Barrel Life with Cast bullets in Rifles?

[KHornet]

I remember from sometime way back, some gun writer wrote that he ESTIMATED barrel life of a rifle shooting
cast bullets to be in the neighborhood of 80,000 rounds. Remember at that time thinking: I wonder if anybody
has ever shot 80,000 rounds out of cast out of a single rifle?

Have a close friend who has a lifetime ambition to pass on to his relatives all of his rifles with shot out barrels. However he shoots very little cast.

Also remember as a kid when the 220Swift, was the hottest thing on the market. Remember that at that time, most shooters were considered lucky if they got 1000-1200 rounds out of a Swift with factory vol's. On the other hand my #3 KHornet, has had a mixture of jacketed and cast (highest percentage jacketed) of well over5000 rounds, and will still shoot MOA.

Recently replaced a heavy bbl on a Sav, after about 3500 rounds of jacketed when it would no longer stay close to MOA. I seriously doubt that I will ever put anywhere near 80,000 rounds of cast thru any rifle. That is a whole whoop of primers, pounds of powder, and pounds of lead.

If anybody has any factual knowledge of actual cast barrel life in rifles and would like to share it, I, and I am sure most on this forum might be interested in same.

Paul

 

[KeithB]

I would think that barrel life with cast bullets would be dependent mostly on erosion due to heat from the powder and primer. Can't imagine that cast bullets made with clean alloy will cause much wear to the barrel proper.

 

[Ian]

The actual projectile means little. I recall reading somewhere in the past how gilding metal bullets produced effectively zero wear on a barrel, although the test did not include the abrasive effects of primer and powder residue between bullet and barrel. The wear will be directly related to heat and ablation. Since most people load cast bullets to very mild pressures and velocities and tend to use powders that burn up mostly inside the brass case, barrel life can be expected to be practically indefinite. On the other hand, if you load to jacketed velocities with your cast bullets and shoot a lot of them, you can expect to see some wear.

Personally, I haven't worn out a barrel with cast bullets, but have managed to barely break in a couple of new ones after a few thousand rounds. My Kimber 1911 with several tens of thousands of both jacketed and cast through it and my JP Sauer K-38 target copy with at least five buckets of WW shot through it show a slight bit of land wear in the throats, but that's about it.

 

[JSH]

Paul, I have cast a fair bit. But I doubt even close to 80k combined all calibers.

That would roughly be 512 pounds of 45 grain 22 bullets.
Or 2057 lbs of 180 grain bullets.

The guy that cast his own of that quanity must have fore arms like popeye.

 

[KHornet]

Thinking about your statement JSH, I don't know how many I have cast and shot
over the last 50 plus years. I figure someplace between 2 and 5 thousand a year
over that period, and in probably 15-20 weapons. Doubt I would have had the
moxie to shoot 80K over that period with one weapon.

I like Ian's thread!

Paul

 

[Eutectic]

I think Ian is pretty close.... He's left out a factor in my opinion however. That factor is our bullet lubricant. Not only is just friction reduced. A flushing action of some sorts is also in place I think..... Some think a hot throat is a hot throat whatever you are launching.... Maybe so..... But I do know a lube film can be a heat shield of sorts for very brief exposure to intense heat. Does it protect in those few microseconds? Like I've said before.... We need a slow motion of our launch. In old Townsend Whelen writings.... I mean cupronickel jacket old.... Whelen commented on greasing jacketed bullets prior to shooting them. He even showed a little 'luber' he made to get a uniform light film on bullets! This was for fouling originally. This procedure was written about later as causing high pressures. This was probably due to the philosophy of if a little lube is good a lot is even better! This still lives today by the way.......

What has stuck in my mind until this day is Whelen's comment about his military target shooting with greased bullets......"I have observed that the useful target accuracy life of carbon manganese Springfield barrels is 3 to 4 times more the number of rounds when greased bullets are fired than with the same loads fired dry."

Something to think about.

