Main Menu
Advertisement
Affiliates
Advertisement
Newest Members
BigHit, Sifat, TJWatkins, Jlivi1224, 65chevy
60473 Registered Users
Top Posters
dogcatcher 77465
stxranchman 52092
RWH24 44568
rifleman 43786
BOBO the Clown 41117
BMD 40539
Big Orn 37484
txshntr 33685
bill oxner 32656
sig226fan (Rguns.com) 30571
facebook
Forum Stats
60473 Members
45 Forums
476079 Topics
6245203 Posts

Max Online: 16728 @ 03/25/12 08:51 AM
Page 1 of 3 1 2 3 >
Topic Options
#6211140 - 03/05/16 08:28 PM Puzzled on "barrel burning" cartridges
jorge Offline
Extreme Tracker

Registered: 02/01/11
Posts: 3944
Loc: Lake Jackson, TX
Ok so certain rounds are coined barrel burners or over bore. It made sense till i starting thinking about it. Maybe someone can clue me in o what im missing.

220 swift vs 308. One has a bbl life that people say starts going south less than 1k the other ppl say can go over 3k without losing a step.

Here are the pressures of some rounds.

220 swift - 54k CUP
223 rem - 55k psi
308 - 63k psi
270 win - 65k psi

Heat and erosion are functions of pressure. So are the supposed staple "barrel burners" really "barrel burners"???
_________________________
Jorge Sakai
South Texas Trophy Outfitters

Contact #: 210-837-6742
GEORGE.SAKAI@YAHOO.COM

Top
#6211278 - 03/05/16 09:37 PM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
RiverRider Offline
THF Trophy Hunter

Registered: 11/11/07
Posts: 6220
Loc: Wise Co.
Erosion is a function of the volume of gas (and therefore the amount of powder burned) in relation to the cross-sectional area of the bore.
_________________________


Originally Posted By: Cleric
God I am hating caliber threads more and more

Top
#6211304 - 03/05/16 10:01 PM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
Hirogen Offline
Tracker

Registered: 07/18/13
Posts: 684
Loc: Ontario, Grey County
In addition to what RR said if you compare the case capacity of the 223 rem vs the 220 swift you get 31 grains vs 47 grains or roughly 50% more powder being burned in the 220 swift. The travel time for the bullet in the barrel is also shorter in the 220 swift - therefore you are expelling 50% more gas (assuming full burn) in less time through a barrel that has the same internal volume. Based on the Laws of Thermodynamics no matter what the initial chamber temperature/pressure is, the pressure and temperature as you proceed down the barrel of the 220 swift will very quickly greatly exceed those in the 223 rem. Shoulder geometry also comes into play as it will affect gas turbulence formation. The more turbulence the more erosion.


Edited by Hirogen (03/05/16 10:03 PM)
_________________________
Never violate a woman, nor harm a child. Do not lie, cheat or steal. These things are for lesser men. Protect the weak against the evil strong. And never allow thoughts of gain to lead you into the pursuit of evil.

-The Iron Code of Druss the Legend

Top
#6211318 - 03/05/16 10:12 PM Re: Puzzled on "barrel burning" cartridges [Re: Hirogen]
FiremanJG Offline
THF Celebrity

Registered: 12/16/08
Posts: 17893
Loc: Wolfe City, TX
^^Answered^^

Thread over. smile
_________________________


800 Yard Steel Rifle Range
Long Range Shooting Instruction
Memberships and Classes Available


Top
#6211354 - 03/05/16 11:04 PM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
blackcoal Offline
THF Trophy Hunter

Registered: 01/19/12
Posts: 7568
Loc: 60 Mi North of DFW
Basically there are three areas that need to be examined. Thermal, mechanical, and chemical but since someone has declared the thread is over who am I to examine the issue any longer. bolt
_________________________
The Greatest Enemy of knowledge is not ignorance,
it is the illusion of knowledge.--Stephen Hawking

Top
#6211363 - 03/05/16 11:22 PM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
NTRP Offline


Registered: 02/06/09
Posts: 1421
Loc: McKinney, TX By God!
Consider the .308, 7-08, .260, and .243 in that relative order. All of them have a .308 parent cartridge and each round has a slightly smaller caliber that the parent case is necked down to. Give or take a little they each have the same basic powder capacity (again +/- to illustrate my point). As the heat and pressure becomes more concentrated moving down to the smaller bore diameter, the greater the throat erosion. So the forces escape through a 7.62mm hole much easier than a 6.00mm hole. The more concentrated the force, the greater the erosion.

