Need help with random light primer strikes in Remington 700, 300 RUM

[Tripplebeards]

I haven’t shot my gun for a good 11 years (on a black bear) till the other day. It’s a model 700 I bought new around 1999’ chambered in 300 rum. It has a timney trigger set a 2 pounds. Been in it since the day I bought it. Never had any hang fires ever with it till my range session the other day…and this morning. I could feel the pin strike and a fraction of a second later boom! It isn’t always, but random. I am using a 180 grain speer round nose with Speer’s suggested minimum charge of 81.1 grains of IMR 7828 SSC powder loaded at 3.350”. I am using CCI 250 magnum rifle primers and Remington brass. Some of the brass was given to me and about 13 of the necks cracked after the first range session yesterday. I have two pieces that didn’t crack but the necks must be so thin because the bullets slide loosely after seating. The remainder of the brass was new. I tumbled my brass and let dry for a few days so I figured there wasn’t moisture in the cases. Some of the brass has been shot several times. All were annealed before these firing sessions. I set the shoulders back .002” to .003”. Primers we’re all seated below flush. Some of the primers did go in easy. I removed the action yesterday and sprayed everything down with Rem oil after cleaning the barrel. It does that the goofy J lock on the bolt. I didn’t take the bolt apart to clean the inside of it yet. The firing pin hole doesn’t have any build up around it and looks pretty clean. Any suggestions besides bolt disassembly and cleaning? I know that j lock pin assembly should be replaced. I am on the look out for a stainless one for my 300 and blued for my 375.

[Texas by God]

I had hangfires with ball powder and CCI large rifle primers in a .358 Norma. Very disconcerting! A switch to Remington 9-1/2 Mag. primers cured it. That's all I've got.

Sent from my SM-A716U using Tapatalk

[Tripplebeards]

I do have a brick of the 9 1/2 magnums. I have a couple bricks of the CCI magnums so I figured I had more to play around with and thought they were a better quality primer. If I remember right the rems are the hottest.

[Winger Ed.]

I Any suggestions besides bolt disassembly and cleaning? .


I'd do that first.
The factory packing/assembly oil/grease turns hard over time and slows down the firing pin.
Cool or cold weather makes it worse.

Also, since you have to take it apart anyway-
That's the perfect time to put it back together with a speed lock Titanium firing pin and their spring.

[Tripplebeards]

I forgot I took a photo of the the primers. The 4 in my hands look like they were hit lighter than the others. Bought the primers brand new this time last year form the LGS for $39 a brick.


https://i.imgur.com/qbdWMj7.jpg


It has the J lock set up with the “snake” spring. If I replace it…the j lock goes with it. I’m guessing a straight spring that doesn’t bind will help.

[Winger Ed.]

From what I'm used to seeing, those look like weak strikes.

Compared to yours:
On all the Rem700s I've handled or owned, the primer strike looked like it was done with a dull punch and a 3 pound hammer.

That gets us back to the firing pin & spring inside the bolt body.
With a slow 'lock time' between trigger pull & primer detonation in a older rifle with factory or heavy grease--
that also speaks to a gummy spring inside the bolt which can cause a weak primer hit.

I don't have any experience with the J lock, so I looked it up.
Everything I found was about its problems, and how to get rid of it, or get a aftermarket Tubb's spring.

From what I've read, I'd remove it just to stay in compliance with 'Man Law' if nothing else.
"Man Law" rule Number One clearly states:
When encountered--- remove, dis-connect, or otherwise bypass all safety devices.:bigsmyl2:

[lesharris]

FWIW try cleaning the bolt. Yes that means a complete disassembly degrease and relube with a light non gumming oil. It should solve your problem. 11 years since last hunt the bolt needs maintenance.

[NSB]

I totally agree with cleaning the bolt, and no harm putting in a new pin and spring as suggested. If it were me and I didn’t have a case gage for headspace I’d get one. Based on what you’ve described about the cases that might be part of your problem.

