How Many Barnes rounds in 375 before you have accuracy degradation from copper fouling

Azklmsr · May 28, 2026

Howdy,

Working up 375 loads for RSA safari in a few weeks. Barnes 300 TSX at around 2625 and 250 TTSX at around 2825. I've found interjecting standard cup and core bullets in the session kills the Barnes accuracy until cleaned thoroughly. Any experience on how many rounds you get before the barrel needs to be clean?

appreciate any exerience

Doug3006 · May 28, 2026

I’ve shot 10-12 in a session with no discernible change. I likely could double that and not see much change but my shoulder won’t permit more than a dozen. If your rifle shoots its first 5 under 2 inches at a hundred, it’ll shoot the rest of the box accurately enough to take even the little guys. Get sighted in and then get away from the bench. Shoot off of sticks and shoot until your comfortable with your accuracy at any given distance. Then clean the rifle. Then shoot a few final rounds to foul the barrel. Then it’s time to go hunt.

C.W. Richter · May 28, 2026

Try it and find out on your particular gun. It's not really an issue as no one is firing 100s of rounds through their 375 (even in handload testing, I prob fired 25 270s and 350s through my 1st 375 with zero effect.) The only rifle that began building up copper was an old 257 Wby I shot a LOT (and it cleaned up nicely with Barnes CR-10 cleaner, so no problemo.) Barnes' old (and Berger) moly-coated bullets would also build up gook. It was more troublesome (again on guns firing 100s of rounds) but it also cleaned up. No worries. Certainly, more copper has been deposited on the intended targets, with a much more profound effect! Even premium and traditional bullets make rifling deposits. It's just that talking about it has an effect on sales...

C.W. Richter · May 28, 2026

What are you hunting? My preference would be to select a do-all bullet or at least bullets of same/similar weight and construction (less fooling around at a range and wasting ammo in Africa!) 270s (esp. Barnes) will do it ALL in 375. Just some casual reloading a few weeks until a safari?

jbirdwell · May 28, 2026

I have not had a problem with accuracy shooting 75 or more rounds with accuracy using all copper rounds like Barnes or Hammer's bullets unless I shoot a different type of bullet and then I generally have to clean again before I go back to the all copper. I'm currently at 67 total rounds though my new 400 H&H and it will still shoot a 1/2" group at 100 yards off a bench when I checked to see if accuracy was degrading. I think the key is a good cleaning before shooting the all copper bullets and then sticking with them if that's what your going to hunt with.

revturbo9967 · May 28, 2026

I shot over 100 at a time before a full scrub but it never really drifted or opened up. I was chasing accuracy for a croc brain shot so I had a lot of time on the bench and prone.

Azklmsr · May 28, 2026

revturbo9967 said:
I shot over 100 at a time before a full scrub but it never really drifted or opened up. I was chasing accuracy for a croc brain shot so I had a lot of time on the bench and prone.

Thanks. I’ve mixed and matched and the std cup and core are fine, but the copper bullets suffer.

I have cleaned to bare metal today and will shoot to see how it holds up copper only

Like you, I have a croc on my list as well as a bull buff. Plains game as time allows. The Bull I’ll definitely be using the 300s. Plains, the 250s

rifletuner · May 28, 2026

The biggest variable will be the finish in the barrel. A hand lapped barrel will copper foul a lot less than a cheaply produced factory barrel. But most barrels will give you good enough accuracy for a hunt firing many rounds without any accuracy degradation. Especially from field shooting positions, it would be pretty difficult to distinguish a fouling related accuracy problem.

ftrovato · May 28, 2026

I suspect (in my experience) it would take many rounds to have a significant impact on hunting type accuracy. But in my experience if you let it go it can be a *itch getting it all out.

Don't get me wrong barnes coppers perform well. But I'm not using them as much as I used to due the fouling issues. Nosler & Swift work well for me.

Azklmsr · May 28, 2026

ftrovato said:
I suspect (in my experience) it would take many rounds to have a significant impact on hunting type accuracy. But in my experience if you let it go it can be a *itch getting it all out.

Don't get me wrong barnes coppers perform well. But I'm not using them as much as I used to due the fouling issues. Nosler & Swift work well for me.

