smith]

I put a 30 in my rifle. I haven’t seen any issues so far.

 

[Ontario Hunter]

What would be the benefit of changing the firing pin spring if you don't know there's even a problem? My 03A3 still has the same firing spring it did through WWII. Still works flawlessly. I've never heard of any raging issues with later Model 70 firing pin springs. Is there something I don't know? This could be important to me since I'm considering changing the 03A3 to Model 70 safety. Model 70 bolt shroud/safety threads onto 03A3 bolt but requires fabricating a new striker.

 

[Wyatt Smith]

What would be the benefit?

If you’ve ever had a weak spring cause misfires you might find it advantageous.

 

[Ontario Hunter]

If you’ve ever had a weak spring cause misfires you might find it advantageous.

I've fired gazillion rounds through my shotguns and rifles and yet to experience a weak firing pin spring misfire. Only misfires have been due to defective primers (particularly Chedite shotgun primers).

 

[RSL]

I put a 30 in my rifle. I haven’t seen any issues so far.

Thanks, Wyatt. My Grandfather’s name was Wyatt. Great name.

 

[RSL]

What would be the benefit of changing the firing pin spring if you don't know there's even a problem? My 03A3 still has the same firing spring it did through WWII. Still works flawlessly. I've never heard of any raging issues with later Model 70 firing pin springs. Is there something I don't know? This could be important to me since I'm considering changing the 03A3 to Model 70 safety. Model 70 bolt shroud/safety threads onto 03A3 bolt but requires fabricating a new striker.

Evidently the new production M70's, Portugal, have an issue with the firing pin springs. And the later New Haven M70s had issues with bad extractors. As far as your 03A3 spring goes, it was probably made with superior material back during WWII. Anyway, Ontario Hunter, I can never leave anything mechanical alone. Character flaw I guess.

 

[Ontario Hunter]

Evidently the new production M70's, Portugal, have an issue with the firing pin springs. And the later New Haven M70s had issues with bad extractors. As far as your 03A3 spring goes, it was probably made with superior material back during WWII. Anyway, Ontario Hunter, I can never leave anything mechanical alone. Character flaw I guess.

I suffer from the same malaise.

 

[Wyatt Smith]

I've fired gazillion rounds through my shotguns and rifles and yet to experience a weak firing pin spring misfire. Only misfires have been due to defective primers (particularly Chedite shotgun primers).

As @RSL said it is a common issue on the new M70d.
For $10 it was cheap insurance.