303 Brit Questions!!!

[Muskrat Mike]

I finally got my first 303 Brit at a gun show. It's a sporterized No 4 Mk1. It shoots factory ammo pretty well but I'm having trouble with the cast bullets. First I tried the pieces of aluminum soda can and found it would close on 3 ,but with difficulty, so I fired formed the brass with the O-rings. It worked well and I load with the Lee Dies and use the collet neck sizer. I have a Lee C312-185-1R mould which throws bullets at .3135 with my alloy. With a 10-12 grain load of Unique at 25 yards it throws the bullets all over the place with most hitting on their sides. I went ahead and slugged the bore and I couldn't believe it so I did it twice. It's a two groove bore and I'm getting .303 for the bore and .3175 for the groove diameter! The gun intriques me. It has a nice old Lyman peep sight on it and I just what to come up with a nice cast bullet to shoot plates at 100 & 200 yds and would like to shoot a Deer with it but I'm too scotch to use jacketed bullets. What do I do next? Can I order a custom mould that would work?

Thanks ahead of time!
Mike B.

[Larry Gibson]

Get a Lyman 323470 mould. Size, lube all the grooves and seat a .32 cal GC at .321 and see if it will slip into the fired case neck. If so you might want to try them at .321. If not then get a .314 Lee sizer and hone it out so the bullets are then sized (after the 1st sizing and lubing) down to .318 - .319. That bullet and method has served me quite well with numerous milsurp bores of .316 - .319. It is quite accurate also.

Larry Gibson

[frnkeore]

I would suggest any of the Ideal/Lyman molds at start with a 319 or 321. Such as the 319295 GC, 321297 GC. They come up on Ebay. Another one that will fit the bill very well is the 32 - 170 GC RCBS. I've seen it on Ebay and on this forum. The 323470 will cast at least .325 and sizing it down to .320 or so will deform it w/o a 2 stage die. At the velocity's that your using (10 - 12 gr Unique) a plain base bullet would work well and that opens the door to many more 32 caliber molds, such as the fairly common 319247 and the use of softer alloys (softer cast smaller, too).

Frank

[Larry Gibson]

The 323470 will cast at least .325 and sizing it down to .320 or so will deform it w/o a 2 stage die.

Negatory on that. That's why you lube and GC them 1st. Here are 2 different 8mm cast bullets, one the 323470's big brother the 323471, sized and lubed at .325 and then sized down to .314 in one pass through the Lee sizer. No deformeing and no second die needed. Thus .318 or .319 should be no problem at all and isn't as I do 323470 to .314, .316, and .318 all the time for such rifles.

Larry Gibson

[wiljen]

May I suggest that NOE runs several of him molds at your choice of diameter and I have had several oversized 30s done to fit my 303s and MNs.

[frnkeore]

I have sized the 323471 (Cast at .326) to .322. Pan lubed, all grooves filled first but. It would go out of round in one pass. I had to make a die that was .326 that would take most of the bullet and allow the placement of the GC. It then had a taper of 1 deg down to the .3215 and with spring back, sized to .322 round and CONCENTRIC. If you size like your 323471 shows, the the lead will flow back in the first two bands (if it's a Lyman and not a NOE) if there is no lube.

BTW, Larry, the bullet that you show on the right, IS NOT a 323470. The bands are to wide, it has a bore riding section and the nose isn't shaped as a 323470.

Another good choise might be the NOE 321471, the group buy maybe still going on.

Frank

[curator]

At the risk of beating a dead horse, allow me to introduce you to the Lee-Enfield 2-groove conundrum. If the boolit fits the throat you can't usually chamber it. Or no one make a mould you can afford that fits your gun. Check out Steve Regwell's website for an article on loading cast for 2-groove Enfields.---
http://www.303british.com/id37.html

[jvg5576]

At the risk of beating a dead horse, allow me to introduce you to the Lee-Enfield 2-groove conundrum. If the boolit fits the throat you can't usually chamber it. Or no one make a mould you can afford that fits your gun. Check out Steve Regwell's website for an article on loading cast for 2-groove Enfields.---
http://www.303british.com/id37.html

+1

Muskrat Mike -

I was in your situation about five years ago and that No 4 was the reason I got into casting. Now I have three 2-groove No. 4s with groove diameters between 0.318 and 0.320! I had limited success with the 8mm boolits and some of the CBE designs, but I wanted to try for better accuracy and more energy. So I absorbed as much info from this site and the site Curator references as I could and had Mountain Molds make the two designs below. They are both 220 gr. cast from WW. The one on the right shoots slightly better with softer alloy (50Pb/50WW). Best accuracy was found at near 100% case capacity with a slow powder (suprise!)

Since I had those molds made, there have been group buys and custom makers offering designs that may also work and possibly better. The designs I offer are for example only. You'll need to determine dimensions for your rifle.

