what spring weight??

S

skeetlee

Active member
Just curious as to how much spring weight you like to run in your ppc or other rifles and what size firing pin you have? I am going to do a little testing with a 25lb spring when it gets here from bat compared to a 21lb spring compared to the 17lb spring that was in my rifles action. I already know the 17lb spring is way to light, as my rifle doesnt shoot very well. Well i hope this is the root of its trouble!! I was just curious if anyone else has done any testing such as this. I figure most of you probably have. I was told that the 25lb spring might be to heavy or in better terms, not a good idea. I will see and report after i do some test if anyone cares to know what i find. One other thing i have heard was that the firing pin should weigh 2oz? Mine does not but i am not real sure this is an issue for the test i am going to preform. Any thoughts? Lee
 
In most cases, the main reason against a really heavy pin spring is the bolt lift after firing. If the bolt lift gets too heavy you are disturbing the bags way too much and having to re-aim every shot.

David
 
very true David!!
I did shoot my troubled ppc this morning before the match started with the 21lb spring and from what limited shooting i did do, its looking better. The other two springs should be here this week. Lee
 
Most of the shooters I know use something around 21 pounds.

I have personally cured a couple of bad shooting Rifles that had too little spring fall, (16 lbs or less), which is probably traced to irratic ignition.

The first cousin to spring tension is firing pin fall. This is one place where Kelblys got it right, at least .230 is considered minimum by many.
 
It's been said many times before but "ignition" is affected by spring strength, firing pin weight, and firing pin travel. Each has its own set of compromises. For example, firing pin mass and length of travel affect lock time, important if you are shooting offhand, most consider it far less so in benchrest.

Of the three, it is true that it is easiest to increase spring tension, but I think it is the least effective way to "improve ignition."
 
This brings up a valid point. With rimfire, ignition is "vodoo", i.e. change the shape and angle of the F.P., spring strength, F.P. travel, and F.P. mass. Too strong a spring and you can have bad vibes. Too long a fall and the lock time increases. The most difficult thing to change probably gives the most positive result, added F.P. mass. Only my .02
willy
 
I got into a corner with firing pin travel once. I ended up trial & error for tightest grouping, as measured with a released pin tip from the boltface.
I've got my finding logged & don't remember off hand. But there truly was a sweetspot that improved grouping beyond what the gun was shooting beforehand.

I ended up here with occasional flyers that I finally traced to a slipping striker setscrew at the cocking piece.
On my 'things to do' list is to design an external adjustment for this on the shroud.

I honestly believe there is a lot to discover with this subject.
Pin travel/mass, spring strength/length, primer strike distance, primer thickness and primer to pocket crush settings.
Sometimes I think this all sums to cause one primer to work better than another in a load -for a particular gun, yet not across the board.
 
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