The Barrel Burner

[ISS]

You should have seen the throat on my 22-378 Wbys after 200 rounds...

 

[linebaugh]

You are doing everything right to get bbl life.N160 burns cool, no rapid fire to cook bbl, good cleaning and not a 7 twist. You might make it farther than you think, or it may quit tomorrow. I shot a lot of the higher capacity .224s and learned a few things (I think).

One of the things you learn is that a barrel can go from shooting fine to shooting like hell over the course of 10 rounds. They can also go from shooting fine to popping bullets in flight in just a few rounds. Signs of gradual accuracy degredation happen over time but in most my barrels they were pretty accurate right up until they gave up the ghost dramatically. I have not shot enough barrels of other caliber out to know if this is common.

The highest round count I acheived was using VV N100 series powders, using the .001 oversized brux bbl and bore paste cleaning every 200-250 rounds.I spent most my time with the bore paste on the throat. My last bbl chambered in 22BRI made it over 2000 rnds in PRS matches shooting 90s. I cut that entire chamber out and set it back/rechambered for another several hundered rounds of play before tossing. I would not bother setting back or a rechamber. That was the 3rd time I tried to repurpose a worn out barrel and have never been impressed.

 

[ELR LVR]

My last 6x284 Barrel went a good 1900 rounds and still shot Long Range (1500 yds) Great.
I rebarreled it because it finally lost enough velocity to be equal to a .243.
( I found approx .001" throat erosion per every 10 rounds fired)
As the throat erodes, then at a certain point, gases can escape past and around the bullet.
The alligator hide don't look appealing none, but you may finely lap it if you wanna make yourself feel better and bring a new type of finish to somewhat burnish or round off any sharp edges in the cracks that pick up copper.
I Lap my own barrels and use very fine diamond compound
This is somewhat of a science so do your research
The Military calls out their own specs for lapping
Kreiger calls out theirs
Everybodies is different , 32 micron, 64 micron etc
The only thing they all agree upon is.... = Do NOT polish your barrel to where it is shiny smooth like glass.
At that point it is almost like the metals wring together and gall the bullet jacket surface,
IE: (Strip Copper faster)
In my world of hot rod wildcats and Ackley's, anything over 1000-1200 rounds and still grouping the same as when new.... is great.
---Barrels are an expendable item
Just like bullets
Just like the Brass (brass don't last forever neither right?)
$400 and get a new barrel
we all spend way more than that just on bullets and powder and dont complain right?
Consider your barrels an expendable item just like your powder and bullets and you will be in the right
mindframe from now on.
John

 

[DLT]

What twist are you zinging out the 69s ? If you already posted it I missed it

 

[STS]

All of these barrels are 8 twist. As I mentioned, I intended to up the powder a couple tenths to see if it would shrink the vertical that it had in the target above. I did that yesterday. I shot it at 100 meters since it was blowing about 20 mph and it shot about .250 straight horizontal with about a quarter bullet hole of vertical. It really is surprising haw well it shoots considering what the borescope shows.

 

[jelenko]

.001" throat erosion per every 10 rounds fired)

Wow!!
In 223, it's about .002 every 100.

 

[K22]

I thought I'd add a short follow up to further illustrate just how wrong a borescope evaluation can be. Old barrel number 3, with that burned up cracked leade, was shot yesterday at the 430 yard mark. Rounds number 1228 thru 1230 yielded the following 3 shot group. It has a 1.5 inch dot aiming point and the 3 rounds measured .740. I'll put up the photos of the leade, and the target, as a vivid comparison of what a crap barrel looks like and how they can shoot if everything else is working. I did notice that the velocity was about 35 to 40 fps slower that it has been and I wonder if it needs a tenth or two more powder to get back in the node and see if some of the vertical will go away. I have never tested barrels with this degree of erosion for loss of velocity.

View attachment 1616799View attachment 1616800

I keep "crying in the wilderness" on firearms related posts, nothing beats shots on target to prove or disapprove an assertion. I mean isn't that the point of what we are trying to do.

I base all my reloading and cleaning processes / decisions on performance results. I would clean the bore with groundhog pee if can be shown on target to give me better performance.

PS: I lost my sense of smell a long time ago working in a chem lab, so the smell of groundhog pee is not impediment.

 

[ELR LVR]

Wow!!
In 223, it's about .002 every 100.

I would agree with that!
223 and 308 have at least 3 times the barrel life of an overbore cartridge.
Long Grain Tubular Powder also affects throats such as the H1000 it likes so much.
But I have other rifles that are more barrel friendly I can shoot also so no biggee.
But I DOOOOOO sure like my hot rod wildcats
Barrel life is the price ya pay for ownership.
I've heard of even worse ones, like a 22/338 or some such thing lasting only 400 rounds lol
By the time you got a pet load worked up and figured out - the barrels toast ha.
That's just silliness but whatever right?