In my opinion, you should first try the Lee C324-175-1R. Get your sizing method worked out. I would have Buckshot make a push-through sizer die. I was able to get decent accuracy (2moa @ 100yds) with it at around 1600 fps. Not the best boolit choice for hunting but those plates won't know the difference.

Take it slow and have fun!

[Muskrat Mike]

Great information everybody! Thank You everybody, I'll let you all know how I make out. This is a challenge I like!
Mike

[303Guy]

Muskrat, did you say it is a two-groove? The bore and groove dimensions fit. I have two two-grooves and both have a simple taper throat from above groove down to bore with a 1.5 degree excluded angle (I think). This limits the length of the boolit and I believe it best to use a boolit with a taper that exactly matches the throat with a parallel base shank that fits the unsized case neck. Perhaps a tiny amount of sizing is needed to hold the boolit. I'm wondering if a small chamfer base would be beneficial to overcome the base distortion from being swaged into the bore.

[chboats]

What does the throat look like? I had the same problem with a 7.65 Argentine Mauser that the bore looked like 100 grit sand paper. I slugged the barrel, the grove diameter was .3165. I made an impact slug of the throat and it was .325 with almost no rifling for the first half inch. I shoot the 323470 sized .325. I had to turn the case necks to .010 so that the rounds would chamber. "If I do my part" it will shoot 2 to 2 1/2 inch groups at 100 yards

Carl

[Muskrat Mike]

Maybe I can learn something again! How do you make an impact slug of the throat??

[Jack Stanley]

The way I did several of my rifles was fill a fired case with lead , oil or grease the outside and chamber it . Drop a slug down the oiled bore followed by a patch and a very close fitting brass rod . Tap the end of the brass rod untill the lead slug fills the area you are trying to measure . For me I noticed the sound was a little different and the rod would bounce when the lead had moved all it was going to .

Remove the case and push the slug onto a towel and you're done .

Jack

[chboats]

A couple of things to add to what Jack said. I works best to use a slug as soft as possible. I didn't want the rod to touch the rifling so I put a wrap of electrical around the rod every few inches. I first learned about making an impact slug from LBT, he says use a big hammer.

Carl

[walltube]

Uncle Tom made this mould for use in my Faz 5 groove No.4 Mk.I. It is a .318" dia. version of Lyman\Ideal 323471. With my secret alloy, cast weight is 219~221 grains . IMR3031 is the current powder of choice. Trials thus far have not yet earned a Cuban cigar; but no matter, getting there is half the fun.

Compare this boolit to NOE316299 at left, NOE311284 to the right. Good luck to you and keep on.

[303Guy]

The first thing that strikes me is the long ogive. That boolit has a long unsupported nose. I noticed it because I've found that even a short nose can 'slump' or set at least bump up with quite light loads. That's with my secret alloy. My alloy is quite strong and not too soft but rather ductile.

This one had a half patch making it a bore-rider. As can be seen the hole of the bore-ride section bumped up to fill the grooves. The nose took a hit so we can't see how that behaved in the bore.



It had a long unsupported nose.



So you can see just how far up the bump up has taken place. A harder alloy is going to be required for this one to work.

[Muskrat Mike]

I've got a .318 sizer ordered from Buckshot and I will have to take the time to do a cast of the throat but Shad Season is starting so I may have to put the project on hold for a while but want to thank everybody for the great advice! Keep it coming!
Thanks
Mike

[35 Whelen]

I finally got my first 303 Brit at a gun show. It's a sporterized No 4 Mk1. It shoots factory ammo pretty well but I'm having trouble with the cast bullets. First I tried the pieces of aluminum soda can and found it would close on 3 ,but with difficulty, so I fired formed the brass with the O-rings. It worked well and I load with the Lee Dies and use the collet neck sizer. I have a Lee C312-185-1R mould which throws bullets at .3135 with my alloy. With a 10-12 grain load of Unique at 25 yards it throws the bullets all over the place with most hitting on their sides. I went ahead and slugged the bore and I couldn't believe it so I did it twice. It's a two groove bore and I'm getting .303 for the bore and .3175 for the groove diameter! The gun intriques me. It has a nice old Lyman peep sight on it and I just what to come up with a nice cast bullet to shoot plates at 100 & 200 yds and would like to shoot a Deer with it but I'm too scotch to use jacketed bullets. What do I do next? Can I order a custom mould that would work?

Thanks ahead of time!
Mike B.

I too had an Enfield with an excessively large groove diameter (.316"). The only mould I had at the time was a 314299 which wouldn't shoot worth a flip as it was .002" undersized.

So, starting with about 18.0 grs. of SR4759, I'd fill the case to the bottom of the neck with PSB shotshell buffer then seat a 314299. Bingo! That did the trick. (Please don't ask me to explain why, because I have no idea) I worked up to 22.0 grs. and all the loads shot good. So, you might try a buffer of some sort, even Cream of Wheat if that's all you have.

35W