Big problem with reloads

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sugb

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This morning I was out shooting a new batch of reloads. When I fired the 11th shot there was some debris blown out the back of the bolt which hit me in the face. luckily I was not injured but the potential was there. Now, I can not figure out why this pinhole blew through the primer. I am very confident that the loads were all charged correctly (61.4 grains IMR7828). I cleaned all the flash holes although with the little tool for cleaning by hand not all of the carbon/residue is removed. There is no evidence that the primer was not seated correctly either.

Does anyone have any idea what may have caused this?
 
sugb said:


This morning I was out shooting a new batch of reloads. When I fired the 11th shot there was some debris blown out the back of the bolt which hit me in the face. luckily I was not injured but the potential was there. Now, I can not figure out why this pinhole blew through the primer. I am very confident that the loads were all charged correctly (61.4 grains IMR7828). I cleaned all the flash holes although with the little tool for cleaning by hand not all of the carbon/residue is removed. There is no evidence that the primer was not seated correctly either.

Does anyone have any idea what may have caused this?
Click to expand...

Try another round and see what happens.
 
Some have less capacity and will produce higher pressures with the same charge.

Federal brass is thicker than most and for me it takes 1-2 grains less powder to get the same velocity as winchester or Remington.
 
I've had a poor batch of primers that would blow a hole through the primer, changed primer and no more problems. Mine was always where the primer had been struck though. Yours looks like it came out the outside of the primer. Loose primer pockets, too much pressure? I don't clean my primer pockets at all. Just the flash hole if it needs it. Keeps primers a little tighter seems to make no difference in accuracy.
 
ok, I am not trying to disagree but how is a guy to know that? I am fairly new to reloading but I have not seen any info in my reloading manual to say that there are different charges for different brass. I measured the base of the brass right in front of the belt and it measures .5125" which is .0005" under what it says in the manual. Please advise.
 
if you measure the case capacity , more than likely you will find that the federal cases have less volume than the others .

when working up a load , don't mix your brass . and when you settle on a load , that is THE LOAD for that brass .

changing your brass means working up a new load for the new brass .


btw you measure your cases by how much water they will hold .


this is what works for me .

i prefer to use once fired cases , fired in the same rifle .

i trim them to all the same length , and then install primers .

i fill them with water so the water bulges out the top of the neck in the same manner .

i then empty the water into a small container on my reloading scale and weigh it .
i do this 4 or 5 times for each case and take the average .

i don't do this with all my cases , just a sample of each brand of cases i will be reloading .

i was relaoding for a 270 win using remington brass and was pretty much at a max loading . by accident a federal brass slipped into the mix and it blew the primer ( locked up the bolt too ) right out of the case that the remington brass had no issue with . ( i was using remington mag primers ) .
 
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Looks like a bad primer or a dirty pocket. Its not too much pressure because the primers would be flattening, if it was low pressure the primer tends to back out. I'd keep shooting and if it does it again change primer brands. Wear your safety glasses.
 
He's referring to case capacity not outside dimensions.
Outside dimensions should be the same but if the brass is thicker, the inside dimensions will be different.
Thicker brass = lower capacity
Lower capacity with same charge = higher pressure
 
sugb said:
ok, I am not trying to disagree but how is a guy to know that?
Click to expand...

You have to keep reading and learning. All cases are not made the same and have different volumes as was mentioned above. I'm new at reloading too but this was one of the first things I learned. Internal ballistics are affected by very small variances in dimensions of the case, bullet, barrel, everything!
 
ya, after measuring the brass it does not seem to me that there was an overpressure. As I said I was at 61.4 grains IMR7828 which is 2.4 grains below max load for this combo. (162gr SST).
 
yes I understand, Im only giving dimesions because this is the only way i know to check for everpressure.
 
K here's my take after reading all of the info here.

I use mixed brass for plinking etc, but I never even come close to max charges or pressure. If you are loading at max charges or close to it then I agree that you shouldnt be mixing brass. What is safe in one kind if brass may be overpressured in another.

Now from your pics I see zero signs of pressure issues in your rounds. I'm thinking a loose primer pocket may have caused this failure. Or maybe the primer pocket had a scratch deep enough to allow gasses to blow backward and rupture the primer.

Just my opinion.

Steve
 
Ok thank you for all the help. I will measure the case capacities with water, I just went out and measured with powder(i know this is probably not very accurate but it was a quick check) my findings were that after measuring several times the brass held the same charge to within 5/10ths of a grain. 85-85 1/2 grains total capacity.
 
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