Pete

 

[RBHarter]

I aquired a 1913 DWM Gew 98' with a Jeager trigger . It was bbl'd in something .09 shorter to the Weatherby shoulder than the 280 AI . The case neck and throat would except a .301 dia bullet as fired 4.5 inches forward from the breach face of the bbl and on to the muzzle the bore was 277x284 . The area of about an inch in front of the case mouth was tapered in a convex curve from 302-284 . No knowledge of round count but I think the thread shank could be cut off , rethreaded and be rechambered in 280AI again or take another 1/2" and do a 7x57 AI . It would just clean up the erosion .
I suspect that the rifle was probably shot with compressed loads of 4831 and 4350 class powders and 154s based on build parts and where it came from . The flame coupled the stick powder grinding through the throat and possibly long strings on assorted chucks makes for a perfect storm of abrasion , heat and compressed gas .

I read once that the life span of an 03' bbl with 1939-44 vintage M2 ball was 30 seconds , .007 seconds at a time or roughly 10,000 rounds .
I have to wonder how many bbls a fighter pilot or bomber crew went through . Round count with empty guns that's 10-14 contact sorties .....

 

[Eutectic]

I read once that the life span of an 03' bbl with 1939-44 vintage M2 ball was 30 seconds , .007 seconds at a time or roughly 10,000 rounds .

Funny thing..... My father is the only person I know who has changed a barrel because accuracy was shot out! He got a double heat treat Springfield when I was a pup. He shot a lot of matches with practice in between with DCM ammo M-2 ball. The jackets were steel with a copper (gilding metal) plating. Varied from 1942 to 1953 as I remember and my brass says. He found two new 4 groove "RA" barrels somewhere. He changed one in the 50's and the other one when I married. He told me accuracy fell off at about 4,000 rounds and he thought the steel jacket didn't help things!
Actually my buddy changed out a 9.3 x 62 barrel on one of his favorite African rifles. Barrel was good but had a 17" (measured) twist. He had wanted 14"! Accuracy fell off in a 1000 rounds... He sent me the rifle to work with and I found the twist discrepancy after a lot of load testing to no avail.

A comment on soft lead loads. I remember the Marine Benner who shot military pistol match years back. He sent his Match Target Colt back to Colt for an overhaul. He told Colt the gun had a quarter million rounds through it! Joe (I think his name was) told Colt he wanted a new barrel and whatever else needed for rebuild. Colt sent it back with several parts renewed and frame/slide fits tightened.....but they left the barrel alone!!!! Colt told Joe they found no measurable wear in the barrel and it was polished into a better barrel than they could put back on!! 250,000 rounds through it!
Guess my Savage Model 23's will outlast me feeding on my grouse loads!

Pete

 

[Minute Of Berm]

..."heat and ablation. "... This is why I love coming here, just seeing these big fancy words makes me smile......;-)

 

[KeithB]

In any case, this thread shoots down the local gunshop wisdom that "cast bullets will shoot out a barrel". In whose lifetime?

 

[Rick]

I don't think I've ever heard that cast will "shoot out" a barrel but I've sure heard a lot of times how they will "RUIN" your barrel.

I agree with Pete, bullet lube plays a huge part in reduced barrel wear. There is still burning powder and gases to consider depending on how hot the load may be. In addition in long range revolver using hot loads and too "soft" of a bullet will cause premature forcing cone wear. This was studied by Dick Casull when he was developing the 454.
.

 

[quicksylver]

It's my option that you loose the throat and leade well before the rifling is gone...that's with jacketed...those barrels will still shoot cast well through another life time....I got one..can't find the rifling with a 312299 and .302 nose seated with only about 1/8" in the case...still shoots under 3/4" with cast at 100 yds....

 

[KHornet]

Sound logic Dan!

Paul

 

[Brad]

22 RF barrels do lose accuracy with time. Rimfire prone shooters do change barrels after a number of rounds. May be 30-50 K but even the humble 22 RAF erodes the throats over time. Worse yet the erosion isn't uniform. The bore can erode worse on bottom because the powder settles there. Imagine what that does to throat concentricity over time?

FYI, many rimfire prone shooters will fire 5-10K rounds per year. A match can require up to 640 rounds for record with unlimited sighters.

