BBL life with cast boolits?

[Shuz]

Assuming a person shoots cast boolit loads that are in the 1500 to 1900 fps range, how many rounds can be shot before the throat starts to erode or the rifling shows wear?

[green mountain boy]

gosh i would love to give you an answer...however many factors come into play. speed you are pushing,powders used,what is the BBL,shot hot?, etc. many here will have a much better answer than can i. all i know is i have shot my Remington 700 30/06 several thousand rds of cast in the 950-1700 fps range and it still shoots better than i can. my childrens children will be able to shoot it as well i am convinced.

[Winger Ed.]

There was a article in a older Lyman Cast book about that.
I want to say it was the one with the orange cover, but that may not be right.

They figured a common sporting rifle barrel will last approx. 2,000 rounds before there is some throat erosion, and accuracy begins to fall off.
They took a new Winchester (I think) in a .30 caliber, and fired it 40,000 times with cast.

Then they ground off the top of the chamber, measured it, and found 'no noticeable wear'.

[M-Tecs]

Barrels do not wear out for the most part. They erode out from heat from the gas and pressures . A standard 308 Match rifle with jacketed bullets will start having long range (600 plus yards) elevation issues around 3,500 rounds give or take. Normal hunting accuracy will be double or triple that.

A 45 ACP match pistol shooting cast should go well over 200K before you note internal barrel wear. Possibly a lot more.

Mostly it's dependent on heat and pressure.

22 Rimfire erode from the ground glass in the priming compound. You can see it with a borescope at the 6 o'clock position at 30K to 50K.

[Hick]

I've got 1960's 30-30 (post 64) that was well used when I bought it-- and I've run close to 20,000 rounds through it and seen no effects yet. If I seat a bullet to touch the lands the OAL is just what it used to be when I first bought the rifle.

[Whole Bunches]

I measure my bbls for throat wear if I have a gage that fits the bbl and action. With the exception of two 5.56 MG bbls, I shoot 5-8 shots (8 shots for the M1 and 5 for all else) and let the bbl cool to ambient temp with the aid of a bbl cooling fan.

This was 14 years ago. I worked up an accurate cast bullet load for my 3006 M1 rifle that functioned 100%. Don’t remember the exact load, but it was IMR4895 with Lyman 311291 with #2 alloy and sized .311”, probably in the the area of 35-40 gr 4895. I fired 800 rounds of the cast bullet load and compared the throat erosion to firing 800 rounds of 168-172gr jacketed match bullets with 46gr IMR 4895 in the same WWII M1. The throat erosion with cast was 1/3rd that of shooting the jacketed bullets. Less powder and bullets softer than jacketed was my thought. A longer test would be more accurate as the wear was very small to gage using my eyes and a gage that has 1/10th inch graduations.

FYI, no bore leading and no leading around the gas port and no leading on op rod. When the gas cylinder plug/screw was removed, there was a thin wall of lead that had formed against the inside end of the screw...easily knocked out. Otherwise, no leading inside the gas cylinder.

Shortly after, my house burnt and 99% of my casting items were lost. I started back into casting about a year ago.

[44Blam]

If you are shooting lubed, cast boolits in the 1500-1900 fps range you will likely pass that rifle on through your great grand kids.

Lead does not really erode a bore too much even when pushed a "little' fast.

Even barrels I've shot jacketed ammo out of don't really degrade.

As a contrast, I had an FN49 that was actually used in war in the middle east - the bore was pitted and scarred and just plain ugly. I could still hit a 2' target with the irons at 625 yards consistently with that thing.

With lead and non corrosive primers/powder you can shoot millions of rounds through a gun and still have a good gun.

Now, the hot-dog rounds like 6.5 creedmore and grendle - shooting those with copper jacket rounds above 3000 fps will very likely erode a bore. But at sub 2000 fps? naw.

[charlie b]

What is your criteria for wearing out?

Bench rest shooters would probably say when the barrel will not shoot less than 0.2" groups anymore. Most 'normal' people would not notice anything until they could not get 1" groups.

[mehavey]

If you are shooting lubed, cast boolits in the 1500-1900 fps range
you will likely pass that rifle on through your great grand kids.What's the scoop (if any yet) on PC'd lead bullets ?
(Otherwise BP shooters, who've maintained/cleaned properly, "essentially" forever.

