Often, when one starts thinking about using cast bullets, the first inclination is to use a bullet shape that mirrors a favorite jacketed number.  And why not you ask?  If a Sierra 168 grain boat tail makes nice tight groups, then a similar cast design should do well to, right?  Wrong!  The answer lies in bullet hardness.  Jacketed bullets are about 100 on the Brinell scale.  The hardest cast bullets are about 35 Brinell.  Most cast bullets run less.  Since cast bullets are softer then jacketed, they require positive guidance to keep them running concentric.  There are three factors we must consider to get good performance from cast bullets.  Bullet shape and bullet size are the first two.  The last is barrel twist rate. However, before we discuss these factors, let’s review how moulds are made and what’s readily available. 

Makers of bullet moulds produce moulds by either the “lathe bore” method; where the blocks are held tightly together and a series of different drills and cutters produce the cavity or cavities.  Or, a single cutting tool called a “Cherry” is rotated and the blocks are moved in to cut the cavity or cavities.   Producing a mould is an exacting process; either method will make a good mould, provided the best tools, machinery, operators and quality assurance inspectors are in attendance.   The initial set up on a mould is expensive and time consuming.

Mould makers know different alloys will drop bullets at slightly different sizes and weights.  Pure lead will make the smallest bullets with the greatest weight.  Linotype at the other end of the scale makes the lightest, but largest bullets.  Production makers strive to have their moulds drop bullets about a certain size.  They have their cavities sized to take into account various alloys.                                                                                              

The custom maker works a bit differently.  The customer chooses a standard mould pattern from the custom makers catalog and specifies what alloy is to be used. Next, the customer specifies what sizes both body and nose of the bullet are to come out with that specific alloy.  The customer maker produces a mould to meet those specifications. Custom makers supply top punches for their moulds to match for whatever Lubricator/Sizer the customer has.  NEI, www.neihandtools.com, is one such maker.  I have a NEI mould I acquired 20 years ago; it is a very elegant mould.  The bullets drop from the mould exactly as I specified in my order.   

Taking it one step further, the customer can totally design his or her own bullet shape from scratch, in addition to specifying both alloy and finished sizes.  Needless to say, when one gets into the realm of custom moulds, things can get a bit pricey.  However, considering one gets it exactly as desired; then price shouldn’t matter.                                                                                                                                  

Most use standard production moulds readily available from catalog companies.  I have moulds from all the mainstream producers.  They all put out good tools.  Trying to pick a “best” mould maker is rather difficult.  All the makers have their strong points.                                            

Lyman, www.lymanproducts.com has some designs that have been in production almost 100 years.  Originally under the name “Ideal”, Lyman cast bullets have achieved legendary status for their ability to group.  Many cast bullet records have been set with a Lyman bullet.    Other makers have copied Lyman designs.  Lyman recently updated their mould handles with a new, superior design.  Lyman has an excellent Lubricator/Sizer; the latest version is a top-notch tool.  (See Note 1)                   

RCBS, www.rcbs.com acquired the Lachmiller Lubricator/Sizer and mould line over 25 years ago.  They have expanded the mould line with many fine designs and have excellent quality control.   They also have some moulds available in their “limited production” line that are specialized, but cost less then custom moulds.  I acquired one of their Lubricator/Sizer’s over 20 years ago.  It functions as perfectly today as it did when new.  (See Note 1)                                             

Lee, www.leeprecision.com, led the way with innovative aluminum moulds.  Their cavity designs are time tested.  They guarantee their moulds to be minus nothing to + .003.  Lee moulds are easy to use and are the least expensive.  Lee moulds have permanently attached handles.  Lee will make custom moulds to customer specifications!  When a mainstream production maker agrees to do a “One Off” mould, it takes a special set up, a lot of time, and there is almost no profit involved.  This is a tribute to Lee’s commitment and loyalty to their customers.    Lee pioneered the “push through” sizer system that attaches to a reloading press.  I’ve not tried it, however, I’m told the system extremely work well.   Lee does not produce top punches for any of their bullet moulds.  Usually one determines the closest matching top punch for their brand of sizer from one of the other makers.  Example: I found a Lyman top punch to match a Lee 8mm mould.                  

Redding, www.reddingreloading.com, has the famous Saeco mould and Lubricator/Sizer line.  (See Note 1)  If I had to pick a favorite producer of ferrous metal moulds, it would have to be Redding/Saeco.  To begin with, Saeco mould handles are a work of art themselves.  Just handling a Saeco mould that’s attached to the handles is a pleasure.   Their moulds are of a special blend Pearlitic iron.  It’s very dense and distributes heat evenly.  Even when filled cold, a Saeco Mould starts dropping good bullets after just a few castings.   No matter which Saeco mould I use, there are always less rejects then with other brands of moulds.   Saeco has an extensive list of moulds; with several design types available.  They have many traditional designs, and some of the newest trends in mould thinking, I really like that.  Saeco doesn’t wed itself to just one school of thought in design. 