 

[ELR LVR]

What twist are you zinging out the 69s ? If you already posted it I missed it

I don't see who you were referring to or asking but....
I chambered a Standard 22-250 with a 10 twist that perfectly shot the
Sierra TMK 69's with great accuracy and distance.
Good to 800 yds
So I'd say you're safe with a 10 twist or tighter
However I am at higher altitude so don't know how it would act closer to see level.
My DPMS 9 twist shot the 69 and 77 TMK's fine out to 700 yds
I'd Opt for a 9 twist over a 10 just for extra insurance though if you like using 69's

 

[Pawnee Bill]

IMO I don't think that qualifies as a real barrel burner. To me a real barrel burner has always been the 220 Swift shooting a 40 grain bullet at 4000 fps. Throat is gone at about 500 rounds.

 

[searcher]

IMO I don't think that qualifies as a real barrel burner. To me a real barrel burner has always been the 220 Swift shooting a 40 grain bullet at 4000 fps. Throat is gone at about 500 rounds.

I've never owned a 220 Swift. That is pretty amazing how that extra powder does so little in velocity gain, yet wipes those barrels out so much faster than, say, a .20 Practical running similar weight bullets at similar velocities. I never realized the erosion was THAT much faster. As others said - that IS an eye opener!

 

[ISS]

I burnt a 220 Swift Ruger factory barrel out in 440 rounds on a PD hunt up in Zortman, MT one day. 220 rounds in four hours in the morning, went back to town for lunch and reloading session, and 220 in the afternoon. Throat was so charred it tore patches. I sent it back to Ruger, and they fit a new barrel, NO CHARGE! They did tell me to slow down on the firing rate, though.

 

[Jonnyofalltrades]

IMO I don't think that qualifies as a real barrel burner. To me a real barrel burner has always been the 220 Swift shooting a 40 grain bullet at 4000 fps. Throat is gone at about 500 rounds.

Are you saying this based on the shallow shoulder angle, or what? The .22 Creedmoor has 11% greater case capacity than the .220 swift.
Run with similar shooting parameters, I don't see how a Swift could be any worse than a Creedmoor. It has 9° less shoulder angle, but 50 thou more neck length.
Am I missing something here?

 

[ISS]

case design, IMHO.

 

[357Mag]

IMO I don't think that qualifies as a real barrel burner. To me a real barrel burner has always been the 220 Swift shooting a 40 grain bullet at 4000 fps. Throat is gone at about 500 rounds.

All -

Howdy !

I believe the original factory .220Swift load that gave 4,000 fps, featured a 48gr bullet.

Not sayin’ barrels can’t be toasted shooting 40gr .224” cal bullets @ 4,000fps…
Offering the thought that a notional 55gr bulleted .220 Swift load that gives 4,000fps might likely need even more powder to do so, than the amount needed to propel a 40gr to that velocity ? And, if a comparatively “ hotter burning “ powder is being used; one imagines what might happen to obtainable barrel life. Hmmmm….

IMHO - the ‘Swift’s 21* shoulder angle doesn’t help any, as regards barrel life of a varmint in that chambering. Using the .220 Swift chambering again as an example: If the shooter were able to utilize a custom barrel of longer length than the “ factory “ offerings,
enhanced velocity might be obtained by nature of the rifle’s increased expansion ratio.
This can also open up the possibility of using a powder selected from a different span of
“ burn rates “ on then “ burn rate “ chart.


With regards,
357Mag

 

[357Mag]

All -

Correction to previous..

“… barrel life of a varmint rifle in that chambering . “


Regards,
357Mag

 

[nwmnbowhunter]

I've been thinking about doing a post like this for a while that will serve as a good illustration of the erosive process in the larger case capacity to bore diameter ratio cartridges, aka 'barrel burners.' I have three .22 Creedmoor barrels that are at different stages of life that demonstrate this progression quite clearly. They also clearly show that some of the comments that are offered as fact regarding barrel burners, are not accurate at all. I want to keep this as short as possible so it doesn't turn into a dictionary length post so I'll post some info regarding the barrels.
1. All 3 barrels are Krieger .218 bore 8 twist 4 groove. I chambered all of them with the same JGS reamer with .110 freebore.
2. These barrels are on my predator rifles and have not been overheated in colony varmint fields.
3. Powder has been predominately VV N-160 with some Rl-26 also.
4. Barrel #1 is a chambered blank that I have waiting in the wings to replace barrel #3 when it officially dies. Round count is 0.
5. Barrel #2 has 598 rounds.
6. Barrel #3 has 1217 rounds.
Borescope image of barrel #1
View attachment 1614846

That's an exceptional finish on that...wooooo!!!!!

 

[STS]

That's an exceptional finish on that...wooooo!!!!!

Good reamer. They aren't all created equally. The old saying "You get what you pay for" is applicable to reamers.