ADvertise hereInline FabricationGraf & SonsRotoMetals2
StainLess Steel MediaMidSouth Shooters SupplyLee PrecisionTitan Reloading

Donate Now Goal amount for this year: 6000 USD, Received: 4840 USD (81%)
We have reached our goal! Thanks to all who donated! I will be updating the donation bar in the next few days!
Our Annual server fund drive is going on now! This donation drive helps fund Cast Boolits for an entire year, and helps support our 2nd amendment rights! You can donate by Paypal by clicking the DONATE button. Or by Cash / Check / MO to the address below:

Willy Snyder
PO Box 2732
Pocatello, ID 83206
****Due to overwhelming e-mails, I will be very slow in updating this list. Please bear with me!****


Results 1 to 8 of 8

Thread: RCBS and Lyman Mold conversion to Magma

  1. #1
    Boolit Mold
    Join Date
    Feb 2017
    Location
    Antwerp area, Belgium
    Posts
    8

    RCBS and Lyman Mold conversion to Magma

    Hello everyone

    I recently purchased a Master Caster and am now in the process of converting my RCBS molds and a few Lymans to the Master Caster configuration, I purchased some extra hardware from Magma for that purpose. I also have a new Magma mold that serves as a reference point to know what my modified RCBS/Lyman mold should look like.

    Here and there I found some informations on how to proceed with the slots and some discussions about drilling all the way thru the block or not, but now that I started the job I notice there are some tricky details that I would like to know of, in order not to destroy a good mold.

    I already opened the slots of my RCBS mold with a file and the mounting hardware fits into the slots.

    I have the following questions:
    1. How do I remove the sprue cutter bolt stop? Do I need to file/mill it away, or is there a more convenient way to remove it? I believe it is in the way for the Magma sprue cutter.
    2. Where should I drill the hole for the sprue plate pivot bolt? I plan to follow the Magma design and mount the complete bolt with tension spring, Magma provided the spring & bolt assembly. I could use the original hole from RCBS and drill it through the entire block, but hesitate if the RCBS sprue cutter bolt pivot hole is in exactly the right spot, is not 100% clear to me. If not, I would drill it in the other half that originally had the sprue cutter stop.
    3. I have exactly the same questions for the Lyman mold, except that these are shorter and this raises more questions, They are too short for the mounting brackets that slide in the enlarged slots, so there is not enough metal to drill and tap inside the slots to attach the brackets on both sides of the block. How do I have to deal with this?

    Thank you on beforehand for your advice gentlemen, I would hate to screw up a good mold or having to buy additional molds if this can be avoided by a succesful conversion.

    Kind regards
    Mr Pebbles

  2. #2
    Boolit Master
    Join Date
    Aug 2014
    Location
    S W Louisiana
    Posts
    240
    Mr Pebbles, I also have a master caster. I have not tried to put the Magma hardware on Lyman, RCBS, Saeco, etc. molds. Magma offers this service, although I do not know their charge. If the hole for sprue plate bolt is not where it's supposed to be, you will have problems. If you are not proficient at this kind of work, you may be inviting disaster. Just something for you to consider. Best wishes on your endeavor.

  3. #3
    Boolit Mold
    Join Date
    Feb 2017
    Location
    Antwerp area, Belgium
    Posts
    8
    I want to add that I live in Europe and that therefore sending the molds to Magma for the conversion, is much less an option than if I would be living in the US.

  4. #4
    Moderator



    Join Date
    Dec 2005
    Location
    Oregon Coast
    Posts
    3,894
    You'll have to use the Magma mold as a pattern for drilling the holes for the sprue cutter. If you can lock the Magma mold on top of the RCBS mold with the sprue bolt removed, then you can mark the location of the hole through the RCBS mold block.

    You'll also have to either remove the sprue cutter stop from the other molds, or carefully grind them off even with the surface of the mold. If you leave the hole for the stop, it will eventually collect lead, which really isn't that big a problem, other than just being a nuisance. I have several RCBS and Lyman molds that have been converted for the Master Caster, and once done, they work well, though the Lyman molds, with their smaller mass, tend to heat faster, and get too hot on long runs.

    Hope this helps.

    Fred
    After a shooting spree, they always want to take the guns away from the people who didn't do it. - William S. Burroughs.

  5. #5
    Boolit Master
    Join Date
    Nov 2010
    Posts
    4,673
    You can simplify things by simply selling your RCBS and Lyman molds and buying new Magma molds. I had a collection of RCBS molds before I bought my Ballisti-cast MKIV. The mold blocks varied in size which made it more fun to try to cast with different molds/bullet sizes. You won't have that problem since the Magma only holds one mold. Machining the key slots and the spru bolt hole can be done provided you own a decent mill or have access to one. The question you need to ask yourself is ...time wise is it worth your time and trouble to do so. Generally the Magma mold is larger and huskier than the RCBS mold is and generally the Magma mold produces a better bullet.....my opinion.

  6. #6
    Boolit Master
    Join Date
    May 2014
    Posts
    577
    I just filed the edge of the magma sprue cutter to allow for the stop pin. This way I can use the mold by hand for small batches. Take one of the tabs provided by magma and bolt it to the base of your Lyman/RCBS block with a longer screw to locate the hole position.

  7. #7
    Super Moderator


    HATCH's Avatar
    Join Date
    Sep 2008
    Location
    Lexington, SC
    Posts
    4,487
    This is from my memory.

    Hardware kit was like $26?
    Magma would convert and provide kit for $40

    In the past, I just shipped them a mold to convert

  8. #8
    Moderator



    Join Date
    Dec 2005
    Location
    Oregon Coast
    Posts
    3,894
    Here's the link to the Magma price list for converting molds:

    http://www.magmaengineering.com/magm...-bullet-molds/

    Hope this helps.

    Fred
    After a shooting spree, they always want to take the guns away from the people who didn't do it. - William S. Burroughs.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check