Reusing brass after over pressure

[M-61]

I used the Sierra manual for their 243 Win 100 grain SP’s. My stupid mistake was using their recommended load for hunting for that bullet. It turns out it is their maximum load.

Ok you found your ‘mistake’ and I commend you for admitting it. However in this game that mistake is not always forgiving.
And 1/4-1/2 at 50 yards is well…. Something is quite wrong.
Just slow down and enjoy an interesting journey.
I’ve got a real problem with mis- reading MAX & MIN

 

[Webster]

After testing new reload, I have a some 243 win brass that have signs of over pressure. All have flattened primers, firing pin cratering, and ejector marks. One had the primer totally blown out. Three have carbon streaks from the primer pocket edges. I actually saw smoke come out from around the bolt on those three. None of these caused excessively hard bolt movement.

Obviously, I have to back off on the powder charge. I am thinking 1/2 to 3/4 of a grain less. The sad thing is, these rounds were the tightest pattern to date for this rifle. (5 shots in a 3/4“ to 1 ” circle at 50 yards)

My question is, should I throw these cases out or can I reuse them.

You don't know how to make safe reloads! 1" at 50 yards is a terrible group.

 

[Homerange]

You don't know how to make safe reloads! 1" at 50 yards is a terrible group.

Never discount the nut behind the butt, we can all shoot terrible too !
Days like that I pack up to return another day.

 

[Propbndr]

You don't know how to make safe reloads! 1" at 50 yards is a terrible group.

Reread my post, I said ”The sad thing is, these rounds were the tightest pattern to date for this rifle. (5 shots in a 3/4“ to 1 ” circle at 50 yards)”. I didn’t say it was a good group. Reloading for this rifle is a work in progress. If I could duplicate the Norma Whitetail ammo, I would be set. My rifle loves it. Unfortunately, the Norma bullet used in that round is not sold for reloading and Norma powders are not sold in the USA anymore.

As far as me not knowing how to make safe reloads…you don’t know me or how I reload. You don’t know how many charge weights I developed before this problem arose. In 20 years of reloading, this is the first time I ran into all of these particular issues. Hence, the my posted question.

I said that I would back off 1/2 to 3/4 of a grain. Why those amounts you might ask…because, I have already fired those charge weights and had ZERO issues. So please, keep your insults about about my lack of safe reloading knowledge to yourself.

 

[BondJamesBond]

Never discount the nut behind the butt, we can all shoot terrible too !
Days like that I pack up to return another day.

yes you are talking about the group size...think the mistake was made determining the start load at the reload bench and proceeding and watching while shooting CAREFULLY to max load

 

[Propbndr]

yes you are talking about the group size...think the mistake was made determining the start load at the reload bench and proceeding and watching while shooting CAREFULLY to max load

That was not my start load. It was the load that I had all the over pressure problems with. Backing off 1/2 grain shows no over pressure sighs at all.

 

[BondJamesBond]

That was not my start load. It was the load that I had all the over pressure problems with. Backing off 1/2 grain shows no over pressure sighs at all.

sorry thats not what I meant...I referred to his comment on group size...if bad go home
I'm old school (before the enterweb and youtube) where you check 3-4 sources for load development starting point and start from low and work to high looking at each fired piece of brass and taking note of all other signs of over pressure....when you reach it...stop and go back a bit
in my earlier years I was a hot rodder.... so I know how to get to the over max load with out going to far, if you know what I mean.
Your separated primers does sound a tad alarming.... something not right...brass/primers/powder charge/who knows
Knowing this site I don't think anyone was trying to be too attacky...think people are more concerned about safety and your success... enjoy the ride.
Larry W
EDIT... I reread a couple things on the first page...I hat a pet load that was everything awesome in 6bra
nothing changed except I started to have pierced primers with the same fed 210M primers????
NEVER pierced a primer before...ever
I asked several well known shooters if they experienced anything like that...just all of a sudden. no help
I resorted to setting aside the last 300 primers of that lot and changing the firing pin spring, problem went away?
hope this may help

 

[Propbndr]

I also read some threads that mentioned having problems with 210M primers. As I said earlier, I looked at all my brass with spent 210M’s. All of them had shoulders that were squared off. I have never had other primers square off, even at max load.

The Sierra manual calls for the 210M. I am going to start over using some Rem 9 1/2‘s I have. I wish I had some CCI’s.

 

[Zero333]

To blow a primer in the 243win you're at least 1 to 1.5 gr above safe pressures.
Powder humidity can also play a roll.
If you develop a load and it shoots great at max pressure while it's humid out, you will for sure be blowing primers when the humidity goes down.

All my 243win rifles shoot best and most consistent with H-4831sc powder and bullets in the 80 to 107 gr range.
80 gr Berger Varmint and 47 gr of H-4831sc
105/107 gr bullets I use 43 gr H-4831sc
Winchester brass and any primer except cci250 works good.

 

[LCazador]

Reread my post, I said ”The sad thing is, these rounds were the tightest pattern to date for this rifle. (5 shots in a 3/4“ to 1 ” circle at 50 yards)”. I didn’t say it was a good group. Reloading for this rifle is a work in progress. If I could duplicate the Norma Whitetail ammo, I would be set. My rifle loves it. Unfortunately, the Norma bullet used in that round is not sold for reloading and Norma powders are not sold in the USA anymore.