Note 1:  Lyman & RCBS sizing chambers and top punches are interchangeable.  Lyman has the largest assortment of sizing chamber sizes.  Lyman sizing chambers also seem to be a bit better quality then RCBS.   Saeco Lubricator/Sizer sizing chambers and top punches are priority items.  If you have a Saeco Lubricator/Sizer you have to use their sizing chambers and top punches.  However, Saeco does make Lyman/RCBS style top punches for people who use Saeco moulds, but, lube & size on a either a Lyman or RCBS Lubricator/Sizer.   

We previously listed the factors in cast bullet success. Let’s begin with twist.  Barrel twist rate is a vast subject, and really needs its own article.   For the moment suffice it to say that Springfield, Enfield, Jap and Mauser bolt guns all have sufficient twist to stabilize cast bullets, With one exception, that being Swedish Mauser’s.  The twist rate of Swedish 6.5 Mauser’s won’t stabilize a cast bullet from most makers’ moulds very well.  However, cast bullets work well in a 6.5 Jap, they have a twist rate befitting cast bullets.  I have heard there is one custom made mould that will work in the Swede, but I have no experience with it.

As stated before, pointy boat tails with a tough jacket perform well because they have hardness of about 100, and will travel straight in a barrel.   Softer cast bullets require more thought to their shape to remain concentric on the trip down a barrel.  There are few moulds that copy a jacketed profile.  The problem is a long, pointy, unsupported nose of a cast bullet is too soft to stay centered.  Without positive support, the nose will slump, causing the bullet to become eccentric.  Once it leaves the barrel the bullet will continue to yaw causing large groups.  Proper cast bullet design will allow for accurate shooting.  However, to decide which cast bullet design to use requires the rifling form be known.                                                                 

Of course, it begs the question, which is correct, exact size or slightly wider?   There is some disagreement on this point.  Some feel .002 or .001 over groove diameter is best.  Others feel right at groove diameter is correct.   Many feel a bullet’s forepart should be right at or .001 over land (bore) diameter.  Individual barrels will vary.  Some barrels will have slight variations from one end to the other.   That’s the most likely explanation for the different schools of thought.  Personally, I like the body .002 over and the nose .001 over.  This seems to have given best service in a number of rifles.  What everyone does agree upon is, the bullet should never, ever be smaller in either dimension, then a barrel.   An undersized cast bullet will run eccentric and lead the barrel.

Moulds can be lapped out to larger sizes.  This wasn’t an option I entertained.  First, it’s permanent. The mould wouldn’t be good for my .30 caliber rifles anymore.  Second, if not done correctly, the mould would be irreparably ruined.   For the last 4 years I’ve been corresponding with a fellow military retiree who also loves cast bullets.  He put me on to the mould taping solution.

Acquire a roll of aluminum tape of the type used for ductwork from a home center or hardware store. Cut thin strips about 1/8 inch wide and affix them as shown in the picture.

Most cast bullets are designed to use a gas check.  A gas check is a small copper or gliding metal cup that fits on the heel of the cast bullet.    Hornady produces all gas checks now, though they may be sold under the Hornady, RCBS or Lyman brand name.  Gas checks (as produced today) are all designed with a small, internal lip.  The lip will bite into the heel when the bullet is sized and lock the gas check onto the bullet.   In the past, Lyman gas checks were not of the lock on variety.

Since gas checks are only one size, (within a caliber family) the fix was simple.  I took a ¼-20 bolt with a round head and chucked it in my drill press.  The drill press was not running; it simply acted as an arbor press.  The round head bolt expanded the checks the .000000000000 necessary to insure clean, square seating.  Lacking a drill press, one could simply use a small ball peen hammer to tap the bolt and expand the gas checks.       I used Hornady crimp-on gas checks for the bulk of this article.  However, I had some older production slip-on Lyman gas checks on hand and tried them, once expanded, they worked fine also.    

The proof is in the shooting.  My trials with a proper fitting Saeco # 301 were disappointing.  As I said before, not all rifles are willing to go “by the book”!   I decided to tape the NEI # 308-180-GC.  Its form is specified for narrow land barrels. I used the same brass, primers, powder, expanded gas checks, PSB filler, tools and loading procedures as with the other bullet.  The large cast NEI bullet grouped right up!

I’m very pleased with the mould tape system.  Many SMLE’s have a reputation for somewhat casual jacketed bullet accuracy due to bore & land size being greater then most bullets designated for the .303.

Here’s another possible use for this system. Suppose you have Mil-Surp barrel that’s now oversize due to excessive wear from firing, corrosion, or incorrect cleaning procedures.  Such a barrel may not shoot jacketed bullets very well.  Oversize cast bullets may well be the answer to restore accuracy.  I plan to try this on a 8mm Turk that has a very worn somewhat corroded bore.  I knew the bore had seen better days when I acquired it, but it has a nice stock, all matching numbers, and a design form rather unique, even for a Turk!  Other then the bore, it is in very nice shape.   Right now the best it will do is hold the black @ 100 yards.  I’m anxious to see if oversize cast bullets can shrink groups somewhat. 

If you have a barrel that runs large on any Mil-Surp I can highly recommend trying a bullet from a taped mould.  Since the tape isn’t permanent, the mould won’t be harmed, and if it doesn’t work out in your rifle, the bullets can be remelted.  You have nothing to loose except lackluster accuracy!