When to throw away brass

[Lefty7mmstw]

On my 300 rum, the only pressure signs I see are very slight ejector marks at 103g of retumbo. I backed it down to 102g and stuck with that. I am getting the best accuracy by far at this load with 3/8"-1/2" MOA @100 yds with 180g Nosler Partitions. The first 3 loadings the primer pockets were normal, but the 4th time they feel very loose. This is all on a factory LSS Remington 700 with a free floated barrel and trigger job. It looks like I need to back down more and try to get the lighter load to group.

With retumbo and 180 hornady bullets in my 30 rum I was getting stiff bolt lift at 100 grains. I switched to rl25 and got the same speed(3300 fps) with a mid-load and less cost to boot(93 gr vs 100 gr). It is also much easier on the rifle, with one finger bolt lift and the ability to load the brass 'till the neck cracks. I'm using a stock lh bdl (6-18x buckmaster on top) with no mods at all(I didn't even bother to float the barrel) and it's a consistant 1/2 moa rifle. I5010 worked very well also with mid charge weights( 5 grains down from top tested) doing 3320 fps with 3/4 moa, but mine went bad and it's rather tough to find good 5010 right now.

 

[AZShooter]

I have heard the same sort of rule that if the brass won't make at least three firings without primer pockets getting loose the load is too hot.

I read in an old issue of Precision Shooting an article titled Make Mine a 6mm-284. The author was getting loose primer pockets with just a few firings. His load was not near max but primer pockets didn't last long. His solution was to talk to the maker of his custom reamer and have him reduce the diameter of the case head portion. The brass still was able to extract fine but his primer pockets stayed tight for many more firings.

None of the posters commented on whether their rifles were factory or custom. Might be interesting to see if there is a difference in primer pocket life.

 

[Bart B]

His load was not near max but primer pockets didn't last long. His solution was to talk to the maker of his custom reamer and have him reduce the diameter of the case head portion. The brass still was able to extract fine but his primer pockets stayed tight for many more firings.

If it was the diameter of the chamber at the case head, how did he reduce the barrel's diameter at that point?

 

[AZShooter]

He used that new reamer with the next barrel.....sorry should have mentioned that. Only alternative would be to cut off old chamber and cut a new one.

 

[Bart B]

He used that new reamer with the next barrel.....sorry should have mentioned that. Only alternative would be to cut off old chamber and cut a new one.

All of which means that if the same loads are used in a smaller chamber in a barrel with the exact same bore and groove dimensions, peak pressure's higher than in the previous barrel.

Seems to me the new barrel's chamber would have to be exactly the same diameter as the case (maybe smaller) to prevent primer pockets from enlarging.

 

[AZShooter]

I don't have the dimensions but yes there would have to be some clearance. I am only reporting what I read.

 

[caltrap]

4-5 loads when start showing web stress pockets loose.I keep all my brass
that is bad and scrap it,some times I get $1.40 lbs

 

[Joe King]

I have heard the same sort of rule that if the brass won't make at least three firings without primer pockets getting loose the load is too hot.

I read in an old issue of Precision Shooting an article titled Make Mine a 6mm-284. The author was getting loose primer pockets with just a few firings. His load was not near max but primer pockets didn't last long. His solution was to talk to the maker of his custom reamer and have him reduce the diameter of the case head portion. The brass still was able to extract fine but his primer pockets stayed tight for many more firings.

None of the posters commented on whether their rifles were factory or custom. Might be interesting to see if there is a difference in primer pocket life.

Makes sense, I'm on 7 or 8?????? maybe more, with nosler cases, I'm pushing it a bit I'm still not seeing anything out of my cases that their getting tired, but I can feel new cases when I close the bolt too. I know I never saw that when it still had the factory barrel.

 

[Bullet bumper]

I use this handy tool to visually inspect inside the case
Otoscope - Wikipedia, the free encyclopedia

If you clean the cases in an ultrasonic cleaner with an organic acid solution like white vinegar with a few drops of washing up detergent . The inside is clean enough to see what is going on . Then if you suspect the start of a case head separation groove . You can also insert the feeler wire and confirm that what you are seeing is a groove starting .
I have used this idea for so long now that I know what to look for without having to clean inside the case at all and know how long most cases last anyway.
It's a good educational tool.

