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I just got back today from the range and noticed my SR 762 has developed an issue. The firing pin has the rear boss chewed up. The pin also bent the cotter pin to the point I had to pry it out and straighten it. Any idea on what has caused this?

The rifle has about 1000 rounds through it at this point and I am using a Geissele SSA-E FCG. The SSA-E has been in the rifle for roughly 800 of the rounds.
 

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I too just bought an SR 762 and have been to outdoor range 2x. The first firing was with Remington UMC .308Win 150gr (140 rnds.). There were no problems whatsoever. Rifle cleaned up beautifully.

The second trip to the range was a PROBLEM. I used Hornady custom .308Win 150gr SST (Hornady model #8093). Shot 100 rounds with 3-4 misfires. The shots were definitely not as well grouped as the cheaper Remington UMC.

When I went to clean the rifle at home I noticed a severely bent retaining pin, massive carbon buildup on the bolt, the forward half of the firing pin and even under the extractor. There was also stress to the firing pin along with pieces of unignited propellant.

Talked to Ruger, Hornady and local gunsmith. My conclusion is that the Hornady ammo was far too "hot" for this rifle. The Hornady casings showed all the signs of too much pressure...rub marks on end of casing, raised ridge around firing pin indent as well as a circular indentation around tip of firing pin. Hornady is going to have me send a box of the ammo back to them for retesting.

Upshot is to replace the firing pin and retaining pin (cotter pin) and use more suitable ammo like Federal Premium Gold Match 168gr or similar.

Anyone else having an overpressured "hot" ammo issue too? Any thoughts.
 

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I have not had problems but have been shooting the FMJ stuff you get in 250 round and up boxes. I was planning on buying 20 round boxes of various 308 ammo and trying in it so nice to know to stay away from the hot stuff.
 

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I would suspect something wrong with a batch of ammo.

The 762 was designed to handle .308. I am not going to shy away from any .308.
 

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I used Hornady custom .308Win 150gr SST (Hornady model #8093).

Anyone else having an overpressured "hot" ammo issue too? Any thoughts.
I would highly doubt that it is too "hot." Yes, 308 is "hotter" than nato, however, if it is supposed to support 308 then there should be no issue. There are a number of issues that it could be...head space [from bolt to barrel or barrel chamber itself] or iirc that round is supposed to gain 100-200fps which I would suspect is from extended burning of the powered which could still be creating pressure when the bolt opens. Looking at the casings can also be of use. There are a number of other possibilities, but the stated examples are worth looking into. If it were mine though Ruger would be correcting the issue. I had to send my sig716 back in for a couple of issue.
 

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I've had the most luck for .308 (Hornady 168gr HPBT Match & Prvi Partizan 168gr HPBT Match) with gas setting #1. Federal AE 7.62 168gr OTM, has had no issues regardless of gas setting. I think there is something to .308 and pressure(s) some known and some not known for this rifle. More gas to the piston seems to cause too quick of cycling.

After 400+ rounds, my firing pin is getting beat up at same locations and cotter pin is showing additional signs of wear as if the pin is riding it at times. I'd definitely consider those two items a part of a future repair kit.
 

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I've had this occur using 7.62x51 NATO. The retaining pin was mildly bent after first 20 rounds. Thought it was an installation issue by Ruger. Called them and they sent a new retaining pin. I had reinstalled the old pin after cleaning. Shot last weekend 40 rounds same NATO XM855 FMJ. Tore it down this afternoon to clean it. Couldn't remove the retaining pin. Had to drive (gently) it out with a punch enough to grab it with a pair of pliers. When out, there were several pieces of propellant on the work bench. Retaining pin has nice half moon strike on the forward section. The firing pin also shows marks of contact on the retaining shoulder. The firing pin is also carbon coated about a 1/16" behind point.

May be over gassed but when the bolt bottoms in the carrier, the firing pin doesn't touch the retaining pin. It's either being bounced back by a hot stroke and it's just the inertia of the firing pin bouncing on the retaining pin that's causing it.

Calling Ruger this week to see if they have any idea.
 

