Ruger American longevity/wear update

RCP Fab · June 6, 2013, 02:29 PM

First off, let me say that I shoot the heck out of this rifle. I shoot it often, I let it get hotter than it should, and I've shot hand loads from 2600-3200 FPS, 130 and 140gr bullets. I would consider this a worst case scenario for the RAR's life.

I got my ruger in mid February of 2013. So we are coming up on 4 months. I have 834 rounds through it now.

Except for the initial factory ammo that I purchased I have fired 100 handloaded 130 gr interlocks, and the rest have been 130gr SST's and 140gr SST's when they ran out of 130gr.

When the rifle was new I was seating my bullets nearly .100" shorter than I am now to reach the lands. My current OAL is 3.400", which doesn't even fit in the magazine. I would say that by 1000 rounds this barrel will be about done.

Now of course if you shot a light weight, thin barreled rifle like it was intended to I am sure you would get quite a bit more out of it.

Current pic:

tahunua001 · June 6, 2013, 06:00 PM

I'm sorry... what caliber is this?
130s and 140s seem very heavy for a 243 and very light for a 30 cal.
3200 sounds about average for a 243 but incredibly hot for 30-06 or 308. I like what you've done with the old girl. I'm sure the RAR was not built to the highest specs so that they could keep it down in price as a cheap hunting rifle, I doubt it was meant to see much more action than annual sight in and a half dozen shots spread throughout hunting season.

taylorce1 · June 6, 2013, 06:11 PM

.270 Win

I didn't want to post again so I decided to edit my post, smokingun brought up a good point. You've used several different bullets in this rifle, are you measuring with the same type of bullet you took your original measurement with and are you measuring with a comparator? If not your measurements aren't accurate, variations in bullet types can lead to the majority of the difference in your COAL.

I don't know what the original ammunition you put through the rifle was, but I do know the Interlock and SST are not the same at the ogive. While I don't doubt there is some barrel wear I'm not sure that it is as extreme as you think. Besides that is a hunting rifle so I wouldn't call the barrel worn out until it closes on a no-go gauge or accuracy opens up to where you can't hold a three shot group of at least 1.5"

3200 fps is smoking fast for a 130 grain bullet out of a .270 but certainly not unheard of. I wouldn't think that it would wear a barrel out that bad, unless you are shooting the barrel beyond warm on a regular basis. I probably wouldn't do a steady diet of bullets at that speed, just because I've shot the .270 enough to know that 3060 fps kills animals plenty dead.

smoakingun · June 6, 2013, 06:50 PM

a barrel done in 1000 rounds? I have a 22-250 that doesn't burn through barrels that fast. Your OAL is 0.100" longer? Are you using the same bullet? how are you measuring the loaded round? From the tip or the ogive? Something doesn't add up

tahunua001 · June 6, 2013, 07:36 PM

Quote:

a barrel done in 1000 rounds? I have a 22-250 that doesn't burn through barrels that fast. Your OAL is 0.100" longer? Are you using the same bullet? how are you measuring the loaded round? From the tip or the ogive? Something doesn't add up

even the OP admitted that it was pushed well beyond normal standards. 1000 rounds is more than most people put through a bolt action in a lifetime no less in 4 months.

jmr40 · June 6, 2013, 07:55 PM

I'm still betting on way more than 1000 rounds before barrel is shot out. Probably somewhere between 5,000-10,000. I'm more concerned about other parts of the rifle holding up for 5000 rounds. It does look promising though.

Metal god · June 6, 2013, 08:35 PM

I have the 308 RAR and I sure hope I get more then 1k out of mine . I already have close to 300 through it now . I will not be pushing it hard and 308s are easy on barrels anyways so I should be good

What did you use to paint the stock . It looks good and I'd like to do the same with mine .

RCP Fab · June 6, 2013, 10:28 PM

Ok, let me see if I can get all of this answered.

