Magnum versus standard primers

[clinker42]

Hi
Is there any issues in using standard large rifle primers instead of magnum large rifle primers.
I have a 270wsm that misfires, I fitted a new firing pin and spring and took some material out of the stock so the bolt handle closed properly. But out of 30 magnum primers I will get two that dont go bang. Out of fifty normal primers they all went bang.
Would hate to have a record sambar lined up and have that misfire.

 

[cmillard]

shouldnt be an issue. just dont push the loads too hot and pierce a primer. the mags typically have a thicker cup, and some also have a little more "spark" also.

 

[JohnnyJohnson]

shouldnt be an issue. just dont push the loads too hot and pierce a primer. the mags typically have a thicker cup, and some also have a little more "spark" also.

What he said. But what is the brand of primer you're having problems with?

 

[RonAKA]

I've shot thousands of rounds of centerfire, and never had one single misfire. In rimfire, yes I have had 4-5 out of several thousands, and I've concluded it was a gun problem, not an ammo problem. So my guess is that it is an issue with your gun.

 

[people]

I can not say if

 

[bozo699]

clinker42,
I have to say I am with RonAKA on this I have also shot thousands of rounds of cf ammo over the years with only a handfull of missfires,that I contributed to miss handling of the reloader (ME) The way priming mix is put into rimfire ammo you WILL get a missfire once in a while. But unless you got a bad batch of primers I would look @ fireing pin protrusion (how many thousandths from bolt face) and I would check head space. I am also interested in what primers you were having troubles with. Good luck to you my friend and let us know.
Wayne.

 

[Laurie]

The other issue you don't mention is powder type used and the temperatures you do your hunting in. Large charges of ball powders in magnum cartridges are notorious for producing misfires and/or severely reduced MVs in very cold conditions, hence the usual advice to use a magnum primer.

I've never seen ignition / primer type investigated for the short magnums, but suspect that the need for magnum primers is marginal in these cases and would only be required for the worst possible combination - difficult to ignite ball powders or very, very slow burning stick types allied to temperatures way, way below zero.

Over here in the British Isles where we'd hardly ever see the sort of temperatures you get in the northern US states or Canada, I'm pretty sure you only need magnum primers for the very largest cased cartridges such as the Weatherby monsters. I have a more or less shot out .300 H&H Magnum F-Class rifle whose cartridge has a really long and narrow case with hardly any shoulder. Books and manuals say that magnum primers are essential in this number to get small velocity spreads and I always primed mine with Fed 215Ms, but plan to do a side by side range-test with standard primers over the coming winter before it gets rebarrelled or sent to the junkyard.

 

[bozo699]

Laurie,
I tend to agree with you, I have used fed 210m primers for years in my .300wm the rounds are very consistant (low es &sd) I am burning 74 grains of H-4831 in RWS cases. I allways use mag primers with ball powders even in say the.223 rem. Powder and bullet manufacturers usually have done most of the testing for you its not in stone but they at least give you a pretty good guide line and they don't allways use mag primers in magnum loads. One must allways proceed with caution when changing components!!!
Wayne.

 

[tunered]

I had hangfires in a 223wssm with br2's, as long as 3 seconds, if i remember right it was with h414. Mag primers fixed it. ed

 

[bozo699]

I had hangfires in a 223wssm with br2's, as long as 3 seconds, if i remember right it was with h414. Mag primers fixed it. ed

WOW that is scary Ed I am glad you got the problem fixed before you or somone got hurt.
Wayne.

 

[bigedp51]

I agree with the others in that it is not the primers causing the problem. Your problem is wimpy hits on the primers caused by a multitude of reasons.

You need to dissemble the bolt and clean it or try soaking it in kerosene or other solvents. It could be a very small piece of brass, dried grease, metal shavings or gremlins.

Gremlins come in many forms, rough machine marks inside the bolt and the firing pin spring is dragging on them. You could have a defective firing pin spring that when compressed drags excessively on the inside of the bolt. Or even a firing pin protrusion problem, your on your second firing pin so you may have a bur inside the bolt causing minimum firing pin protrusion. (really mean sadistic gremlins)

Last resort, head gap clearance or the air gap between the rear of the case and the bolt face.

Measure a new unfired case for length and write it down.

Seat a used fired primer in the primer pocket just starting the primer with your fingers.

Now chamber this test case closing the bolt slowly and seating the primer. Now re-measure the case and subtract the first case measurement from the second and this will be head gap clearance. If you have tight head space you should have very little head gap clearance (.003 to .006)

Long head gap clearance and short firing pin protrusion equals wimpy hit on your primers.

On milsurps, its 60 year old plus dried cosmoline that has returned to its original carbon state along with pieces of cartridge brass from long forgotten wars are the normal problem. But its those pesky gremlins that get you when your not looking.

 

[bozo699]

bigedp51,
I agree with your post, and welcome to the forum

 

[precision.riflecraft]

The other issue you don't mention is powder type used and the temperatures you do your hunting in. Large charges of ball powders in magnum cartridges are notorious for producing misfires and/or severely reduced MVs in very cold conditions, hence the usual advice to use a magnum primer.

I've never seen ignition / primer type investigated for the short magnums, but suspect that the need for magnum primers is marginal in these cases and would only be required for the worst possible combination - difficult to ignite ball powders or very, very slow burning stick types allied to temperatures way, way below zero.

Over here in the British Isles where we'd hardly ever see the sort of temperatures you get in the northern US states or Canada, I'm pretty sure you only need magnum primers for the very largest cased cartridges such as the Weatherby monsters. I have a more or less shot out .300 H&H Magnum F-Class rifle whose cartridge has a really long and narrow case with hardly any shoulder. Books and manuals say that magnum primers are essential in this number to get small velocity spreads and I always primed mine with Fed 215Ms, but plan to do a side by side range-test with standard primers over the coming winter before it gets rebarrelled or sent to the junkyard.

I'm really grappling with this at the moment. I just took delivery of a Cadex .300 PRC and I'm beginning load development. I'm in Canada, where the winters are cold and primers are antimatter. I'm fortunate to have a supply of LRs, but no LRMs and no leads on them as yet. I don't want to take shortcuts out of impatience, so I might have to bide my time.

 

[kiwijohn]

All the information I have ever seen on LARGE RIFLE style primers either in magnum or standard says that the cup thickness is 0.027 across the board on all typical brands.
Smalls differ but not large. Happy to be corrected.

 

[fkimble@charter.net]

Yep, sounds like an ignition problem. Check all the usual suspects, clean inside bolt, check firing pin protrusion, verify minimal headspace, verify primer seating to bottom of pocket, and make it a clean pocket while your at it. Cold weather, and large amounts of slow powder need very good ignition. And remember cold weather turns oil into grease and grease into a semisolid. These are just the basics. And a combination of several of the above added together can be very hard to diagnose! Your new firing pin, was it a factory replacement or maybe a Wolf extra power spring? An extra power spring, while it doesn't fix all the little problems, it usually does over come them enough to make the gun go bang.

Frank