Rough Throat on Barrel

[ldg397]

I reload for my .260 remington Rem 700 lss mountain rifle and I got frustrated with only being able to get 1" to 1 1/4" groups with my reloads. I took it to a very respected gunsmith he said the 3 point bedding is perfect and and is recommended for the lighter profile barrels in lieu of free floating. He did say the first 1 to 2" of my barrel is pretty rough compared to other remington factory barrels they have seen. He actually didn't recommend any work be done as he thought it might be too much for too little improvement.

I was wondering if anyone has any experience with fire lapping like the Tubb's finish system and if it would help in this situation? It is still a wonderful $7/tag deer rifle but may have to find something else for long range more expensive hunts.

Thoughts?

 

[Guest]

Before I tried anything like the fire lapping, I'd consider JB's bore paste (or Iosso's version, or Break-Free's version). Just get a tube or tub and follow the directions, paying careful attention to the throat area of your gun. Try doing it a couple of times, and then head back to the range. Maybe you save yourself a lot of hassle in loading the lapping bullets.

 

[Guy Miner]

I have used the Tubb Final Finish bullets on a rough 7mm Rem mag Sendero. It seemed to work rather well - doggone thing shot 1/2" groups at 100 yards after the treatment, but admittedly still copper fouled pretty badly.

Have also used JB Bore Paste on a rough chambered .308, and it worked great. I'd try that route first.

Good Luck! Guy

 

[JD338]

+1 on the JB Bore paste.
2nd step might be fire lapping.

If you want to make it a real shooter, I'd suggest blueprinting the action and getting a premium barrel shuch as a Hart.

Let us know how she shoots after the JB's.

JD338

 

[6ppcar]

Its hard to breathe new life into a barrel that's fire cracked or has a very rough throat . Keeping the barrel from copper fouling is the problem.
I'm with JD on this one , blue print the action an put on a new barrel.

 

[Guy Miner]

A new Hart, Lilja, Krieger or Pac Nor is sure to please! :grin:

 

[6ppcar]

A new Hart, Lilja, Krieger or Pac Nor is sure to please! :grin:

Or Shilen :grin:

 

[Guest]

I get the feeling this barrel is not eroded from shooting, but just rough from the factory. If I'm wrong, I'd like to change my vote to a new barrel. To add one more to the mix, I have a friend who has several guns rebarreled by Douglas, and loves them.

 

[ldg397]

It has about 200 to 250 rounds through it so I would hope it is not barrel erosion.

Just thought I would try the fire lapping pretty cheap and couldn't hurt.

Next step would be a new barrel or trade up to a kimber or sako in 260 remington.

 

[ldg397]

One plus is shilen is only about 60 miles away from my house.

 

[Guest]

I'd bet you can get that throat smoothed out. Consider as well that you're talking about a rifle with a barrel with the profile of a drinking straw, so it will not be as accurate (on average) as heavier sporter weight barrels, and nothing like what a heavy profile could provide. Then again, you bought the 700 Mountain for a reason, I suspect, and it is a pleasure to carry, I'm sure. If you get it down close to 1" (be sure to let the barrel cool a long time to ambient temp when shooting for groups) then you've probably gotten all you'll get from it. If you're shooting warm groups under 1.5", I wouldn't complain a bit about it, as that's plenty good for white-tails and muleys, as well as pronghorns and other medium game. Rebarreling will probably give you better accuracy, but at the cost of weight, wait, and dollars. If you go back with a thin profile (lightweight style) barrel, the gains will likely not be tremendous.

 

[ldg397]

With reloads it is consistantly in the 1 1/4" range and can get 1" with factory core lokts occasionally. I have read some more on the subject and I think I will try the JB first and see how that goes. Otherwise I will try reloads with a flat base bullet and see if that works. Otherwise probably live with it for an excellent deer rifle. I hunt in Missouri with very little stand hunting and a lot of walking, fences and brush and this rifle is a dream to carry and shoot.

 

[spclark]

Some of us high-power shooters find a lot of utility in a diamond lapping compound called LusterLap for keeping throats cleaned up.

Several grades depending on use; the yellow (grade 3) works for really rough bores, the light green (or white, grade 1) for polishing bores in general.

http://diamondtooling.com/catalog/diamo ... ds_01.html

<or>

http://www.mcmaster.com/ & go to catalog page 206.

More expensive than JB or aluminum oxide compounds, but it works.

 

[Savage99]

ldg397,

Lets see if the usual suspects have been eliminated? You must have made up a number of loads, checked the scope by switching it, and the usual bedding problems like guard screws that bottom out on their ends, magazine boxes that are too high etc.

I would try the Tubbs system but I would break the corner on the crown first.

Above are 270 and a 308 barrels that I broke the corners on the crowns. Now they shoot much better.

 

[ldg397]

ldg397,

Lets see if the usual suspects have been eliminated? You must have made up a number of loads, checked the scope by switching it, and the usual bedding problems like guard screws that bottom out on their ends, magazine boxes that are too high etc.

I would try the Tubbs system but I would break the corner on the crown first.

Above are 270 and a 308 barrels that I broke the corners on the crowns. Now they shoot much better.

Yes I have switched scopes and tried several loads and powders that is why I took it to the gunsmith. He checked everything and says bedding is perfect, magazine is good, crown is also good. He scoped the bore and said the throat was rougher than a standard remington 700 barrel should be. I have a recessed target crown from the factory are you suggesting recrowning to more of the bell shape or just shaping inner edge?