Barrel Life by shooting Cast Boolits?

[Bad Ass Wallace]

Folks who know me know that I am very particular about which rifles are fed "J" boolits and which are only fired with cast boolits. Any Winchester levers, Martini's, Sharps and several classic bolt actions are only fed cast.

The cheapness of cast boolit loads means that I can afford to shoot much more than if I was relying on store bought boolits. Shooting more may mean that the barrel would be worn out quickly but I haven't seen that.

The payback is absolutely polished barrels that only get better with time. But the burning question that I am often asked is what barrel life can be expected? I simply don't know and don't have a clue. A Google search is even more confusing with 'estimates' running from 40,000 to 250,000?

I have new rifles and some old ones where changing the cast boolit size has made a rifle with useable accuracy. This is something you can't do with "J" boolits.

Tight Grouping from a 7x57Mauser

https://i.imgur.com/OXxKE9Cm.jpg

My Favourite - 30.06 Springfield.

https://i.imgur.com/4aMC0cKl.jpg

[Der Gebirgsjager]

I don't believe that you can ever wear a good barrel out shooting only cast boolits.

[Winger Ed.]

One of the older Lyman books had a 2-3 page article on that.

According to the article:
The biggie is throat erosion.
It can be compensated for by longer OAL, chopping off the back of the barrel, and rethreading/chambering it.

They figured a regular, sport barrel was good for about 2,000 or so full house rounds
before accuracy started falling off from the erosion or burning of the throat.
A Chrome lined GI type barrel was good for about 5,000 before it started to wear out.

They took a new, everyday Win. Model 70, I think in .308 and shot only cast boolits in it.
After 40,000 rounds, they ground off the top of the chamber and first bit of rifling.

They found 'no measurable wear'.

[M-Tecs]

Barrels mostly wear out from heat/pressure erosion. The lower the pressure and heat the longer the life. For low pressure rounds like the 45 ACP 250,000 rounds and still maintaining competitive accuracy is not unheard of.

On the other end of the spectrum some of the high pressure jacketed rounds used for long range competition lose their competitive accuracy life around 2,000 rounds. A standard 308 normally goes about 4,000 for usable accuracy life. It will still group at 200 or 300 yards but you will start to shots dropping at the bottom at longer ranges. Hunting accuracy should be double or more.

[Biggin]

Well if any of that is true I'm probably gonna wear out before the barrels on anything I own. Lol!

[Win94ae]

I have new rifles and some old ones where changing the cast boolit size has made a rifle with useable accuracy. This is something you can't do with "J" boolits.

I do it all the time. Actually I shot "oversized" jacketed bullets today with my 30-30. It has a worn barrel, which is much like a funnel now.


https://www.youtube.com/watch?v=E3qbhC3cePU

That is a Speer 31cal 180gr bullet, that I size to .310 so I don't get a 4MOA high flier every 5 to 10 shots.

I'm pretty sure, the cast bullets were what effected my bore. I was under the assumption that cast bullets were "polishing" my bore also; when in actuality, they were polishing and compacting the fouling and causing a problem. Now, in my other rifles, I don't shoot many cast bullets at all without a thorough to bare metal cleaning.

That reminds me, I need to thoroughly clean the Marlin 1894. I've shot a lot of cast in that lately. Powder coated, hopefully the absence of the lube fouling will make a huge difference.

P.S. I have about 25,000 rounds through the 30-30, I had maybe 15,000 rounds through it before I started using cast, and the bore wasn't a funnel at that time.

[akajun]

as stated, yes you can the question is "when is it worn out" to you and your uses. You know you can wear out even a 22lr? top rimfire prone shooters will wear them out, the throat will go, the crown erodes, etc. Now the top shooters will replace those smallbore barrels at about 30-50k rds but they will still shoot very well for an average Joe, just not for someone trying to shoot a 1200.

