300WM Barrel Life Question / Scope Report

[GBMaryland]

I’ve been playing with the Warner Tool 160gr bullets in my Sako TRG-42.

I noticed I had a bit of copper in the barrel, as my patches were not coming out cleanly (without blue/green),

The barrel has ~800 rounds on it, and I decided to scope it to see what the deal is.

Interestingly, the first several inches near to throat look like cracked skin (but in steel). There is some light copper build up I need to clean out, but nothing really interest.

Otherwise, the barrel doesn’t look bad, and it shoots in the same hole at 100.

What causes that very fine crackeling in the steel? (I shoot suppressed exclusively.)

 

[Awag1000]

it could be a combination of the pressure,the heat, and the friction that could be doing that. I've noticed this too with my Savage 300WM.
I dont shoot suppressed but my handloads are in the upper end of the pressure spectrum.

 

[Lunchbox27]

Pressure and heat cause what you are seeing. Expansion and contraction of the metal will wear it down. It will happen to them all eventually, some faster than others. Also depends on how you run it and the caliber.

 

[BCX]

Add the harmonics or barrel whip while the barrel is hot. Fire cracking is normal. I have seen it... as little as 100 rounds in my 338 LM AI.

 

[GBMaryland]

Wow! Thanks guys. As I said, it's shooting totally fine. I can aim at the last home and put a bullet right through it!

It does get DAMN hot with the supressor on it. Though I've been using a 338 YHM to keep things a little less stressed. (It's it pretty quite on the 300WM.)

 

[Huskydriver]

That's called fire cracking

 

[rustyinbend]

Just curious ... is the recommendation to "not" shoot 338-Lapua suppressed ... to avoid this cracking? Or does it not matter?

 

[Huskydriver]

Just curious ... is the recommendation to "not" shoot 338-Lapua suppressed ... to avoid this cracking? Or does it not matter?

All calibers can firecrack a barrel. How fast depends on how hot that throat gets. Some of my match barrels are fire cracked in less than 200 match tempo fire rate.

It doesn't necessarily mean the barrel is toast shoot it until it doesn't.

I have seen 300wm throats with 1" worth of throat rifling gone and still shooting under 1 moa.

 

[Frank Green]

A lot of things effect the cracking / wear that is going on. Some things have been mentioned but I will recap here.

How the barrel is made will effect the wear and barrel life. Not just the type of steel.
Type of powder being used.
Type of bullets being used.
What the barrel is chambered in.
Rate of fire.
Cleaning/maintenance.
Suppressor being used will effect it some but more so in a gas gun.
Environment being shot in.

Barrel life and what and when you consider it done you have to determine at times on your own. What you have to ask yourself is what is your accuracy requirement, velocity spec. Also keep in mind a barrel that is done or close to being done might shoot good at short range like a 100, 200 yards etc...but when you get out to 500 yards and further the groups/accuracy could and will be night and day different.

All that being said.... a 300wm for an average numbers barrel life wise is usually around 800ish to 1500 rounds for top accuracy.

Later, Frank
Bartlein Barrels

 

[GBMaryland]

Well frank, if you want to make me a nice drop in TRG-42 barrel... I did pick up a few extras from KRG, just in case. Heh.

Thanks for responding sir!

 

[GBMaryland]

Just curious ... is the recommendation to "not" shoot 338-Lapua suppressed ... to avoid this cracking? Or does it not matter?

Not at all.... I just assume that suppressing a rifle will allow heat to build up and potentially wear things out faster. That's an assumption on my part...

 

[Frank Green]

Well frank, if you want to make me a nice drop in TRG-42 barrel... I did pick up a few extras from KRG, just in case. Heh.

Thanks for responding sir!

We've done TRG42 contours. No sweat there.

Sorry no drop in's at this time.

Welcome on the responding!

 

[GBMaryland]

So, what do folks think, bad news?

(No seriously)

Up the bore... toward the last 1/3...

 

[GBMaryland]

Followup: Are there types of steel that are less resistant to this?

Its shoots fine... it's becoming a pita to clean the copper out...

I literally had to plug one end to and soak it in bore shine to get it this clean...

 

[Steel head]

So, what do folks think, bad news?

(No seriously)

View attachment 7368573
View attachment 7368574
View attachment 7368575

Up the bore... toward the last 1/3...

