Lyman U molds

[JRParrish]

I recently bought a Lyman U311291 bullet mold on EBay. I had wanted one since 1963 but poverty, school, work and such kept it away. Does anyone know when Lyman quit making U molds. I was taught no sized bullet can shoot as well as a cast bullet of the right diameter(s). I have heard it mutter that Lyman made more money selling lubrisizers than molds and made oversize molds to pressure casters to buy the lubrisizer ands stuff that they require. My old U molds shoot well and I look forward to loading .30-06 with U311291s.
JRP

[Char-Gar]

Lyman was able to sharpen their mold cherries a couple of times before they became too small to use. When they were sharpened for the last time, a run of molds was made and marked U for undersized.

I have a U311291 which casts bullets .299 X .310 (nose and body). I have a number of other 311291 and the largest casts .302 X 316 (nose and body). In general the U mold is the lest used because I prefer .300 to .302 on the nose for good shooting in most .30 cal barrels.

However I had a Browning Traditional Hunter SS in 30-30 and the action does not have enough caming power to engrave oversize bullet noses, so I am stuck with thumb pressure only. This is where the U shines.

Now let's talk about sizing and what you have been taught. It was/is the common thinking that sizing a bullet reduces accuracy and sizing .003 will destroy the accuracy potential of a bullet. Well that is pure crap. Let me illustate.

In the above Browing SS rifle, I took my largest 311291 (.302 X .316) and sized them to .299 X .310 which is the same as those from the U mold. I then shot them side by side in the same rifle with the same load, on the same day. I fired four five shot groups with each bullets and the average of the groups showed the bullets that were sized down gave a hair better accuracy than the U bullets. All groups were no larger than 1 MOA at 100 yards.

The sizing of the bullet does no harm. However when done on a traditional machine, the pressure on the nose can bend the bullet or deform it in other ways.

I sized my bullet nose first, with the pressure being on the base. It is not how much you size that causes problem, it is how you size that can cause problems.

There are many myths, old wives tales and general falsehoods that are repeated as fact until they are assume to be fact. Even some folks who should know better buy into them. The folks on this board have exposed some of these myths with hands on testing instead of repeating oral tradition as fact.

Enjoy your mold and good shooting...

[BruceB]

JR, pard;

Unfortunately, what you've heard is mostly flat-out wrong.

I have on hand no fewer than FOUR 311291 moulds, NOT the "U"311291. The one reason I bought all of them was a search to find one that is BIG ENOUGH in its critical diameters, because most of the ones out there are too small both in nose diameter and band diameters.

The latest 311291 I bought is a 4-cavity made under the Ideal name, which pre-dates the Lyman version. Many older moulds do cast a tad larger than present-day production, which is why I bought this one on nothing more than "hope". In this instance, I finally DO have 311291s with a nose diameter of just over .300" and band diameters of about .311". These dimensions are BARELY acceptable (meaning, large enough) for most .30-caliber rifles. I look forward to giving the boolits from this mould a lot of testing.

The story about bullets being harmed by sizing is mostly an old-wives tale. Bullets which are BADLY sized, i.e.: out-of-round, or scraped on one side, or bent, are definitely bad news. However, given good tooling and technique, bullets can be reduced an astonishing amount without harming their accuracy or usefulness. You should consider that a bullet cast a few thou oversize, along with a lube-sizer, puts YOU in control of your bullets' final diameter. There is most definitely NO guarantee that any mould will cast the "right" diameter.

I personally special-ordered a couple of "U"-for-undersize 4-cavity moulds back in the '70s, long before I got wise to a lot of things in this business. Fortunately, they were handgun moulds, one for the 356402 9mm bullet and the other for some .38 design I don't remember. The 402s cast at about .354-.355" in linotype and were some of the worst-leading SOBs it has ever been my misfortune to see. The .38 mould, as I recall, cast about .356 and was somewhat useable for most of our guns of the day.

When you get to casting some bullets from that mould, I'd sure like to hear what dimensions you're getting. My three regular 291s, apart from the 4-cavity job, have noses which run about .297-.298". It is CRITICAL for bore-riding designs like this to actually make bore contact all around the nose circumference, so that the bullet is guided on a straight course without "wiggle room".