As far as me not knowing how to make safe reloads…you don’t know me or how I reload. You don’t know how many charge weights I developed before this problem arose. In 20 years of reloading, this is the first time I ran into all of these particular issues. Hence, the my posted question.

I said that I would back off 1/2 to 3/4 of a grain. Why those amounts you might ask…because, I have already fired those charge weights and had ZERO issues. So please, keep your insults about about my lack of safe reloading knowledge to yourself.

I don't think primers are the issue but it's possible. Was this new unfired brass or has it been fired in your rifles chamber? How much shoulder set back do you have? Too much shoulder set back introduces excessive head space
and reduces case volume. I'm not sure that dropping the powder charge 1 or 2 grains is going to do it. More like 3 or 4 grains less. What bullet are you using? Measure the case diameter just ahead of the extractor groove with a .0001" resolution micrometer or caliper. Use this number to monitor case head expansion. No more than .001" is acceptable.

 

[Propbndr]

I don't think primers are the issue but it's possible. Was this new unfired brass or has it been fired in your rifles chamber? How much shoulder set back do you have? Too much shoulder set back introduces excessive head space
and reduces case volume. I'm not sure that dropping the powder charge 1 or 2 grains is going to do it. More like 3 or 4 grains less. What bullet are you using? Measure the case diameter just ahead of the extractor groove with a .0001" resolution micrometer or caliper. Use this number to monitor case head expansion. No more than .001" is acceptable.

It was new, unfired brass.
I don’t know the shoulder setback. I never worried about it before. I have to buy the tools to measure it.
It is a Sierra 100 gr SP with a flat base. Over 36.2 grains of IMR-4064.
I have calipers that measure to .0001. The used brass was .0008 larger than unfired brass.

 

[Murray Brook]

Ran your #'s through Quickload. I don't have your specific #'s but using the default settings your load comes in 50674 PSI. Not a very hot load

 

[Kracken McGraw]

It was new, unfired brass.
I don’t know the shoulder setback. I never worried about it before. I have to buy the tools to measure it.
It is a Sierra 100 gr SP with a flat base. Over 36.2 grains of IMR-4064.
I have calipers that measure to .0001. The used brass was .0008 larger than unfired brass.

Are you using Sierra’s 5th or sixth edition manual loads. The sixth edition will be lower.

 

[Propbndr]

Are you using Sierra’s 5th or sixth edition manual loads. The sixth edition will be lower.

5th edition. The gun shop I support didn’t have the 6th edition in stock. The sales rep was kind enough to allow me to copy the pages I needed.

 

[JFrank]

5th edition. The gun shop I support didn’t have the 6th edition in stock. The sales rep was kind enough to allow me to copy the pages I needed.

Which primer were you using that popped and blew smoke ?

 

[Propbndr]

Federal GM210M. It is the one referenced in the data. I happen to have some. I normally use CCI or Remington.

As I said previously, I have noted that the Federals, unlike CCI or Remington, seem to flatten no matter what the charge. They don’t impress me.

 

[Kracken McGraw]

It was new, unfired brass.
I don’t know the shoulder setback. I never worried about it before. I have to buy the tools to measure it.
It is a Sierra 100 gr SP with a flat base. Over 36.2 grains of IMR-4064.
I have calipers that measure to .0001. The used brass was .0008 larger than unfired brass.

For others looking the new Hornady manual shows 34.2 grains of IMR 4064 as a max load for 95-100 bullets in the 243 Winchester. New Sierra manual only list much slower powders for those bullets.

 

[LCazador]

It was new, unfired brass.
I don’t know the shoulder setback. I never worried about it before. I have to buy the tools to measure it.
It is a Sierra 100 gr SP with a flat base. Over 36.2 grains of IMR-4064.
I have calipers that measure to .0001. The used brass was .0008 larger than unfired brass.

Bingo! You have new brass that is probably short of your actual chamber size together with a load that is over maximum. Almost all new brass is made shorter than actual SAMMI dimensions. You must fireform to your chamber first before working up loads. Fireform with a moderate load then proceed to load work. Start with a few cases 20 or so. If the Norma Whitetail load shoots well try to stay within the dimensions of that cartridge for starters. Personally, I would go to a slower burn rate powder like N160, N560, or 4831SC with the heavier bullets. I've been loading the 243 since 1968, great cartridge.

 

[243Lapua]

3/4-1 at 50 yards. Blown primers.
I’d start from the very beginning. There’s lots wrong with your load.
There must be every imaginable load in the manuals for a 243

Something is wrong, definitely.

 

[DShortt]

This thread is already full of a whole bunch of opinions and suggestions but I think the best place to start is to get a comparator and measure the base to shoulder of the brass you fired against the a few cases you haven't fired and see if your die setup is creating too short of a case for the particular chamber you have.
When a problem surfaces like this I prefer to start with some fundamentals. I sure wouldn't just back off the charge and try again because you're telling us there isn't good accuracy either. It's quite possible that you're seeing multiple problems from the same cause and a case that's too short for the chamber would explain a lot.