I don't get it - 7rnds w/ 2 missfires & 1 hangfire

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LloydM

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I have been reloading for a Remington 700P in 7mm Rem Mag for a little while now, the rifle was new when I bought it, has always been kept clean, and is now less than a year old. Until now all loads I have fired used Federal large magnum rifle primers with IMR 4350. I have never had a missfire with either factory rounds or handloads. Today I went to the bench with 10 rounds made with 54grains of IMR 4350, CCI BR2 large rifle primers, Hornady 162grain AMAX bullets, all housed in brand new unfired nosler custom brass - now the interesting part:

I fired 2 rounds of factory ammo and then the handloads; out of 7 trigger pulls I had 2 missfires, and one "click BANG" hangfire. The hangfire was quick; the delay was long enough to hear the hammer land before the shot, but quick enough that I did not understand what happened untill after the shot. Frustrated, I did not care to try the remaining 3 rounds. Every round had a nice mark from the firing pin.

So what is going on? The only promlem I can think of was the air temperature at approximately -10 C. I have never had a problem before at this temperature. The BR2 primers are new to me, I have fired a few rounds made with these primers at the same temperature in an M14 with no problems, but the powder was IMR 4895. I hope there is no problem with the BR2 primers in cold weather, because I do a lot of cold weather shooting and have no other choice for match primers.
 
I had my first ever hang fire on Thursday, it was about -9 and I use a cci 200 large rifle primer in my 270. I don't recall which powder it was as I am not in front of my reloading bench. Primers were all well struck. At least I know I'm not flinching as even with the hangfire I recall a good group.
 
I don't think you will find it clogged flash holes as I had the same thing happen with my 25-06A1 with 4831, 2 hangfires in a row, pulled the other 3 rounds and there was no problem with primers, gun was in trunk of the car over nite in -20 weather, I can only relate to cold temps, as that has not happened since, been reloading 30some years and that was the first for hangfires, as stated above they were quick but enough to get your attention. Just my thoughts.
 
I read another thread from a few years ago and someone suggested checking for clogged flash holes... I admit having not checked the flash holes, but this is brand new brass out of a clean box, and at $80/50 cases it is top quality so there won't be any manufacturing defects. Also, I have went through almost 100 other cases so far and no problems until todays fiasco.

Does anyone know if the BR2s are especially cold weather sensitive?
 
Cci primers are a little harder than others, but what I'd check is that your primers are seated fully; if not, the strike of the pin will only seat the primer, but not crush the anvil enough to ignite the priming mixture.
 
Blame the CCI primers and the cold weather. I've had some recent grief (December) with the CCI mag primers that I was using in my Edge.It's a Carlock kind of thing. I was getting a pile of misfires, so checked the normal suspects. Since it is a Savage firing pin protrusion is adjustable, but checked out.No thick grease, freeplay at the cocking button. CCI primers are well known for a tougher primer cup which is why I was using them in the Savage action which are known for primer cratering. I thought I had it beat with a #32 Wolff spring, but was rewarded with one more misfire before giving up on them. When pulling down that last round the powder was bleached yellow and half caked in so it had to be scraped out with an Allen wrench. The weird thing is that when I decapped that primer is that it had gone off, but only burnt in a small area. I'd say about 1/3 of the compound was burnt and the rest didn't catch. I would have thought that impossible, but there it was.The other misfires showed nothing wrong at all.
Switching to Federal 215Ms straightened out all firing issues, but I had to back the loads off a grain. I can't say whether I got bad primers, but I sure have a lot of them.:( Lifes too short to fight with something that doesn't want to work.
 
I second that Holleyman - I would be willing to pay well above retail price to get ahold of some Federal primers. If anyone wants to sell some for profit PM me... So if in fact the BR2's are temp sensitive, and the Federals are impossible to find, what is the best option?
 
It is shock that sets off the primer. You can do a few things to maximize shock:

Rinse the bolt to get out any lube that might be slowing down the firing pin in cold weather.

Make sure the bullets do NOT touch the rifling.

With fired brass, don't size the shoulder back. make sure you have some brass compression with the bolt handle closing.

Switch to a Winchester Standard primer.
 
Ganderite said:
It is shock that sets off the primer. You can do a few things to maximize shock:

Rinse the bolt to get out any lube that might be slowing down the firing pin in cold weather.

Make sure the bullets do NOT touch the rifling.

With fired brass, don't size the shoulder back. make sure you have some brass compression with the bolt handle closing.

Switch to a Winchester Standard primer.
Click to expand...

All good, But I would NOT switch to a standard primer. 7mm RM uses mag primers for a reason. Don't have my books with me, but 54 grains of 4350 sounds pretty weak to me, and that's possibly your problem. 7 Rem mag can be a little twitchy - stay within the suggested powder ranges, and generally the belted mags prefer charges in the upper half of the scale. If you're under the start load charges be damned careful here. You can get more than misfires - you could generate strange pressure spikes and hangfires you've probably just learned are no fun.....
I just checked the hodgdon site - you're 2 full grains UNDER their starting charge weight. I'd pull them and get up to the minimum 56 grs. You should be using mag primers, like a CCI250 or Win LR magnum - you're using a pretty large case and relatively large amounts of pretty slow burning powder.
Don't take my word for this - go check the reload data center for yourself. Always stay within the parameters set by the guys who write this stuff - the bullet and/or powder manufacturers. We stray outside too, but always within burning rates appropriate for what we're working with and always with recommended primers.
 