[Whole Bunches]

What is your criteria for wearing out?

Bench rest shooters would probably say when the barrel will not shoot less than 0.2" groups anymore. Most 'normal' people would not notice anything until they could not get 1" groups.

MY criteria for wearing out: I am not a bench rest shooter. I don't compete except in local military rifle matches shooting at 50 and 100yd targets. I do hunt, mainly hogs for hog control for multiple farmers. But my main shooting is simply plinking at cans and steel with the guys. I use the USGI criteria for small arms of 1" of throat erosion (rifling has worn away for 1" in front of the chamber) = new bbl time. I've worn out several M1919A4 MG 3006 bbls. When the gage showed 1" of wear (the reject line on the gage), within 250-500 more rounds the 100yd "group" would suddenly go from a few inches to feet wide. Those unlined bbls would consistently be worn out at 5000 rounds (fire a burst of no more than 20 rounds and let cool). USGI 5.56 and 30 caliber gages all used the 1" worn criteria. Note: Been retired from the military since 1988...I do not know what the current criteria and manuals now say. A M16 bbl when at the gage reject line would also now be inaccurate with sometimes keyholed hits.

And, FWIW, I have a "collection" of various 300 Blackout bbls of different steels and/or bore treatments I've been shooting for years as a hobby/personal project with a total Blackout round count in the 20,000 range now. Going from shortest life to longest: Plain 4140 button rifled, plain 4140 CHF, plain 4150 or 41V50, 4150 CHF, 4140 nitrided, 4150 nitrided, 4140 chrome lined, 4150 chrome lined, 4150 CHF chrome lined, 4150 CFH double chrome lined. Based upon throat erosion so far, in the Blackout, plain 4140 will go about 11,000 jacketed rounds until the TE = 1" wear. 4150 or 41V50 CHF double chrome lined will go about 23,000 rounds. This is all 5 shots and let cool. In other words, anything added to a bbl beyond plain button rifled 4140 steel adds to its life in regards to throat erosion (TE). Life calculations are done with rounds fired so far vs TE so far, extrapolated out to 1" wear...as more rounds are fired, the calculations will get more accurate.

I don't care what people post, in my experience, using TE gages, at least with the Blackout, nitriding (or whatever you want to call it) does not last as long as chrome. CHF in and of itself adds about 500 rounds to a plain bbl. Firing .310" or .311" jacketed bullets does not wear the bore any faster than using .308" in the Blackout (I shoot a bit of pulled 124gr 7.62x39 FMJ bullets in some of the Blackouts for plinking/practice). In the .223/5.56 I don't have as much measurement data, other than to say plain 4140 wears faster than nitrided, and nitrided, so far, is wearing faster than chrome lined, but not by much. I do have 2 4140 button rifled chrome lined M16 bbls shot full auto (20-30 rounds and let cool) that are only used for full auto...holding up fine with that level of shooting, but only a couple of thousand rounds through each so far. 1 11.5" and 1 20" from Model One Sales. Without looking up my records, I'm pretty sure they've shown no TE wear so far.

Others certainly can have their own bbl wear criteria. So far, none of my Blackouts have turned inaccurate. As far as which is more accurate, there's no telling for me. A Daniel Defense Blackout bbl is the most accurate I have. It was so accurate that I bought another...it turn out to only be "average" accurate. I have 2 Ruger American Ranch Rifles in Blackout. Both are nicely accurate and like the same loads, but one shoots consistently slower than the other. Another maker (Delta Company) of a plain 4140 bbl said if I ever wear it out, he'll replace it for free...he went out of business, oh well. A Ruger engineer said if I wear out a RARR Blackout bbl (plain 4140 CHF) they will replace it for free if they an have the old bbl, my firing records, and can cut the bbl in half lengthwise to examine, and will give me the other bbl half. Most companies were very upfront with what steel and making methods they employed. SIG wouldn't tell me at all, saying it's propriety info, but I got some bbl info from reports and SIG advertisements. It's a fun journey, and I like keeping records that add to my enjoyment.

[Shuz]

What is your criteria for wearing out?

