Small/Bushed firing pins and cold weather

[boltfluter]

Hey guys,

Looking for your input on small/bushed firing pins for cold weather hunting. Occasionally I do some coyote hunting in temps approaching 10 deg above to -5 deg below. On several occasions I have had misfires due to the extreme cold. Usual suspects have been accounted for. As is in degreased firing pin spring, properly head spaced cases, and new Tubbs silicon firing pin spring.
To my question. Seems to me a slimmer firing pin tip would impart more energy to a smaller area on the primer and therefore help with ignition in the temperature extremes. Looking forward to your theory's/ input on this situation.
Nothing worse that putting the sneak on a coyote and hearing the dreaded click.

Paul

 

[hogpatrol]

What brand of action and trigger? Savage, Remington? Other?

 

[LHSmith]

I'd suspect the type of primer used in conjunction with the powder choice.

 

[msinc]

I bushed one of my 700's {223} back in June...has a .062" firing pin diameter and I am only running like .001"-.0015" clearance. Did it so it is fully guided/captive. Could maybe be a little more or less...kinda hard to mike holes that small accurately. I have fired it in temps down to 7 degrees F. Haven't had any misfires yet. Don't really have a lot of cold weather around here either...7 degrees is about as cold as it's been here in 10 years.

 

[DaveTooley]

Paul,
I don't have that much experience in extreme cold weather. A primer is pretty primitive. Either it is seated deep enough to sensitize it and it receives enough energy to set it off or it doesn't. There has been questions about reliability with a small pin. I have never heard of any problems but......
You may have found the lucky combination. I would change a few things and see what happens. The easiest is go back to the original firing pin spring. Next try a primer with a different style anvil.
By chance have you pulled the bullets and checked the primers to see if they went off?
Do they go off if hit a second time?

 

[spclark]

Paul you’re correct in thinking a smaller FP tip transfers more energy to primers. 0.062” is what to work towards if a stock bolt/pin is larger than that.

Not being a hunter I don’t bother shooting in temps lower than maybe 40F so my sole experience with anything lower was April ‘16’s Fullbore Fundraiser at Winnequah (Lodi WI) when it was 19F when we started the match. Small-primer Lapua Palma brass & Wolf/Tula 223M primers didn’t mind the cold whatsoever. My fingertips sure did though!

 

[boltfluter]

Good info guys.
Remington action/factory trigger(1985) with standard spring and pin. Primers are CCI-450's. They will ignite on second hit every time. Everything seems sluggish at these temps. For comparison, my Borden action with fitted Jewel has much better/heavier pin drop with stock firing pin spring. Wondering if I need to get the action timed for maximum pin drop. Keep the ideas coming.

Thanks, Paul

 

[Dusty Stevens]

Sometimes match tolerances dont work in the field and a factory action woulda worked fine. Ive never been concerned with blanking a primer on a hunting rifle

 

[FeMan]

I have gone to the small bushed firing pin in all my hunting rifles, including 7 STW and 30 Nosler. I have hunted as low as 20F below zero with no problems. The small fp flat works and I believe is less susceptible to piercing. A personal theory that may be BS but I can run them HOT and no issues.

 

[DaveTooley]

If they go off the second time around it might be primer sensitivity. Seat them deeper/harder. I would not recommend reseating the primers on the misfires.
What primer are you using?
I can dry fire rifles that I build with Remington actions and I can tell you something about their personality. Clean crisp ring and they will digest a lot of different ammo. Dull and sluggish and they're particular about what they like.
Try disassembling the firing pin and see how all the different parts interact.

 

[timeout]

If they go off the second time, is there any possibility that the primers were not fully seated? You can ask me how I know. I know because I had a hand primer that the handle bottomed out before the primer was fully seated.

 

[carlsbad]

Without looking at all the other possible causes, I will say that small firing pins can do nothing but help. The smaller pin takes less energy to dent the primer. So if the cold does anything to slow down your pin, your chances of a good strike are increased.

Small firing pin head cheerleader,

Jerry

 

[boltfluter]

If they go off the second time around it might be primer sensitivity. Seat them deeper/harder. I would not recommend reseating the primers on the misfires.
What primer are you using?
I can dry fire rifles that I build with Remington actions and I can tell you something about their personality. Clean crisp ring and they will digest a lot of different ammo. Dull and sluggish and they're particular about what they like.
Try disassembling the firing pin and see how all the different parts interact.

Dave,
CCI-450 primers. K@M priming tool that would literally crush a primer. No problems until temp hits the teens or below.

Paul

 

[Zero333]

All the primer FTF's I've ever had were in the very cold with cci primers ( excluding cci-250 )
Never had a problem with federal primers.

 

[DirtySteve]

If you have any type of lubricant in the bolt assembly it will thicken in the cold weather. This would cause miss fires.

 

[spclark]

If you have any type of lubricant in the bolt assembly it will thicken in the cold weather. This would cause miss fires.

Mostly true.

Graphite powder or hexagonal Boron Nitride (hBN) aren’t affected by temperature, can make good substitutes if necessary. If clean & dry works, leave well enough alone.

 

[DirtySteve]

Mostly true.

Graphite powder or hexagonal Boron Nitride (hBN) aren’t affected by temperature, can make good substitutes if necessary. If clean & dry works, leave well enough alone.

What you say is true. I use a spray type dry lube which has graphite. I know most folks use oil type lubes.

 

[Zero333]

I like to make sure there is never any lube inside the bolt. Especially in the deep cold.

 

[alf]

A couple 3 years ago on my annual Montana deer hunt, I sat in -20 from before first light till late morning, and with it still at -4, I shot 3 rounds from my 6.5x47 to dispel any cold weather myths. All went bang as expected. 700 short action bushed by Gre-Tan with 130 Bergers over Varget lit by 7 1/2's.

My #1 coyote smacker is my Bat actioned 6x47, & while I don't have it out for hours on end in brutal cold, I've never had any issues with H-4350 and 7 1/2's.

 

[spclark]

My #1 coyote smacker is my Bat actioned 6x47, & while I don't have it out for hours on end in brutal cold, I've never had any issues with H-4350 and 7 1/2's.

Something useful there maybe? Certain combinations - primer, powder, case, action design - are less susceptible to problems with cold than others?