A little help with bore-scope interpretation ...

[rustyinbend]

I was in another thread talking about how I thought I'd shot through the barrel on my MPA 300-WM rifle. It's got about 1,200-1,400 rounds through it (combination of factory and handload), and for the last 200 rounds or so, groups have gone from sub-MOA to 4+ MOA ... getting consistently worse. I just thoroughly cleaned the barrel and bore-scoped it, and here are the results. Any seasoned pro's that know what they're looking at are encouraged to tell me what you see. There are five photos ... working down the barrel from chamber to muzzle.

Thanks for the help figuring out if it's "me", or the "barrel", or "both".

Start of the lands ...

Just beyond the start of the lands ...

One foot down the barrel ...

Two feet down the barrel ...

Just inside the muzzle ...

 

[Mike Casselton]

Pics 4&5 look good. The rest of your barrel looks like a dried up lake bed

 

[swampbuck]

Time to rebarrel

 

[rustyinbend]

Pics 4&5 look good. The rest of your barrel looks like a dried up lake bed

Is that the normal profile of a "toasted" barrel ... where it gets that "toasted" look closer to the chamber but looks fine down the barrel?

 

[Tokay444]

Most of that is just hard carbon.
get some Iosso in there and she’ll come back to life.

 

[swampbuck]

Is that the normal profile of a "toasted" barrel ... where it gets that "toasted" look closer to the chamber but looks fine down the barrel?

Yes. That is why some guys will set the barrel back and rechamber but it is usually not worth the expense. Time to rebarrel

 

[rustyinbend]

Most of that is just hard carbon.
get some Iosso in there and she’ll come back to life.

What is "losso"?

 

[theLBC]

Bore Cleaner

NEW BIO-Based Formula. Highly effective concentrated paste formula that lasts longer and takes less time to clean with than ordinary liquid or aerosol type cleaners.

iosso.com

 

[swampbuck]

Lasso is a lapping paste. Or a paste with an abrasive grit. Think toothpaste. Anyway it can help clean out and polish (lap) the bore. And that might help for a little while but at 1200-1400 rounds your barrel has reached its life expectancy. I stay away from lasso as it is really best used by someone who knows what they are doing

 

[rustyinbend]

Lasso is a lapping paste. Or a paste with an abrasive grit. Think toothpaste. Anyway it can help clean out and polish (lap) the bore. And that might help for a little while but at 1200-1400 rounds your barrel has reached its life expectancy. I stay away from lasso as it is really best used by someone who knows what they are doing

Good advice ... as that person that "knows what they're doing", is most assuredly NOT me.

I just ordered a new barrel.

 

[Supersubes]

Doesnt look bad to me at all. The fact that the leade is sharp and defined is unusual for a toasted barrel. Certainly nothing there to explain 4 moa.

 

[swampbuck]

I think that it best. You can play with a tube of Lasso as it won't hurt your toasted barrel at this point. You may learn something. Lasso does have it's place and is used successfully mostly by benchrest shooters who require a super clean barrel and know more about shooting in their pinky finger than you and I will ever know. Guys like us usually do more harm then good on a premium custom barrel.

Supersubes is right. I have seen much worse. It's your call.

 

[celltech]

Plug the barrel and and let it sit full of CLR all night...lot of carbon in there.

 

[Stoweit]

Is that round count normal 300wm barrel life?

 

[Wannashootit]

Doesnt look bad to me at all. The fact that the leade is sharp and defined is unusual for a toasted barrel. Certainly nothing there to explain 4 moa.

That's what I was thinking as well. Sure doesn't look like tomato stake territory.
Certainly wouldn't explain 4 minutes, but the lands are definitely eroded a bit at the throat (zero freebore). If OAL hasn't been checked/adjusted to whatever jump was most accurate might help?

You did check the obvious shit, like action screws?

 

[spife7980]

Soak it in boretech c4 and hit it with a brush, itll clean up.

Order a barrel though, a win mag isnt a barrel saver.