Yes, its .270

I've loaded (in order) 130 interlocks (1 box) 130 SST's (2 boxes). All the rest have been 140gr SST's because that's all I've been able to purchase. I shoot my current load until the groups start opening up. Then I remeasure and set the bullet .003 off the lands.

Here is one of my first reloads, 130gr interlock

Here is 140gr SST from mid april

Here is one from today, 140gr SST

All set .003" off the lands. The last 2 pictures are the same bullet, you can easily see an easy .100" difference.

The majority of my 140gr loads are in the 2700-2800 FPS range.

Please note, I said it in the first post and I'm saying it again.

I shoot the heck out of this rifle. I shoot it often, I let it get hotter than it should. I would consider this a worst case scenario for the RAR's life.

There have been range days when the barrel was hotter than it should be, for the entire 2-2.5 hours of shooting.

I painted it with rustoleum camo, just used the "deep forest green color". It holds up fine to handling and shooting it (after curing for 7 days), but it scratches pretty easy. I bumped a powder can into it and it left a little black mark.

**JohnKSa** · June 6, 2013, 11:02 PM

Quote:

There have been range days when the barrel was hotter than it should be, for the entire 2-2.5 hours of shooting.

Shooting a barrel while it's hot puts a lot more wear on the bore than shooting it the same amount through a cool barrel.

RCP Fab · June 6, 2013, 11:20 PM

No argument there.

Quote:

Shooting a barrel while it's hot puts a lot more wear on the bore than shooting it the same amount through a cool barrel.

**JohnKSa** · June 6, 2013, 11:35 PM

When you decide to rebarrel, it would be interesting to try to duplicate conditions as closely as possible and do some sort of test. Maybe one of the "magic" bore coatings, or moly-coating the bullets, or maybe even trying a stainless barrel if what you have now is carbon steel or vice versa if it's not.

mxsailor803 · June 7, 2013, 06:42 AM

I've been following this build up since the OP started this transformation and it has helped convince me that I could "use" another rifle and I'm really just trying to decide on caliber now lol. Hhhhhmmmm already got 1 .243, 1 .270, 1 .308, .1 30-06........decisions decisions.

geetarman · June 7, 2013, 06:58 AM

^^^^^^ Think backups for each. . .

fineredmist · June 7, 2013, 07:14 AM

A barrel is "shot out" when it no longer gives the accuracy the shooter wants. A target barrel which requires groups of .5" or less is shot out when it opens to .75" whereas a hunting rifle that gives 1 - 1.5" @ 100 yds. is still serviceable when it opens to 2 - 2.5". The problem is with the powder charge, the bigger the charge the faster the throat is eroded and accuracy falls off. A competent gunsmith can correct this problem by gutting 1 or two threads from the barrel and re chambering. It is not a perfect solution but it is less costly than a barrel replacement.

mxsailor803 · June 7, 2013, 08:12 AM

Geetarman - you are no help lol.

TnTnTn · June 7, 2013, 10:09 AM

Tahuna said: 'I'm sure the RAR was not built to the highest specs so that they could keep it down in price as a cheap hunting rifle, I doubt it was meant to see much more action than annual sight in and a half dozen shots spread throughout hunting season.'

Just wondering what specs in your opinion were compromised to meet a price point? New designs certainly can and will have weak points that manifest themselves as use and time accumulate.

I have a new American 22-250 and I am really pleased with it. The positive features IMO are price, trigger, hf barrel, smooth operation, ff barrel, safety, stock design/shape, accuracy, and let me say price again. Features I don't care for- magazine appears a bit flimsy(but has worked fine thus far), would prefer that the safety locked bolt when 'on' or a 3 position like the Stevens 200. Also the bolt release retaining pin needs to be longer so that it can't migrate 'too far' before it touches the stock.

All in all the RAR is a great rifle and I don't expect any longevity issues.

RC20 · June 7, 2013, 11:20 AM

What I would like to know is not the speculation on a hot barrel (see the end) but some of the useful information like........

1. How accurate are the RAs you are shooting
2. How is the recoil in the 270, 30-06 with that light a gun?
3. How do you like the recoil pad?