 

[Robinhood493]

On my 300 rum, the only pressure signs I see are very slight ejector marks at 103g of retumbo. I backed it down to 102g and stuck with that. I am getting the best accuracy by far at this load with 3/8"-1/2" MOA @100 yds with 180g Nosler Partitions. The first 3 loadings the primer pockets were normal, but the 4th time they feel very loose. This is all on a factory LSS Remington 700 with a free floated barrel and trigger job. It looks like I need to back down more and try to get the lighter load to group.

I'm on my 5th loading, and the pockets are still holding the primers. I will try a 6th loading this week sometime. I will say this though, the Winchester brass I have at 7-8 loadings in my .270 and 7mm Rem Mag look a whole lot better than the Remington in my .300 RUM, and they are all loaded hot. It seems like the Remington brass is hard as @#&!. The Winchester brass looks new. I think I will have to anneal the Remington brass before I load it again. The neck tension seems very inconsistant, but I didn't get a split neck yet. I wish that they had a more affordable brass to use in the .300 RUM so I could get away from Remington. I love my Winchester brass.

 

[Bart B]

When a friend and I took a new Federal brass .308 Win. case and reloaded it about 50 times, the primer pockets were still tight. Load was 44 grains of IMR4895 atop Federal 210M primers under a Sierra 168 (57 reloads on his case) and a Sierra 165 SBT (for me, 46 reloads on my case). That's a max, safe load. Case bodies were reduced about .003" in the RCBS FL dies and the die's necks were lapped out to .335" for a loaded round diameter of .337". Fired case shoulders were set back .002" No case neck annealing whatsoever. No loose primer pockets

Both 1:11 twist Hart 26" barrels had standard SAAMI minimum spec chambers, .2998" bore and .3078" groove diameters. Muzzle velocity spreads were about 25 fps around 2720 average for both his and my case and barrels. My friend's rifle was fired from a machine rest and all 57 of his shots went into 3/10ths MOA. A buddy shot my rifle while I reloaded the case and his group for all 46 shots was 3/4 MOA. Both rifles test fired at 100 yards.

 

[jsthntn247]

When a friend and I took a new Federal brass .308 Win. case and reloaded it about 50 times, the primer pockets were still tight. Load was 44 grains of IMR4895 atop Federal 210M primers under a Sierra 168 (57 reloads on his case) and a Sierra 165 SBT (for me, 46 reloads on my case). That's a max, safe load. Case bodies were reduced about .003" in the RCBS FL dies and the die's necks were lapped out to .335" for a loaded round diameter of .337". Fired case shoulders were set back .002" No case neck annealing whatsoever. No loose primer pockets

Both 1:11 twist Hart 26" barrels had standard SAAMI minimum spec chambers, .2998" bore and .3078" groove diameters. Muzzle velocity spreads were about 25 fps around 2720 average for both his and my case and barrels. My friend's rifle was fired from a machine rest and all 57 of his shots went into 3/10ths MOA. A buddy shot my rifle while I reloaded the case and his group for all 46 shots was 3/4 MOA. Both rifles test fired at 100 yards.

I see no reason that's not possible. A moderate load, neck sizing, and annealing every 4th firing, brass will last a loooong time.

 

[Bart B]

I see no reason that's not possible. A moderate load, neck sizing, and annealing every 4th firing, brass will last a loooong time.

Those loads are maximum, case was full length sized and never annealed.

 

[dbhostler]

What signs do I need to look for to determine when to throw my brass away? I have Remington cases in 300rum. They have been loaded 3 times FL and the primer pockets seem really loose on some cases. I loaded them up for a 4th times and was very careful and I didn't have any soot around the primers. My guess would be that I need to chunk them now and get new ones.

I toss my 300 RUM brass when the primers seat with little or no effort, usually 4 loads. You can also check the primer pocket with a decapping probe before adding powder. If you can push out the primer with hand pressure, the pocket is too loose. FC Premium brass no better than Rem. Watch for cratering around firing pin, if you see the beginnings, you're keeping the brass too long.
db