 

[AllenOne1]

Your barrel is still pretty dirty but it isn't a 4 MOA barrel. I would be looking for other issues, loose action screws, loose scope mounts, bad optic, bad ammo. It would be a shame to install a new barrel and have the same issue, although to install a new barrel you will have everything apart. Take it apart now and find the issue, change ammo brands, swap a new scope onto it, check the cheapest stuff first.

 

[theLBC]

since you ordered a replacement, so i see no reason not to troubleshoot and clean the current one, if only to milk out life as a spare for the coming zombie apocalypse.

 

[rustyinbend]

I think after reading these great suggestions, I'll do a few things:

1. Order a new barrel (Done - McGowen Precision Custom Barrel ordered - 10+ weeks out)
2. Pull the barrel, plug, fill with CLR overnight - scrub and bore-scope to compare
3. Clean with Bore Tech C4 with extra attention on the throat - bore scope to compare
4. Shoot it some more after that and see what happens

Since the new barrel is on the way ... screwing with the old one a little more seems fine.

This is really a "1st World Problem", since I have a 300-WM barrel for my Barrett MRAD to use in the meantime.

 

[Army First]

I think after reading these great suggestions, I'll do a few things:

1. Order a new barrel (Done - McGowen Precision Custom Barrel ordered - 10+ weeks out)
2. Pull the barrel, plug, fill with CLR overnight - scrub and bore-scope to compare
3. Clean with Bore Tech C4 with extra attention on the throat - bore scope to compare
4. Shoot it some more after that and see what happens

Since the new barrel is on the way ... screwing with the old one a little more seems fine.

This is really a "1st World Problem", since I have a 300-WM barrel for my Barrett MRAD to use in the meantime.

I've bookmarked the page to see the results if you decide to post them

 

[37L1]

What does your crown look like?

 

[Criver600]

Severe carbon & copper fouling, throat is not that bad.
1300 rounds, try this wrap a brush with OOOO steel wool, load it up with JB bore paste, Iosso, Flitz, etc and get all that fouling out, shiny barrel steel. Tighten your groups right up. Use a bore guide. The bulk of my 300 WM experience is shooting NRA Long Range. Sighters plus 20 shots for record, very hard on your barrel.

 

[pmclaine]

Judging by my .308 barrels it doesn't take much to get that "fire cracked" look at the throat.

It's when you start noticing squares of material in those cracks missing things would suck.

 

[SupressYourself]

I have a 22-250 barrel that looks much worse than that and still shoots .5 - .7. I agree with others, clean the shit out of it and make sure everything on the rifle is torqued properly.

 

[rustyinbend]

What does your crown look like?

Crown looks fine ... protected by an ASR brake I use to mount my suppressor.

 

[rustyinbend]

I have a 22-250 barrel that looks much worse than that and still shoots .5 - .7. I agree with others, clean the shit out of it and make sure everything on the rifle is torqued properly.

Yup ... that's the plan. I have plenty of time on my hands to work on this since (depressingly) my local range here in Central Oregon is now closed indefinitely due to fire risk.

 

[Mike Casselton]

You have all the BLM land and the mountains around you and you use a range?

Plenty of Rockchucks around you. Set up a small box with a target on it to verify... ahem...
And then go kill some chucks. That's you're excuse for shooting...

 

[rustyinbend]

You have all the BLM land and the mountains around you and you use a range?

Plenty of Rockchucks around you. Set up a small box with a target on it to verify... ahem...
And then go kill some chucks. That's you're excuse for shooting...

That works fine for the near-in stuff (like rock-chucks), but what I love is 1,000-yard-plus shooting, and that requires COSSA to be available.

 

[918v]

300WM barrels last 2000-3000 shots if you treat them right. It looks carbon foul d to me. Do you use a nylon brush to clean it? If so, get a bronze brush and clean it right.

 

[my human host]

Judging by my .308 barrels it doesn't take much to get that "fire cracked" look at the throat.

It's when you start noticing squares of material in those cracks missing things would suck.

This.

Use a mild abrasive on it. If you have a borescope, you have everything you need to learn to use Iosso, etc.

 

[Slides]

Clean the carbon out, but I would be stripping the action, rail/rings, cleaning and re-torqueing all the fasteners. That sounds like a scope flopping around.