The only type of shooting that will normally cause a barrel wear issue being hot is a machine gun. If the OP is accurate with his stuff (not sure what the color has to do with it or why he is trying to destroy the gun) it looks like he has indeed induced TE. That TE is probably powder caused, not barrel wear (he is burning out the throat with excess powder much like blanks will do on a parade rifle)

note that he does not list the powder he is using though I see 4350, 4831 and 782? in the background (nor what the charge is). With that I could make a more considered judgement on how far outside the envelope he is running.

Accuracy wise a hunting rifle barrel getting hot will not hold a good group (3 shots groups are legitimate with that setup for an accuracy report) but once cool it will come back. If it does its not shot out, its just been used past its intended use.

Hot rounds (at the high end or over the high end of FPM per the bullet weight) will wear a barrel out fast, does not matter which caliber. Fast twist barrels will wear out faster than slow twist.

A 308 is not barrel friendly unless its a low load. Otherwise it wears a barrel out at the same rate.

Military ammo would war a military barrel out in 5 to 10k round counts. Military ammo is on the hot side.

RCP Fab · June 7, 2013, 11:35 AM

1) In the area of 1 MOA at 100 yards, I'm not the best of shooters.
2) Harsh, I've added over 3 pounds to the stock and its significantly reduced.
3) Works great, but the bottom corner of mine is coming off of the plastic a little. (nothing to worry about at this point).

The gun doesnt loose accuracy with heat. The POI changes. Last weekend cold would shoot about 3" left when cold, and move to POA as it got hot. It would stay there as long as the barrel stayed hot. Let it cool to shoot the m&p or something and it would be off to the left again until it got hot.

The RAR going from cold to REALLY hot, is like 3 or 4 shots.

What has been throwing off the accuracy of the gun was the bullet jump to the lands. Every few hundred rounds or so the groups would start to grow, 2.5-3" groups. Adjust the bullet seat depth and I'd be good for another few weekends of shooting. I say that the barrel is about done because it's getting to the point where too much of the bullet is hanging out, let alone they really don't fit in the magazine this go around (I bumped them back .010 so they do).

Kachok · June 7, 2013, 11:54 AM

1,000 rounds is awful quick, but if you shoot them hard and fast it can happen, barrel life of a machine gun can be as little as 150 rounds that is why crew served weapons come with an extra barrel. I let all of mine cool at leased 5 min between each 3 round string and I have alot more then 1,000 rounds through my 6.5x55 with no noticeable loss in accuracy even with my rather hot loads.
I would bet that the Ruger does not use the premium steel that my Sako barrel does but I would expect more then 1,000 rounds even from my Savages.

tahunua001 · June 7, 2013, 12:02 PM

over in the semi forums people tend to quote the lucky gunner stress test that they did over the winter where 4 identical AR15s were given solid diets of wolf, tula, brown bear and federal xm193(control). if i recall correctly, all of the barrels showed significant wear despite only firing 5000 rounds which is quite low for an AR15 but this was done over a very short amount of time and was with factory velocities, not hot handloads.

williams480 · June 7, 2013, 03:33 PM

Hey RCP,

Did your COAL start to change before the barrel was removed for one of your other threads ?

This is a really curious issue you have with your .270 RA.

RCP Fab · June 7, 2013, 05:41 PM

Yes, its been an on going change. I think I only have 100 rounds or so though it since I pulled the barrel off, maybe 150.

shadowviper · June 7, 2013, 09:22 PM

Quote:

barrel life of a machine gun can be as little as 150 rounds that is why crew served weapons come with an extra barrel

A mg barrel will not be shot out in 150 rounds. For one, there are only 100 rounds in a belt so you cant go cyclic for 150 and even in cyclic fire you dont have to change the barrel for 1 minute. You basically have to warp a mg barrel to destroy it. Keep in mind, these barrels arent designed for MOA groups. Crews have multiple barrels to keep from warping a barrel under sustained fire and change it out in different time intervals depending on their rate of fire. For example, 6-9 round bursts the barrel is changed every 10 minutes, 10-13 rounds bursts every 2 minutes, and cyclic every minute. Thats all for a 240B.