View attachment 7368576

That’s a lot prettier than my 7 saum barrel.

 

[Huskydriver]

Followup: Are there types of steel that are less resistant to this?

Its shoots fine... it's becoming a pita to clean the copper out...

I literally had to plug one end to and soak it in bore shine to get it this clean...

Looks like a 300 wm that's not a safe queen. The fire cracking is inevitable but as long as it's not throwing flyers.... Shoot it....


I fire cracked a 300wm barrel in less than 50 rounds lol

 

[GBMaryland]

No shit... really!??!

 

[Jscb1b]

So looking at GBMaryland's barrel, would J B bore paste help it?

 

[Steel head]

So looking at GBMaryland's barrel, would J B bore paste help it?

Help what?
For a magnum that bore is in great shape

 

[Jscb1b]

Help what?
For a magnum that bore is in great shape

He was talking about cleaning it. Would the bore paste help clean it?

 

[Huskydriver]

No shit... really!??!

True story. That barrel is still hammering

 

[GBMaryland]

You see this is what happens when you buy a borescope and start checking all your crap out!!!

I also have a 375 H&H magnum that I put about 400 rounds through after purposely building it to see how far I could shoot using that massive round. (The answer is roughly 600 yards depending on the bullet... and no, when when I was screwing around with this crap all we had were the BTBT bullets from nolers.)

So the other day I decide to see what the bore looks like...

It looks freaking fantastic compared to my 300.

Until I get to the end of the barrel… There are literally craters at the end of the barrel... and never had any rust and I’m at a loss as to why.

Anyway so I’ll shoot this 300 a bit more and see how it does...

 

[Steel head]

He was talking about cleaning it. Would the bore paste help clean it?

When they start getting bad you just clean them more often or screw on a new one.

My current 7 saum is far worse and I just clean it every 150 rounds now.

That barrel lost 75+ fps in the last 50 shots and wasn’t kicking ass yesterday on steel so I’ll probably shoot the rest of the loads I have for it and then yank it.

 

[GBMaryland]

Thanks a lot guys… I’m just gonna keep chronoing things occasionally and making sure that it looks like my pressure staying up.

So far I’m not actually having any problems with you no flyers or any weird stuff like that the barrel on the TRG put bullets in the same hole...

 

[Steel head]

Thanks a lot guys… I’m just gonna keep growing things occasionally and making sure that it looks like my pressure staying up.

So far I’m not actually having any problems with you no flyers or any weird stuff like that the barrel on the TRG put bullets in the same hole...

My speed was super stable then I noticed-10 fps And then -20, added powder and ran with it but within another 200 I had to add more powder again.
Played that game till Monday when I was shooting low again and it had lost 75ish fps almost instantly and seemed a bit off on how it shot at a mile.
That was my first cut rifled barrel and it was very good.
I’m sad to see it go

My button barrels seem to start getting fliers before they drop much speed at all.

 

[GBMaryland]

Rgr

 

[Jscb1b]

My speed was super stable then I noticed-10 fps And then -20, added powder and ran with it but within another 200 I had to add more powder again.
Played that game till Monday when I was shooting low again and it had lost 75ish fps almost instantly and seemed a bit off on how it shot at a mile.
That was my first cut rifled barrel and it was very good.
I’m sad to see it go

My button barrels seem to start getting fliers before they drop much speed at all.

Do you have a round count on that barrel?

 

[Steel head]

Do you have a round count on that barrel?

I think it hit 1900.
I can look in my log tonight.

 

[Jscb1b]

I think it hit 1900.
I can look in my log tonight.

That's good enough. Thank you.

 

[DIBBS]

Don't borescope gives you one less thing to worry about. When the accuracy doesn't meet your needs, clean or get a new barrel.

 

[Steel head]

That's good enough. Thank you.

That’s a 7 saum barrel and honestly I abused it.
Multiple pressure tests and lots of hot strings as it was a learn the cartridge barrel.


A 300WM should last a bit longer.

Don't borescope gives you one less thing to worry about. When the accuracy doesn't meet your needs, clean or get a new barrel.

I disagree.
I like having a bore scope.
It’s an interesting observation tool and I got to see how trashed a barrel could be and still hammer.
I am by no means a barrel expert so I just use the bore scope and observation tool, not a diagnosis or prediction tool.