I want a FREE LUNCH 300 Rum Erosion

[rhouser]

I have just finished the break in on a new 7MTU Hawk Hill 1:10 twist 28" barrel with a 4 port non-magnum Muscle brake mounted onto my Rem PSS action and HS Prec stock. All my recoil issues are gone and this is really a good setup now. A little heavy for snap shooting, but, on the bipod or over a log etc. it is awesome. It is also very nicely accurate

The problem is barrel life. I have maybe 450 good HUNTING LOAD LEVEL shots left on the barrel before I have to start worrying about barrel replacement. I want to fun shoot the rifle because it is really a sweet ride. I am 65 years old and have been hunting an shooting for half a century now (scary huh). Every now and then a gun comes together and is just pleasing.

I believe that the erosion in overbore cartridges is the product of the pressure and heat duration provided by the large cartridge capacity being blasted into the small throat diameter. It seems to me that if I want to shoot rounds that do not significantly contribute to the throat erosion of my new barrel, I go after the burn duration (faster powder) and pressure (decrease amount of powder).

I am proposing a load that has a velocity down to the mid 2000 fps ranges and uses a bullet in the 165 - 180 gr range to allow me to shoot a large number of rounds for fun without greatly affecting the throat and my barrel life for the hunting loads.

Am I missing some logical reason why this won't allow me to shoot FUN gun time without affecting the hunting life of the barrel. The safety of a load like this is not at issue here, only the question of whether this should reduce throat erosion to a level where I could shoot a few hundred rounds for fun without taking out my barrel.

I am looking for opinions here, any, yours would be appreciated.

thanks in advance.
rch

 

[MudRunner2005]

The only way to improve barrel life, will be to step down in cartridge size to something with less powder capacity that is a more efficient cartridge, like a .300 Weatherby, or .300 WinMag.

High velocity + excess heat + increased friction + More flame on the throat = shorter barrel life.

Moving down in bullet weight will increase the useable powder capacity (lighter bullets create less pressure) which means more powder to burn. With more powder to burn, the flame on the throat burns longer. More powder and a lighter bullet also means increased velocity. Increased velocity, in-turn creates more heat from excess friction. So, going down in bullet weight will most likely decrease your barrel life even more.

My personal opinion, if you're looking for something just to go to the range and plink steel and paper with, I would buy/build a range-only target gun that way you don't keep burning out your hunting rifle.

 

[tbrice23]

Im not trying to be a smart ***, but if you had a similar build rifle in 308 winchester you could practice your shooting form and maybe offhand /hunting positions.
But not so much drops/ballistics.

Also, barrel replacement is one of the reasons I love Savages.

 

[FEENIX]

Also, barrel replacement is one of the reasons I love Savages.

You Sir is a smart man!

 

[IdahoCTD]

If I was worried about barrel life from the get go I would pay another 6-700 and have a duplicate barrel chambered from the start. That way you are a barrel vise and a action wrench away from a fresh barrel. Or do a Remage set up.

 

[FEENIX]

Or do a Remage set up.

... and another smart man!

 

[rhouser]

Ok, I did ask for opinions, and I am greatful for all of you that gave them.

I just wanted some free time with this rifle and new barrel.

I have plenty of other rifles to shoot for fun, target practice, 600 yd BR, F-Class etc. Each has their own place in my world. I shoot 223 in a space gun with 8 twist, 6BR 12 twist, 243 AI in a 9 twist for the Bergers, 260 Rem in 8 twist, 308 in a 11 and 10 twist. 30-06 in 10 twists both auto loaders and bolt, 375 H&H for my bear rifle, 38-55 for deer in the woods with holy black and barnes originals, 45-70 in both a lever gun and a HighWall 30" barrel. The 300 rum is just my long range hunter.

I was honestly trying to confirm that an overbore cartridge creates it's damage with the powder gas volume and duration as it goes through the throat to it's confining work space in the bore.

I guess an example of my work around load would be that I could lauch a 165 grain bullet with 13 gr of red dot in a 300 rum and the bullet would clear the bore. I suspect that I could do this 100 times with less effect than a single shot of my hunting load (91.5 of retumbo with a 200 gr accubond).

I meant no sacrilige by my question. If anyone want's to get this post deleted, I won't be offended.

very respectfully, rch

 

[gohring3006]

You can load it down to 30-06 velocities and that would help. I shoot my 300 Weatherby once maybe twice at the range and let it cool completely. Doing both of these will help with barrel heat/life.

 

[Trickymissfit]

The only way to improve barrel life, will be to step down in cartridge size to something with less powder capacity that is a more efficient cartridge, like a .300 Weatherby, or .300 WinMag.

