How to tell when your throat/barrell is finished?

[jdmason480]

I've been hunting with a Ruger M77 7mm RM for coming up on 30 years. I'd say about 80% hand loads over its life. Who knows how many rounds? It started getting a little squirrely a few years back so I bought a Browning A-Bolt in 7mm STW which has been as accurate as can be.

Last year I cleaned the heck out of it leaving some Hoppe's #9 sitting in it overnight and scrubbing it out with a wire brush the next day. The accuracy seemed to improve. I maybe shot 20 rounds through it at the range last year, lightly cleaned it, stored it, and this year it's back to its old shenanigans of 2" groups at 100 yds.

So, tonight I scrubbed it again. I noticed some (lots of) turquoise/blue on the cleaning patches.

Is it just fouled with copper or do I need a new barrel?

 

[Guest]

The only sure way to tell is to have the bore scoped so that a competent smith can evaluate how badly eroded the throat is. It could be that you've got a boatload of copper built up, and you cleaned it enough to be good for a bit, and the existing copper swiped enough off the 20 bullets to get really fouled again. Or it could be that you have a nastily eroded throat and need to rebarrel it.

Try laying a piece of printer paper (white paper) down on the floor beneath a decent light (overhead or lamp, but bright). Then pull the bolt and look through the bore at the piece of paper, using the paper as a reflector. Specifically look at the throat area of the rifle and see if you notice a dark ring around the throat, or maybe a dark band. If you do, it may be eroded. That's not foolproof (thus the idea of getting a smith to scope it) but it will give you an idea. Try some of the foaming cleaners or perhaps BoreTech Eliminator (I've not used the BoreTech stuff, but I've heard it's the best solvent around).

 

[Guy Miner]

From what you've written, I suspect it's badly fouled. That of course doesn't rule out the barrel being toast too...

There are far better copper solvents than good old Hoppes avail. Try some Wipe Out, particularly with the Accelerator. Or the copper solvent Barnes sells. Or Sweets. Careful with the Sweets though. Too much of a good thing sometimes. But it will clean out the copper...

I'd estimate the accurate barrel life of one of the hot mangums like a 7mm Rem mag to be around 1500 - 2000 rounds depending on many factors. A quick trip to a good rifle-builder with a bore scope can tell you the condition of the bore and the throat - which is where most of the erosion generally takes place.

Worth trying a more aggressive bore cleaner, then replace that barrel if you must. I often look forward to a new barrel. Yes, it's expensive, but suddenly Old Betsey is shooting great again...

Best of luck! Guy

 

[remingtonman_25_06]

I agree with it being badly copper fouled.

Try a real aggressive copper cleaner like sweets or barnes with a nylon brush.

Wipe out is also really good from what I read, just haven't tried any myself.

It would take a good 2000-2500 rounds or so to shoot out a 7 RM barrel. Depending on loads and how hot you let it get and so forth.

 

[jdmason480]

I've used Hoppes for 30 years too and didn't really consider that there might be something more aggressive out there. Excellent advice. I'll try something else and post an update.

Thanks!

 

[1Shot]

If you really want to get the fouling out get an Outers electro bore cleaner. Even when you think you have got all the fouling out this thing will astound you. I have seen on the internet before how you can make your own electro cleaner out of an old flash light, a couple of wires and a steal rod and some rubber corks. You might do a search.

If your throat is toast and the rest of the rifling is OK have your chamber reamed out for the 7mm STW. My buddy did this with one of his Rem 700's in 7 mag and he got at least another 1000 rounds of hunting accuracy out of it.

 

[Antelope_Sniper]

I've saved more then one "shot out bore" with my Outers foul out electronic bore cleaner, Barnes CR10, and the Hoppies tornado brushed. The Tornado burshes are really important. With them, you can actually feel the fowling in the barrel, feel the tight spots, and feel the barrel smooth back out. 8)

If you have only used Hoppies for in the past, once you try the Barnes, or something similar, you will never go back.

Clean the barrel as well as you can with the CR10 and Tornado Brushes. Follow this with a good degreaser to make sure the barrel is absolutely clean, the pull out the Foulout.

With a barrel in your condition, it will probably take several days, and several changes of the solution, but you could very well save your barrel.

 

[old #7]

I've used Hoppes for 30 years too and didn't really consider that there might be something more aggressive out there. Excellent advice. I'll try something else and post an update.

Thanks!

Butches bore shine works good. Keep your cleaning area well ventilated.

 

[cloverleaf]

Sounds like a copper or Carbon problem. +1 to what folks have said about wioe out or the outers "foul out". IF your ready give up on it send it to me :grin: I gotta lot a faith in "Wipe-out". CL

 

[DrMike]

Few shooters actually shoot enough to erode the throat, even on overbore rifles. The 7 RM requires a steady diet of "hot" loads to suffer significant erosion. My rifle is nearing 5K rounds, and still delivering sub-MOA groups. I don't shoot it hot. The loads are not full-throttle. I keep the barrel clean. I'm convinced that this will preserve a rifle's accuracy.

 

[FOTIS]

Clean the crap out of her....Literally.

 

[JD338]

I agree, use Sweets 7.62 copper solvent and get all the fouling out. If she doesn't shoot, time for a new barrel.

JD338

 

[Guest]

Hey, JD, is Sweet's ammonia based? I'm asking because I've finally found a rifle that the foam cleaner I use won't get the last bit of copper out of. Not sure why, but there are a few streaks that remain after a run of foam, wait 15min, and then patch it out. No blue on the patch, no dirt on the patch. But once I get the barrel dried, looking in with a bore light shows copper streaks like a shiny new penny in this thing. At first I thought it was rust, but it's copper. So I need something stronger, and I've always been concerned about ammonia salts in the bore after using something ammonia based. What's your experience, and do you think it will take out the copper I'm seeing leftover in this one rough bore?

Thanks for the loan of your experience.

 

[FOTIS]

Yes it is as is barnes cr 10

 

[DrMike]

dubyam,

Use the Sweet's (or CR10) and after the final two-patch wipe out, run a patch saturated with rubbing alcohol through the bore, followed by two dry patches. Certainly, it is not a good thing to leave ammonia in the bore, this regimen will ensure that no residue is left behind.

 

[cloverleaf]

dubyam- read bout you having trouble w/ the foam cleaners. Long story short- my best reslts have been when I leave the foam in overnight. For really badly carboned bores I have used it 4-5 nights in a row. Just me though. CL

 

[Guest]

Thanks, CL. I'm a real proponent of the foam cleaners, and I've had excellent results from them. Never tried leaving them in longer than about 30min, so maybe that's the ticket. It's just this one barrel that's giving me crap, and I can't figure out why, but it's copper streaks that simply won't budge. After cleaning, they're shiny like a new penny, but won't come out. Thinking I may use some of the tube of Blue Wonder that's on my shelf. It's got ammonia in it, so it should dissolve the copper, but I'm still concerned about ammonia salts in the bore and future rust issues. Anybody have long term experience with using an ammonia-based cleaner they can share? Are they worth the trouble? Will they get the deeply embedded copper out?