What to do with a severely underbored barrel?

D

Doyle

New member
My hunting/shooting buddy picked up a beautiful Remington 700 in .300WSM for what he thought was a good deal. One shot told him different. One shot shook apart a high-dollar Leupold scope. When he went to clean the barrel, he found that he couldn't even push his normal patched jag down the barrel (for .30 he uses a 7mm brush with a small patch over it).

This bore is severely undersized. Short of rebarreling, is there an easy way to open up the bore to normal .30 size?
 
This is an unaltered factory rifle?

Pretty skeptical about Remington shipping a rifle with an undersized barrel.
 
Yes, as far as I know it is a factory rifle -but it is one of their custom special edition models.

If it were a Savage, he could just pick up a take-off barrel and rebarrel it himself. However, I know that Remington barrels can be a bear to get off. I'm wondering if some kind of reaming would be cheaper.
 
Your buddy should probably slug the barrel so that he actually has some solid measurement on bore size before he starts spending big bucks or talks to Remington.
 
Exactly. Slugging the barrel is pretty easy to do, and a tutorial can be found via Google. It is almost outside of the realm of possibility that the bore is undersized, yet the chamber is correct, due to how the chambers are reamed during manufacture. Slug it and use a caliper to do some measurements of the recovered slug. That will tell the story.

Another possibility, and I assume he got this rifle for a song because it is not new, is that the bore is very copper fouled. VERY copper fouled. Not too unusual considering the cartridge. Get after it with a good copper solvent such as Sweets or something similar. Maybe an Outers system. A really mucked up bore will be undersized a bit, and give poor accuracy to boot.
 
Some folks might buy a used or abused rifle and go straight to the shooting bench. Of course they should inspect the bore before they buy but maybe that didn't happen and there are a lot of ways to acquire a used rifle. I always clean before I shoot new to me rifles and the least you should do is verify the bore is un-obstructed.

Send the scope back to Leopold they'll repair or replace. Next clean that barrel until a copper solvent patch comes clean and the bore is visibly sparkling. Might as well slug and mike to see what it really is just to be sure.

By the way patches can vary enough to require the next size down jag.
 
Leupold will replace or fix the scope for free if it truely came apart because of recoil. Also, any chance it is a 7mm short mag?
 
* First off, measure the bore with a set of calipers. If it is undersize, it will show with calipers. Save slugging the barrel for fine measurements. It is highly unlikely that a Remington left the factory with an undersized barrel, and a 300 WSM will not fit in a 7mm WSM chamber without some major effort.
* If the bore is truly undersized, tell your friend to all Remington Customer Service and see what they want him to do (typically they will want the rifle returned).
* Leupold Customer Service can tell your friend how to return a scope for service or repair.
* If all else fails, take the rifle to a smith who can tell you what the issues are with the rifle.
 
Is the barrel rifled?

I have read several accounts of firearms making it out of the factory with unrifled barrels.

In any case, you need to find out what the actual bore size is. Then, see what Remington wants to do, while the scope is on its way to Leupold.
 
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