It was a Dud, to much powder, to small of a hole
What is the most overbore cartridge YOU HAVE USED?
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It was a Dud, to much powder, to small of a hole
It was a Dud and barrel life has never concerned me
Jeff Heeg osoh
Well-Known Member
I had a slightly shortened 50 cal with a radius shoulder necked down to a 375 that held 25 grains more powder than a 416 Barrett. It was easy to push a 400 grain 3480 fps with H50 BMG. ** First barrel made it through load development only and was done.
Then the second barrel made it - 10 rounds in Colorado and 35 rounds at the KO2M, we did load development based off the widest window in bullet jump with the least fps spread and ran with it. The barrel was history after the 45 rounds through it even though we switched powders and was using US869 because the small ball material powder was less abrasive to the throat versus cylindrical design of the H50 BMG. The rifle preformed very well and made it to the finale that year.
The rifle was a tack driving laser if one was messing around at a ELR range and taking their time, but if forced to shoot a dozen rounds fast at multiple target as the timer was counting down you were combining a cutting torch and a sand blaster all in one.
Never wanted the title or bragging rights but this had to be the King of the barrel burners.
Just a note - 2 of us were running these and in time we opened the brass up to a 416 re-chambered barrels to the same chamber just in a 416 now versus the 375 and have been pushing the 550s at 3060 with ease using 20N29 and the barrel/throat has been holding up well.
Cheers
Osoh
JH
Then the second barrel made it - 10 rounds in Colorado and 35 rounds at the KO2M, we did load development based off the widest window in bullet jump with the least fps spread and ran with it. The barrel was history after the 45 rounds through it even though we switched powders and was using US869 because the small ball material powder was less abrasive to the throat versus cylindrical design of the H50 BMG. The rifle preformed very well and made it to the finale that year.
The rifle was a tack driving laser if one was messing around at a ELR range and taking their time, but if forced to shoot a dozen rounds fast at multiple target as the timer was counting down you were combining a cutting torch and a sand blaster all in one.
Never wanted the title or bragging rights but this had to be the King of the barrel burners.
Just a note - 2 of us were running these and in time we opened the brass up to a 416 re-chambered barrels to the same chamber just in a 416 now versus the 375 and have been pushing the 550s at 3060 with ease using 20N29 and the barrel/throat has been holding up well.
Cheers
Osoh
JH
Calvin45
Well-Known Member
That's astounding to hear from you haha.
Kirby Allen aka fiftydriver has done quarter bores off the RUM and .338 Norma case.
To be fair these are out of very long barrels.
What barrel length did you find it to be a dud out of, and what bullet weights? What were you hoping for vs what did you get, performance wise?
I'm very interested as a bigger-than-.257 weatherby wildcat is on my horizon. Almost certainly going to do a .25-300 weatherby out of a 32 inch barrel.
Huntnful
Well-Known Member
Mine is my current 7-300 Norma Mag Improved. I shot the first barrel out with 90gr. of H50 and N570 in 123 rounds forming brass, test bullets and charge weights and shooting longer shot strings than necessary. Now it's a fire forming barrel
But learned a lot from it. Second and third barrels have looked great using mostly H1000. N570 also isn't terrible as long as the shot strings aren't too long and I let the barrel cool.
I can't see switching back to another cartridge at the moment. It should get better life than a 28 Nosler with N570, and out perform it, but with a cleaner and cooler burning powder.
But learned a lot from it. Second and third barrels have looked great using mostly H1000. N570 also isn't terrible as long as the shot strings aren't too long and I let the barrel cool.
I can't see switching back to another cartridge at the moment. It should get better life than a 28 Nosler with N570, and out perform it, but with a cleaner and cooler burning powder.
Mine was a 6.5-300 Weatherby (WWH) I had built in the early '90s. Ballistics were amazing, throat erosion even more so.
Had it set back after 750 rounds - had to take 2" from the chamber-end, another 1" from the muzzle.
Had it set back after 750 rounds - had to take 2" from the chamber-end, another 1" from the muzzle.
Aussie Hunter Steve
Well-Known Member
6.5-300 Weatherby….but I love it! It's my favourite deer round. Next was a 7mm STW that I had back in the '90's. Also on my second 257 Weatherby, hard on barrels but is an awesome flat shooting round.
270-338 RUM IMP. light weight monos 126-128 class 3600-3700 fps. or 165 matrix 3300fps which was the intended bullet. first barrel with load development and fireforming didn't last long under 500 rounds, second was better at 800, still have third, don't shoot much anymore 95-100gr. of RL-50 is not cost efficient in today's market and the loss of matrix bullets years ago has put a damper on it.
According to this chart, a very high percentage in my inventory is overbore. Luckily, I never paid attention to it.
240, 257, 6.5/300, 30-378, 6.5/7PRC and I have everything to put my 270/7 Rum together. Fun Hot Rods .
Nimrod
Well-Known Member
Mine was a 6mm Mach4, I used slower twist barrels trying to keep pressures down a little but I just couldn't get the results I was after. The Mach 4 was replaced by a 6mm/06 and a 6mm-.284. The only one still around is the 6mm-.284 and I haven't shot it in years. I was after the ultimate pronghorn rifle and I concluded that the 6mm was not the right bore diameter with the bullets around at the time.
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26 Nosler, my Buddy basically brought one over with dies, ammo, and a box of case for about half what a bare rifle cost. It likes really slow ball powder and gets really dirty really fast. The ballistics don't justify the downsides. I'm currently running a 127 LRX@3520 or so. I'll probably deer hunt with it for quite a while though because I have enough cheap pulled brass and WC870 to last for the rest of my and the rifles life.