I hope that explanation helps.
_________________________

North Texas Rifle Precision
Josh (Jay) Ruby
Team Shooter for Short Action Customs and Kahles Optics

Top
#6211370 - 03/05/16 11:58 PM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
jorge Offline
Extreme Tracker

Registered: 02/01/11
Posts: 3944
Loc: Lake Jackson, TX
Yep, i dunno why but i thought i was really on to something driving down to the ranch today. Man, i feel like a total moron now.
_________________________
Jorge Sakai
South Texas Trophy Outfitters

Contact #: 210-837-6742
GEORGE.SAKAI@YAHOO.COM

Top
#6211372 - 03/06/16 12:14 AM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
syncerus Offline
Pro Tracker

Registered: 12/01/08
Posts: 1992
Loc: Dallas, TX
I thought this thread was about my 7mm RUM. I bought three extra barrels for it and fully expect to use them all over the next x number of years, Providence willing.
_________________________
NRA Endowment & DSC Lifer

Top
#6211379 - 03/06/16 12:36 AM Re: Puzzled on "barrel burning" cartridges [Re: syncerus]
NTRP Offline


Registered: 02/06/09
Posts: 1421
Loc: McKinney, TX By God!
Originally Posted By: syncerus
I thought this thread was about my 7mm RUM. I bought three extra barrels for it and fully expect to use them all over the next x number of years, Providence willing.


Lol you have a barrel burner for sure. My .300RUM has 600 rounds on it and it's gonna go tits up in the next 100 - 200.
_________________________

North Texas Rifle Precision
Josh (Jay) Ruby
Team Shooter for Short Action Customs and Kahles Optics

Top
#6211393 - 03/06/16 01:31 AM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
5 Stand Dan Offline
Pro Tracker

Registered: 06/23/12
Posts: 1489
Loc: DFW
It's like the safety video I saw back in the day, "Speed Kills". Yes it does, barrels.
_________________________
Dead Pair!

Top
#6211430 - 03/06/16 06:52 AM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
charlesb Offline
Pro Tracker

Registered: 04/07/10
Posts: 1408
Loc: West Texas mountains
Barrel life in the "barrel burner" chamberings can be extended dramatically by letting the barrel cool thoroughly between shots. The cooler the barrel is just prior to firing, the less damage there will be.

The only person on the planet who is stupid enough to think that fire cannot weaken and melt steel is 9-11 truther Rosie O'Donnell. - And pre-heated steel is much more susceptible to damage than cold steel is.

Another dodge to prevent barrel damage with an over-bore cartridge is to back off a bit on the load. Starting loads for the .300WSM for example give you velocity in the 30-06 level - and guess what? They also give you 30-06 barrel wear and recoil level too.

Why would one load down a .300WSM to 30-06 level? - Because magnum velocity is not a perfect fit for every hunting situation. If you are just shooting at pigs or whitetails at normal hunting distances, all that magnum velocity does for you is tear up the dead critter a bit more. It's not going to be any deader.

Why have a 300WSM if you are not always going to shoot maximum loads? - Because if you do need magnum velocity the .300WSM can deliver that for you - and the 30-06 cannot.

Having one rifle that delivers either 30-06 or 300 magnum velocity by just changing the loads means that just one rifle covers all of that territory instead of two. Using one rifle for a wide variety of hunting situations means that you are going to be putting in more time with that one rifle - and you will get to be good with it. You can also put more money into that one rifle (optics would be a good example) and have a higher quality firearm than you could wind up with if the same money had to buy two of them.

The reduced loads are great for practice. They recoil less, are less expensive to load, and you can practice a lot more without wearing out your barrel. More practice means that you will be a better shot with that particular gun. You'll be so comfortable with it that bringing it up to your shoulder will be like slipping on an favorite old pair of shoes.

