I just fired some of my first cast rifle loads this afternoon. I have cast quite a bit for pistol but rifle is different. Half of my rounds cut through my target sideways at 25 yards when I was sighting in. I was shooting 303 British with a Lyman #314299 which is a 200 gr RN with 11.5 gr of Unique, which is moving about 1350 fps. The bullets are cast from an alloy close to #2 and dropped from the mold at .3135. I used Lee Alox with no gas check. Is the keyholing caused by the low velicity, or is there something I am overlooking? Thanks for your imput.

Dan

I do not believe your problem.is low velocity
I believe your bullet is undersize for your throat.

I would load some more and seat them long and loos so that chambering the cartridge will have the bullet pressed into the origin of the rifling. Trying this will help to prevent gas cutting past the bullet as it makes its way into the rifling.

If you bullet fits the throat you should be receiving good accuracy at this velocity.

I am assuming of course you have acceptable accuracy using jacketed bullets.

My 303 gets about 2-3 MOA. Not to bad for a service rifle that is 96 years old. It is a lot of fun to shoot. I was hoping that cast bullets would make it cheaper and thus more fun. This rifle has a very long throat. One problem is that I run out of magazine room long before the bullet hits the rifling.

Dan

You have the accuracy potential. What I am hoping to see is the long seated bullets shooting accuratly. If they shoot accurately you can then vary powder type and charge weight to achieve accuracy with your bullet seated to work through the magazine.

I would cast these as soft as you are able. I am surprised at the as cast diameter, I would have expected them to be a bit larger.

It helped me some to recover a bullet shot into water. I could see engraving marks and such. I used milk jugs lined-up in a row. Gotta "soft-stop" that bullet to see!

Cheezywan

Trash bag set into carboard boxes works well too. Fill the trash sack with water and tie off the top. Three in a row will stop most bullets with the exception of the big Lyman round nose for the Whelen. I have a few of these which are probably still flying on their quest to circle the globe!

I am surprised at the small as cast diameter. In my opinion you need a .315" bullet in the SMLE and some will accept a larger diameter bullet seated just a bit deeper - say .355" deep or so.

If I were shooting these well undersize bullets I would use fast pistol powder too burn all of it in the case before the bullet left the neck of the case.

Try shooting a few with gas checks installed. Without gas checks the base can sometimes be pushed off center.

I'm concerned about the velocity. You are starting the bullet right smack in the middle of the transonic range where drag spikes. Many bullets that are fine when they are supersonic will start to tumble in this velocity range. Even the famous Sierra 168 grain MatchKing fired from 10" twist barrels in .30-06 will start keyholing at about 700-750 yards due to the transonic drag spike. It's a matter of the bullet length and twist rate and muzzle velocity. Muzzle velocity and barrel twist determine how many RPMs the bullet is spinning, which is not very fast starting out that slow. Bullets lose rotational velocity more gradually than linear velocity, so starting out faster will leave the bullet with more RPM's when it drops into the transonic range from a higher velocity.

To follow up on the other suggestions, as Slim said, loose fit will also knock a cast bullet sideways. Two things contribute to this. One side of the base or the other gets more gas cutting, so that when the bullet exits, the muzzle blast pushes the base away from that side. Any slant or unevenness on the base of a bullet will ruin its accuracy. As Harry Pope commented about a century ago, the base steers the bullet, and he knew his cast bullets. The other thing I've seen in loose bullets is uneven rifling engraving depth. That unbalances the mass of the bullet and makes it wobble in flight. I've seen two guns in my life that were made with off-center rifling. One a 4" Dan Wesson .357 change barrel, and the other a Smith & Wesson model 41 .22 rimfire barrel. Just looking in the muzzle of either gun showed lands higher on one side than the other. Both keyholed bullets mercilessly, even at short range. So, an undersized cast bullet leaning a couple thousandths to one side could be expected to do the same thing, even with a gas check in place.

I would slug the lightly oiled bore at both ends with pure lead slugs (the Hornady swaged lead balls for cap and ball work well). Use an OD thimble micrometer with 0.0001" vernier scale to see what groove diameters you actually have? Figure you want your bullet 0.001" to 0.002" bigger than groove diameter at the throat end, and you want a muzzle that doesn't open up. One that is funneled by over-cleaning from the muzzle end will chew up lead bullet bases with gas cutting. You can also slug for constrictions that can be firelapped out. They seldom are large enough to matter to jacketed bullets, but lead bullets go bananas after passing through constrictions.

I've forgotten whether your rifle has an odd or even number of lands? If it is an odd number, you'll need to get the actual land engraving depth to add to a diametric micrometer measurement. The easiest way I know is to start the slug into a sized case just hard enough to grab it, then use the indicator on a case runout gauge to see how many thousandths the step from land to groove engraving is? It is usually about 0.004", but wear can affect that; especially cleaning rod wear at the muzzle.

i'd suggest trying a slightly larger bullet. with the load you stated over-pressure is still a long ways off (and next to impossible to reach in an enfield anyway) so firing a .315 or .316 bullet is safe. not only can it possibly solve your problem, it'll make the round more accurate as well.