Bench rest shooters would probably say when the barrel will not shoot less than 0.2" groups anymore. Most 'normal' people would not notice anything until they could not get 1" groups.

Charlie--My criteria is not being able to shoot sub MOA groups at 100 yards in CBA matches. OK folks, here's the whole story:
I have a Savage Mdl 16 "Weather Warrior" stainless steel in .250 Savage. I worked up a load of 14.3g of Reloder 7 behind a 100g Saeco 100 boolit. It always shot "around" 1" at 100 yards, sometimes a little more, sometimes a little less. Well, last Saturday the 4/ea five shot groups that I fired measured 1.507,1.375,1.583 and 1.680. Needless to say, I was disappointed based on the way this gun used to shoot for me. I've had this rifle for about 10 years and I figure it has 3 to 4 thousand rounds of only cast boolits thru it. Based on the answers already received on this issue, I'm beginning to think that the problem lies with the shooter, not the gun. Last Saturday I had many times where the Savage Accu-Trigger kinda released, but the safety kept the gun from firing. This happens if the blade in the middle of the trigger is not compressed completely before the rest of the trigger is squeezed. When this happens 3 or 4 times and you have to open and close the bolt each time, it tends to break ones concentration. I think this is happening because I have developed periferal neuoropathy and I've lost the feeling in my fingers and therefore I am applying pressure to the side of the trigger instead of making sure the blade is depressed completely. Anybody else have this problem? Any suggestions to help me?

[AndyC]

Fascinating data, Bunches - thanks for sharing!

[DonHowe]

The thing to worry about ain't bullet material unless you are shooting steel jacket maybe. The culprit is the heat generated by full factory level pressure/velocity loads. That varies to some extent according to powder used. There are other factors, one of which is cartridge design. As has been stated before, how a rifle is used and what is expected of it in terms of accuracy help determine how much barrel life vs accuracy potential matter to the rifle owner. If that matters and you shoot full pressure jacketed ammo buy a .308. If it doesn't buy a 6.5 Creedmoor.

People who buy a six five Creed (that is as hard for me to type as to say) based on advertising hype and the BIL's testimonial and actually shoot it a lot AND EXPECT ACCURACY (as hyped) are in for a surprise in terms of barrel life. In shooting disciplines rounds like Creedmoor and the 6mm PPC were designed for users KNOW they will have to replace barrels due to throat erosion. The same is true for .308 but barrel life is much longer.

[waksupi]

Assuming a person shoots cast boolit loads that are in the 1500 to 1900 fps range, how many rounds can be shot before the throat starts to erode or the rifling shows wear?

I think it was Felix that stated a barrel with some throat erosion will shoot cast better than a pristine barrel.

[charlie b]

Shuz, Good info.

I can only say I also have those good and bad days. I also have a Savage for shooting cast, 12BVSS in 308 (it has just over 3000 rounds through it, about 2000 of those cast loads).

It might be the trigger. Mine will sometimes 'trip' for what seems like no reason at all. It is the varmint trigger and set to minimum. It will 'trip' if I move the rifle too much (like lifting if off the rest and then reposition). I know that kinda screws up my tempo as well. It usually happens when I am in a great position, rested, relaxed, shooting well and then.....nothing. If the trigger continues to act up then try increasing the pull weight just a little and see if the problem continues. If so, then it might be from not pulling straight. Dry firing would help pinpoint this.

Barrel erosion could be a key if you consistently see larger groups than what you used to shoot. I would definitely keep track of group sizes just to be sure. But, cast are kinda different as waksupi said.

[Bang Switch]

There's a good possibility that you won't life long enough to wear out a rifle barrel shooting lead bullets.

[country gent]

Another factor that directly affects barrel life is rate of fire. Those blasters who go thru 300-400 rds a day at high rates of fire barrels will go much faster than the slow methodical shooter. High power shooter see this when they shoot the infantry trophy match ( rattle battle ) roughly 120 rds thru the gun in 45 mins. The barre; on a garand or M1A ill be so hot it will raise blisters. This is also hard on bedding and the rifle itself not just the barrel.

Over bore cartridges ( large powder capacity small bore) ate harder on the barrel than milder cartridges. the 30 cl mags are harder on throats than the 30-06 which is still harder than the 308. the mild 762 x 39 is one of the easiest 30 cals.

