birdiemc
Well-Known Member
By starting low and working up, not running an extra 2 grains cuz theres room. I dont know anything about weatherbys, but I do know I start at a safe low charge weight and work up to higher
Help me figure out why I'm blowing primers
- Thread starter smithjasona1978
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smithjasona1978
Well-Known Member
You must not have read the entire post. I did start low. I loaded 5 each of 5 different loads with 3 different powders. Only variable was the charge weight. I examined each case with a magnifying glass after I fired it before moving to the next load. I never saw any signs of pressure. All of the primers looked exactly like the lowest load and or my fired factory rounds.
birdiemc
Well-Known Member
My apologies, it was in an earlier post and I had forgotten that...but the way you mentioned having 2 extra grains in the case made it unclear.
smithjasona1978
Well-Known Member
I have followed standard reloading practices to the letter. My problem is that .300Weatherby rifles have standard. 361 inches of free bore. So its impossible to get close to the lands. Maybe with one of the new super long high bc bullets, but that won't work because the barrel is 1/10 twist. So I was just trying to find my most accurate load. And my possible oal is between 3.56 and 3.85. That's a lot of real estate to play with. It also adds a ton of case capacity. So during my load development at 3.75 coal, I blew 2 primers. And I am asking for advice.
birdiemc
Well-Known Member
Have you tried it at the max length stated in the reloading manual?
kiwikid
Well-Known Member
According to the Hornady X edition manual both the top loads that you stated in post 5 are above their recommended Max Loads for the 208 grain bullets. Being new to reloading I would suggest that you start with Hornady's COAL of 3.560" and stay below their Max Load at least until you get more experience under your belt. The other members have given you great advise and please be aware that all of us just want you to stay safe.
Skimbleshanks
Well-Known Member
The weatherby cartridges and chambers were designed with the oal and freebore lengths for a reason. You are discovering that. Back off to starting loads at or below book max coal and I imagine your blown primers and pressure will go away. You dont have to be near the lands for it to shoot well. Some like being close to the lands some like a bit of a jump and some NEED a bit of a jump. 7RUM had like .400" freebore if memory serves. The rifle will tell you. Being new to reloading isn't the time to push things to the max. 300 weatherby loaded to the book isn't something to turn your nose up at. Try and be happy with what it is and don't blow your face up trying to gain 50fps. If you absolutely HAVE to have more velocity then you might want to look for a 300 RUM, or some wildcat based on the Lapua case.
59FLH
Well-Known Member
I would start with scale calibration and accuracy, and then look at seating die adjustment, could be some crimp going on.
If rounds fit the magazine and don't jam into the rifling, a longer COL can be used. A jam/contact with rifling may raise pressure 10,000 PSI
Custom barrels can be chambered to work with a bullet of the reloaders choice, so there is minimum jump to the rifling. Or the bullet is jammed into the rifling.
On factory chambered rifles, a longer the normal COL , with little bullet shank in contact with the case neck, may produce crocked bullet on loading. Bullet nose hits the feed tamp.
Weatherby-
Neck tension is lower when there is little bullet shank in contact with the case neck. The bullet moves to soon. Not good when using slow burn rate powders. Weatherby chambers add to the problem. A secondary pressure spike is possible. Photo in above post.
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Note the working PSI @ 65,000 & pressure limits on cartridge brass.
From Olin Brass- modulus of elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI, when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.
From Olin Brass- modulus of elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI, when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.
All good comments. My question is centered on how many times have you reloaded the brass? Max loads will kill the brass lifespan no matter what you do to extend it. You may not be able to get more than 4-6 loads out of a 300Wby due to the high pressure anyway without brass annealing etc. Brass has a definitive life span in belted magnums when loaded to full potential.
birdiemc
Well-Known Member
What in the world are you talking about here?
I've never seen an explanation like that before. I see where you're coming up the the numbers 16,000 and 76,000 but I dont even know what to google to learn what you're saying here.
No expert here.
Above 65,000 psi , brass may not spring back after firing. This shows up as hard bolt lift.
With no pressure testing equipment, we can only guess.
But 1 thing for sure, when the primer falls out within 5 firing, pressure is to high. Reduce the powder charge.
SAAMI Proof loads are 93,000 PSI maximum for the Weatherby. I would love to know how they get brass out of a chamber.
Sorry, not much help.
LaHunter
Well-Known Member
What primers are you using?
What type of priming tool are you using?
When priming your brass, there should be a little resistance when seating the primer? Are you noticing this? also, you need to make sure the primer pockets are clean and the primers need to be fully seated. Also, after firing a round, have you notice your bolt is just a bit more difficult to open (sticky bolt)? This is a good indicator of being over pressure. Just some thoughts. Going above 'book max loads' is not uncommon.
