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Hi,

I've finally got round to casting and trying out some cast boolits for my mk4. Found a nice load at 9.5 gr unique, but some of those and most of the faster ones in the ladder keyholed spectacularly. The boolits are 312 150gr from a lee mould and sized to .311. I haven't slugged my bore and I'm guessing I need larger diameter Boolits.

Can someone kindly point me in the direction of where I could buy 30 or so different boolits so I can find one my rifle likes?

Thanks

why don't you just slug it, and then look for something the right size (2 thou larger than slug)

The first mistake you made was sizing them to .311 why did you do that if the mold drops at .312 you should of left them at .312.
Ask more questions I'm sure we can set you on the right path.
More info required:
What mold are you using.
SLUG YOUR BORE. Its the first thing you need to do before even thinking about getting into cast boolits.

Cast bullet shooting is easy if you understand cast bullets, jacketed bullet thinking does not apply to cast.

All you need to do is get bullets that are a good fit for the rifle that means 2 thou over groove diameter or cast to throat diameter whichever is larger commensurate with chambering.

So the first thing you need to do is slug your barrel and take a chamber cast so that you know the dimensions your gun needs for good bullet fit.

Secondly you must use a soft alloy for the application. Commercial cast bullets are inevitably too hard and too small for most applications.

The two main causes of inaccuracy and lead fouling is badly fitting bullets (i.e. too small) and too hard an alloy.

Guessing is no way to cast bullet success.

Finally Lee moulds are invariably undersized and if you are serious about cast bullet shooting then investing in a decent mould will make the whole process more enjoyable and effective.

You can increase the diameter of your cast bullets by about .003 if you beagle the mould.
All you need is some self adhesive aluminium foil which is available from your friendly DIY store (See photo)

ukrifleman

Many thanks for your replies, I'll try and address all your points and give the information you asked for.

Slugging and or casting are part of the plan. I'm nervous about walloping a slug the wrong way down my 75 year old rifle myself without seeing how it's done by someone who knows what they are doing. I have not found a friendly person locally or a gunsmith who doesn't want a lot of money for this yet.


The mould is an old single pot Lee c312 185 1r. (Gas check) Alloy is 50/50 range scrap/lead coming in around 10-12 bhn using my lee tester.

I found a useful load for my 3030 Winchester through trial end error (aka guessing!) but the rifle was mint and I had access to a range of boolits and moulds. My 303 is a 1942 longbranch mk4*1 whose bore looks well used but still bright and well defined. It shoots well with factory ammo.

I would like to find a load I can cast myself for 25-50yd plinking at my local range. The speed needs to be below 1500fps and the energy below 1200j

The mould and sizer came from a pal who had some success with them and I used the sizer to get uniformity and also to seat the gas check. I haven't experimented seating gas checks other ways and in any event I hope to pick up a second hand lubrisizer soon so will be able to seat without sizing.

My plan was to, as with the 3030, get a selection of boolits and have fun experimenting seeing what happened. I live in Suffolk so if someone is local to show me the ropes slugging a bore and to point me in the direction of some suitable moulds as a result I'd be very grateful. I may try beagle but my mould as well.

Many thanks

Ron.

What has being a 75 year old gun got to do with slugging a barrel?

You are quiet happy to drive a harder lead slug down the barrel with powder behind it at pressures far greater than you will ever manage, with a hammer and rod. But you are timorous about slugging the barrel with a soft lead slug?

Slug it and chamber cast it! Then you will know what you have to work with, if not loading for it is a lottery.

My recommended 303 mould is the NOE 316299, if you don't fancy bore riding then the NOE 316291.

If you persist in floundering around without knowing your barrel's freebore/groove/bore dimensions then the Loverins are the way to go but they need to be big enough to fill the freebore. The NOE 314466 might be worth a try.

dromia wrote:What has being a 75 year old gun got to do with slugging a barrel?

I find the idea that a firearm degrades with age alone particaulrly annoying. A well mainted firearm from 1860 is far safer to shoot than a poorly maintained firearm from 2017.

Slugging a bore can look a little traumatic but it's not even close to firing a round through it. As long as you don't take a ball-peen hammer to your crown you'll be fine.

If you are looking for a short range load then the standard is an NOE 314-115 RF 314316 PB (this will usually drop around 0.315") used as cast, tumble lubed in xlox over 3-4 gns of N310 or N320.

There have been hundreds of thousands of such rounds shot in our 25 yrd indoor range over the years, it just works.

For any loads up to 1800 fps make sure that you are not using too hard an alloy BHN 12 is tops for hardness.

Also make sure that the barrel is completely copper free before using cast also with a clean barrel it may take a few hundred cast rounds for it to settle down and consistently group, beware over cleaning the barrel.

BTW the slug does not need walloping down the barrel, once it is seated in the rifling it will just push through unless there are tight spots in the barrel which slugging will also inform you about.

Have you read the pertinent article in the library?

https://www.full-bore.co.uk/viewtopic.p ... re#p296196

Have read of this.