Barrel shot out?

[C.Smith]

How do you know if your barrel is shot out? I bought a used Remington 700 in 7mmrm, and I am having accuracy issues. I reload and have never had this problem with other rifles. I have cleaned the snot out of it and I am quite frustrated.

Any help would be greatly appreciated.

Corey

 

[YoteSmoker]

Look closely at the throat area. If it is blackened really bad and won't clean up, it is likely burnt out. If the rifling looks fine, there is hope. You can throat reamed and the barrel set back and headspaced by your gunsmith. If crowning is an accuracy issue, he can take care of that for you at the same time.

 

[C.Smith]

If I had to re-barrel, what would I expect to pay, ballpark figure wise?

Corey

 

[YoteSmoker]

Do you want a replacement chrome molly or stainless steel, or a match grade such as krieger, shillen, douglas...etc? Anywhere from about $100 an much more depending what you want, barrel only.

 

[Guy Miner]

If you've really cleaned it good, and everything else is squared away & snug, then the barrel just might be shot out. Not hard to imagine a 7mm Rem mag being toast after a few thousand rounds. Sometimes I've seen barrels brought back to life by a thorough scrubbing of JB Bore Paste, right in the throat area. Also well worth checking to see if there are any dings in the crown area.

Sometimes a used factory barrel in good shape can be picked up. I think I have a line on a 7mm mag factory barrel right now, cheap. I don't know how many rounds are through it though.

I understand that Remington is pretty reasonable price-wise to re-barrel.

Most of the custom tubes, Hart, Krieger etc, are spendy, around $250 - $300 for the barrel, and then the 'smith will want $100 - $200 to true the action, chamber it and screw on the new barrel. Worth it if you really like the rifle and want to make it into a tack driver. Otherwise, not.

A bright side is that with that belted magnum, it's easy to make it into almost any of the belted magnums, just by re-barreling. Ever wanted a .257 Weatherby? A .264 Winchester mag? How about a .338 Win mag? It's just a barrel swap away at this point.

Best of luck, I've burned out a few barrels and understand the dilemma.

Regards, Guy

 

[JD338]

Guy is dead on as usual.

If JB Bore Paste doesn't work, I would agree that the barrel is gone.

If you go with a custom barrel, make sure you have the action blueprinted which means the smith will square up the action perfectly to the bore. Then by adding a custom barrel, you will have a tack driver. Advantages of a custom barrel are exact contour and length you want, great accuracy and it will be a snap to clean up.

I have a Hart barrel, stainless flutted, #5contour, 24" chambered for 280AI. With 160 gr AB's, she shoots in the .2"s.

JD338

 

[Savage99]

From my experience I have seen barrels with 5" ripped out that would still shoot well under MOA. What you need is a good crown.

Crowns get damaged. Learn to cut your own crown. There is a thread on AR on how to do it.

Wally Siebert makes a mini bore scope that sees throats really well. Here is the link to who sold them http://www.shooters-supply.com/ Thats a really nice item for under $30 and good for gunshop and show prowling also.

Siebert Mini BoreScope .. $29.95

Of course the major reason for bad groups is something being loose.

Here is a pic of the borescope.

 

[FOTIS]

Give us a little target analysis so we can diagnose the problem. What loads have you tried? Factory or reloads? What do the groups look like? etc etc.

 

[Jeff Olsen]

If I had to re-barrel, what would I expect to pay, ballpark figure wise?

Corey

I had Pac-Nor rebarrel 2 rifles for me. Using one of their fine Supermatch barrels, lapping the lugs, and doing some action truing (not sure how much) they charge around $400 if memory serves. If you have them match the profile of your barrel you *shouldn't* have to do an stock work.

I see 2 advantages to having them do it, as opposed to having your gunsmith do it using a premium barrel. First is time; especially this time of year, PacNor would have your rifle back in your hands in about a month. Your gunsmith will tell you that it takes up to 6 months- several months for him to get the barrel, several to put it on. Second is accountability. If they make the barrel and put it on your action, if there's a problem then there's not going to be any finger-pointing about it. In fact, they cut the throat too short for heavy bullets, contrary to my request, on my .358 Win. and then took care of it very quickly and politely when I pointed it out. And, during the time I was fighting with it as a short-throated barrel and having trouble getting a load that shot well, they offered to replace the barrel for free if I couldn't get it shooting! Once the throat was longer, I had no problem getting the speed and accuracy I wanted.