Had a similar thought and picked up some HD bonded and Nosler partitions. I'll do the experiment this next week and if I get enough rounds before fall off that its not an issue, go with the Barnes. That said, there are a lot of good conventional bullets to choose from.

revturbo9967 · May 28, 2026

Azklmsr said:
Thanks. I’ve mixed and matched and the std cup and core are fine, but the copper bullets suffer.

I have cleaned to bare metal today and will shoot to see how it holds up copper only

Like you, I have a croc on my list as well as a bull buff. Plains game as time allows. The Bull I’ll definitely be using the 300s. Plains, the 250s

I used 300s on everything. Didn’t think it was worth working up two different loads. My rifle also shoots factory Barnes very well, so I ran those in Africa and hand loads at home for practice

skydiver386 · May 28, 2026

Start with CR-10 and they seem to go forever. Used to use Sweets, or Butch's, but can't find either one now.

Beware, this stuff is aggressive and you don't want to leave it in the barrel. Soak patches and run them down the barrel and when they stop turning teal green run a dry patch then a few oil soaked patches and done, 15 minutes tops.

revturbo9967 · May 28, 2026

skydiver386 said:
View attachment 767072
Start with CR-10 and they seem to go forever. Used to use Sweets, or Butch's, but can't find either one now.

Beware, this stuff is aggressive and you don't want to leave it in the barrel. Soak patches and run them down the barrel and when they stop turning teal green run a dry patch then a few oil soaked patches and done, 15 minutes tops.

Use wipe out, it takes minutes and won’t harm the barrel

NIGHTHAWK · May 28, 2026

It takes 8 -10 rounds before my .375H&H is fouled in after a proper cleaning. Beyond that, I would say 80 rounds before you notice a POI shift. You’re rifle will let you know…

Daryl S · May 28, 2026

The 270gr. TSX at 2,650fps from my .375/06IMP do not foul the bore any more than the 300gr. Hornady RN'S bonded (gold) or the copper/brass coloured regulars at 2,472fps. I have not noticed any drop-off in accuracy switching back and forth. My bl. Is stainless, from Bevin King, Pouce Coupie, B.C. I believe Bevin is retired now. His bl. puts both those loads into a 1" circle at 100 meters, grouping just slightly apart, but close enough not to make any difference.

coreydb · May 30, 2026

I've not experienced any accuracy degradation. That said, I do periodically clean my barrels specifically to rid the barrels of brass residue. There are many leaning compounds on the market specifically for "de-brassing".

Azklmsr · May 30, 2026

Thanks all. Did a rigorous clean. Will shoot next week to finalize my loads

LeftySixgun · May 31, 2026

Educate me please. I’ve never messed with all copper bullets. Is it a different copper than cup/core copper jacketed bullets? Why would all copper bullets build more copper in the barrel vs cup/core bullets?

BeeMaa · May 31, 2026

I shoot cup & core 300 grain PPU softs for target practice and Barnes 300 grain TSX for hunting. They are being shot from a Blaser R8 barrel, and these are know for good accuracy.

For a deep clean after 100 rounds or so, I run patches wrapped over a bronze (.325" or .358" so it's not too tight) brush down the barrel that are soaked with Clenzoil CLP until they come out clean.

After each range session or day of hunting (even if I didn't shoot), I use a bore snake with Clenzoil CLP for three passes. This removes any debris picked up through the day and gets it ready for the next one.

The PPU shoots MOA and the Barnes TSX shoots sub MOA. If anything, this process has made the barrel more accurate from some sort of polishing that's taken place.

Num64 · Jun 1, 2026

Once you're purely on Barnes TSX/TTSX after a proper deep clean ammonia solvent like Sweet's or CR-10, most guys get 40-80 rounds in a .375 before accuracy starts to drift noticeably.

One .375 H&H owner reported 80 rounds before POI shift. Your high velocity loads will foul a bit faster, so watch groups and clean when they open up. For safari prep, do your workup clean, shoot 3-5 foulers, then go. Barrel quality matters a lot.

How Many Barnes rounds in 375 before you have accuracy degradation from copper fouling

Azklmsr

Doug3006

C.W. Richter

C.W. Richter

jbirdwell

revturbo9967

Azklmsr

rifletuner

ftrovato

Azklmsr

revturbo9967

skydiver386

revturbo9967

NIGHTHAWK

Daryl S

coreydb

Azklmsr

LeftySixgun

BeeMaa

Num64

Members online

Forum statistics

Proudly sponsored by

Latest posts

Latest profile posts

Share this page