[Tripplebeards]

I just got done disassembling and cleaning the bolt. I know it doesn't help with the photo below to solve my problem.... because I got sidetracked and wiped the grease off the spring with after photo below. IMO it doesn't really look too bad but I'm sure the grease didn't help all over the spring. The grease didn't seem dirty and was light grey in color.

https://i.imgur.com/aa76cjF.jpg

There was either some oxidation or carbon on the firing pin in front of the spring I didn't remove above. After the photo I polished it. It looks like shiny chrome now. I also scraped the inside of my bolt hole where the firing pin comes out of in case there was carbon build up. I didn't notice any when I cleaned it. I cleaned all the grease out of the bolt housing. I put a thin coat of EWL slip 2000 synthetic lube on the spring and inside the bolt housing and then lightly wiped it off. I put a little red shooters choice grease on the treads and back of the bolt lugs and reassembled. I then grabbed 4 casings. I primed them and fired them without any powder charge...or bullets. The primers on my hand were the "before" light hit primers I saved....

https://i.imgur.com/oAp6ojt.jpg

I'm sure with a loaded round there would be a heavier indentation? I also measured the seating depth of the 4 cases I used. They were discarded cases with either loose case neck and cracked necks. The primers were .013 on average below flush...

https://i.imgur.com/MijcnWR.jpg

Wondering if the primer pockets are worn out causing the primers to seat to deep? The primers all seated with little to no resistance.

[Winger Ed.]

Wondering if the primer pockets are worn out causing the primers to seat to deep? The primers all seated with little to no resistance.

Doubtful.
I've had primer pockets loosen up, as in the diameter seems to enlarge, but not the depth of the hole.
Even if the primer is a little deeper than you're used to seeing, the firing pin has plenty of over travel to reach it.

I full length size, and when I've fired a primed & empty case, I'm used to seeing the primer back out a little.
I figure it comes out to adjust itself to the headspace length difference in the chamber & FL sized brass.

Did ya notice if the lock time seemed faster with the cleaned out bolt?

[dverna]

Those primers look too deeply seated to me. I seat primers just barely below the case. Never measured it and just do it by touch. Likely .003” below flush.

Looks like someone went overboard prepping the primer hole and/or too much seating force.

[Tripplebeards]

Never did a slow squeeze on the trigger for lock time. Guess I’ll try a few more.

Never prepped the primer holes. Maybe too much seating force at some time? The brass is from 1999’ and has been shot quite a bit. Lost count of the firings. I will probably anneal them every firing or two till they are not usable. I did get a new bag of 50 from Swamp today! He gave me a great price. Thanks swamp!!! I’m sure my money order didn’t make to him yet since I sent it out yesterday. Couldn’t get to post office fast enough to beat the brass.

[Hickok]

I had a similar problem with a Remington M700 in 7mm08. I had trued up the primers pockets with a tool from Sinclair that actually made the primer pockets too deep. The primers were then seated too deep and I began to experience misfires.

My "bad", not the Remington rifle. I gave up the practice of truing up primer pockets. I was ham-fisting the primers with too much pressure, and along with the "trued-up" primer pockets, I created my own malfunctions. A hard lesson learned by myself.:oops:

Also, if you push the shoulder back too much when resizing your brass, the case will be pushed forward in the chamber by the primer strike, causing a hang-fire or missfire. This is creating excessive head-space, and causes misfires and also case head separations.

Not saying you did this, but these can be two causes for hang fires/miss fires.

I agree with Dverna, those primers look excessively deep seated.

[Tripplebeards]

I thought they looked extremely deep. The guy I got them from might have messed with the primer pockets back in the day. We both purchased 300 RUMs in 1999’. At the time I didn’t reload yet. We were “taught” the wrong way from a guy we bear hunted with which motivated me to buy a rock chucker kit and did ALOT of reading since the Internet and YouTube wasn’t really around yet. It wouldn’t surprise me if they tried to ream out the primer pockets and ended up cutting them to deep. I don’t mess with them myself…or haven’t for a couple of decades anyways. I’ll have to see how deep my primers seat in the new brass VS these. I will also measure all my current brass after I seat primers in them being my brass got mixed with the ones he gave me. I believe I have some once or twice fired casings mixed in with them. I’ll definitely sort and divide them….and keep my new casings separate. Shoulders were set back two to three thousands.


When seated the primers it doesn’t come to a “hard wall” like most my other calibers do. It’s like they stop and I can can keep squeezing my RCBS hand primer slowly till the handle is flush with the primer grip. I wonder if my brass is too soft or the primer pockets are to big in diameter and the primer sidewalls are expanding outwards to fit the worn out pocket?

Either that or the primer pocket is so wide that maybe the primer seater is slowly sliding down till it touches the base of brass’s primer hole? My hand primer I can squeeze the handle completely flush with little effort. It would make sense anyways.


So another issue I’m having ….

I also have had a few of these cases with loose neck tension. They haven’t cracked yet but the bullets can easily be pushed inside the case after seating. I’m down to two of them that haven’t cracked yet with lose necks. The bullet starts with little resistance and then slides in for no force. I experimented and took my die apart. Cleaned the neck expander ball and polished it. I also Cleaned and and polished the inside of my expander die and reassembled. I then annealed the two casings, full length resized, and seated bullets with the exact same results. Like beating a dead horse…those went in the scrap pile. Maybe I’m blind and there are hair line cracks half way down the necks or the necks are getting so thin that they won’t hold bullets?

