6 o clock firing pin?

Hey Tim....

You asked: .define"almost".
Happy to! A very conservative time for the "burn" (or detonation, or explosion, or pop, or whatever you want to call it ) around the primer compound in the rim of a 22 rimfire is .000007 seconds. I choose, arbitrarily, to call this, almost instantaneous.

I suppose that considering bench resters, and some bench rest gunsmith's obsession with very small numbers as being important to their quest for accuracy that this time is actually large enough to be have a meaningful effect. If you are one of these shooters then do what you will with this amount of time.
 
DonMatzeder said:
One gunsmith believes it helps and several will do it for you if you want it. It has never been shown to improve ignition.
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How would one show that??


PS Just read Kents comments. That is a good way(via competition)-any other?

Does competition really prove one is better than the other?
 
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langenc,

"Does competition really prove one is better than the other?"

Not really:) But in the past I've had things working great in testing and practice, that didn't seem to work out as well when you showed up on match day. I always like to test whatever it is I'm tinkering with at the time in actual matches and see how it works. I feel better about the idea if it'll win matches, if it won't, no use to waste time with it.

Like I said, there are several rifles out there shooting very well with 6 oclock pin setups. It's definitely not a disadvantage to have one, but I'm not sure it's an advantage either, provided the firing pin/bolt/trigger group is working like it should providing consistent ignition, time after time after time, etc. etc.
An action that repeats itself on every firing pin drop, exactly like the last.
Its' virtualy impossible to tune a rifle with poor ignition.
I had originally though the 6 oclock firing pin might cause a little less vibration, because of the lower stike on the bottom of the rim, figured I'd have to retune the rifle, but it didn't seem to matter.
Of course others may do the same test and get different results, rimfires are like that.
 
pacecil said:
You asked: .define"almost".
Happy to! A very conservative time for the "burn" (or detonation, or explosion, or pop, or whatever you want to call it ) around the primer compound in the rim of a 22 rimfire is .000007 seconds. I choose, arbitrarily, to call this, almost instantaneous.

I suppose that considering bench resters, and some bench rest gunsmith's obsession with very small numbers as being important to their quest for accuracy that this time is actually large enough to be have a meaningful effect. If you are one of these shooters then do what you will with this amount of time.
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Well, maybe it's not a time issue at all. Maybe it's a flame propagation issue[if anything]. Why, for instance, do guys shooting cast bullet BR, mostly shooting someting .32 cal., often 32 40's most often get the best groups by shooting around 13-14 grains of 4227, usually with the small charge tipped forward in the case with no wad, behind a breech seated slug. Now, this ain't a .22 and nobody I know has ever climed inside to measure anything but I'd bet powder, priming and strike on the rim got something to do with flame propagation. It might also have something to do with fouling residue/post ignition,...hint.
 
i'm with george. why not make a firing pin in the shape of a + so that it hit totally across the entire rear of the shell? it would set more of the prime off at the sametime. if a small strike at 12 o clock or 6 o clock or 12&6 does good a full on + shaped strike should be even better.

just rambling here, but think about it.
 
Just to get my $0.02 in...I felt that was kind of a smart-a$$ comment, but couldn't really tell...nonetheless, I think they would refer to that as a center fire...not to mention I'm not so sure there would be ignition without actually striking the rim of the cartridge...also the size of the firing pin would be a little large...I'm going to stop rambling now...
 
Lowey said:
Has anybody seen or heard of an Anschutz 54 action being converted to a 6 O clock firing pin ? Curious

Lowey
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If I recall a gentleman from Australia made a new bolt body to fire at 6 oclock for his 54 Anschutz around 2006-07
 
Reason for not many multiple strike firing pins...

A good friend of mine did an experiment with one of his prototype .22 actions back in the early 90's with multiple strike firing pins. He tried 1, 2, and 3 points of impact on the case rim. His conclusion, from his testing, was that the single strike firing pin worked far better for accuracy than multiple ones.

For starters, he found that his best accuracy was with the minimum striker spring force necessary to achieve good ignition. Further, he found that if you had more than one firing pin strike on the case, you had to proportionally increase the striker spring force to get it to ignite consistently. If you use the same spring that worked fine with a single impact, multiple strikers wouldn't ignite the cartridge. When you get the striker spring strong enough to ignite with multiple strikers, he concluded that you have: a) made the rifle harder to cock, and b) upon firing pin impact cause a larger disturbance/wave/oscillation in the barrel before the bullet reaches the muzzle. Maybe you can tune this out of a gun, as he was trying this before tuners were really out there.

I can only imagine what kind of striker spring force you would need to ignite a rimfire with a + cross section or even a line from one side of the rim to the other. I'm guessing that it would be rather large, and the resulting increase in the vibrations induced would more than overcome any ignition advantage.

Sorry, this doesn't answer anything about 6 o'clock firing pins. I have an opinion, but you know what those are like...

Eric
 
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Eric,
It's interesting that you mentioned the minumum striking force. That's something I'm experimenting with now myself using 40X Remingtons. I've always tfelt they were a bit overkill. It's probably been done already, but I want to see for myself. I think if I can decrease bolt lift cocking the action and if accuracy remains the same it will be a plus. If accuracy improves too, that'd be a big plus. It'd just been too cold to do any serious accuracy testing outdoors the past few weeks.
 
Soft vs hard

I've found that Heavy stiff FP springs cause undue vibrations. I like the softer springs with the properly sized and postioned FP.
 
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