.303 Brit sporter key holeing

[motorcycle_dan]

Purchased a used .303 SMLE sporter. Has a loose bore and groove. What are my options on shooting this gun accurate. Factory (Wolf) ammo was going through the paper sideways at 100yd. Purchased some Cast bullets sized to .315. They too went through the paper sideways.

Giving thought to smokeless paper patching or experimenting with various sizes.

Don't want to overpressurize the rifle finding out the wrong load.

How do I determine the correct diameter to size to. I've pushed a soft lead slug through the bore but not sure how to measure the 5 groove rifling.

I've never done paper patching but would like to learn the process (without the excitement of overpressurization)

How much of what kind of powder and how to do the paper patch.

[303tom]

Here maybe this will help.

[motorcycle_dan]

I knew it was big. The bore diameter is about .308 or .310
The groove diameter is about .315

In a perfect world I would give this fine shooting rifle to my brother-in-law. My thought is to take it on as a project. See if I can get it to shoot using cast bullets and or paper patched cast bullets.

Having difficulty determining what diameter to size bullets to, then paper patch up to what size, Size again after paper patch, any lube on the paper at all, just wet and let dry then size?

I would think there is some secret formula that would allow the bullet to stabilize in flight rather than tumble randomly. I did have the muzzle recrowned to 11º so now I have $100 worth of gunsmithing into a $150 rifle that has a fair market value of about $80 as it is.

[versifier]

If your groove diameter is that big, you will need .317 or .318. Not surprised the factory ammo didn't do much - that's the way it usually is with milsurps. But, Wolf is a great source of affordable reloadable brass.

I hate trying to measure 5groove barrels. Usually I can sidestep it with a S&W by just measuring the throats and cone. If you really want to do it right, do a search on "5groove" over at CastBoolits - someone over there came up with a cool jig for it a few years back.

IME, .303's do tend to like heavier cast bullets, over 160gr up to around 220gr, and you need a gas check, too. They may be tumbling due to the wrong velocity, but likely they are simply too small as is. Undersized bullets will tend to lead foul very quickly at rifle velocities, too, so watch the bore.

What is the mould, and how much of what powder did you try? I would be starting with around 32.0gr of either IMR3031 or IMR4895 and work up a grain at a time until the bullets stabilize and the groups tighten up.

I have written here (and elsewhere) at length about loading the .303 and being aware of headspace issues. You will have to neck size to get any brass life. Relying on FL sizing will get you head separations after only a few loadings. Search ".303Brit" here to find the postings. There is no reason at all why you can't turn your .303 into a decent deer rifle. Do not expect match accuracy, but it shouldn't be hard to find a load that will pieplate out to 200yds consistantly.

[runfiverun]

for smokeless paper patching you size the bullet to bore and patch up to or slightly over groove diameter.
use a starting jaxketed load and work up from there.
most guys will size thier casting down to bore.
then patch.
then slightly lube something like lee sizing lube or johnsons paste wax is used very sparingly.
then size again for the final size.
when you size the patch you may be sizing the casting again.
it's all in the measurements.
i'd prefer to have a final unsized size a thousandth over than to size that last bit.
the key is to have the paper shred at the muzzle,the paper to fill the groove depth, and the bullet to ride the lands or very slightly engage.
if you think your bore is 308, but not sure, try pushing a 308 diameter bullet through there.

[Paul B]

I pretty much agree with what versifier posted. With a properly sized bullet, there should be no need to paper patch. A charge that has worled well for me in the .308 Win. amd 30-06 with cast bullets is 25.0 gr. of either IMR or H4895 with bullets in the 190 to 200 gr. range. Velocity is not all that high but accuracy is quite good. The .308 is a 1.5 MOA gun at 200 yards and will do 2.5 MOA at 300 yards if it's not very windy. The 30-06 will drop the 300 meter pigs on the silhouette range if you hit hit them in the top one-third of the target. You'll hear a dull clank as the pig very slowly falls over. I think a bullet sized to .317" to maybe .318" should do the trick. A properly set up full length die should enhance brass longevity as most SMLE's have fairly sloppy headspace.
Whether you go to a full length die or use a neck sizing die, proper set up so that the round headspaces on the shoulder rataher that the rim will go a long way in keeping brass life good.

This is how I set up my sizing die for bottleneck cartridges.

1. Take a once fired factory round and blacken the neck and shoulders with a Magic Marker or Sharpee pen. Some people like to smoke the neck and shoulder, but I find the Magic Marker/Sharpee pen a bit better.

2. Carefully lubricate the case.

3. Loosen the lock ring on the sizing die and back off about two turns from when the die is set to touch the shell holder.

4. Size the case. Note where the marks are on the case and turn the die down about a half a turn and size again. Turn down some more, and resize again. What you are looking for is the marks on the blackening just touching the shoulder.

5. Clean the lube from the case and try it in the rifle. It may chamber just a bit on the snug side. If so, turn the die down ever so slightly, lube and size again. Wipe off the lube and try in the rifle. If it slides in as easily as a factory round, you should be good to go. If not, usually one more very slight adjustment should fix the problem.

6. Tighten the locking ring for the die and you're done. You have just set your sizing die up for a custom fit to your specific rifle, rather than a generic one size fits all guns.

Paul B.

[303Guy]

I have a 303 Brit with a .308 bore. I don't feel handicapped by it at all. In fact, I consider it a good find because a throat sized boolit - patched or plain cast is going to fit the unsized neck and give minimal distortion on firing, thus keeping the boolit base edge relatively undistorted. That's my theory anyway.

I've no idea what the groove diameter is.

[303Guy]

I've just tried chambering a pig gun cartridge in the .308 (more like .309) bore Brit and it goes in quite far. It measures .314! (The pig gun has a rust modified bore so is quite large).

motorcycle_dan, is your rifle's bore in good condition? Mine is. We could have some fun trying to get our guns to shoot well. Mine is a SMLE barreled LE I. (That means a No1 MkIII barrel on an original MkI action dated 1896).

[Morgan Astorbilt]

Dan, Odd groove rifling must be measured with a "V" anvil micrometer, used for measuring odd flute milling cutters. They come in 3 & 5 flute styles, so you can use a 5 flute. Unfortunately, they are fairly expensive, I don't know of anyone marketing offshore "cheapies". A good bet would be to push a few slugs down your bore, and visit a local machine shop that has one of these micrometers, and ask them to measure the slugs for you.

Morgan

[gunnerd]

303Tom, do you have one of those diagrams for the two-groove Enfields?