[john.k]

Good question for powder coat......all plastics contain fillers ,which can include fine silica ,talc,ground glass,ground mica ,alumina,and colours like titanium dioxide .....TiO2 is a very common whitener .So how abrasive are powder coat bullets?...Obviously depends on the powder .....which is made to give a smooth ,long wearing coating on metal objects ,doubt bullets come into consideration.

[Jeff Michel]

I think a cleaning rod has ruined more barrels than anything else.

[Winger Ed.]

I think a cleaning rod has ruined more barrels than anything else.

Good point.
I had a Confederate issue musket that was very used.
The barrel end at the muzzle was oval. Probably from the ram rod going in & out so many times.

[Cosmic_Charlie]

I have a Model Seven in .308 that I bought 25 years ago. Put several thousand rounds of ball ammo through it. Now I shoot a gas checked .311 boolit in it and it's back to sub moa, at least at 50 yds. I doubt that 16 grains of 2400 is going to wear that barrel very much from here on out. It won't see anymore j word bullets.

[GhostHawk]

Cast boolits and 1% carnuba wax in my BLL. Bores just keep getting shinier.

[M-Tecs]

You know you can wear out even a 22lr? top rimfire prone shooters will wear them out, the throat will go, the crown erodes, etc. Now the top shooters will replace those smallbore barrels at about 30-50k rds but they will still shoot very well for an average Joe, just not for someone trying to shoot a 1200.

Rimfire ammo does not have an anvil in the primer. In lieu of an anvil they use powder glass in the priming compound. Starting at about 20K you can see a sandblasting effect 6 or 9 inches in front of the chamber at the 6 o'clock position from the powder glass.

[Cosmic_Charlie]

Cast boolits and 1% carnuba wax in my BLL. Bores just keep getting shinier.

Does the carnuba readily dissolve?

[GhostHawk]

No, it has to be heated with the Alox. Once all melted together I combine with the floor wax/mineral spirits and all is good.

I love what it does for bores, it also makes a non sticky film on the surface of boolits. Which is also a nice side effect.

Microwave works for warming. I also did it once with a soldering iron in the alox bottle till it started looking runny. Added my Carnuba crystals and hit it again with the soldering iron. Then put the cap on and shook it hard. Then mixed as normal.

[B R Shooter]

I chambered a new barrel before the 2019 shooting season, 30BR. Once chambered, I polished the leade to remove the perpendicular reamer marks. I checked it with the borescope, there were a few faint marks left, but otherwise matched the surface finish of the lands and grooves. I shot quite a bit between Febuary and August, then decided to change the barrel for a different twist. I checked the first barrel again with the borescope, those slight marks were till there. Between matches and practice, I estimate 500-600 rounds, looked like new, no change in seating depth. I cast linotype and powder coat the bullets. Polishing the leade as I did using j-bullets, those slight marks are gone in 10 rounds.

[Larry Gibson]

Barrels mostly wear out from heat/pressure erosion. The lower the pressure and heat the longer the life.…....

This is correct. With low end cast bullet (regular lubed bullets) loads using small charges of fast to medium burning powders many, many thousands of rounds would need be fired before you'd measure or find any noticeable throat erosion. This especially so if the shooting cadence is slow where the barrel never gets to hot to grasp and hold in front of the action.

Over the years I have shot out (loss of match or varmint accuracy....basically would no longer hold 10 ring for a match rifle (M14/M1As & M1903s) or hold moa or better for a varmint rifle/bolt action match rifle. I have also shot out several other rifle barrels of various calibers simply because I shot them a lot.

Conversely, I have shot thousands upon thousands of cast bullets in numerous rifles and handguns over the years and have yet to discern any measurable throat wear from shooting the cast bullet loads......with two exceptions. Those two exceptions are my 308W Palma barrel with 14" twist and my 30x60 XCB with 16" twist. Both of those have had quite a few top end HV cast bullet loads using slow burning powders at 48 - 50,000 psi (measured). I have tracked every round fired through the 30x60 XCB and it's just over 3,000 rounds. There is measurable and discernable throat wear.

