Help with weak firing pin spring?

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colegobin

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I have a Ruger M77 Mark II in 7.62x39. It seams to have a weak hit from the firing pin. It will not fire on the first trigger pull, I have to action it again and the second hit is deep/ hard enough to fire. I this happens with both surplus and American Eagle ammo. The bolt and firing pin are clean and lubed with WD40 only. The end of the firing pin doesn't look damaged.

I would like to order another firing pin spring, maybe a stronger one than factory? Can anyone recommend somewhere to get one? Will be able to change it myself? Is there anything else I'm missing? Here are some pics of the first primer hit (left) and the second (right)

Thanks Cole
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Ruger had a problem with these. The misfiring resulted from differences in chambering specifications vs ammunition dimensions, and from the hard primers sometimes found in the ammunition. I sent a customer's rifle back to Ruger, they fixed it. This was in the days when mailing a rifle across the border for service wasn't a problem. I would suggest that you call Ruger, and ask.
AFAIK, only 5000 of these rifles were made for a large US distributor.
Changing the mainspring yourself is not a big deal. Installing one with a higher rating might help.
 
tiriaq said:
Ruger had a problem with these. The misfiring resulted from differences in chambering specifications vs ammunition dimensions, and from the hard primers sometimes found in the ammunition. I sent a customer's rifle back to Ruger, they fixed it. This was in the days when mailing a rifle across the border for service wasn't a problem. I would suggest that you call Ruger, and ask.
AFAIK, only 5000 of these rifles were made for a large US distributor.
Changing the mainspring yourself is not a big deal. Installing one with a higher rating might help.
Click to expand...

Do you know what they fixed on the customers rifle? If it was anything on the receiver or barrel it might be a difficult problem for me, but if its a bolt related problem maybe they can fix me up with some replacement parts?
 
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From gunsprings.com

RUGER 77, MKI & MKII - Long & Short Actions
BLITZSCHNELL Load-rated striker springs
* Factory - Reference Only.: 21 Lb.
* Ratings available.................: 24 and 28 Lb.

Anyone think the 28LB one would be enough to solve my problem?
 
colegobin said:
From gunsprings.com

RUGER 77, MKI & MKII - Long & Short Actions
BLITZSCHNELL Load-rated striker springs
* Factory - Reference Only.: 21 Lb.
* Ratings available.................: 24 and 28 Lb.

Anyone think the 28LB one would be enough to solve my problem?
Click to expand...

I'd bet on it. I've put a lot of Wolff springs in over the years, and a few Tubbs that were probably made by Wolff. I just stuck one in a Savage this week, come to think of it. Anyway, Brownells seems to be willing to send parts under $100 up to Canada again, I got the spring up here for $8.50 US, postage included. The Savage no longer goes click on hard CCI primers when it was supposed to go bang. Life is good.
 
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