Case design also plays a big part a shoulder angle neck length that keeps the first "hit" of powder gases in the neck has a venturi effect lowering the effect. The 6 ppc showed this when it was introduced. I had a good friend that shot a 6 mm 284 in 1000yd matches and he claimed 1300-1500 to a barrel

The lowered powder charges, methodical pace, and lowered heat all extend the life with cast bullets. Very few cast bullet shooters run the high rates of fire in rifles

[Nobade]

Reading the Harry Pope book, he said after 125,000 rounds his barrel had .0001" of wear. Those old 32-40s were pretty easy on barrels!
As for the creedmoors, I typically see customers wanting to replace barrels at about 4,000 rounds with the 6.5. At that point a good shooter is losing matches because of his rifle. In the 6mm version, they are toast at 900 rounds. That lighter recoil comes at a price!

[M-Tecs]

The 6MM Creedmoor is basically the same 6mm XC, 240 National Match, 6mm Internal and a whole host of other 22-250 based cartridges. Most of them are lasting 2,500 to 4,000 rounds competitive barrel life before that start losing points to elevation at the 600 to 1,000 yard range.

The 6mm XC is a ballistic twin to the 6mm Creedmoor. My personal ones plus the ones I have barrel have all made it over 3,000 rounds competitive life and in the case of my personal guns they are still going strong as prairie dog rifles.

The 6mm Competition Match is a 243 based cartridge with a steeper shoulder angle and increase case capacity. Using slower powders and abrasive cleaner the designer Joe Hendricks is claiming normally over 4,000 rounds competitive life. He won the National one year with a barrel with over 2,500 rounds on it.

https://www.longriflesinc.com/products/6mm-competition-match-sizer-die?variant=11004783681

https://www.longriflesinc.com/blogs/news/the-ins-outs-of-the-6mm-competition-match

https://www.longrangehunting.com/threads/6mm-competition-match-by-mcr.95524/

https://forum.accurateshooter.com/threads/6mm-competition-match-questions.3947022/

Those barrels will still have a significant barrel life left for under 500 yard applications like prairie dog shooting and an even longer life as a deer rifle.

[Bad Ass Wallace]

I have rifles that shoot 'J' boolits and 'special' rifles that only shoot cast boolits. I shoot a lot (6-7000 rounds per year) and in 50 years I have never shot out a barrel with cast boolits! I do delight in showing off the pristine mirror bores of my Cast boolit shooters.

[44Blam]

What's the scoop (if any yet) on PC'd lead bullets ?
(Otherwise BP shooters, who've maintained/cleaned properly, "essentially" forever.

My Marlin 1895 has never had a copper jacketed bullet through it. I've shot only lead/pc'd boolits. I have leaded it with rounds that were a little over powered and I have cleaned that lead out... That rifle is my second favorite long range gun I own. It has a Montana 101 sight and I can consistently hit 2-3' targets out to about 1000 yards. I've shot well over 10k rounds through it and the barrel looks just like it did when I bought it.

When I die, someone will get that gun and hopefully appreciate it as much as I do. But I doubt very highly that the barrel will be shot out.

[44Blam]

My Marlin 1895 has never had a copper jacketed bullet through it. I've shot only lead/pc'd boolits. I have leaded it with rounds that were a little over powered and I have cleaned that lead out... That rifle is my second favorite long range gun I own. It has a Montana 101 sight and I can consistently hit 2-3' targets out to about 1000 yards. I've shot well over 10k rounds through it and the barrel looks just like it did when I bought it.

When I die, someone will get that gun and hopefully appreciate it as much as I do. But I doubt very highly that the barrel will be shot out.

I remember a day that I did lead that gun. I just bought a keg of H335 and loaded up a ladder. I was shooting a 400 grain boolit and the first level of the ladder was sending them about 1850 fps. The 5th level of the ladder was sending them about 2100 fps with one round that spiked to 2250 fps.... The accuracy up to the 5th level was good and then it was very poor.

My friend was with me and each "level" I went up he stepped back about 5'. He told me later that each level had an exponentially higher concussion...

