Friday, November 18, 2011

The Affect of a Nose Punch on Accuracy - 358-477 Lyman & 358-429 Keith

The Lyman 358-477 is one of the most accurate moulds for my 357 6.5 inch Blackhawk.  For my 357 20" Rossi lever action carbine the 358-477 bullets won't even group at this point.  That just doesn't seem right,  Thinking through the different accuracy tests ant the results (over the past several years and tens of thousands of bullets), I knew this bullet shot best when sized in a custom Lee sizer and tumble lubed.  The Lyman 450 sizer produces bullets that perform almost as well in the Blackhawk, but both lube approaches just failed in the Rossi.

  • I decided to try some tests with different nose-punches, to see if the 358-477 would at least group out of the Rossi.

  • If it worked, I would then run the same test on 358-429 bullets from my new Mountain Mold (see prior posts for more details).

The primary rationale for a nose punch test is that the nose first sizing of the Lee die pumps out "well-centered and square" bullets more often than the Lyman.  Could a loose fitting nose punch in the Lyman cause the bullets to be less accurate?  It's an easy enough test.  Here's the lineup of nose punches with a 358-477:

The flat punch is my standard, it is widely accepted as affective so it made sense to use it.  The deep fit / snug fit middle punch came with a NOE mould.  It also makes sense to give it test and see if there's any improvement in the Rossi.  The RCBS sits in between, but is loose fitting with not much more support than the flat punch.  I included here as a visual reference to show just how deep and snug the test punch is.

I loaded up test loads using 5.4 grains of Unique, using the deep seating NOE punch and headed to the range.  Using the same 2X scope as before, I didn't expect much.  This exact same load was a dissapointment every time I shot it in the Rossi.  So how did it do?  Here are the two best groups, the single flyer in each is shooter induced (sorry about that, I'm only human after all... with no Ransom Rest):

So much for low expectations.  The bottom 4 shot single hole (above the dime, excluding the fifth flyer) measure .190 inches, center to center.  That is the single best group I've ever shot.  Ever.

A quick recap: the 358-477, when sized with the Lyman & a loose nose punch, or the Lee, doesn't group from the Rossi lever action.  There is no before picture, so just think "swiss cheese" and randomly placed holes.  I change the punch to a deep fit / snug fit punch to see what happens.  This bullet goes from zero to hero, unseating the Lee TL 358-158-SWC as the most accurate in the Rossi. WOW!

  • The improvement comes from the bullet being centered while running through the sizer, and being very square and straight as it's sized. 

It's time for the next step, how would this work with the beautiful 180 grain, 358-429 Keith bullets cast with my new custom Mountain Mold.  First, the punch lineup:

The flat punch produces good results with this large meplat bullet, with groups less than 1 inch, at 25 yards & off a rest.  How does the deep fit / snug fit NOE punch affect accuracy. 

These are two different loads. On top is a 5 shot group with13.5 grains of H110.  Very impressive, the real story is the bottom .  It's a 4 shot group (I ran out of test bullets) and my very first revolver group less than .5 inch.  That's pretty special in my book, rarified air IMHO.  It is now the number one most accurate bullet and load, measuring .380 inches, center to center.  WOW AGAIN!

These are spectacular results.  The problem is, my one NOE custom nose punch isn't very helpful to you or anyone else.  It doesn't help me either, with new bullet besigns in the future that need a different size punch.

Luckily, I recently came across Keith Benedict and his unique nose punches.  I've just order 4 for future use.  He offers standard nose punches for a many calibers.  What's so different about his "open" design punch:

They are open so then can be filled with epoxy, or hot glue, and then form fitted to a specific bullet.  That gives a deep fit / firm fit, every time, for any bullet.  If the standard nose punch doesn't quite meet your needs, you can order one custom sized one.

I'm not connected with Keith or his busness.  This is the best solution I've found and need to pass the info along.  You can contact him directly at and he will provide all the information needed.  Including instructions.  If you have a loose fitting nose punch, it may work with epoxy or hot glue, give it a try with what you have.

Either way, taking advantage of a deep fit / snug fit nose punch for maximum accuracy makes good sense.

Saturday, November 5, 2011

Mountain Molds Custom 3 Cavity SWC, 358-429 Keith Style

For folks that can't seem to get a 358-429 mould that drops full diameter bullets, here is one great solution.

