Home Main Category General Firearms

Why is an .357" LBT FN better than a SWC?

knitepoetknitepoet Senior MemberPosts: 22,374 Senior Member
I understand the allure of the WFN (wide flat nose) bullets, HOWEVER, LBT doesn't add the "W" until you get to .41 caliber.

So the allure with the meplat (flat nose) is the fact that the larger the meplat, the more tissue is cut/crushed/damaged by the bullet's passing than a bullet with a rounder profile. I get all that.

What sparked this question is comparing the 162.5gr SWC-GC bullets I cast the other day, and was lubing/sizing/adding the GCs to this evening.

I kept thinking about how large the meplat on the SWC was, and started wondering about it compared to the LBT FN. So I grabbed one of the LBT 180gr FN bullets I bought last year off the shelf and stood it on top of one of the SWCs. If there is a difference in the diameter of the meplat, it's too small to discerned with my bifocal assisted, MKII, eyeballs.

SO, same sized meplat and you have a driving band (secondary shoulder) on the SWC and an ogive on the LBT.

I was planning on getting a 160gr FNGC mould from LBT, I'm now seriously re-thinking that purchase.

So can anyone explain to me what I would gain from going with an LBT FN weighing the same as the SWC mould I already have???

edited to add:
Oh, and the reason for going with the lighter weight as opposed to the 180gr FNs that I bought, is two fold: Deer around here aren't that big and speed.
Of the 50 or so deer I've killed over the years, only 3 have stopped the bullet. In two of those 3, it was because the bullet disintegrated on impact, the third was the quartering shot on a doe with the 'wulf, the bullet was under the hide on the off-side.
So I'm doubting a deer will stop one of the SWCs with 12-1300fps MV.
Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


Replies

  • BigslugBigslug Senior Member Posts: 8,792 Senior Member
    On the matter of terminal performance, it's been pretty well proven that the sharp SWC shoulder doesn't do anything for you. The meplat pushes meat out of the way and the second flat doesn't actually touch anything. The main functional benefit to the SWC shape is cutting clean holes in cardboard past ranges where a full wadcutter ceases to be accurate (conventional wisdom being that the groups of WC's peter out beyond about 50 yards).

    For the same weight, the LFN/WFN concept lets you put more of the bullet's weight forward of the case mouth, which gives you more room in the case for powder. Going with a WFN cut to place the nose as far forward as possible would be the main attraction - at least if you plan to make them scream downrange.

    There's a school of thought that feels the ogival slugs have more accuracy potential in a revolver because they guide a cylinder more gently into final alignment with the barrel, disrupting the shape of the bullet less. Not sure how solidly I buy that, as the full wadcutter has been the Bullseye revolver standard for decades.

    If your gun shoots accurately and you've got speeds you want, you probably won't see any difference on the terminal side.
    WWJMBD?

    "Nothing is safe from stupid." - Zee
  • knitepoetknitepoet Senior Member Posts: 22,374 Senior Member
    Bigslug wrote: »

    If your gun shoots accurately and you've got speeds you want, you probably won't see any difference on the terminal side.
    Which is why I asked the question. Never heard any complaints of LBT's moulds, just trying to justify the outlay of cash.

    Concerning the shoulder on the SWC, either Brian Pierce or Jim Wilson did an article a while back and showed the "wear" on the shoulder of a SWC they had killed a deer with (mule deer IIRC) and claimed that the wear proved the shoulder did impact meat :uhm:
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • BigslugBigslug Senior Member Posts: 8,792 Senior Member
    I'm sure someone could work up a formula for factoring meplat diameter, impact speed, nose-to-shoulder length, and tissue elasticity to determine what's going on. Not sure it's worth the effort, but someone could. As long as you're crushing a 0.5" to 1.5" diameter hole through both sides of a deer, transecting something important, the deer is unlikely to stand up and say "I know what one of Elmer Keith's bullets feels like. That HAD to be one of Veral Smith's".