[Bad Ass Wallace]

Conversely, I have shot thousands upon thousands of cast bullets in numerous rifles and handguns over the years and have yet to discern any measurable throat wear from shooting the cast bullet loads......

From you very informative posts, it would seem that I need not worry about my "cast guns". I have recovered many cast boolits and find that medium loads (1500-1800fps) and the right soft alloy will kill game emphaticaly with a not to hard alloy.

https://i.imgur.com/cArT9w1l.jpg

[Wayne Smith]

So I guess that the shorter way of thinking about this is that it is powder that erodes throats, not boolits or bullets.

[samari46]

I read an article in the no longer published magazine Precision Shooting magazine regarding barrel life. Springfield rifle barrels 30-06 will last about 5000 rounds then accuracy falls off. 22rf barrels will last for thousands of rounds but the ground glass they use in the priming mix will cause a ghost ring due to the ground glass. I have a 1946 Win M52 that showed the erosion about an inch in front of the chamber. It starts at about 6 o'clock and extends to 3 and 9 o'clock which means it has had a many thousands of round shot through it. Two options there, set back the barrel or replace it with a new one. I had mine set back. Shoots better than I do. American Rifleman mag also did a test with a few 22rf target rifles that showed this ghost ring. If I remember right all showed an improvement in accuracy after having the barrel set back and rechambered. One that did show improvement also did so using different brands of 22 rf match ammo where previously it was limited to only a few brands. Bench
rest shooters regularly swap out their barrels in as little as 1000 rds. They load hot to get the accuracy they demand. Tony Boyer who probably has more records than most BR shooters usually replaces his barrels around 8-9 hundred rounds cause the accuracy he wants is usually gone about then. And then the heat and gasses from the burning powder definitely contribute to barrel life. Shoot hard and fast like the BR shooters do trying to get their shots off in favorable wind conditions. Match shooters shooting hard and fast to get their shots off in the time allowed. Old guys like me who shoot cast bullets at reasonable velocities (for me about 1600fps) and at reasonable rates of fire will most likely never have to replace a barrel. I have a Finn Model 27 made in 1935 that had a brite and shiney bore when I get it. Now 3000 rds later it's still very brite and shiney. One thing that does have an effect on barrel life is the hardness of the steel in which your barrel is made of. Lotta BR barrels would be at 22-25 BHN Some commercial barrel makers go to 28 or slightly higher. But not because of barrel life but for ease of manufacture. Sako had at one time the reputation as there barrels were hard as H**L which they should last a good long while. My sako 75 now long discontinued has about 2000 rds through it. With a bore light I see no visible wear. But a good bore cam most likely would tell a different story. Even the ambient temp at which the rifle is fired can affect how fast or slow your barrel life is shot away. Interesting subject as many variables can and do affect bore life. Frank

[Bazoo]

For a time they used ground glass in primers. I don't remember when they stopped, but it was due to barrel throat errosion. So, if a report from yesteryear happened to use those primers, it wouldnt be accurate with today's primers. Does anyone know when the priming mix using glass went out of favor?

[MostlyLeverGuns]

One of the theories on barrel wear is based on amount of powder, haeat and pressure. A certain caliber barrel will be worn out by a certain amount of powder. In theory, a 30 cal shooting using 40 grains of powder will last twice as long as a .30 using 80 grains - 308 and 300 Win Mag come close in this respect. Bullet fit anf hardness can affect heating and pressure, bullet friction has more to heating a barrel than that hot powder charge. The barrel steel has internal friction from flexing due to bullet passage, swelling like a snake swallowing an egg as the bullet passes through along with actual lead or copper on steel friction. The softer lead bullets and the lower charges used by MOST boolit shooters lengthen barrel life by burning less steel AND creating less heat friction in the barrel. It would take hundreds of barrels, tens of thousands of rounds in very controlled conditions to actually create a scientific finding. Generally what we know, lighter powder charges, softer bullets make a barrel's accuracy life longer. Only you can determine when a barrel is too worn to meet your requirements. last longer