The last couple of Lyman 358-429's that I bought cast .356-.357 bullets.  Too small to be lapped, especially since they are made of a steel/lead material.  It's too difficult to lap them to .3604 or so, which my guns like sized to .360.

My NOE mould 5 cavity is awesome, but it's only run once a year so you can't order one right now!  There are a few places that can help you out.  Mountain Molds is one of the most unique, with an online design tool.  There are ton of options and measurements that can be changed to make the mold you want.  If the tool can draw it, Mountain Molds can make it.

My new custom 358-429 shoots as great as bullets cast from the NOE and Lyman moulds.  It's one of the top bullets, one of the most accurate and it loves magnum full-house loads.  It is 100% of everything I had hoped for and expected. I did tweak it for a wider meplat, it's a beefed up Keith! 

Before I get to the details, here's a quick look at the top 3 designs that I've found:

A quick review of these great bullets, from left to right:
  1. Lyman 358-477:  The 150 grain mould came already dropping nicely sized bullets.  To get exactly  the size I want, with my soft alloy, took some minor lapping.  With the softer, and also heavier alloy, it drops 4 160 grain bullets.  I shoot a bunch of these every month.
  2. The Lee TL-358-158-SWC  was easier to lap, since it's aluminum, unlike the steel/lead construction of the Lyman.  This now drops at 168 grains, with the soft & heavy alloy.  The Ruger Blackhawk leads at the lands, unless it gets a heavy dose of Liquid Alox.  It's incredibly accurate.
  3. The last two are both 358-429 bullets.  I didn't have a NOE handy for this picture, because I shot all that I had on hand!
    1. This is the Lyman bullet.  It's a little longer than the NOE, but they are similar.  I used this as the model for my custom Mountain Mold.
    2. This is the bullet from the Mountain Mold.  I wanted a little bigger meplat, specified it using the online tool, and it's right on the money.  It fits the Blackhawk really well, and even cycles in a Rossi Lever Action.  A few more thousanths and it probably wouldn't. You can decide how big you want your meplat.  The orignal Keith was (I believe) .250, this one is also .250.
How do you design your own mould

 Go to Mountain Molds website, and select 35/9mm in the drop down.  The measurements that I used are in this screenshot:

Click on the image to get a full size version, use this for input if you are interested.

It takes some learning but in no time you will be used to the interface.  It's a lot of fun and very easy considering that you are actually designing a bullet mould.

Let me say, this mould is awesome.  Mountain Molds will cut either one, two or three cavity moulds.  Check out the absolutely wonderful sprue plate.  If you enjoy casting as much as I do, it's easy to get excited over the Mountain Mold design.  It's thick, it cuts great and the recessed holes making casting a breeze.  I can cast more bullets with this 3 cavity than most other 4 cavity moulds.

What does a Mountain Mold look like (after casting about 10lbs of bullets):

The RCBS handles fit it, or Lee handles fit as well.  It's easy to cut the sprue, and the bullets just drop out of this mould.

Nice looking vent lines and a big block help make this cast so well.  Note the block size in the design tool screen shot above.

Attention to detail is evident in the alignment pins, and the overall look and feel,  This mould is a joy to cast with.  Now you can get any bullet you want, without having to waiting for group buys.  Modeling a design after a known bullet can get you started quickly.

One of the more important decisions is the diameter.  You must decide if you want the specified diameter to be the maximum or minimum, or in the middle of the tolerances.  I choose for .360 to be the minimum.  Since I size and lube, and my guns love fat .360 diameter bullets, this works.

I'll be working up additional design specs in the near future, stay tuned for those results.

At the beginning, I was concerned that the bullets from my custom mould would not be as accurate as I demand and expect.  After all, testing thousand of rounds, testing endless alloys, unending moulds, lapping, sizing, lubes and alloy temps, it all resulted in a finely tuned set of a few excellent moulds.  

Not to worry.  The design is close enough to the model design, which is proven.  Then adjusted for the diameter my guns want, with my alloy.  It surpasses the accuracy and performance of the others, to make it into the top three bullet moulds.  Gotta love it!

I hope this provides another way to get that bullet you really want.  Now, if you design something your gun doesn't like to shoot,  that's another story.  Stay close to a proven masterpiece (the 358-429 Keith in this case) and tweak to suite your guns, and you'll be one happy casting handloader.

Coming soon there will also be another post regarding testing with nose punches (on a lubrisizer), and how a good fitting punch can improve accuracy.

Have fun, be safe and shoot tight groups!