I also had a black/blue bruise on my shoulder from that day.

[Nobade]

The 6MM Creedmoor is basically the same 6mm XC, 240 National Match, 6mm Internal and a whole host of other 22-250 based cartridges. Most of them are lasting 2,500 to 4,000 rounds competitive barrel life before that start losing points to elevation at the 600 to 1,000 yard range.

The 6mm XC is a ballistic twin to the 6mm Creedmoor. My personal ones plus the ones I have barrel have all made it over 3,000 rounds competitive life and in the case of my personal guns they are still going strong as prairie dog rifles.

The 6mm Competition Match is a 243 based cartridge with a steeper shoulder angle and increase case capacity. Using slower powders and abrasive cleaner the designer Joe Hendricks is claiming normally over 4,000 rounds competitive life. He won the National one year with a barrel with over 2,500 rounds on it.

https://www.longriflesinc.com/products/6mm-competition-match-sizer-die?variant=11004783681

https://www.longriflesinc.com/blogs/news/the-ins-outs-of-the-6mm-competition-match

https://www.longrangehunting.com/threads/6mm-competition-match-by-mcr.95524/

https://forum.accurateshooter.com/threads/6mm-competition-match-questions.3947022/

Those barrels will still have a significant barrel life left for under 500 yard applications like prairie dog shooting and an even longer life as a deer rifle.

Are you using those rifles like PRS shooters, pounding hundreds of rounds through them in a day? I am surprised at the life you're getting. I haven't seen anyone yet who is a serious competitive shooter who has gotten more than 1000 rounds out of a 6mm Creedmoor. The casual shooters and coyote hunters seem to be happy for a lot longer but their needs are different.

[Larry Gibson]

I've shot out numerous rifle barrels using jacketed bullets loads in competition, varmint shooting, etc. I've even shot out a 22 Hornet barrel........

It is heat and erosion that "shoots out" the throat/leade. The hotter the barrel gets, the higher the temperature of the powder, the higher the psi, the expansion ratio and the longer the time pressure curve are the main suspects. Rapid fire exacerbates all the mentioned.

As to cast bullets? With what is considered "normal cast bullet loads", which are low pressure with smaller amounts of faster burning powders generally shot at a slow rate of fire, one would have fire thousands upon thousands of rounds before any throat erosion is measured or observed.

However, I one is shooting high intensity loads with cast bullets then throat erosion does occur about as frequently as with jacketed bullets. In the last 12 + years I have fired a lot of higher pressured loads of slower burning powder through both my 14" twist Palma 308W and my 16" twist 30x60 XCB rifles.

In the 308W a lot were of those rounds were testing numerous medium and slower burning powders under 150 - 180 gr cast bullets with measured psi's in the 40 - 50, 000 psi range. That entailed burning 35 - 50 gr of powder with each shot. I have not tracked the number of shots through the Palma barrel as it was also used with jacketed bullets. However, the majority were with cast bullets. I shows considerable throat erosion.

With the 30x60 XCB rifle I have tracked the exact number of rounds through the rifle. I have fired 3,260 rounds through the Broughton barrel. Most of those have been with the 30 XCB bullet (164 gr) over 53 gr of AA4350 which pushes 50,000 psi at 2900+ fps. While accuracy is still excellent there is observable (with bore scope) throat erosion and it is slightly measurable. I expect another maybe, or hopefully, 2000+ rounds of accurate shooting [holding lest than 1.5 moa with 10 shots at 300 yards with the cast bullet].

Yes, you can "shoot out" a rifle barrel with cast bullet loads.......if you're going to dance, you have to pay the band........

[M-Tecs]

Are you using those rifles like PRS shooters, pounding hundreds of rounds through them in a day? I am surprised at the life you're getting. I haven't seen anyone yet who is a serious competitive shooter who has gotten more than 1000 rounds out of a 6mm Creedmoor. The casual shooters and coyote hunters seem to be happy for a lot longer but their needs are different.

NRA HighPower, F Class, and NRA Long Range. That was what the Creedmoor was developed for.

Rates of fire and round count are roughly the same as PRS but since PRS has no set course of fire it's not an head to head comparison. If shooting the NRA Across the Course matches the rate of fire is faster and double the round count over PRS.