Im guessing new brass will probably take care of my issues.

[Hickok]

Tripplebeards, I am just making a guess, but it sounds like your friend who gave you the brass was doing the whole "benchrest Target shooters" treatment to the brass, i.e. truing up primer pockets, neckturning the brass etc. Thus the deep primers pockets and the thin case necks that wont hold a bullet and are prone to cracking.

I bet new brass will solve the problem. Keep us posted.:smile:

[Rich/WIS]

Seat to the bottom of the primer pocket, is not seated fully the firing pin has to drive the primer to the bottom. This uses some of the firing pin force and can led to misfires or erratic ignition.

[Tripplebeards]

Appreciate all the help and replies. I'll have to load up some of the new brass and see how the neck tension is and primer seating depths are compared to my current worn out brass. Here is the die set before I cleaned and polished. I was hoping for better neck tension after cleaning.

https://i.imgur.com/8wv9nWv.jpg

And one random piece of brass with a weird dent after firing. Im guessimg it hit something on the way out or when it hit what ever it was ejected into?

https://i.imgur.com/eTMntqW.jpg

I'm sure it will pop out when firing but looks pretty severe.

[NSB]

Throw that one out, it has a sharp crease on top. It’s very deep, too deep to fire that way.

[dverna]

Find another source for brass. I would throw all that stuff into the recycle pail.

[BK7saum]

Appreciate all the help and replies. I'll have to load up some of the new brass and see how the neck tension is and primer seating depths are compared to my current worn out brass. Here is the die set before I cleaned and polished. I was hoping for better neck tension after cleaning.

https://i.imgur.com/8wv9nWv.jpg

And one random piece of brass with a weird dent after firing. Im guessimg it hit something on the way out or when it hit what ever it was ejected into?

https://i.imgur.com/eTMntqW.jpg

I'm sure it will pop out when firing but looks pretty severe.

I have had that happen wiith fireforming loads thst dont seal the neck. gas bleeds by and ended up with a dent. It didnt hit anything, came out of the chamber that way.

i wouldn't remove any material from the expander. Your new brass might have issues with bullet seating. factory expanders are notoriously undersized already. Your old brass seems to be the problem.

[Jim22]

If you are full-length resizing your brass you may be pushing the shoulder back causing excessive heeadspace. That could easily cause what you are experiencing.

Jim

[Tripplebeards]

I'm measuring my shoulders with the hornady comparator. I've been bumping them back two to 3 thousands.

I loaded up 20 brand new cases today. The primer depths on 2 random cases I grabbed were .0003". When I seated them the RCBS hand primer i felt a firm stop like the normal stop felling I'm use to. Also I had a good amount of resistance when seating bullets. My old brass is definitely getting worn out imo. The old batch of 8 casings I still have loaded up that had decent neck tension. The primer measurement depths of those casings are .0005", .0007,.0008,.0009,.0010,.0013,.0011, and .0014. The primer cavity depths on the new brass average is . 0127". The worn brass primer depths are anywhere from .0127" to .0130". I have not retested the my delayed primer strikes with loading up a few new.emply cases with primers and popping them off again but I'm guessing the new brass with primers seated .0003" will probably have solved my issues along with cleaning my firing pin assembly.

[BK7saum]

It sure seems like the primer pockets were reamed too deep on the older cases. Also, i have never had brass get less neck tension as it gets older/shot more. The necks work harden and have more neck tension as they are sized and shot more.

[Tripplebeards]

I heated those necks that didn't have tension till they were light orange. I FL sized and tried again. Still no neck tension for some reason.

Ripped open my new bag of brass today...

The new brass case necks measured .0008/.0009" longer than my fire formed brass right out of bag.. Out of curiosity I tried cycling the unsized brass in my gun before running them through my FL sizer. I didn't feel any resistance. So I set my sizing die flush with the shell holder and didn't cam it over to set my necks back. I did candle one of the .0008" taller empty case shoulders a couple times and closed my bolt. I still couldnt feel any resistance but I can see it touched. I figured it was fine and loaded my 20 rounds for hunting.

https://i.imgur.com/JkOGwaA.jpg


I do own a hand held forester neck turner. Bought it when I first got into reloading. I think the previous owner of the brass, and, or, I might have experiemtned and turned some necks back in the day on 300 RUM and a few 243 casings. Which makes me think that the brass necks might have been turned and to thin??? FYI I don't think I've turned necks since and never plan on doing so again. Hard to remember because it was 20 years ago.