 

[Ian]

Ha! Lube. Yeah, it's a big deal, glad you brought it up, Pete. A lot of it ends up in the throat area due to hydraulic compression of the bullet and some being blown around the bullet before it even exits the case. In this part of the barrel the lube is likely at its most viscous, and protects the best. Two inches in to the bore and I don't think it really matters much whether the barrel or bullet is lubed or not speaking strictly from a barrel wear standpoint. We do know the bullets wear exceedingly by the time they have reached muzzle end of a rifle barrel if the alloy is too brittle and the lube has insufficient boundary lubrication characteristics.

12 square feet of Amerimax aluminum flashing makes a lot of 6.5 mm gas checks. I know one person who claims to have shot that many through a Swedish Mauser, all with various and sundry slow ball and stick powders at probably excessively high pressure most of the time, all to no effect on the throat. I also believe most of that shooting was done with a soda soap lube which does not melt in the throat, and that may have contributed to the longevity of that and several other of his rifles. After all the lube testing I've done, the soap lubes have impressed me the most with their very high viscosity index, high thermal coefficient, and insanely tough film strength. The film strength at relatively low room temperature viscosity is something that impressed me from the very start with a sample of soap lube I'd been given, even before I knew what was in it. No other lube formula in my experience has an equal when it comes to this, and I have quantitatively tested lube film strength at a variety of temperature ranges with a little Timkin-style gizmo I created for the purpose. Maybe throat wear isn't affected much by weaker lubes, and maybe it is, but regardless of the lubricant of choice, traditional wax/grease/oil bullet lubes no doubt are a huge factor to the life of a cast bullet barrel, particularly when the heat and pressure are up.

 

[Eutectic]

About .22 rimfire.......

My observation is that SO many things are designed today for convenience rather than best for their applications.... As several of you know I like to 'study' things! It goes back to my earliest memories too. I put target .22's here. I've studied .22's for 70 years in one way or another.... I have seen convenience 'take over' in so many things.... Modern .22 ammo is dry.... Shoots good as minimal lube can do... But too dry?? I remember shooting shorts when I was well 1948.. You saw a faint lube star then... That old Model 90 of mine started life with a new Winchester replacement barrel (yeah, I can remember when you could buy them; my Dad did this one!) I KNOW that barrel has well over 100,000 rounds through it over 70 years! Maybe a lot over!

Bottom line here... I believe it is more important these days to have .22 shells that you can put in your pocket than .22's the most accurate; even best for longevity of barrel. I have shot tens of thousands of the old Western "Xpert" too, in the old blue and yellow boxes. We bought them from DCM back then cheap. Heck! I've shot thousands of them in my Match Target Colt just practicing long range. These rounds actually had a greased bullet! So did some orange boxed Eley match that I still have a horded supply of. I believe these greased rounds were way easier on your barrel. Forgive me for speculating because I don't have enough left to run a real test!!!

Pete

 

[fiver]

the biggest factor to cast wearing out a barrels the heat in the rifles throat.
the second factor would be antimony dendrites on the surface, they are always scraping and pulling at the steel.

 

[KeithB]

Let's remember that the steel used in most .22 rimfire barrels isn't always the same as the steel used in center fire barrels, especially in older guns. Any wear comparisons should take this into account.

 

[Brad]

I was speaking of high dollar target rifles for 22 RF. Most every day rimfires will get little wear from shooting, they just don't see the volume.
A rimfire prone shooter may shooter 10K rounds a year so round count is a serious factor as is the accuracy demand.

I need to back thru my copies of PS and see if I can find the article.

Pete, you would enjoy the articles on rimfire BR. They noticed a problem when rifles were fired and shot great but 30 min later wouldn't shoot near as well. A few slugs thru the bore showed the bullets got chewed up by dried up lubricant in the bore. CORE is a real factor here. Long as a clean bore was kept warm and relubed from shooting all was well. Let it sit even 30 min and the bore condition changed and couldn't be brought back by just shooting.

 

[Eutectic]

I bet a few drops of A/C ester oil in their tumble lube formula might help that semi-cold start problem Brad!

One reason why I keep it in my grouse loads lube. Those soft loads are not fussy about lube until you factor in 'cold start'. I've got a new plain base I'm using in the .25-20 for grouse. The Savage 23 sat in the basement for a month uncleaned..... Shot one yesterday morning was 'grouse eye' dead on! (at 70 yards)

Pete