Floating a light barrel

[Montell C. Williams]

I recently aquired a M700 mountain rifle through trade and the bbl was pretty rough looking inside and it shot about 4in groups, thinking I needed a new bbl I wasa little upset but decided to try floating it before investing hundreds of $$ on a new Barrel.

After floating I went back to thr range in Hyner and tried it out with some 140gr Federal ammo with ballistic tips, It shot about 3 inches higher than before but the groups shrank to about 1 1/4 for 5 shot groups waiting about 8 minutes in between shots. The ammo came with the rifle.

Glad I tried floating before spending for a new barrel. It went from a piece of crap to a pretty
good hunting rifle, cal. is 7mm-08.

I was always told not to float light bbls but in this case it worked.

[Lycanthrope]

I float everything.

You may even see some improvements with adjusting the tension of the action screws on your gun.


Lycantryitthrope

[Xringshooter]

I wonder why you were told not to float a light barrel? A light barrel has more tendency to move as it heats and cools and if the stock were to move from moisture than a heavy barrel. I'm with Lycan, I always float a light barrel.

[Tomcat088]

I float every barrel as well. As lycan said, adjusting the screws on the action can affect the accuracy. You might also check out the crown on the rifle. A bad crown can really wreak havoc on accuracy if there's a big burr hanging down snagging on the bullet as they exit the barrel. Getting a barrel recrowned is a heck of alot cheaper than getting a new barrel. I believe they also make a do it yourself crown thing that I've heard works, but have no personal experience with it, but it couldn't be much worse than big burred crown. I'm not sure what you mean by the "inside" of the barrel looks pretty bad. Is it pretty rusted, or do you have a good borescope that you checked it out with? Factory barrels tend to look pretty rough under a bore scope compared to a custom built, hand lapped barrel. Something else that you should be aware of, if the barrel has some really rough spots in it, you probably don't want to clean ALL of the copper fouling out of it. Some people are sticklers about getting all the copper out of the bore, but on a rough factory barrel, it can really smooth things out to leave a little copper fouling in the barrel. You can clean out all the carbon and it's just fine, but you might find that it'll shoot a little better with a little bit of copper fouling.

[Lycanthrope]

To add what TC said.......I never use a brush on a good barrel..just wet patches to clean.....but barrels are like women....they vary.

[Montell C. Williams]

I'm prtty happy with 1 1/4 inch for 5 shot groups with factory ammo in a light Mountain Rifle, in the field I'm only good for 300yds IF I can get a good sitting position with my back aginst a tree or lean on a tree or something,kneeling 200yds and offhand 100-125yds is it for me.

I've been in this group for around 2 years and can't remember Lycanthorpe being wrong, I'm getting over the hill now and am easier to please than I used to be so 1 1/4 inch is OK for me.
By rough I mean in the bottom of the grooves starting about 1/2 way up the bbl there are stryations running crossways between the lands best described as chatter marks they are evenly spaced as though a manafacturing defect, also one of the lands about 1/16 inch inside the muzzle appears to have slight pitting on it.

[Xringshooter]

What you described are machining marks na unless you want to lap the barrel to make everything nice and smooth I wouldm't worry about them. My first thoughts also were "it's a pitted barrel, buy a new one" but with the later description it doesn't seemto be anything out of the ordinary.

[Montell C. Williams]

I thought they might be machening marks because of the regularity of them but I have owned many other rifles and never saw them so pronounced. In any case it shoots OK since floating.