The OP seems to be having problems with throat erosion from hot loads not from the barrel getting too hot. I would just back off the loads some to make the barrel last longer or have a gunsmith take a few threads off and rechamber.

Metal god · June 7, 2013, 09:48 PM

Quote:

A 308 is not barrel friendly unless its a low load. Otherwise it wears a barrel out at the same rate.

I always thought velocity and rate of twist matters . If I understand you correctly , You are saying a standard 308 168gr GMM with a velocity of 2650 will burn out a barrel just as fast as a standard Hornady 270 130gr sst with a velocity of 3050 . Both having a twist of 1-10 . I always thought bullets that travel over 3000fps are the barrel burners .

Kachok · June 7, 2013, 10:22 PM

Barrel burners have less to do with the speed of the bullet and more to do with the amount of powder going through a given bore, and barrel heat.
A 223 can quite easily exceed 3000fps with light bullets and it is far from a barrel burner, while a 7mm Rem Mag won't touch 3000fps with 180gr and it is well known for short barrel life. The whole barrel does not wear out at the same rate, the throat wears out much faster as a result of the rolling flowing vortex off the shoulder of the brass, the gases in that vortex are as hot as anywhere in the system and are moving faster then anywhere else, combined with unburnt powder creating an abrasive effect that is where the erosion comes into play.
Measuring the volume of powder being burnt per sq inch/mm of bore is a much better indicator then the speed of the bullet, though in general higher speed cartridges are more overbore.
A 270 Win is a bit overbore but not excessively so, 2000+ rounds would be the norm probably twice that if you did not need match grade accuracy.
The rate of erosion is not a linear equation, a .308 pushing aprox 45gr of powder through a .30 cal bore can have an effective barrel life in excess of 8,000 rounds, while a 300 Win Mag pushing aprox 72gr or powder through the same bore can cut that to 1,500-2,000.

June 6, 2013, 02:29 PM	#1
RCP Fab Senior Member Join Date: February 22, 2013 Posts: 113	Ruger American longevity/wear update First off, let me say that I shoot the heck out of this rifle. I shoot it often, I let it get hotter than it should, and I've shot hand loads from 2600-3200 FPS, 130 and 140gr bullets. I would consider this a worst case scenario for the RAR's life. I got my ruger in mid February of 2013. So we are coming up on 4 months. I have 834 rounds through it now. Except for the initial factory ammo that I purchased I have fired 100 handloaded 130 gr interlocks, and the rest have been 130gr SST's and 140gr SST's when they ran out of 130gr. When the rifle was new I was seating my bullets nearly .100" shorter than I am now to reach the lands. My current OAL is 3.400", which doesn't even fit in the magazine. I would say that by 1000 rounds this barrel will be about done. Now of course if you shot a light weight, thin barreled rifle like it was intended to I am sure you would get quite a bit more out of it. Current pic:

June 6, 2013, 06:00 PM	#2
tahunua001 Senior Member Join Date: July 21, 2011 Location: Idaho Posts: 7,839	I'm sorry... what caliber is this? 130s and 140s seem very heavy for a 243 and very light for a 30 cal. 3200 sounds about average for a 243 but incredibly hot for 30-06 or 308. I like what you've done with the old girl. I'm sure the RAR was not built to the highest specs so that they could keep it down in price as a cheap hunting rifle, I doubt it was meant to see much more action than annual sight in and a half dozen shots spread throughout hunting season. __________________ ignore my complete lack of capitalization. I still have no problem correcting your grammar. I never said half the stuff people said I did-Albert Einstein You can't believe everything you read on the internet-Benjamin Franklin