 

[acudaowner]

Just to ask you how does your gun shoot ? In your opinion it still shoots great it's hit or miss could not shoot an apple of a entire tree of apples ? I Get the two rounds are different but I heard when I got my 6.5 that I could expect 1400 to 2000k rounds before needing a new barrel now at 6000k rounds and its still shooting great as better shooters than my self keep reminding me it's my mistakes not the gun not preforming . I ordered a new barrel anyway so Id have it on hand should the time I need it arrives but till it no longer shoots good , but I have no plans to have it switched out yet . good luck to you and your barrel may it last you long enough to make you happy .

 

[SERE8541]

Does this sound like a job for David Tubb's Final Finish?

 

[10X Rifles]

I've toasted One or Three .300 WM barrels in LR High Power. anywhere from 1000-1200 is usually the life of a barrel for match accuracy.
after 500 rds down range, I start looking for a new barrel. My barrels have been Kriegers.

 

[Supersubes]

I've toasted One or Three .300 WM barrels in LR High Power. anywhere from 1000-1200 is usually the life of a barrel for match accuracy.
after 500 rds down range, I start looking for a new barrel. My barrels have been Kriegers.

The real question is do yours go from match accuracy to 4 moa at 1200 rds?

 

[rustyinbend]

Update ...

I disassembled the barrel from the action, plugged the action-end, and filled the barrel with Bore-Tech Carbon Remover. After soaking for 24 hours, I drained, scrubbed, and did a massive cleaning on it. The results were interesting ...

1. The chamber end at the lands was even better defined with crackling and fire damage. After cleaning, because everything "movable" was scrubbed away, the start of the lands looks even worse than before I soaked and scrubbed it.

2. A few inches from the start of the lands I got the same result, where the crackling looks worse because all the carbon and copper that filled cracks is gone.

3. Further down the barrel and into the muzzle, everything looks gorgeous ... clean and shiny.

I'm going to take it out and shoot for groups at 100-yards, and see if anything improves. With the damage on the chamber end, I'm not so sure how that will work out. My guess is no change, and I'll install the McGowen barrel I have on order, and start shooting accurately again in a few months.

Here's a few pics ... (post soak/scrub/clean):

Start of the lands:

2-inches down the barrel:

A foot down the barrel:

Near the muzzle:

Hope you guys found my "journey" at least semi-interesting.

 

[pmclaine]

I predict it will suck until you refill all the cracking with copper than the fresh front end will be sending them in the X ring.

 

[rustyinbend]

I predict it will suck until you refill all the cracking with copper than the fresh front end will be sending them in the X ring.

Wouldn't that be nice ... I hope you're right. Another 1,000 rounds out of this barrel would be terrific, with the new one sitting on the shelf waiting its turn. Time will tell ... might try to head to the range tomorrow. That said, it's damn hot and smoky here in Central Oregon right now. Not great range weather.

 

[spife7980]

That said, it's damn hot and smoky here in Central Oregon right now. Not great range weather.

Its a damn sight better than the alternative!

 

[rustyinbend]

Its a damn sight better than the alternative!
View attachment 7683093

AMEN BRUTHA !!!

BTW ... for those of you still working ... I want you to know that "retirement" is even BETTER than it sounds !!!

 

[pmclaine]

Wouldn't that be nice ... I hope you're right. Another 1,000 rounds out of this barrel would be terrific, with the new one sitting on the shelf waiting its turn. Time will tell ... might try to head to the range tomorrow. That said, it's damn hot and smoky here in Central Oregon right now. Not great range weather.

Give it enough rounds to "restore" the copper lining that is beneficial and see what it will do.

The down side is that if it gets better than quickly goes to shit well it may be done.

 

[AllenOne1]

Update ...

I disassembled the barrel from the action, plugged the action-end, and filled the barrel with Bore-Tech Carbon Remover. After soaking for 24 hours, I drained, scrubbed, and did a massive cleaning on it. The results were interesting ...

1. The chamber end at the lands was even better defined with crackling and fire damage. After cleaning, because everything "movable" was scrubbed away, the start of the lands looks even worse than before I soaked and scrubbed it.

