Guys,

I have a 30-06 which hits the primer a fair bit off center. About as far off as I have seen personally. Depsite that, it shoots a few factory loads quite well, right at MOA.

So, what is the question...

I am wondering what the general opinion is about this sort of thing. Are off center primer strikes a non issue as long as the thing shoots? Nonetheless, does it suggest or indicate, that certain things are just not quite right and a little out of spec?

What typically is the cause of off center strikes? Is it usually in the action/bolt/striker, or is usually in the barrel i.e an eccentric chamber?

The gun is a p-64 Model 70 made in 1953...std weight.

I will post a pic later today for interest.

TIA

well, if the gun has been shooting OK since 1953, i wouldn't worry to much about it

Could the firing pin be bent ?. A simple dis-assembly and inspection might be in order .

On the other hand ( She wore a glove Ha Ha Ha sorry old joke ) if it's not broke don't fix it .

quote:

if it's not broke don't fix it

+1

First, as stated above, if it ain't broke don't fix it. But, a couple of major causes are the firing pin hole being off center in the bolt or the bolt and barrel not being on the same center line in the action or the bore isn't in the center of the barrel. I'd suspect the firing pin hole being off in the bolt. It can be fixed by pluging and reboring but if it isn't causing a problem try not to worry

Thanks for the replys guys!

This is a new-to-me rifle, so I don't know how well it has worked for the past 50-some years, though it doesn't appear to have been shot a whole lot.

No, I wasn't really looking to fix this at present. As you say, I fully subscribe to the "if ain't broke..." doctrine.

That said though, I suppose I was wondering about the potential suitability of this action as a donor for a some-day custom project, and if there were perhaps some inherent flaw in the action that caused this.

The other thing that made me a bit curious too is that with some factory loads, like the Rem 180 core-lokt, it shoots horrible, like 2.5 inches. With 180 core-likt ultrabonded, I have shot several sub MOA groups. I haven't shot much else yet as I just got it scoped.

It has been my general experience that a "quality" rifle will shoot most everyting (within reason) fairly well, and with stuff it really likes it will shine. So, this makes me wonder too....

I will post pics of brass later...

TIA

I'll ask a silly or stupid question . Have you removed the bolt and looked at the

firing pin hole location in relationship too the bolt face ?. While looking check to see if

the hole has elongated . Just curious is all .

Well it has taken longer than it shoulda, but I think I finally figured out how to post some pics. Lets see if this works...





If this worked you can see that the off center strike is consitent with the slightly off center hole in the bolt face. I marked some cases and determined that the primer strike is consistent with the apparent off center stiker location in the bolt face. Using calipers, it appears as though the strike is about .020 off axis of the case.

So, there have been no misfires, and, in fact, the rifle is quite accurate. At what point (how far off) would one expect to see some issues, ie misfires?

Thanks for the input!

Bob

Okay, finally figured the pic thing and added them below...

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Another cause of off center strikes can be blamed on over sized chambers and gravity. Quite often a factory chamber is slightly over sized for the case and so the case ends up sitting on the bottom of the chamber and out of alignment with both the firing pin and the bore. This not only causes off center hits, but accuracy issues as well because the case and the bullet are sitting at an angle to the axis of the weapon.

Looking at those images of your primers, you are fine. Unless you are competing I wouldn't worry about it. It is typical of those I see during the normal course of business.

I would only worry about off-center primer strikes if it was a newly barreled, high end custom gun.

quote:

Originally posted by Hot Core:
Funny how the "Holy Grail" of rifle lovers rarely mention the many minor issues like this on the M70s and Mousers.

Glad they love them though. Best of luck with the rifle, it might shoot great just the way it is.

Well you can't bad mouth the stuff you own. You went through all the trouble to rationalize the purchase
Everyone does it to some extent. Do you realize the faults of the rifle and accept it or do you cover it up and praise the rifle as the best ever built and none can even be in the same class.

But seriously I don't worry about off center hits until it dots the caliber marking on the case head.

i'd be tempted to mic' the case heads.... could have a batch of greatly undersized brass.... it does happen. i've seen brass that looks like it is bulged on one side come out of a good(tight and concentric) chamber, only to find that the brass mics' real small.

Obviously off center


look at the primer polishing the bolt face

matters not at all, it's still lighting off primers,,,

Until you have tried it you don't realize how difficult it is to drill a small deep hole on dead center. I am amazed that so many firing pin holes are as close as they are.

quote:

Originally posted by jeffeosso:
Obviously off center


look at the primer polishing the bolt face

matters not at all, it's still lighting off primers,,,

Jeffe, you are correct, the primer ring is off center indicating that the case is sitting below center.

Blackbart2,

Thanks for posting. I have the exact same problem, calibre also 30-06 based but a wildcat-"30MC", M70 based action too - MRC1999 and mine shoots unbelievably well too. I have other M70 based actions that all pretty much strike at centre - so this was my first encounter too.

Having said that its good to find out that there is nothing to worry about since it is the best shooting of all my M70 based rifles! Go figure!

regards,
JohnT