Finally, a CB to fit my K31!

[madsenshooter]

I finally found a mold for a CB that will fit the throat of my K31! No doubt some of you already have one. Its the Eagan MX3 30AR. I bought the cherry and just received the mold Bernie Rowles cut for me with it. I knew by measuring the cherry it was going to be close. I'd previously tried the Lee 165gr TL, but the throat on my K31 is on the "tighter than some" side. With the Lee, OAL has to be 2.781, and that leaves the base of bullet at, or slightly below, the neck/shoulder junction. Consequently the bullet is sometimes pushed even further into the case when chambering a round, back to 2.724" (on the right in the first photo). No such problems with the Eagan. OAL is 2.940" and the base of the bullet is slightly above the neck/shoulder junction aka "the doughnut". .270" of the base of an unchecked bullet is in the neck. The rifling engraves nearly the whole cylindrical portion of the bullet. Even though I'm using a very high tin alloy with a BHN of 23, the cylindrical portion of the bullet just ahead of the ample lube groove is .307" Just right for my K31. The only thing that gets sized on this bullet when sizing to .308, is the driving band and the gascheck.

[dromia]

Looks and sounds the business, how does it shoot?

[madsenshooter]

I'm off work till Wednesday, so I'm going to get my lubri-sizer set up and find out. Due to winter weather, probably only at 50yds. I'm going to be so glad to get away from that tumble lubing! The Lee bullet however, fits the throat of my Krags well, so I'm not completely out of tumbling. I'll get some pics of the shooting results.

[Vly]

I saw those cherries for sale on Ebay. What material was used for the mold? Any photos of the mold? What kind of cost was involved in getting it done?

[runfiverun]

the rcbs 165 silhouette boolit fits both of mine just fine and shoot well at 1900 fps.

[madsenshooter]

I saw those cherries for sale on Ebay. What material was used for the mold? Any photos of the mold? What kind of cost was involved in getting it done?

Bernie's molds are done in brass, I sorta like them, they resemble the original Eagan molds. Cost was $85 sans handles. The bullet is very similar to the RCBS mentioned above, but it's a nose pour. Here's few photos of another mold I have from Bernie, this one is for the MX3-30G. Unfortunately, it appears these may be one off things, Bernie is primarily into BPCR molds and doesn't want to be bothered by nit picky 30 caliber shooters, he's returned my cherries, so I may be dealing with NEI in the future.

[Ben]

and doesn't want to be bothered by nit picky 30 caliber shooters

Hey ! ! Wait a minute , I think I resemble that remark !

[madsenshooter]

Looks and sounds the business, how does it shoot?

Taking a lot of things into consideration, I'd say the bullet has some potential. They weigh 166.4grs checked and lubed with Rooster Red HVR. (23BHN alloy) Charge was 17.5grs of Blue Dot, which I don't see many folks here using, but I found a lot about it on the Precision Reloading Forum. Shot #1 was with the Lee TL, #s 2 & 3 also with the Lee after moving 8 clicks left (remember 50 yards). 4,5, 6 &7 were with the Eagan bullet. After 4 & 5 the snow was coming down in big flakes, so the K31 was in it's native element, and I wish the Swiss would take the crap back! I mentioned there were things to take into consideration. It was cold (16 degrees), my rest (crouching behind the rail on the back porch) wasn't solid, it's the first time I've shot the rifle, and the aforementioned snow. But all in all I think it'll be a good bullet and I can't wait for some better weather so I can do some shooting from the bench. Im guesstimating velocity of 1700-1800fps, if anyone knows any different let me know. I noticed that on the first couple shots, there was a considerable amount of lead flakes blown back on the neck of the brass. Is this something normally encountered with the K31? Other than throwing a few cast bullets aimlessly out of an Arisaka, these are my first shots with cast bullets using a rifle. Thanks to all the contributors here that helped to make it something worth doing! I'm not at all disappointed with the Eagan, and it appears the Lee is no slouch either, and I almost threw that mold away!

[MtGun44]

I'm amazed that you can get a .307 nosed boolit to chamber.
My 3 K-31s have a bore diam of .297" to .2965"

Bill

[madsenshooter]

I'm amazed that you can get a .307 nosed boolit to chamber.
My 3 K-31s have a bore diam of .297" to .2965"

Bill

I think I measured mine at .295"or .296", the bearing surface of the Eagan is tapered from .295" to .308" in about 1/2 inch, it appears to fit the throat of the K31 very good. Anyone here know John Ardito? He's the designer, maybe the K31's throat is what he designed it for. It's tapered a lot more than the Lee TL. I'm thinking about getting a .307 or .3065 sizing die made by Lee to try to eliminate the shaving at the throat (end of chamber, I guess one should call it). Then I should be able to get the old B&M Squib bullet to touch the rifling too. Sized at .308 the forward edge of the driving band stops it a tad short.

[mto7464]

I have to size mine to 308, at 309 I was getting the shavings too.

[Ricochet]

That Lee CTL-312-160-2R wouldn't chamber at all in my K-31 unless I seated it all the way down so just the semipointed tip was protruding from the case mouth. The straight side of the bore rider is .308" on mine! Full groove diameter, long before you get to the tapered transition to the body. The people on here using those boolits either have K-31s or Lee moulds that are very different from mine.