June 6, 2013, 06:11 PM	#3
taylorce1 Senior Member Join Date: November 18, 2005 Location: On the Santa Fe Trail Posts: 8,242	.270 Win I didn't want to post again so I decided to edit my post, smokingun brought up a good point. You've used several different bullets in this rifle, are you measuring with the same type of bullet you took your original measurement with and are you measuring with a comparator? If not your measurements aren't accurate, variations in bullet types can lead to the majority of the difference in your COAL. I don't know what the original ammunition you put through the rifle was, but I do know the Interlock and SST are not the same at the ogive. While I don't doubt there is some barrel wear I'm not sure that it is as extreme as you think. Besides that is a hunting rifle so I wouldn't call the barrel worn out until it closes on a no-go gauge or accuracy opens up to where you can't hold a three shot group of at least 1.5" 3200 fps is smoking fast for a 130 grain bullet out of a .270 but certainly not unheard of. I wouldn't think that it would wear a barrel out that bad, unless you are shooting the barrel beyond warm on a regular basis. I probably wouldn't do a steady diet of bullets at that speed, just because I've shot the .270 enough to know that 3060 fps kills animals plenty dead. __________________ NRA Life Member Last edited by taylorce1; June 6, 2013 at 09:43 PM.

June 6, 2013, 06:50 PM	#4
smoakingun Senior Member Join Date: April 12, 2009 Location: melrose, fl Posts: 634	a barrel done in 1000 rounds? I have a 22-250 that doesn't burn through barrels that fast. Your OAL is 0.100" longer? Are you using the same bullet? how are you measuring the loaded round? From the tip or the ogive? Something doesn't add up __________________ Hundreds of years from now, it will not matter what my bank account was, the sort of house I lived in, or the kind of car I drove... But the world may be different because I did something so bafflingly crazy that my ruins become a tourist attraction.

June 6, 2013, 11:35 PM	#11
JohnKSa Staff Join Date: February 12, 2001 Location: DFW Area Posts: 24,973	When you decide to rebarrel, it would be interesting to try to duplicate conditions as closely as possible and do some sort of test. Maybe one of the "magic" bore coatings, or moly-coating the bullets, or maybe even trying a stainless barrel if what you have now is carbon steel or vice versa if it's not. __________________ Do you know about the TEXAS State Rifle Association?

June 6, 2013, 07:55 PM	#6
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,805	I'm still betting on way more than 1000 rounds before barrel is shot out. Probably somewhere between 5,000-10,000. I'm more concerned about other parts of the rifle holding up for 5000 rounds. It does look promising though.

June 6, 2013, 08:35 PM	#7
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	I have the 308 RAR and I sure hope I get more then 1k out of mine . I already have close to 300 through it now . I will not be pushing it hard and 308s are easy on barrels anyways so I should be good What did you use to paint the stock . It looks good and I'd like to do the same with mine .

June 6, 2013, 10:28 PM	#8
RCP Fab Senior Member Join Date: February 22, 2013 Posts: 113	Ok, let me see if I can get all of this answered. Yes, its .270 I've loaded (in order) 130 interlocks (1 box) 130 SST's (2 boxes). All the rest have been 140gr SST's because that's all I've been able to purchase. I shoot my current load until the groups start opening up. Then I remeasure and set the bullet .003 off the lands. Here is one of my first reloads, 130gr interlock Here is 140gr SST from mid april Here is one from today, 140gr SST All set .003" off the lands. The last 2 pictures are the same bullet, you can easily see an easy .100" difference. The majority of my 140gr loads are in the 2700-2800 FPS range. Please note, I said it in the first post and I'm saying it again. I shoot the heck out of this rifle. I shoot it often, I let it get hotter than it should. I would consider this a worst case scenario for the RAR's life. There have been range days when the barrel was hotter than it should be, for the entire 2-2.5 hours of shooting. I painted it with rustoleum camo, just used the "deep forest green color". It holds up fine to handling and shooting it (after curing for 7 days), but it scratches pretty easy. I bumped a powder can into it and it left a little black mark.