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sbtennex: "Always stay within the parameters set by the guys who write this stuff - the bullet and/or powder manufacturers"... I think this is good advice, but nobody ever agrees, even the 'experts' and manufacturers.

From the Hodgdon/IMR website (powder manufacturer):
Starting load 56.0 grains IMR 4350 = 2704fps / 49,700 PSI - Max load 60.0 grains IMR 4350 = 2861 / 58,100 PSI

From the manufacturer of my bullets, The Hornady Handbook of Cartridge Reloading 4ed. printed in 1991 shows on page 295:
Starting load 52.0 grains IMR 4350 = 2600fps - Max load 59.5 grains IMR 4350 = 2900fps

Indeed I am 2 grains under the recommended start load from IMR, but I am 2 grains over the start load by Hornady. The max loads are pretty close 59.5 vs. 56.0 grains, so they are probably on par... the 4 grain difference in starting load is likely just a difference in accepted safety margain by the companies. Normaly I would give more credit to the powder manufacturer than the bullet manufacturer, but I chose to start where I did because it is right in the middle of the 2 starting loads, and I would not have wanted to begin with the higher of the 2 starting loads because the Nosler custom brass I am using is very thick, which means less case capacity.

Also for the record, I chronographed the first shot at 2684fps, so it looks to be roughly on par with the load data.
 
I also forgot to mention that 56grains of the same powder pushing the same bullet gave me quite a difficult extraction when using Federal Large Magnum Rifle primers... mind you I have had my chamber polished since then, it was a little tight just above the belt.
 
I also forgot to mention that 56grains of the same powder pushing the same bullet gave me quite a difficult extraction when using Federal Large Magnum Rifle primers... mind you I have had my chamber polished since then, it was a little tight just above the belt.

I would still like to hear more about the cold, because I am extremely anal with my reloads, and can't imagine any other reason for my troubles. That being said, it would be nice if the cold is not the problem because if it is then I need to find another type of primer to use.
 
If I'm reading it right, you had the chamber polished after these problems showed up. That may well have fixed the problem of sticky extraction, but still doesn't address the misfires. In colder weather at the light for caliber load you're using, extraction shouldn't be caused by excess pressure - on the contrary. Colder weather, more specifically cold ammo, will generate considerably less pressure (and velocity) with the same ammo as warmer weather. OTOH, as I mentioned, light 7 Mag loads can get hard to understand pressure-wise.
Hornady, almost across the board, publishes a lot of lawyer friendly data - somewhat lighter than a lot of other data. I've loaded a lot of 7mm RM ammo and have never had a problem like this, probably because as I mentioned I tend to load pretty hot. Nothing I shoot is ever more than 1 grain under max because that's where the guns I load for in this caliber seem to like their feed. For primers all I use is the CCI250, somewhat "cooler" than a Federal LR mag or a Winchester LR mag version. To get to the cause of your problem really would mean starting at the beginning. If the brass is once fired from your gun, I'd hope you're not FL resizing. It makes the most sense to headspace off the shoulder, not the belt. I believe one of the reasons the 7mm is "twitchy" with minimal loads is because of the over generous tendency a lot of rifle builders have when sizing the chambers for the 7mm RMag and that leads to a lot of brass stressing. Make sure you trim the flash holes, you only need to do it once, and we always run the brass over a primer pocket reformer/sizer first. Be fussy with the prep work. More I think about it, the more I'm convinced it's a combination of low temps aggravating the minimal load issue and being compounded by the wrong primer - not hot enough.
Only other 7mm Rem Mag I've seen giving problems from a misfire plus a really tough extraction, all in the same clip, was from a friend who'd had somebody load his ammo for him because it was cheaper. I found mismatched primers, all brands of brass imagineable of unknown history and powder charges that were so varied it made me sick. All in the same box. Weirdest thing was he'd managed to shoot a real nice sheep with the same stuff not 2 weeks prior. That's s***house luck pure and simple.
7mm Rem Mag is a wonderful cartridge - don't quit on it. It's still in the running for the very best one cartridge for everything on this continent.
BTW, what's the rifle you're using and what kind of history does it have?
 
For clarification/summary: the rifle is a Remington 700 Police in 7mm Rem Mag. It was purchased brand new last year, and has always been well maintained. My first reloads were the ones giving extraction problems - this was mainly because my loads were too hot, but an extra tight chamber was also contributing a small portion to that problem. I only mentioned that to illustrate that the brass I am using is very thick and requires reduced loads... Since then I have had the chamber polished, and the problem I am having now is with missfires and hangfires; they extract fine, but the primers are flattened out. Yes I have been neck sizing only, but this is using brand new unfired Nosler custom brass - it comes from the factory fully preped for loading with flash holes deburred, etc., even weight sorted. The load is 54 grains of IMR 4350 with BR2 primers (LR not LR mag), pushing a 162gr. Hornady AMAX. At first this does sound to be towards the lighter end of the powder range, but as mentioned before I have always had to use lighter loads - I attribute this to the smaller case capacity from the heavy brass. Later on I will pull the trigger again on the missfired rounds and see if they fire.
 
I wouldn't put 100% of the blame on the CCI Primers, there is something else contributing to the problem.

I have been using CCI primers all winter (50/Sunday for the past 7 or 8 Sundays) and have yet to have one not light up properly and we have shot on days as cold as -20.

As stated before, gunk in the bolt body may be slowing the firing pin down enough to not get a full strike on the primer.
 
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