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I stumbled on this forum today looking for an answer to the same problem described above. I just bought my SR-762 and have only put 120 rds down range. Today, my rifle fired a round, it didn't eject and tried cycle another round. After I cleared the jam, I fired a few more rds and I noticed that the firing pin was punching holes through some of the primers and unseating some of the others. When I got home I noticed the cotter pin in the bolt assembly was bent and partially sheared. I had to carefully cut out the cotter pin because it was damaged so badly. I was shooting 3 different types of rds to see what it likes: Remington Core Lokt 150gr, Winchester Supreme Ballistic Silver tips 150 gr, and Hornady Superformance 150gr SST. I don't see any noticable damage to the firing pin. I'm not sure if it was a particular round that caused this or something unrelated. Should I replace the cotter pin and try some different cartridges or have a smith look at it? Has anyone heard anything from Ruger? I'm thinking about calling them tomorrow.
 

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I had a bent firing pin retaining pin after about 80 rounds of Winchester XP, Super X and Remington Core-Lokt. I straightened it out and then fired 400 rounds of PMC Bronze 308 Win with no further issues. I may try the Winchester and Remington ammo again and set the gas valve to 1. But considering what it costs per round I don't think I'll be using it much. The PMC was just a little over half the price per round and I didn't have any issues with it so I think that's what I'll be buying in the future.
 

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762 firing pin issues

I too had this exact same problem this past Sunday. I just picked this rifle up new this past week. I shot 140 rounds of various mixed ammo that I was given by my dad a few months ago.....nothing elaborate or hot......mostly a mixture of Remington and Hornady hunting ammo that he shot in his bolt action rifle. I had several issues.....probably 20 or so..... where the brass was partially ejected.....the rim was sticking out of the firearm and the neck seemed to be stuck in the bolt assy.....I thought that was strange. Normally a partially ejected case, or stove pipe, would be in the opposite position......nose out and rim stuck in the bolt. Also.....when I returned home and cleaned the rifle I noticed that the firing pin retainer was bent so badly that I had to tap it out with a small brass punch and a nylon hammer. I then noticed that the firing pin had what appeared to be significant discoloration at the tip where it had struck the primers and excessive scoring and scratches where it came into contact with the bent retainer. I didn't find anything else peculiar at that time.....but the bent retainer concerned me. I also own the Ruger SR 556 and have had no such problems shooting a wide variety of ammunition.

Has anyone heard anything about a fix for this ? This rifle is of no use to me if I have to scrutinize every round I shoot thru it.

Has anyone heard anything from Ruger ?
 

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It's that unshrouded bolt carrier. I was worried the SR-762 would have that. Ruger seems to be intent upon having that to prevent slam fires. I replaced the BCG on my AR556 because of this. My firing pin was getting chewed up.
 

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Same for me, My cotter pin is getting bent and the FP is a bit beat up. I'm shooting Sig 308 match 168gn, with a gas port setting of 1 (with suppressor) and it seems like my gun is over gassed. I have a heavier buffer on order to see if it correct my cycling issues. I was also thinking of getting another gas regular and drilling a smaller hole in the 0 position.
 

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The cotter pin on my SR556 was bent after the first 100 rds. I pulled it and replaced it with a real steel pin. No worries since then and my firing pin is in good shape.
 

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It's that unshrouded bolt carrier. I was worried the SR-762 would have that. Ruger seems to be intent upon having that to prevent slam fires. I replaced the BCG on my AR556 because of this. My firing pin was getting chewed up.
Just joined the forum doing a search for the cotter pin issue.
I've had the same issues with my SR762. Ruler sent me a new cotter pin, but after 100 or so rounds of mixed stuff (mostly 168 go stuff from Privi Partizan (sp?), same thing again.
Is there a replacement BCG for the SR762? I love the rifle (except for this issue), and would spend the $$ on something that would solve the problem.
Thanks,
Marc
 

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The cotter pin on my SR556 was bent after the first 100 rds. I pulled it and replaced it with a real steel pin. No worries since then and my firing pin is in good shape.
MKIV: which cotter pin did you use to replace the one in your SR556?
Would automotive-grade stainless cotter pins work?

Does anyone know the exact dimensions of the cotter pin for the SR762?
 
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