June 7, 2013, 06:42 AM	#12
mxsailor803 Senior Member Join Date: February 8, 2010 Location: SC Posts: 1,344	I've been following this build up since the OP started this transformation and it has helped convince me that I could "use" another rifle and I'm really just trying to decide on caliber now lol. Hhhhhmmmm already got 1 .243, 1 .270, 1 .308, .1 30-06........decisions decisions.

June 7, 2013, 06:58 AM	#13
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	^^^^^^ Think backups for each. . . __________________ Geetarman Carpe Cerveza

June 7, 2013, 07:14 AM	#14
fineredmist Senior Member Join Date: November 2, 2008 Location: Wethersfield, ct Posts: 128	A barrel is "shot out" when it no longer gives the accuracy the shooter wants. A target barrel which requires groups of .5" or less is shot out when it opens to .75" whereas a hunting rifle that gives 1 - 1.5" @ 100 yds. is still serviceable when it opens to 2 - 2.5". The problem is with the powder charge, the bigger the charge the faster the throat is eroded and accuracy falls off. A competent gunsmith can correct this problem by gutting 1 or two threads from the barrel and re chambering. It is not a perfect solution but it is less costly than a barrel replacement.

June 7, 2013, 08:12 AM	#15
mxsailor803 Senior Member Join Date: February 8, 2010 Location: SC Posts: 1,344	Geetarman - you are no help lol.

June 7, 2013, 10:09 AM	#16
TnTnTn Senior Member Join Date: June 2, 2013 Location: Middle TN Posts: 140	Tahuna said: 'I'm sure the RAR was not built to the highest specs so that they could keep it down in price as a cheap hunting rifle, I doubt it was meant to see much more action than annual sight in and a half dozen shots spread throughout hunting season.' Just wondering what specs in your opinion were compromised to meet a price point? New designs certainly can and will have weak points that manifest themselves as use and time accumulate. I have a new American 22-250 and I am really pleased with it. The positive features IMO are price, trigger, hf barrel, smooth operation, ff barrel, safety, stock design/shape, accuracy, and let me say price again. Features I don't care for- magazine appears a bit flimsy(but has worked fine thus far), would prefer that the safety locked bolt when 'on' or a 3 position like the Stevens 200. Also the bolt release retaining pin needs to be longer so that it can't migrate 'too far' before it touches the stock. All in all the RAR is a great rifle and I don't expect any longevity issues.

June 7, 2013, 11:20 AM	#17
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	What I would like to know is not the speculation on a hot barrel (see the end) but some of the useful information like........ 1. How accurate are the RAs you are shooting 2. How is the recoil in the 270, 30-06 with that light a gun? 3. How do you like the recoil pad? The only type of shooting that will normally cause a barrel wear issue being hot is a machine gun. If the OP is accurate with his stuff (not sure what the color has to do with it or why he is trying to destroy the gun) it looks like he has indeed induced TE. That TE is probably powder caused, not barrel wear (he is burning out the throat with excess powder much like blanks will do on a parade rifle) note that he does not list the powder he is using though I see 4350, 4831 and 782? in the background (nor what the charge is). With that I could make a more considered judgement on how far outside the envelope he is running. Accuracy wise a hunting rifle barrel getting hot will not hold a good group (3 shots groups are legitimate with that setup for an accuracy report) but once cool it will come back. If it does its not shot out, its just been used past its intended use. Hot rounds (at the high end or over the high end of FPM per the bullet weight) will wear a barrel out fast, does not matter which caliber. Fast twist barrels will wear out faster than slow twist. A 308 is not barrel friendly unless its a low load. Otherwise it wears a barrel out at the same rate. Military ammo would war a military barrel out in 5 to 10k round counts. Military ammo is on the hot side. Last edited by RC20; June 7, 2013 at 11:29 AM.