2. A few inches from the start of the lands I got the same result, where the crackling looks worse because all the carbon and copper that filled cracks is gone.

3. Further down the barrel and into the muzzle, everything looks gorgeous ... clean and shiny.

I'm going to take it out and shoot for groups at 100-yards, and see if anything improves. With the damage on the chamber end, I'm not so sure how that will work out. My guess is no change, and I'll install the McGowen barrel I have on order, and start shooting accurately again in a few months.

Here's a few pics ... (post soak/scrub/clean):

Start of the lands:
View attachment 7683071

2-inches down the barrel:
View attachment 7683072

A foot down the barrel:
View attachment 7683074

Near the muzzle:
View attachment 7683073

Hope you guys found my "journey" at least semi-interesting.

Hate to say it but it still isn't clean. Run some Bore Tech Eliminator down it and let it soak for 15 minutes and you are going to see a lot of blue copper coming out, then you need to attack the next layer of carbon.

 

[SERE8541]

I still think you should give Final Finish a try. It is made for these circumstances, along with the Throat Management System. They aren't expensive and at this point what can it hurt? You might squeeze a little more life out of them.

 

[Supersubes]

Update ...

I disassembled the barrel from the action, plugged the action-end, and filled the barrel with Bore-Tech Carbon Remover. After soaking for 24 hours, I drained, scrubbed, and did a massive cleaning on it. The results were interesting ...

1. The chamber end at the lands was even better defined with crackling and fire damage. After cleaning, because everything "movable" was scrubbed away, the start of the lands looks even worse than before I soaked and scrubbed it.

2. A few inches from the start of the lands I got the same result, where the crackling looks worse because all the carbon and copper that filled cracks is gone.

3. Further down the barrel and into the muzzle, everything looks gorgeous ... clean and shiny.

I'm going to take it out and shoot for groups at 100-yards, and see if anything improves. With the damage on the chamber end, I'm not so sure how that will work out. My guess is no change, and I'll install the McGowen barrel I have on order, and start shooting accurately again in a few months.

Here's a few pics ... (post soak/scrub/clean):

Start of the lands:
View attachment 7683071

2-inches down the barrel:
View attachment 7683072

A foot down the barrel:
View attachment 7683074

Near the muzzle:
View attachment 7683073

Hope you guys found my "journey" at least semi-interesting.

Still doesn't look bad to me.

 

[Huskydriver]

If you think this barrel is toast just from these pics..... You don't want to see my 6.5cm still hammering with no rifling for the first 2 inches and fire checking 2/3 of the way down the barrel like a topography map of the grand canyon....

Firecracking does not tell the full story.

I agree though that it ain't "clean".

Are you able to pull the barrel can't remember if you said this was off an mrad or something?

 

[Supersubes]

Update ...

I disassembled the barrel from the action, plugged the action-end, and filled the barrel with Bore-Tech Carbon Remover. After soaking for 24 hours, I drained, scrubbed, and did a massive cleaning on it. The results were interesting ...

1. The chamber end at the lands was even better defined with crackling and fire damage. After cleaning, because everything "movable" was scrubbed away, the start of the lands looks even worse than before I soaked and scrubbed it.

2. A few inches from the start of the lands I got the same result, where the crackling looks worse because all the carbon and copper that filled cracks is gone.

3. Further down the barrel and into the muzzle, everything looks gorgeous ... clean and shiny.

I'm going to take it out and shoot for groups at 100-yards, and see if anything improves. With the damage on the chamber end, I'm not so sure how that will work out. My guess is no change, and I'll install the McGowen barrel I have on order, and start shooting accurately again in a few months.

Here's a few pics ... (post soak/scrub/clean):

Start of the lands:
View attachment 7683071

2-inches down the barrel:
View attachment 7683072

A foot down the barrel:
View attachment 7683074

Near the muzzle:
View attachment 7683073

Hope you guys found my "journey" at least semi-interesting.

Still doesn't look bad to me.

 

[Frank Green]

Most of that is just hard carbon.
get some Iosso in there and she’ll come back to life.