    I bought my LBT mold because I'm experimenting with .45 ACP and Veral's LFN profile seems to elegantly solve some of the problems I've been facing. Now that I've seen and used the mold though, you could almost justify having one around as an example of how molds SHOULD be made. I hesitate to call it the Cadillac of molds, because it might well be the starship Enterprise. If a 160 is redundant to your needs, you might either try the 180 or see what else you need a mold for. If you are placing an order, you should also think about getting a copy of his book "Jacketed Performance with Cast Bullets". Lots of useful intel in that one.
    WWJMBD?

    "Nothing is safe from stupid." - Zee
  • HAWKENHAWKEN Senior Member Posts: 1,720 Senior Member
    Paul, I have SWC's and RNFP bullets, of the same weight, per caliber, in both, .41 mag and .44 mag, and I truthfully cannot tell the difference in performance on live game. The SWC's make nicer holes in paper. It's just a perceived difference, in my mind, that makes me prefer the RNFP's. Wasn't much help was I, sorry...........Robin
    I don't often talk to people that voted for Obama, but when I do I order large fries!
    Life member of the American Legion, the VFW, the NRA and the Masonic Lodge, retired LEO
  • knitepoetknitepoet Senior Member Posts: 22,374 Senior Member
    Slug, my mold is actually considered a "Thompson" SWC. I'm not sure of all the differences, I think some of it has to do with the size of the meplat (65 vs 70%) and the width of the driving bands.

    Also, in doing some checking, Lyman has apparently tweaked the 358156 mould quite a few times over the years. Mine's an OLD one, marked "Ideal" and it's a 2 different bullets in one block mould. One cavity is the 358156 GC mould (has 2 crimp grooves) and the other is a plain based SWC with only 1 crimp groove. It has the second number on the block, but it's out in the shed, I'm not and I am too tired to go out and get it right now, after helping my folks move today.

    Bro Robin, Actually you were a LOT more help than you think.
    and I truthfully cannot tell the difference in performance on live game
    pretty much seals the deal that I don't need the LBT mould, so I can have my folks spend their budget for my B'day/Christmas gifts on something else.
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • BigslugBigslug Senior Member Posts: 8,792 Senior Member
    cpj wrote: »
    My question for those who want a big fat meplat is (I'm included) why isn't a wadcutter that's been......streeeeeerttrrcccchhhhed popular? For instance a standard wadcutter is 148-ish grains. Why not just make a 160-ish grain wadcutter and seat it further out?

    Cylinder throat length for one. Ideally, you size your bullets for a slip fit through the cylinder and the forcing cone steps down a bit narrower from there. If you don't have the means to precisely measure the throats, you could jam up a full WC so the round won't seat.

    Application, for another. Accuracy that craps out past 50 yards is no big deal for a Bullseye shooter, because they don't shoot beyond 50 yards, and paper doesn't care if it's hit by 148 grains or 200. Folks who care about size of payload generally want something with more versatile legs.
    WWJMBD?

    "Nothing is safe from stupid." - Zee
  • knitepoetknitepoet Senior Member Posts: 22,374 Senior Member
    What he said :agree:
    Also, a full WC has the aerodynamic properties of a BRICK.

    I have heard they're great for SD with cast bullets, never tried them though
    Also, most WC moulds are plain base designs and I HATE mining lead from my barrels :nono:
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • jbohiojbohio Senior Member Posts: 5,600 Senior Member
    Bigslug wrote: »
    For the same weight, the LFN/WFN concept lets you put more of the bullet's weight forward of the case mouth, which gives you more room in the case for powder. Going with a WFN cut to place the nose as far forward as possible would be the main attraction - at least if you plan to make them scream downrange.

    This. And they look cool.:tooth:
  • knitepoetknitepoet Senior Member Posts: 22,374 Senior Member
    Well, Teach was in the neighborhood for work today, and stopped by for a visit. I let him compare the LBT FN to the SWC and he agrees they are so close that it would take a micrometer to tell the difference.
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


Sign In or Register to comment.
Magazine Cover

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get the top Guns & Ammo stories delivered right to your inbox every week.

Advertisement