RepackboxLee PrecisionRotoMetals2Wideners
Titan ReloadingMidSouth Shooters SupplyLoad DataInline Fabrication
Reloading Everything
Results 1 to 10 of 10

Thread: Removing Gas Check Grooves

  1. #1
    Boolit Grand Master
    Join Date
    Nov 2008
    Location
    Central VA
    Posts
    5,513

    Removing Gas Check Grooves

    There have been several mentions here about modifying factory moulds that came with gas check grooves so they would cast plain base bullets. I’ve known a couple of machinists in the past who did this kind of work, but they are gone now, and this kind of work is above my pay grade in the shop. Does anyone know of a machinist who still might offer this service? I’m specifically thinking of having my double cavity Lyman 358156 altered since I shoot these bullets with naked bases most of the time anyway.

    TIA ~ Froggie
    "It aint easy being green!"

  2. #2
    Boolit Grand Master Outpost75's Avatar
    Join Date
    May 2013
    Location
    over the hill, out in the woods and far away
    Posts
    10,158
    I've had Erik at www.hollowpointmold.com enlarge the GC heel or entirely remove it, either by boring it out to make a heavier bullet of larger diameter, or by shortening the blocks to make a lighter bullet.
    The ENEMY is listening.
    HE wants to know what YOU know.
    Keep it to yourself.

  3. #3
    Moderator Emeritus


    Join Date
    Mar 2005
    Location
    SW Montana
    Posts
    12,452
    NOE sells a pb 156. I have done some on a drill press with minimal run out and a good machinist vise. This was and is just for my own use. The hardest part for me was determining if the cavity is parallel to the mold edges. If you do err and get a larger base the sizing die can fix most of it. My criteria was being cheap and having an easily replaced mold.
    [The Montana Gianni] Front sight and squeeze

  4. #4
    Boolit Grand Master

    gwpercle's Avatar
    Join Date
    Sep 2011
    Location
    Baton Rouge, Louisiana
    Posts
    9,254
    Never pass up an excuse to buy a new mould .
    Keep the 358156 GC ...you will want to load some 357 magnum loads some day...trust me.
    Gary
    Certified Cajun
    Proud Member of The Basket of Deplorables
    " Let's Go Brandon !"

  5. #5
    Boolit Master
    NoZombies's Avatar
    Join Date
    May 2009
    Location
    N. Florida
    Posts
    2,493
    Quote Originally Posted by Outpost75 View Post
    I've had Erik at www.hollowpointmold.com enlarge the GC heel or entirely remove it, either by boring it out to make a heavier bullet of larger diameter, or by shortening the blocks to make a lighter bullet.
    I second this, Erik isn't cheap, but his work is worth the price.
    Nozombies.com Practical Zombie Survival

    Collecting .32 molds. Please let me know if you have one you don't need, cause I might "need" it!

  6. #6
    Boolit Grand Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    7,933
    You can buy reamers from McMaster Carr in readily available sizes at 0.357", 0.3575", 0.358", 0.3585", 0.359", 0.3594", 0.3595", 0.360" for about $15 to $30 and use a drill press then hand turn to remove a gas check shank.

    Ben has posted info on moulds he removed gas check shanks from that way using just a standard twist drill.

    Its not that hard to do if you want to do it or get it done but... as stated above, maybe a new PB mould is a better route?

  7. #7
    Boolit Grand Master
    Join Date
    Nov 2008
    Location
    Central VA
    Posts
    5,513
    Thanks guys, you've given me a couple of viable options here. I didn't know about the NOE mould... a nice DC brass in a 358156 PB might be my best bet since I've fallen in love with brass moulds too. I'm still not too hep on doing it myself, but if NOE doesn't pan out, Eric will be a good option. Thanks again my friends.

    Froggie
    "It aint easy being green!"

  8. #8
    Boolit Grand Master
    Join Date
    Nov 2008
    Location
    Central VA
    Posts
    5,513
    Quote Originally Posted by MT Gianni View Post
    NOE sells a pb 156. I have done some on a drill press with minimal run out and a good machinist vise. This was and is just for my own use. The hardest part for me was determining if the cavity is parallel to the mold edges. If you do err and get a larger base the sizing die can fix most of it. My criteria was being cheap and having an easily replaced mold.
    I spent the better part of an hour perusing Al’s site last night and never did figure out which of his mould number is the equivalent of the ideal 357156. I saw a couple that seemed close, but none I found was an exact match. Do you have a Mould Number you could give me, please?

    TIA ~ Froggie
    "It aint easy being green!"

  9. #9
    Moderator Emeritus


    Join Date
    Mar 2005
    Location
    SW Montana
    Posts
    12,452
    https://noebulletmolds.com/site/prod...360-165-swc-t5
    When I ordered mine 5 years ago or so this weighed in at 158. Dimensionaly it looks similar but I sure can't see a 156 in there now. Sorry, I should have looked before posting.
    [The Montana Gianni] Front sight and squeeze

  10. #10
    Boolit Grand Master
    Join Date
    Nov 2008
    Location
    Central VA
    Posts
    5,513
    Thanks, MG. That looks like it may be the one. Additionally, unsized bullets from this mould should be perfect for my little 38 S&W Terrier. Al seems to be sold out of all the variants I would be interested in buying, but I’m in no hurry. A solid point plain base version of this in a 2 cavity brass mould is now officially on my wish list!

    Of course a spare double cav Lyman 358156 would still be in danger of being altered at my house.

    Froggie
    "It aint easy being green!"

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