Delayed fire

[Bigguy1951]

Had an unusual day at the range today. I was testing the bedding job I had done on my sons 1970 .300 Weatherby Mark V. I had loaded 15 rounds with 73.5gr of IMR 4350, 165 gr Sierra HPBT Gamekings and Tulammo magnum rifle primers. The very first round I fired, which fired normally, was dented in from the shoulder down toward the base for almost 3/8 of an inch. I didn't catch this till after my second delay fire when I started checking primers for abnormalities. Of the 12 shots I fired, 7 were delayed. It is disturbing to hear the firing pin strike and wait for the gun to go off. It was a much longer delay than any muzzle loader I have ever fired, even in wet weather. Almost enough time to think OH S**T! I brought the remaining shells home and broke them down. All 3 had the correct amount of powder and there were no signs of any moisture contamination (unlikely here in the desert). I carefully removed the primers and compared them to the other magnum primers I have just to be sure that what I had written down was correct. They are definitely Tulammo primers. This box of primers was partially used, but the missing primers may well be in other ammo that has not been fired. This is actually quite likely. Any thoughts about this and what steps I might take or investigate are certainly welcome.

 

[DaveTooley]

I had a similar issue with those primers. They have to hard seated on the bottom of the primer pocket to sensitize them. More so than any other primer I've used.

 

[Bigguy1951]

I believe they were seated properly, but not 100% sure. I received an RCBS priming tool for XMAS and these were seated with it. Prior to this they were always seated with the priming arm on my old Rockchucker.

 

[XTR]

Hard seated to the bottom of the pocket (I use a hand primer) and make sure your firing pin is clean and there isn't any hardened gummed up cleaning fluids or lube in the bolt. Though not as bad as you are describing, I had some hang fires like that in a R700 F-TR rifle a couple of yrs ago. Pulled the pin and cleaned the bolt good and the problem went away.

 

[dkhunt14]

I would do like XTR said and check your bolt and firing pin assemble. Make sure it is clean and not all gummed up with grease or oil. AS others have said some primers need seated hard or you get misfires and hangfires. Matt

 

[Joe Salt]

Had this problem with a light gun at the Nationals one year it would go click but took a while to go off. It was the main spring in the trigger. And yes I had it all apart and cleaned and it still did it. Sent it back to Jewell, they sent me a new one. And that is what they told me. But if you are getting dents down the sides of your brass, that's low presser!

Joe Salt

 

[243winxb]

http://thefiringline.com/forums/showthread.php?p=4928827#post4928827 Like this?

If the bullet moves to soon from light neck tension, pressure will not build correctly. A long OAL when trying to get close to the rifling may be a problem also.

 

[Bigguy1951]

The dent above is just like mine. I was aware that low pressure could cause this which is why I didn't worry too much about it. If the primer was slow firing then perhaps a slow ignition would cause the low pressure situation, just a guess. I will of course break the bolt down and clean it up to see if this is the issue along with being sure to seat very firmly.

 

[Dusty Stevens]

I think since you just bedded it that your firing pin is dragging. Check the rear action screw and anything catching on the side of the trigger

 

[rogn]

I had the same problem with a lot of Wolf LRM primers. Had several misfires with Browning and Savage rifles with smaller firing pins. I only had 1 misfire with the Rem 700- bigger pin and more momentum. I still have about 1200 left, the problem only seemed to occur in one or 2 of the 100 paks. Out of about 800 rounds less than 10 misbehaved, mostly misfires but some hangfires too. Accuracy was exemplary however when they fired correctly.

 

[Bigguy1951]

It's not the rear action screw. Complete clearance between it and the trigger/firing pin. I even took some off the top of it when I reassembled to be sure of clearance. I will check again tomorrow to be sure.

 

[Dusty Stevens]

Check the stock inlet around the trigger too

 

[savagedasher]

Check the primer seating with a hand tool they probably aren't seated . Try them without powder and bullet . Larry

 

[Bigguy1951]

Thanks for the idea Larry, I will give it a try as well.

 

[savagedasher]

Thanks for the idea Larry, I will give it a try as well.

I had primer problems when I went to Michigan hunting . Only they wouldn't fire .
My wolf primers hang fired with a hand seating tool. Larry

 

[wapiti25]

Try CCI 250's with the same load. It does look like low pressure also.

 

[savagedasher]

I would never load a 300 wby without a magnum primer. Larry

 

[243winxb]

Primers- try a different magnum primer. http://www.shootingtimes.com/ammo/ammunition_st_mamotaip_200909/ If your "magnum" primer is not performing as it should, this may happen.

We tested loads at both maximum normal pressures and at the starting loads (some labs calculate start loads—we shot them). Standard primers caused no ignition issues at the max load but posted higher extreme variations in pressure and velocity in the lower pressure regimes of the start loads. In extreme cases, the start loads produced short delayed firings—probably in the range of 20 to 40 milliseconds but detectible to an experienced ballistician. Switching that propellant to a Magnum primer smoothed out the performance across the useful range of charge weights and completely eliminated the delays.

 

[savagedasher]

Primers- try a different magnum primer. http://www.shootingtimes.com/ammo/ammunition_st_mamotaip_200909/ If your "magnum" primer is not performing as it should, this may happen.

 

[savagedasher]

Any time you have a case that has large case capacity and is filled with slow burning powder . Basic 101 in reloading always use mag primer . Has been that for ever.
When seating primers they must be seated firm at the bottom or you get delayed ignition. That hasn't changed from the 50 tys when I started loading. Larry