There is no free lunch though... The .300WSM for example can deliver 30-06 performance with starting loads - but it will use a bit more powder to do that than a 30-06 would. Not a lot - but some.

I have used the .300WSM and the 30-06 as examples here. - But the concept applies to all of the barrel-burner, over-bore cartridges.

270 WSM - 270 Winchester
22-250 - .223
340 Weatherby - 338-06
325 WSM - 8x57
257 Weatherby - 25-06
25-05 - 257 Roberts
etc. etc..



Edited by charlesb (03/06/16 07:10 AM)
_________________________
Kind regards, charlesb

Top
#6211493 - 03/06/16 08:09 AM Re: Puzzled on "barrel burning" cartridges [Re: jorge]
Dien Offline
Bird Dog

Registered: 08/16/12
Posts: 391
Loc: Grand Prairie
You cant compare bore size vs powder capacity alone.

IF what GAP has been reporting as true, a 6.5 SAUM with 60 grains last almost as long as a 6.5CM with 44grains.

It will take me quite a while to confirm it myself unfortunately as I don't shoot 100 rounds of each caliber every week.

Top
#6211536 - 03/06/16 08:48 AM Re: Puzzled on "barrel burning" cartridges [Re: Dien]
kmon1 Offline
junior

Registered: 09/27/06
Posts: 20293
Loc: Texas
Originally Posted By: Dien
You cant compare bore size vs powder capacity alone.

IF what GAP has been reporting as true, a 6.5 SAUM with 60 grains last almost as long as a 6.5CM with 44grains.

It will take me quite a while to confirm it myself unfortunately as I don't shoot 100 rounds of each caliber every week.


True but if what I have read on the 6.5 GAP SAUM is correct they are running it at 5000+ PSI less than normal pressures of the Creedmoor.
_________________________
Guidelines / Rules of Conduct
http://www.texashuntingforum.com/rules.htm

RULES for using the TRADING POST
http://www.texashuntingforum.com/forum/u..._PO#Post1959111

Top
#6211586 - 03/06/16 09:24 AM Re: Puzzled on "barrel burning" cartridges [Re: NTRP]
dee Offline
Extreme Tracker

Registered: 04/10/10
Posts: 4665
Loc: Red River way
Originally Posted By: NTRP
Consider the .308, 7-08, .260, and .243 in that relative order. All of them have a .308 parent cartridge and each round has a slightly smaller caliber that the parent case is necked down to. Give or take a little they each have the same basic powder capacity (again +/- to illustrate my point). As the heat and pressure becomes more concentrated moving down to the smaller bore diameter, the greater the throat erosion. So the forces escape through a 7.62mm hole much easier than a 6.00mm hole. The more concentrated the force, the greater the erosion.

I hope that explanation helps.


What are your thoughts on case design being a factor? I've heard a lot from the older guys shooting that the 30° and up shoulder designs help force the gasses more down the center of the bore. I know several prs guy's running x47 and saying at 2750 4k rounds but other rounds don't seem to make it as long.
_________________________
"A vote is like a rifle; it's usefulness depends on the character of the user" Theodore Roosevelt

Top
#6211626 - 03/06/16 09:56 AM Re: Puzzled on "barrel burning" cartridges [Re: NTRP]
charlesb Offline
Pro Tracker

Registered: 04/07/10
Posts: 1408
Loc: West Texas mountains
Originally Posted By: NTRP
Consider the .308, 7-08, .260, and .243 in that relative order. All of them have a .308 parent cartridge and each round has a slightly smaller caliber that the parent case is necked down to. Give or take a little they each have the same basic powder capacity (again +/- to illustrate my point). As the heat and pressure becomes more concentrated moving down to the smaller bore diameter, the greater the throat erosion. So the forces escape through a 7.62mm hole much easier than a 6.00mm hole. The more concentrated the force, the greater the erosion.

I hope that explanation helps.


It makes awfully good sense to me. I think you've hit the nail on the head.
_________________________
Kind regards, charlesb

Top
Page 1 of 3 1 2 3 >



© 2004-2016 OUTDOOR SITES NETWORK all rights reserved USA and Worldwide