It's an ongoing and very serious frustration to knowledgeable casters today, that we CANNOT get it across to the big-name mouldmakers that they're cutting the cavities TOO DAMNED SMALL in diameter. It is endlessly aggravating to try to work around such undersize tooling, when just a few thousandths' increase would make our hobby so much easier.

I hope that mould will work for you, but I don't hold out a lot of warm fuzzies about the possibility.

[floodgate]

JR:

"Does anyone know when Lyman quit making U molds?"

Strictly answering your question, without getting into all the variables of Ideal / Lyman moulds, they had a table on pp. 82-86 of the 1958 "Handbook of Cast Bullets" showing those available as "undersized", and moulds I ordered from that book around 1960 WERE marked "U-xxxxx". The 1973 Second Edition "Cast Bullet Handbook"*does not list these.

Also, Lyman Gun Sight Corporation continued to mark their moulds "Ideal" right from their original purchase of the "Ideal" line in October, 1925 at least until 1970, when they were absorbed by the Leisure Products Group during the great sporting goods merger era; they switched to marking them "Lyman" either then, or when J. Mace Thompson separated the Lyman line from Leisure Products and re-established it as "Lyman Proucts Corporation" in 1978 - most likely the latter date, but does anyone here have any better info on the name change?

Trivia, I know, but this question gets asked every now and then.

floodgate

*Attached photo shows these two 6" x 9" issues; great sources of mould info, and well worth grabbing if you see them at a gun show. fG

[Frank46]

I have to agree with all of you. In my limited experience the normal size of both my 311291 and 31141 the noses are way too small, even with lyman #2 alloy the noses barely come out at ..299. In my estimation they should be at least .302 to perform well. Frank

[Wayne Smith]

Then is my single cavity 309291 a different series or simply truth in advertizing? It shoots fine in my K31s, for which I bought it, so no complaints.

[floodgate]

Wayne:

Is your mould actually marked "309291", or is it "308291"? The latter was the number used for this bullet throughout the Ideal and Marlin era, and I am looking at an old fixed-block example that came in a Marlin box (1910 - 1915) that is so-marked; I've got to warm it up and see how it casts. The "size-to" prefixes (the first three numbers) of many Ideal moulds have changed back and forth over the years, but how this relates to the actual as-cast diameters is a moot issue, in view of the wide diameter variations we are seeing in the individual moulds.

Floodgate

[drinks]

Wayne;
What does your barrel measure, my K31 is .299-.307 and just about everything works in mine.

[JRParrish]

Thanks for the information.
JRParrish

[Wayne Smith]

Floodgate - u'er right, it's 308291. My mind plays with numerals without my supervision. I have to watch carefully what comes out, and often fail to catch errors. LOML does all the numbers in the household!

Drinks - believe it or not, I never cast or slugged that barrel. I just loaded some up and shot it. Gotta get a scope on it, I can't reliably see the rear sight any more!

[Maven]

As Bruce, Frank & Wayne suggested, molds are often undersized (body and/or nose if a bore rider). However, what's undersized for the "standard" .308 bore often works perfectly in the slightly smaller 7.5 x 55mm, the K-31 specifically. For example, the Lee C309-180R, Lyman #311291 and Saeco RG-4 that I complained about as being too small for my .30-06 (Mod. 70 Win.) fit my K-31 perfectly and are astonishingly accurate.

[JRParrish]

Lots of experience out there.

Any suggestions for a load for a US Rifle Model 1917? The only .30 bullet I have that is not a U is a 311291. Haven't cast any yet so no dimensions.

Near 40 years ago I got 1" groups out of my O3 Springfield which I rebarrelled with a new 2 groove 03A3. U311291, cast full of surplus 4831 to the should, NRA alox lube and linotype shot good and was cheap to feed. The 2 groove barrels were generally regarded as second rate but those I've worked with shoot good. Some thought a 2 groove supported a cast bullet well and the rifdling on a 1917 need a larger diameter bullet.

Good Shooting follows good casting,

JRParrish