Never shot PRS but I have barreled a couple of rifles for PRS. One was 6m XC and the other was a 6mm Creedmoor.

[John Boy]

Shuz, velocity of rounds is what’s the factor to wear our barrels. Example, 220 Swift with max velocity jacket bullets will wear our a barrel in about a 1000. On the other hand, have a Rossi M92 that has had over 20,000 black powder 45 Colt, 850 FPS reloads down the bore and it is still perfect

[lotech]

I can't answer the question when it comes to cast bullets but bore life with cast has never been a concern. I'm pretty sure that very few shooters really keep up with the number of rounds fired through any barrel. Best estimates may not even be close. I would guess many of the numbers are exaggerated. Some do keep up with this, maybe not exactly but pretty close since they keep notes. Their claims are likely valid and believable.

In contrast, I have a New Ultra Light Arms bolt-action rifle chambered in 7x61 Sharpe & Hart Magnum (ballistically a 7mm Remington magnum that uses three or four grains less powder). It's on it's third Douglas barrel. I use only jacketed bullets in it. With the first barrel, I actually kept up with the number of rounds fired until I got in the 500 + range. However, my range notes continued when I went shooting, and at about 900 + rounds, groups began to enlarge. Instead of getting 1/2" -3/4" groups with fair consistency, I'd get only one good group out of four or five. The rest would be up to 1 1/4". I seated bullet out farther and this did help somewhat for about 300 more rounds.

When I called the rifle builder, Melvin Forbes, and told him I needed a new barrel, he asked if I had fired a thousand rounds yet. He stated that the 7mm Magnums of this size were good for about a thousand rounds with very good accuracy. I'm sure this man knew what he was talking about. Same thing for the second barrel. The third barrel has only a couple of hundred rounds through it and I don't shoot this rifle as much as I once did, so it should last for a while.

[Shuz]

Folks--Thanks for all the replies.I rather suspect the problem is with my not being able to cope with the Accu-Trigger the way it currently operates with me behind it! I shall take charlie b's advice and increase the weight of pull to see what that does. There was several times when the safety tripped when I closed the bolt. That should be a clue that something needs attention. In addition to the trigger issues, this rifle does not always eject the fired cartridges. I have put 3 new ejectors in over its life and the problem still exists. Talk about destroying one's concentration, between the trigger and the ejector it has been quite a challenge, but I just love shooting that. 250Savage cartridge.

[Nobade]

NRA HighPower, F Class, and NRA Long Range. That was what the Creedmoor was developed for.

Rates of fire and round count are roughly the same as PRS but since PRS has no set course of fire it's not an head to head comparison. If shooting the NRA Across the Course matches the rate of fire is faster and double the round count over PRS.

Never shot PRS but I have barreled a couple of rifles for PRS. One was 6m XC and the other was a 6mm Creedmoor.

Interesting. I wonder what could account for the difference? Maybe our customers just like spending money? Or blame their equipment for misses? Who knows.

[M-Tecs]

Interesting. I wonder what could account for the difference? Maybe our customers just like spending money? Or blame their equipment for misses? Who knows.

Do you build PRS rifles? What barrels are you using? I mostly use Krieger's since I get a volume discount coupled with the fact that I have not found anything better. Equal yes but not better. Did a couple of Bartlien's but they are both still under 1,000 rounds per the owners. One in a 6mm Dasher and the other in a 6mm XC.

I do have limited experience with the 6mm Creedmoor but I do have a lot with the 6mm XC. The 6mm Creedmoor does have about a 1 1/2 greater H2O capacity. The earliest I have pulled a 6mm XC for anyone was around 2,200 rounds. The most was about 4,100 for a 6mm XC. Most are around 2,500 round or a little more. A 3% capacity increase with basically the same neck shouldn't reduce barrel life to 900 rounds.

https://precisionrifleblog.com/2018/12/14/rifle-caliber/

[M-Tecs]

What 750,000 rounds of wadcutter will do to a bore.


https://www.youtube.com/watch?v=hQP5IAKtUAI

[charlie b]

Folks--Thanks for all the replies.I rather suspect the problem is with my not being able to cope with the Accu-Trigger the way it currently operates with me behind it! I shall take charlie b's advice and increase the weight of pull to see what that does. There was several times when the safety tripped when I closed the bolt. That should be a clue that something needs attention. In addition to the trigger issues, this rifle does not always eject the fired cartridges. I have put 3 new ejectors in over its life and the problem still exists. Talk about destroying one's concentration, between the trigger and the ejector it has been quite a challenge, but I just love shooting that. 250Savage cartridge.