I'm sure, pretty sure, that the other main barrel makers will also install them for you. My only experience was with PacNor and it was a great experience- i'd use them again in a heartbeat. Good folks!

-jeff

 

[Powerstroke]

Everyone is pretty much dead on !
I have a Rem700 Varmit @ the smiths right now. Aprox $500.00 to re-barrel, but I've changed it from a 22-250 to a .260. ( Easily done ) but also gone with a 22in Lilja Stainless Fluted tube.

The 7mag is an awesome round ! If you do have to re-barrel like mentioned above you can always change.......I'd look long and hard @ a 7mm-STW

 

[C.Smith]

Holy cow, lots of great responses, thank you. As for my targets I was so disgusted with them that I left them. I can tell from memory first shot out of a clean barrel shot inch to two inches low. The other three would be two to three inches high. And the other two would be over to the right an inch or so.

I have adjusted the trigger and I'm pretty sure it's not me, I'm a rifle instructor where I work.

As for loads I have mostly shot handloads through it. I have tried the bullet seating depth in as close as .010 to the lands and as far out as .030 from the lands with no luck. In fact it got worse as I stepped out, not surprising there.

If I do re-barrel I was actually thinking about seeing if I could get it chambered in the 280 AI. I'm not sure that is possible with the action I have though.

I plan on shooting it again, more than likely tommorow and I will save some targets and try and post them to see if that helps figure out the deal.

Corey

 

[C.Smith]

Savage99, do you have a link to "There is a thread on AR on how to do it."

I'm not sure what AR is? The crown is not in the best shape in the world.

Corey

 

[wingnut]

AR =

http://www.accuraterifle.com/

 

[Savage99]

"The method that I use now to recut a crown is to put this Dremel grinding bit
in a battery powered variable speed 3/8" drill.

I place the tapered wheel in the muzzle when its not rotating. Then I start the drill and turn it right off again. I leave the wheel lightly pressing into the crown the whole time.

That wheel is very course and remember that you can always cut it again if the first rip does not work.

I tried polishing the crowns with 400 paper set in at tapered wood dowel. It looks a little smoother but did not change the accuracy."

 

[Savage99]

Link to the above topic. Sorry but I have not mastered URL's here.

http://forums.accuratereloading.com/eve ... #949101006

 

[WVHILLBILLYJLM]

I know that this is an old thread but I believe that I am experiencing the same problem with my 7mm RM! My groups have opened up and I have lost velocity on my favorite loads. Is this an indicator of an eroding throat?

Thanks!!
WVHILLBILLYJLM

 

[JD338]

How many rounds have you sent down the pipe and what do you use to clean the bore?

JD338

 

[WVHILLBILLYJLM]

I have around 800 shots threw it. I use Hoppes Benchrest bore cleaner.

WVHILLBILLYJLM

 

[Guest]

I'm going to sound like a broken record here, but go buy a can of Break-Free Foaming Bore Cleaner and follow the directions on the can. I bet the gun has plenty of copper still in it, and will shoot better after a real thorough cleaning. One thing to know - be sure to oil the bore really well with something that will penetrate (like Birchwood-Casey's Barricade, or some other low viscosity gun oil) after you clean it, because the foam really takes it down to the bare metal, and I've seen small streaks of corrosion develop afterward if it isn't oiled well enough down the bore. I usually over-oil it, then leave it muzzle angled down in my cleaning cradle for a few hours, then patch it out with a single patch just to remove the gross excess.

 

[rick smith]

Many things that could cause the rifle to shoot poorly other than a bad barrel. Stock pressure, bad crown, something loose, bad scope, just to name a few common things. I wouldn't replace the barrel until I checked all of them. You have a magnum bolt face and the 280AI would not work without a bolt change or shimming the bolt face.Rick.