.308 In a .303 Brit?

So I'm just beginning to get the hang of handloading, but i'm having a hard time finding .311 diam bullets for my Parker & Hale Sporterized 303. I can't seem to find them in Bass Pro or any local gun stores, so i started loading .308 bullets into my brass. They give mediocre accuracy with IMR 4895 an even worse with 4320. Right now i have 20 or so loads with Sierra Varminter 110gr hollow points. They push 3000-3100 fps with 40.0 gr of 4895. Any tips or tricks to help me improve my accuracy? (Without the obvious of using actual .311's please? )

Cheers,
Cody.

Heavier bullets might be more adapted to the barrel twist.

Buy surplus 7.62x54R and pull the bullets. Actually you should slug your barrel first as some of them 303 were as big as 32/8mm.

Paper patch. Ross Seyfried wrote an article for Handloader Mag; he used patched jacketed bullets for slightly bigger obsolete british calibers.
Some have used adhesive paper (address tags for mail?).

kg

I use the 312 hornady bullets for the 303.
The #3120 SP 150gr bullet has worked very good. Got three deer with it last year.

that 150 gr interlock is a good bullet as is thier 174 rn.
my number 4 prefers the sierra pro hunters in 311.
you should measure your bbl as i have seen 303's all over the map
from 308 up through 317.
the obvious is actually the best answer. if your bullets don't fit you will NEVER gain any appreciable accuracy.
and you will have lower velocities, and lots of fouling.
look online, midway, graf and sons, wideners, pats reloading.
all should have a selection of 311-312 diameter bullets.

Welcome to the Guide.

You picked a rather difficult round to start out with. The only military rifles with a greater variation in actual bore size are the Moisin-Nagants. I don't often recommend starting off by slugging the bore for shooting jacketed bullets, but for rifles chambered for this round you really need to measure your bore and groove diameters. I also doubt you will ever see decent accuracy with undersized bullets and will go through an inordinate amount of bore brushes, patches, and copper solvent trying to stay on top of the fouling. Add that to poor neck tension and you get poor round to round alignment with way too much runout so the bullets do not start out parallel to the bore and do not properly stabilize in flight. I don't think it's worth the time and effort to try to make do with .308 bullets since they are commonly available in the proper size. You won't see the variety and selection that can be found with .308 bullets, but they are easy to get and usually in stock. Local gun shops seldom stock components for anything but common sizes and in the USA that means .311 bullets are only available if special ordered, so I just order them online. I have had good luck with the three Sierra ProHunter bullets in 125, 150, and 180gr and would expect to see better accuracy across the board, especially with the heavier bullets. 4895, 3031, and 4064 are my favorite powders for the .303.

The other thing you need to watch very carefully is your brass. There is also a great variation in chamber dimensions in the .303, and if you FL size every time you are going to be seeing head separations after only a few (possibly as few as two) reloadings. The cartridge headspaces on the rim, so it does not move back and forth in the chamber during the firing cycle and this causes greater stretching of the cases which weakens them in the area just above the solid head. The brass needs to be treated like a fireformed wildcat and neck sized for better case life, and for the same reason it also needs to be checked each time for incipient head separation. (Straighten out a paperclip and put a right angle bend of about 1/8" on one end. Use the angled end to feel up and down the inside of the case head for anular rings - a slight groove all the way or part of the way around the body of the case head. Toss the brass when you feel it unless you want an unwelcome education in removing broken shells from your chamber as the extractor pulls off the case head leaving the rest in the rifle.)

Remember that these rifles were never designed to be using reloaded ammo in, but rather to feed and fire cartridges loaded at many different locations with great variation in actual dimensions under extremely adverse battle conditions. No bolt action battle rifle ever made has a better record of reliability in the worst possible conditions and those loose tolerances which made that reliability possible call for some creative and well thought out techniques for those wanting to reload for them.

Alright thanks guys. I just finished up today and loaded 60 some virgin brass with 180gr sierra pro-hunters in 311. They have superb traj and accuracy. My new Ncstar 4-9x40 is zeroed at 220 for this new load lol. I clocked em in today between 2750 and 2800 fps. 4895 is a great powder for these guns. Oh and versifier, i've had many an instant with my old brass separating at the head. I haven't had much trouble freeing the rest of the brass from the inside of the breech though, I just have a straightened clothes hanger that i push against the neck mouth. Careful not to scratch the inside of the barrel of course lol.

Oh before i forget, my previous loads before my sierras were 150gr Hornady flat points that i borrowed from my uncle that he used to reload his 30-30 brass. I had some of the most accurate shots i'd ever taken with those loads. Picked a coyote off at about 175 yards or so running at full speed lol. Almost felt bad for the bugger... I'm sure i'll stick with the sierras tho. Especially since yote hunting season is at the doorsteps. Hopefully lol. Thanks for all the replies guys!!

Cheers,
Cody.