I don't recommend using Iosso. For starters you use a brush with the Iosso/paste type cleaner and I'll guarantee bore damage especially to the lands. Will end up looking like this...

I've seen barrels start to get damaged/shooting poorly with in 100 rounds.

Also ever wonder why when you use Iosso and similar abrasive cleaners the patches keep coming out really black in color? Your basically polishing the bore and also can be removing material. The bore too smooth will also lead to copper fouling and a loss in accuracy in as little as less than 20 rounds.

Yes every shooter cleans they're barrel differently and some shooters are more aggressive then others....there are a lot of variables involved.

If you have to use anything I would use JB Bore Compound or Rem. 40x cleaner (years ago the 40x cleaner use to be called Gold Medallion).

Again patches only and never with a brush. Make sure you get it all out with patches and solvent afterwards also. Again with the abrasive cleaners I feel at times shooters don't get them completely out of the bore of the barrel and then fire rounds down the bore....when this happens you might have well had rocks inside the barrel.

Later, Frank
Bartlein Barrels

 

[Frank Green]

What your seeing in the pictures starting at the throat area is cracking mostly on the edges of the lands and when you start losing little chunks of metal off the edges accuracy goes sour.

The black in the barrel is carbon fouling. The reddish tint/color is copper fouling.

1000-1200 rounds on it...depending on your accuracy requirement... I'll say barrel is toast especially if it went from sub moa to 4moa. The average pressure test barrels in 300WM don't make it past 800-1000 rounds. Why? As the throat wears the pressure and velocity will start to vary which in turn will lead to bigger extreme spreads in your ammo. At short range the gun might shoot good or appear to shoot good but when you start getting out to 500 yards and further you will notice the groups will open up more than what the accuracy is showing at 100 yards. Follow me?

How the barrel is made also can dictate barrel life.

How the barrel is maintained/cleaned and how often will dictate barrel life as well as rate of fire and types of bullets shot thru it and not to mention powder type.

Just looking at the pictures....as has been mentioned it might not be done yet. It does need a really good cleaning. Get it good and cleaned and see how it shoots. If it starts out shooting good but by the time you get say 15-20 rounds on it from being clean and the groups are opening up....that will tell you it's done.

Also check the muzzle crown for any damage....even the slightest amount of damage from cleaning can cause accuracy issues. If in question get it recrowned and you might see the accuracy come right back. Also make sure you get the crown edged chamfered after refacing the crown of the barrel. The chamfer on the bore edge helps with the gas cutting effect which will prematurely lead to crown wear. I never run a sharp crown edge. Also the chamfer will help with premature cleaning damage as well.

Later, Frank
Bartlein Barrels

 

[pmclaine]

I think I suck at barrel cleaning.

After using stupid stuff in the USMC to try and get my rifle turned in my current mentality is patches only and letting the solvent (usually Hoppes) get time in the barrel to do its job.

I have rarely used a brush but lots of cotton.

I dont know if it makes my barrels happy but I have peace of mind.

 

[Tokay444]

I don't recommend using Iosso. For starters you use a brush with the Iosso/paste type cleaner and I'll guarantee bore damage especially to the lands. Will end up looking like this...

View attachment 7683331
I've seen barrels start to get damaged/shooting poorly with in 100 rounds.

Also ever wonder why when you use Iosso and similar abrasive cleaners the patches keep coming out really black in color? Your basically polishing the bore and also can be removing material. The bore too smooth will also lead to copper fouling and a loss in accuracy in as little as less than 20 rounds.

Yes every shooter cleans they're barrel differently and some shooters are more aggressive then others....there are a lot of variables involved.

If you have to use anything I would use JB Bore Compound or Rem. 40x cleaner (years ago the 40x cleaner use to be called Gold Medallion).
View attachment 7683332
View attachment 7683333

Again patches only and never with a brush. Make sure you get it all out with patches and solvent afterwards also. Again with the abrasive cleaners I feel at times shooters don't get them completely out of the bore of the barrel and then fire rounds down the bore....when this happens you might have well had rocks inside the barrel.

Later, Frank
Bartlein Barrels

I stay away away from the brushes, and just wrap a larger patch tight on a jag, but I see what you mean.