High velocity + excess heat + increased friction + More flame on the throat = shorter barrel life.

Moving down in bullet weight will increase the useable powder capacity (lighter bullets create less pressure) which means more powder to burn. With more powder to burn, the flame on the throat burns longer. More powder and a lighter bullet also means increased velocity. Increased velocity, in-turn creates more heat from excess friction. So, going down in bullet weight will most likely decrease your barrel life even more.

My personal opinion, if you're looking for something just to go to the range and plink steel and paper with, I would buy/build a range-only target gun that way you don't keep burning out your hunting rifle.

The .300 Win mag is a pretty good hunting round, but also a poor design. With a 25 degree shoulder and a .264 neck length it's gonna be hard on throats. Still for the guy shooting twenty rounds a year it won't mean anything. On the other hand the .300 WBY mag has a .327" neck with roughly a 44 degree shoulder. probably twice the throat life even though it's far greater in overbore. I like the .300SAUM from Remington, and the .300WSM. They use a lot less powder for a loss of maybe 300fps (I doubt it's that much). Barrel is gonna last a lot longer, and whatever you hit down range is never gonna know the difference. For me, I'd like to have a .308 Norma case with a .300 Ackley neck and shoulder. (better yet a .300 Jarrette neck and shoulder)
gary

 

[MudRunner2005]

The .300 Win mag is a pretty good hunting round, but also a poor design. With a 25 degree shoulder and a .264 neck length it's gonna be hard on throats. Still for the guy shooting twenty rounds a year it won't mean anything. On the other hand the .300 WBY mag has a .327" neck with roughly a 44 degree shoulder. probably twice the throat life even though it's far greater in overbore. I like the .300SAUM from Remington, and the .300WSM. They use a lot less powder for a loss of maybe 300fps (I doubt it's that much). Barrel is gonna last a lot longer, and whatever you hit down range is never gonna know the difference. For me, I'd like to have a .308 Norma case with a .300 Ackley neck and shoulder. (better yet a .300 Jarrette neck and shoulder)
gary

Why not just build a .300 Ackley? I love the case design of mine. Very efficient cartridge. And like you said, 40* shoulder for good brass life and efficiency, and a long neck for excellent throat life. Also, with it's BR 1K track record, it's well-known for its accuracy.

 

[Trickymissfit]

Ok, I did ask for opinions, and I am greatful for all of you that gave them.

I just wanted some free time with this rifle and new barrel.

I have plenty of other rifles to shoot for fun, target practice, 600 yd BR, F-Class etc. Each has their own place in my world. I shoot 223 in a space gun with 8 twist, 6BR 12 twist, 243 AI in a 9 twist for the Bergers, 260 Rem in 8 twist, 308 in a 11 and 10 twist. 30-06 in 10 twists both auto loaders and bolt, 375 H&H for my bear rifle, 38-55 for deer in the woods with holy black and barnes originals, 45-70 in both a lever gun and a HighWall 30" barrel. The 300 rum is just my long range hunter.

I was honestly trying to confirm that an overbore cartridge creates it's damage with the powder gas volume and duration as it goes through the throat to it's confining work space in the bore.

I guess an example of my work around load would be that I could lauch a 165 grain bullet with 13 gr of red dot in a 300 rum and the bullet would clear the bore. I suspect that I could do this 100 times with less effect than a single shot of my hunting load (91.5 of retumbo with a 200 gr accubond).

I meant no sacrilige by my question. If anyone want's to get this post deleted, I won't be offended.

very respectfully, rch

P.O. Ackley told all of us many years ago that overbore is a recipe for disaster. Of course that also depends upon how far into overbore your going. The Ultra mag is pretty bad, but if your a guy shooting twenty to thirty rounds a year it's OK. Then there are neck length and shoulder angle issues to seriously compound matters. Now I'm not a fan of Ackley's 40 degree shoulder, as it creates other issues. I'd much prefer a 30 degree or a 35 at the most. Plus a neck length of at least 1.2 calibers
gary

 

[MudRunner2005]

I'm not aware of any issues with the 40* shoulder...Only positive improvements. None of my 40* Ackelys have any issues. I don't have any feeding issues with any of mine, either. Which issues are you referring to?

 

[jmd025]

I wish the initial post would have read : " help make my 300 RUM perform like a 30-30"

Strictly for my own entertainment though

 

[MudRunner2005]

I wish the initial post would have read : " help make my 300 RUM perform like a 30-30"

Strictly for my own entertainment though

We're all thinking it, and Josh just says it...