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45-70 Trapdoor smokeless loads

Discussion in 'Handloading and Reloading' started by Stormin.40, Oct 19, 2011.

  1. Stormin.40

    Stormin.40 Well-Known Member

    Looking for powder recommendations mainly. I have manuals and am leaning towards Varget 41 grains or IMR 4198 28 grains.

    Would a slower/higher volume powder like Varget being easier on the action but maybe not enough initial pressure to seal the bore? Does Varget burn well at lower pressures?

    Would a faster powder like IMR4198 be too fast and shock the action on a trapdoor?

    I would like to use 405 grain and 500 grain lead bullets. I don't cast so these would need to be purchased, any suggestions would be nice. I like the idea of using Lee's hollow base 405 grain Lead FP.

    Should I use standard large rifle primers or magnum large rifle primers?

    Should I adjust the COAL to my rifles chamber, about 0.001 gap between the bullet and rifle lands.

    Sorry for all the questions, I have never loaded rifle rounds before.
  2. rcmodel

    rcmodel Member in memoriam

    IMR-4198 has been the goto Trapdoor powder longer then I can remember.

    Lyman #49 lists it as the "potentially most accurate" with a Max charge and 405 grain cast bullet.
    It should also work well with 500 grain bullets.

    Varget would work as well, but is right on the edge of being too slow.

    So why reinvent the wheel?

  3. Stormin.40

    Stormin.40 Well-Known Member

    Since this is such a large case is there a need to use mag. primer and/or some sort of filler/wad to hold the powder back?
  4. rcmodel

    rcmodel Member in memoriam


    Any powder that isn't a ball powder is easy to light with standard primers.
    IMR-4198 especially so as it is a relatively fast rifle powder.

    No need for fillers either.

    I think you will find the 45-70 case isn't as big as you think it is when you stuff a powder charge and a 405 or 500 grain bullet down it.

  5. Slamfire

    Slamfire Well-Known Member

    Try AA5744. Accurate claims it was developed for these large blackpowder cases, I suspect they found it and it worked well. Either way it is bulky and provides low SD's and ES's in the 45/70 with good accuracy.

    It also does very well with cast bullets in the 30-30, 308, 30-06 and 303 Brit.

    45/70 Martini Henry 26" Shilen Barrel

    405 LRN 26.5gr AA5744 R-P cases WLR
    29-Apr-04 T = 80 °F

    Ave Vel = 1294
    Std Dev = 14
    ES = 40
    Low = 1274
    High = 1314
    N = 15
    Group Size Very . good

    405 LRN 27.0gr AA5744 R-P cases WLR
    24-Mar-04 T = 70 °F

    Ave Vel = 1284
    Std Dev = 23
    ES = 80
    Low = 1263
    High = 1343
    N = 12

    405 LRN 27.5gr AA5744 R-P cases WLR
    15-Apr-05 T = 75 °F

    Ave Vel = 1363
    Std Dev = 25
    ES = 97
    Low = 1298
    High = 1395
    N = 20

    Group Size good offhand at 100 yards


    Winchester BPCR M1885 30" Badger barrel

    Ladder Sights: 5 graduations per 1/4 inch major.
    1/4 inch major is 25 MOA, 1 grad is 5 MOA, 1 Veriner is 1 MOA

    405 LRN 27.5gr AA5744 R-P cases WLR trimmed 2.085"

    29 May 2010 T = 89 °F

    Ave Vel = 1324
    Std Dev = 9
    ES = 26
    High = 1338
    Low = 1312
    N = 6

  6. Asherdan

    Asherdan Well-Known Member

  7. jerkface11

    jerkface11 Well-Known Member

    Trailboss perhaps?
  8. Tallinar

    Tallinar Well-Known Member

    I've had excellent results with 12 grains of Trailboss and a 405gr RN bullet. Very comfortable load with a high-volume powder.
  9. Dr. A

    Dr. A Well-Known Member

    If you use a lead bullet, you can get by using the above stated Trail Boss. Before trail boss, many of us used this Greg Mushial data:


    I've used several of the pistol powders. In his notes, Greg mentions there is no need for fillers because of complete combustion, especially on position insensitive powders such as Unique. I've used 10 to 16gr. of Unique for 405gr. cast for years. I get aobut 1150fps out of it (13gr) and it is accurate. My son is hunting with it this year. His dose is right at 13 gr. My favorite load is 25gr. of 2400. This is from Lyman 47. Its slightly more position sensitive, but still a very effective load, and depending on your rifle, will give you between 1400 and 1500fps with a 405gr. bullet. Regular rifle primers are preferred, though I use WLR predominantly. I adjust the COAL for my particular rifle simply to cycle. You can order just about any cast, but if shooting a Marlin or H&R, (Ruger as well), you should order a .459 sized and larger for best accuracy. My Marlins will shoot .460 as well.
  10. ArchAngelCD

    ArchAngelCD Well-Known Member

    The only other powder other than IMR/H4198 I would use in 45-70 TrapDoor ammo is AA5744.
  11. Stormin.40

    Stormin.40 Well-Known Member

    Well it wasn't on my list but it was cheap, <1lb can, so I picked up some trailboss. I will probably try IMR4198 and maybe AA5744 later, their pressure to velocity ratios looked good, at least on paper. Need oversized bullets now, .459 or .460. Any good sources? I would like to use either a 405 gr Hollow Base or 500 gr oversized. I haven't slugged by barrel so I don't yet know what I need.
  12. TonyT

    TonyT Well-Known Member

    I have used very light loads of Unique with a 405 gr. cast lead bullet. I am planning to use Trail Boss powder for my next experiemnts with lead bullets in 45-70.
  13. trap1873

    trap1873 Member

    300 gr / Trail Boss powder / 1873 Trapdoor

    New to reloading and the forum. I look forward to learning from you all. In have 50 rounds primed and ready to charge with Trail Boss powder and 300 gr lead bullets. I'm questioning my choice of both the powder and the bullets.
  14. ArchAngelCD

    ArchAngelCD Well-Known Member

    Welcome to the forum.
    Your question would have probably gotten more attention if you started a new thread instead of bringing back a year and a half old thread.

    Trail Boss is a very low pressure powder which was developed to mimic the velocities and pressures generated by Black Powder. Nothing wrong with Trail Boss from what I've read but i do like a 405gr lead bullet instead of the lighter bullets. If you don't like the results you get with TB give AA5744 or IMR/H4198 a try. Just don't load all those cases before you decide if you like the results TB delivers.
  15. joecil

    joecil Well-Known Member

    As for bullets I just got 1000 405 gr lead cast from Badman Bullets. I have several made by others but then I'm loading for a modern lever rifle though using different powders from black powder, trailboss, IMR 3031, IMR 4198 and Reloader 7. Some other bullets I get from either Montana Bullet or Oregon Trail. Montana has the largest selection of all of them.
  16. tbob38

    tbob38 Well-Known Member

    I haven't shot my trapdoor for years but when I did, I used Ideal 457124 385 gr bullets with 3031. 4198 and Unique powders. Used tufts of Dacron to hold the Unique in place. Shot 1 1/2" groups at 50 yds, open sights.

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