Winchester .303 hunting ammo with smallish bullets?

[AdrianM]

Hi All,

Forgive me if this topic has been discussed already. Tried a quick search, but found nothing.

A friend of mine has a sportered .303 that he wants to hunt with. He had a scope mounted and found that the rifle won't group. He says it used to shoot fine.

Only thing that changed other than the addition of the scope is that he bought a new box of Winchester ammo. I read somewhere that a guy had a similar issue and when he measured the bullet diameter he found that they were .308 bullets. The guess is that so much .308 ammo is produced that maybe Winchester is now using .308 bullets for .303 ammo.

I measured four bullets, two from two separate boxes of winchester .303 ammo and bullet diameters ranged from .307 to .309.

Shouldn't they be closer to .312?

What should I tell my buddy to buy to feed his .303 and shoot whitetail?

Adrian

 

[Butcherbill]

He should slug his barrel, then he'll know the diameter of bullet he needs to use. What was he shooting prior to the Winchester box, was it grouping nicely? Maybe it's the scope.

 

[Chrossphyre]

4/1000 is a lot to ask of older Enfields, especially if the barrel is worn at all. I agree with Butcherbill: slug the barrel and find out what you really need. It could be out as far as .314 so your Winchesters could be pinballing down the barrel on the way out.

 

[zenmagic]

What does slug the barrel mean as well as pinballing.

 

[Potashminer]

Hi All,


I measured four bullets, two from two separate boxes of winchester .303 ammo and bullet diameters ranged from .307 to .309.

Shouldn't they be closer to .312?

What should I tell my buddy to buy to feed his .303 and shoot whitetail?

Adrian

I would have expected .311 for 303 British. Did you actually pull the bullets and measure the bullet shank, or are you just measuring forward of the mouth of the case?

 

[tacfoley]

Prvi Partizan make a 174gr softpoint cartridge, and I'm told that they are .312" to suit 'most' .303 rifles and carbines 'in good condition'. I have little to no experience of .303 shooting as I've never owned one, but all my reloading manuals START with a .311/312" bullet - many note that the bore can go up to .315".

tac

 

[tacfoley]

What does slug the barrel mean as well as pinballing.

Slugging the bore mean forcing a pure lead slug up the bore from breech to muzzle, which you the measure using a precision caliper or micrometer.

Pinballing is used to describe the path of a loosely-fitting bullet that literally carooms off one side and then the other as it progresses up the barrel, without engaging the rifling.

tac

 

[IronCanadian]

Normally boxed rounds will be loaded with .311 bullets, chances are so are the ones your shooting. It is completely possible that he bought a different brand before and they performed better, it happens.

You can slug the barrel, but unless you're going to cast your own bullets and reload it would be a wasted effort. IMHO

If he can, take the scope back off and see if it is indeed the scope that's the issue. If not you have a few options. Buy several boxes of different brand and size of ammunition ie. Winchester, Remington in 150gr and 180 gr, you can also pick up the PRVI 174gr and see if they help.

The other option would be get into reloading, pick up some Hornady 174gr RN flat base bullets in .312", IMR 4895 and find a recipe the gun likes. The flat base bullet obturates and does a better job of filling the barrel, when fired, than boat tailed bullets (which most retail rounds are loaded with.

 

[green]

Are you measuring the bullets ahead of the case mouth on a loaded round? If so pull a bullet and measure it on the portion that would be inside the neck.

 

[blasted_saber]

Keep in mind this rifle could be shot out. its not like its a new production firearm.

 

[kawicrash]

Measuring the slug from a 5 groove barrel isn't so straightforward. Lands and grooves are opposite each other. My old gunsmith had a special mic for measuring 5 groove barrels.

 

[tbuckton]

My No1 MK3 won't group smaller than about 8" at 100yards with the winchester super x. With prvi fmj cheapies or federal powershok I can get it to group around 3" at 100yards. I gave up on buying winchester ammo for my 303 unless I want to shoot at pop cans or sure shot

 

[222Rem]

Quick check.
Take the ammo and see if the bullets fit in end of muzzle.

 

[plinker 777]

Quick check.
Take the ammo and see if the bullets fit in end of muzzle.

This. If the projectile falls more than half way into the muzzle, you've either got the wrong projectile or a blown out barrel.

Slugging is the proper way to get a measurement, but this is a quick check. (Read: if it fails this test, there's no point in slugging really. Look for another barrel.)

 

[AdrianM]

thanks for the replies everyone.

Adrian