[madsenshooter]

Best I can measure, the .296" portion of the nose on my Lee bullet is .381" forward of the top lube band. That leaves said top lube groove just below the case mouth when seated to 2.810". The bullet is seated solidly into the rifling, a bit of a tap will close the bolt. I've read other posts about variation in the nose of these Lee molds, mine is a single cavity purchased off their closeout page. It appears that in my rifle, the lands taper from .304" at the beginning, to .296" in about .350". They don't start out at .296", so it really does has a throat. That reminds me, the milspec (PRVI) 168gr BTHP bullets Widener's is selling really fits this throat well, they have a tapered bearing surface and are only .308 at the edge before the fall off to the boat tail.

[madsenshooter]

That Lee CTL-312-160-2R wouldn't chamber at all in my K-31 unless I seated it all the way down so just the semipointed tip was protruding from the case mouth. The straight side of the bore rider is .308" on mine! Full groove diameter, long before you get to the tapered transition to the body. The people on here using those boolits either have K-31s or Lee moulds that are very different from mine.

Ricochet, I just noticed that we're talking about different bullets. The one I been usiing is the one for 7.62x39 designed by Ed Harris. If I can get enough lube to hang on to it to make it through a 30" barrel, I think it will work well in my Krags, all of which have .310" groove diameters. Got some loaded, just waiting for a break in the winter weather.

[Ricochet]

Yes, I'm talking about the Ed Harris designed tumble lubed boolit for the 7.62x39. Mine has a fairly long cylindrical bore rider section of .308" diameter in front of the .3145" body bands and behind the 2R tapered nose. Works in a Mosin, and in most longer throated .30 calibers, but not in my K-31. .296" is at the base of that pointy nose section on mine. Nearly all of the bore rider would have to go inside the case. I do suspect we're dealing with issues of Lee's variable dimensions. I also have a C309-200-R that has .302x.304" bore riders, when others have posted that theirs are .298".

[madsenshooter]

Now I've got a real boolit for my K31. Joe Wiest (smokemjoe) made me a bumping die for my Lyman 450 that makes the Ideal 308329 fit the K31 like a large hand in a small glove. Before Weistling the boolit was being stopped by the front band against the lands. The ogive touched the rifling, but just barely. Bumping the front band down a few thousandths let me get it all the way into the rifling, the base is forward of the neck/shoulder junction, and the loaded round just fits the magazine. Probably as close to the GP11 as a caster is going to get. The boolit weighs 178.5gr lubed and checked, cast at 24bhn (secret mix). Here's a photo of the before and after, using the rifle as the final seating mechanism. Joe's thinking of making these dies for sale, if there's enough interest. If you think you're interested, wiest4@juno.com is the place to inquire. It should work for some other bullets too, I'm going to try it on the Belding and Mull "Squibb" bullet eventually. Right now, I have all my 7.5 brass full, so I either have to go shoot some or order some more brass!

[Ricochet]

Very interesting. How does this bumping die work? Is it a die for a lubrisizer or loading press?

[madsenshooter]

It's for a lubrisizer Ricochet. After you've sized and lubed your bullet in a regular sizing die, you can put this die in the sizer, the bullet goes in nose first and gets sized down a wee bit more where it matters. It takes very little effort and it comes back out really easy since you're pushing the bullet into a taper. I even squeezed down one of my Squibs that was only 12bhn and it came out with no damage to the nose at all. I should note that the damage to the bullet noses in my pics was done previously, not by Joe's die. As is, it should work for some other bullets to make them K31 compatible, and if you let Joe know the dimensions of the particular bullet you have in mind it may be a bit more customized. Lead edge of the front band measures .306", rear edge of it measures .307. Back of the rear band still measures .308, .0015" over bore diameter of my K31. That ought to eliminate or certainly minimize the shaving. Of course you can adjust how far you push the bullet in to vary the results. Will get some shooting results when it gets a bit warmer.

[Jeffreytooker]

Anyone here know John Ardito? He's the designer, maybe the K31's throat is what he designed it for.

The Ardito design was taken from the Morse taper used on the drill chucks for machine shop work. The principal of the tapered nose bullet was to fit into a tapered throat in the rifle barrel. The throat of the rifle is cut to the same included angle as the taper on the bullet nose. This was to improve bullet/bore alignment over the bore riding bullet designed and used originally by Sinclair in CBA competition. IIRC the included angle was one or two degrees. It was designed for CBA competition. Most commonly loaded in the 30 BR which started out as a CBA competition cartridge. I have three original Egan moulds. Two of them are Ardito.

Jeffrey Tooker

[madsenshooter]

Thanks for that info Jeff. I see Ardito has also designed some of Lyman's molds. I'm pretty anxious to shoot some more of them out of my K31, I think it'll do better than what I did the other day and I take all the blame for the shots not touching like 4&5 in the pic above. I think if I'd have done my part 6&7 would have been there too. Whatever the angle of the bullet is, the K31 throat must be nearly the same as the rifling lightly engraves nearly the whole bearing surface. The bullet isn't much use for anything but the K31 without a tapered lubricating die. Trying to size and lube over .308 with regular dies will have the lube squishing forward of the groove.