[BK7saum]

For neck turned cases i use a FL bushijg die or a neck bushing die to adjust the neck tension. If going to the trouble of neck turning, i will splurge on a die that will properly size the turned cases.

[ulav8r]

I heated those necks that didn't have tension till they were light orange. You over heated the brass and ruined it. That is proven by the way the shoulder collapsed. Going by color the brass should just be starting to turn red when viewed in dim lighting.

[Lloyd Smale]

my take on it after looking at the pics is that it does look like the primers are a bit low but it also looks like they were hit hard enough to ignite. First thing id try is a differnt batch of primers then that one or a differnt brand. That would eliminate or show if it was the primers causing it. Id also take the advice of some and pull apart the bolt and clean it. I had problems with misfires in my model 7 one year when it was real cold and it ended up being some of that foam barrel cleaner got into the bolt while i was doing load development earlier that summer and gummed it up. I know its hard to throw away brass. Especially for something like the 300 ultra because its hard to find and expensive but i think id have to deposit that bunch if necks are cracking for no other reason.

[Lloyd Smale]

got a 300 ultra story. I was doing crop damage control shooting and shot a big doe at about 450 yards with mine. At the shot it headed for the woods but i could see it was hurt. Got there and where it went in the woods there was blood everywhere. On the ground, bushes even the trees. It was a blood trail that you about could keep from getting on your clothes let alone your shoes. I thought the deer couldnt have went ten yards but it went over a 100 yards with a blood trail a 2 year old could follow. Got to the deer and i had it it a tad low and about 3 inches above the arm joint. It blew the whole arm off. Just a stump left and the bullet then went into the brisket and blew a hole you cold have stuck a soft ball in. I dont know how that deer made it a 100 feet let alone a 100 yards. It couldnt have had a drop of blood left in it. I learned something that day. Before ive said a few times that deer cant have blood left in it when tracking but ive never had deer bleed a 1/3 as much as that one. I made my longest ever shot on a deer with that gun too. 620 yards which beat my 7stw by 40 yards.

[Tripplebeards]

I shot a Pronghorn with it at a 1000 yards back in 2000’. Have it head mounted on my wall. I used a 125 grain Nosler ballistic tip loaded just under 4,000 FPS. It ran 40 yards in a circle and tipped over. Looked like I hit it with a FMJ bullet at that distance. Pencil hole in and out. I shot another one at 200 yards that put a coffee can sized hole trough it. I stopped shooting that bullet and that far after my pronghorn hunt. I’ve taken 2 black bear and a 10 point buck with it. Black bear were shot with a 180 factory load swift scirocco (DRT) and a 200 grain partition thst I had a 30 yard track job. The deer was running directly under Heath my tree stand. Bang, flop with a 180 grain Nosler ballistic tip. This year I’m using 180 grain Seirra round noses loaded light. A minimum charge of IMR 7828 SSC at 81.1 grains with a velocity of 2,900 FPS. I tried 4 different powders at with the round nose all at Sierra’s minimum book load and 7828 shot the tightest at MOA. I’m sure the old, worn out casings and hang fires didn’t help my accuracy testing. I’m guessing once the new cases are fire formed I’m guessing my groups will shrink. My shots are normally under a 100 yards so I removed my KDF brake along with some recoil using a starting load. Seems like there is ALOT of extra room in the case and wondered if that was part if the issue at first. Haven’t used the gun for 11 years and figured it is going to get some woods time this year.

I know I should toss the rest of the old brass but will hold onto it till I find another bag of RP brass to replace it. I’ll just use my new brass for hunting this year. Between the mew brass and bolt cleaning n sure my issues are taken care of. I will end up getting a Grey-Tan firing pin assembly to replace the JLock one of these days.

[Tripplebeards]

You over heated the brass and ruined it. That is proven by the way the shoulder collapsed. Going by color the brass should just be starting to turn red when viewed in dim lighting.

I am with you. I normally don’t heat them to that point but i figured I’d experiment on those 2 cases. Thanks for the reminder to dim the lights. I normally don’t wait till my cases turn red in dim light since I’ve collapsed a few in years past. It’s an eye opener when you try to seat a bullet and the neck wrinkles and collapses.

[Lloyd Smale]

I dont ever aneal brass. Never seen a need to do it and you risk ruining it. Also ive had my best luck in the 300 ultra, 7stw and my new 6.5-300wby with the various 50 bmg powders. 7828 is a bit fast and probably the fastest powder ill even bother with anymore is re25 even that is on the fast. 860 870ect are what i have good luck with and i about exclusively use fed match mag rifle primers with those big cases to get consistent burn.