Accutrigger. Tripping when closing the bolt is an indication it is set for too light a pull weight.

Ejector. For some reason I had very few problems with the ejector on my Model 12, until recently. Now about every 20 rounds I get one that doesn't get pulled out of the chamber all the way. Maybe the springs are getting 'soft'.

I do not count the number of bullets I shoot in my two rifles. But, I do keep track of how many bricks of primers I hav bought for each. I am on my 4th brick for both of them now. I had 4 boxes of primers left for the .308 last time I grabbed some more. So, allowing for some 'losses' it has around 3500 rounds through it. What I can't tell are how many were jacketed and how many were cast. I've gone through two boxes of gas checks and about half of the third. But, I get rejects that will count against that as well. So, a bit more than 2000 cast.

I don't measure the chamber for erosion but I do keep track of groups so I can see if they start to grow on me.

[Nobade]

Do you build PRS rifles? What barrels are you using? I mostly use Krieger's since I get a volume discount coupled with the fact that I have not found anything better. Equal yes but not better. Did a couple of Bartlien's but they are both still under 1,000 rounds per the owners. One in a 6mm Dasher and the other in a 6mm XC.

I do have limited experience with the 6mm Creedmoor but I do have a lot with the 6mm XC. The 6mm Creedmoor does have about a 1 1/2 greater H2O capacity. The earliest I have pulled a 6mm XC for anyone was around 2,200 rounds. The most was about 4,100 for a 6mm XC. Most are around 2,500 round or a little more. A 3% capacity increase with basically the same neck shouldn't reduce barrel life to 900 rounds.

https://precisionrifleblog.com/2018/12/14/rifle-caliber/

Any more it's mostly Bartlein 5r barrels. Sometimes Kreigers, sometimes something the customer brings in. What you said made me think, perhaps 5r rifling isn't all it's cracked up to be and since it looks half worn out when it's new maybe it really is? They shoot incredibly well when new but possibly have a shorter life span?
For a while we were building mostly rifles for PRS and the newer NRL, but at this point it's probably half of those and half hunting rifles. Though the lines are kind of getting blurry with people wanting heavy magazine fed chassis stocked rifles for long range hunting so essentially PRS guns in large calibers.

[Bigslug]

As the astronaut from Toy Story will tell you, "To Infinity, and Beyond!"

The military throat erosion gauge for the M16 will fall something like two inches past the start point of a new barrel before it gets to the reject/do-not-deploy stage. Barring other failures in the rifle, Uncle Sam still considers it good enough to defend the Free World with up to that point.

That is after THOUSANDS of rounds down a bore that was chrome plated at manufacture, shooting 3000 fps / 50,000+ PSI jacketed rounds, undisciplined full auto, abusive troops with segmented steel cleaning rods. . .

Also worth considering is that some would consider that kind of "burned out" throat ideal freebore for shooting cast.

An anecdote - when Kevin Thomas was still working for Sierra, he related that the fixture barrel they used for quality/accuracy testing jacketed .45ACP match bullets had been in service for some decades and was (IIRC) in the tens if not hundreds of thousands of rounds with no plans to retire it.

Paper patching will cause some specific types of wear to the rifling.

Some cases with more tapered shoulders can theoretically "sandblast" a throat by pushing powder that has not yet begun combusting. More of an issue with the big charges of slow burning stuff - much less so with the faster burn rates used for de-tuning a .30-06-class cartridge down to cast levels.

I think if you're ten years old, are just starting the experiment, and will only ever have the one rifle in your lifetime, it MAY be just outside the possibility that you'll have something to worry about.

[Hanzy4200]

In my humble experience, cast will produce almost no wear. Considering the metallurgy, copper, or even worse bimetal, is significantly harder than lead. I have several barrels with 10's of thousands of rounds that are still mirror.