June 7, 2013, 11:35 AM	#18
RCP Fab Senior Member Join Date: February 22, 2013 Posts: 113	1) In the area of 1 MOA at 100 yards, I'm not the best of shooters. 2) Harsh, I've added over 3 pounds to the stock and its significantly reduced. 3) Works great, but the bottom corner of mine is coming off of the plastic a little. (nothing to worry about at this point). The gun doesnt loose accuracy with heat. The POI changes. Last weekend cold would shoot about 3" left when cold, and move to POA as it got hot. It would stay there as long as the barrel stayed hot. Let it cool to shoot the m&p or something and it would be off to the left again until it got hot. The RAR going from cold to REALLY hot, is like 3 or 4 shots. What has been throwing off the accuracy of the gun was the bullet jump to the lands. Every few hundred rounds or so the groups would start to grow, 2.5-3" groups. Adjust the bullet seat depth and I'd be good for another few weekends of shooting. I say that the barrel is about done because it's getting to the point where too much of the bullet is hanging out, let alone they really don't fit in the magazine this go around (I bumped them back .010 so they do).

June 7, 2013, 11:54 AM	#19
Kachok Senior Member Join Date: January 22, 2012 Posts: 304	1,000 rounds is awful quick, but if you shoot them hard and fast it can happen, barrel life of a machine gun can be as little as 150 rounds that is why crew served weapons come with an extra barrel. I let all of mine cool at leased 5 min between each 3 round string and I have alot more then 1,000 rounds through my 6.5x55 with no noticeable loss in accuracy even with my rather hot loads. I would bet that the Ruger does not use the premium steel that my Sako barrel does but I would expect more then 1,000 rounds even from my Savages.

June 7, 2013, 12:02 PM	#20
tahunua001 Senior Member Join Date: July 21, 2011 Location: Idaho Posts: 7,839	over in the semi forums people tend to quote the lucky gunner stress test that they did over the winter where 4 identical AR15s were given solid diets of wolf, tula, brown bear and federal xm193(control). if i recall correctly, all of the barrels showed significant wear despite only firing 5000 rounds which is quite low for an AR15 but this was done over a very short amount of time and was with factory velocities, not hot handloads. __________________ ignore my complete lack of capitalization. I still have no problem correcting your grammar. I never said half the stuff people said I did-Albert Einstein You can't believe everything you read on the internet-Benjamin Franklin

June 7, 2013, 03:33 PM	#21
williams480 Junior Member Join Date: May 2, 2013 Location: Wytheville, Va. Posts: 11	Hey RCP, Did your COAL start to change before the barrel was removed for one of your other threads ? This is a really curious issue you have with your .270 RA.

June 7, 2013, 05:41 PM	#22
RCP Fab Senior Member Join Date: February 22, 2013 Posts: 113	Yes, its been an on going change. I think I only have 100 rounds or so though it since I pulled the barrel off, maybe 150.

June 7, 2013, 10:22 PM	#25
Kachok Senior Member Join Date: January 22, 2012 Posts: 304	Barrel burners have less to do with the speed of the bullet and more to do with the amount of powder going through a given bore, and barrel heat. A 223 can quite easily exceed 3000fps with light bullets and it is far from a barrel burner, while a 7mm Rem Mag won't touch 3000fps with 180gr and it is well known for short barrel life. The whole barrel does not wear out at the same rate, the throat wears out much faster as a result of the rolling flowing vortex off the shoulder of the brass, the gases in that vortex are as hot as anywhere in the system and are moving faster then anywhere else, combined with unburnt powder creating an abrasive effect that is where the erosion comes into play. Measuring the volume of powder being burnt per sq inch/mm of bore is a much better indicator then the speed of the bullet, though in general higher speed cartridges are more overbore. A 270 Win is a bit overbore but not excessively so, 2000+ rounds would be the norm probably twice that if you did not need match grade accuracy. The rate of erosion is not a linear equation, a .308 pushing aprox 45gr of powder through a .30 cal bore can have an effective barrel life in excess of 8,000 rounds, while a 300 Win Mag pushing aprox 72gr or powder through the same bore can cut that to 1,500-2,000.