[fastdadio]

Interesting thread, something I always pondered but never worried about. Barrel life will be what it will be, so I just keep shooting. Seems the idea is that heat and pressure may be more of a factor to bbl life than the boolit material itself. So, one thing I do often think about, is my use of TightGroup powder for light loads and how hot it burns. One of my favorite loads is 6.0 grs in 30-06 under the Lee 170, for a subsonic load of about +/- 1035 fps. 5 quick rounds through my Vanguard heats the bbl up noticeably faster and hotter than any other powder I use.
Anybody have an opinion on weather prolonged use of this powder may be leading to a shorter bbl life vs using something else? There certainly are other powders besides TightGroup that are suitable for this loading. I simply use it because it's economical, works well and I currently have over 4 lbs of it. What say the collective?

[Winger Ed.]

Anybody have an opinion on weather prolonged use of this powder may be leading to a shorter bbl life vs using something else??

Barrel throat erosion is largely from heat.
If you can restrain yourself from letting the barrel get to hot to hold onto---
Wearing it out, or needing the rear of the barrel cut off a inch, and chamber set back and re-cut
from shooting cast boolits is the least problem it will ever have.

[fastdadio]

Barrel throat erosion is largely from heat.
If you can restrain yourself from letting the barrel get to hot to hold onto---
Wearing it out, or needing the rear of the barrel cut off a inch, and chamber set back and re-cut
from shooting cast boolits is the least problem it will ever have.

Knowing full well TightGroup burns hot, I have never run a long quick string of it. I shoot an easy pace, and sometimes have two rifles on the bench and rotate them. The Vanguard has a light contour bbl, and I suspect if I heat it up proper, it would start to walk on me. No point in that.

[M-Tecs]

Any more it's mostly Bartlein 5r barrels. Sometimes Kreigers, sometimes something the customer brings in. What you said made me think, perhaps 5r rifling isn't all it's cracked up to be and since it looks half worn out when it's new maybe it really is? They shoot incredibly well when new but possibly have a shorter life span?


Krieger offers 5R as an option. I have not used very many 5R's in a Krieger but I have done a bunch of Boots Oberymeyer's 5R. Krieger is doing a true version of Boots 5R and he pays Boots $15 dollars a barrel. I have done them mostly in 308, 300 Win Mag and 6.5 x 284. Can't say I have seen or heard any issues with Krieger's or Boot's 5R's other than when a bunch of the custom barrel makers all got a bad batch of steel about 30 years ago. Other than that all had barrel life within the expect norms for the chambering.

Boots had a major stroke years ago and is in very poor health. When I order 5R's they are Krieger's out of respect for Boots. I enjoyed shooting, dining and many conversations with him. Almost all of the cut rifle makers learned from Boots. John Krieger has treated Boots properly thru the years. Some of the others not so much. I am not referring to Bartlein. I have zero knowledge of Bartlein' s history with Boots and 5R. I know both John and Boots personally.

https://www.kriegerbarrels.com/caliber#r5

5R® RIFLING FORM
In 5R® rifling, the barrel has 5 grooves and the sides of these grooves are not straight, (i.e. not parallel to each other), instead they are angled or ramped as shown in the drawing above. Many shooters find this groove style to be advantageous, which has led us to offer it in many of our calibers.

True 5R® rifling is an official registered trademark of Boots Obermeyer of Obermeyer Barrels. Krieger Barrels has express permission to use both his "5R" terminology and the groove geometry he developed to produce our 5R® barrels. Our 5R® barrels are produced using the same methods and standards of match-grade quality as all of our barrels.

There is an additional fee of $15 for 5R® barrels.

[Goofy]

Not going to worry about bore wear with cast bullets in this life. Awful lot of variables involved in wearing out a barrel, the most influential being pressure. The correlation is direct an predictable.

[Bad Ass Wallace]

There are other significent factors that would affect barrel life. Depth of rifling in ex-military barrels appears to br deeper than found on sporting rifles. On my 7mm Marser FN military rifle the bore and groove are 0.285/0.276 or 0.009". On my Ruger 0.284/0.277 or 0.007" difference. Typically rifles reserved for cast boolits exhibit deeper rifling, and therefore barrel life would be longer.