1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Questions about CRIMPING .45/70

Discussion in 'Handloading and Reloading' started by Mullins81, Mar 31, 2010.

  1. Mullins81

    Mullins81 Well-Known Member

    I am new to reloading....I plan to reload for a Marlin 1895 Cowboy rifle. Another member suggeted that if I use plain lead bullets I should use the "cowboy" die set and a "seater plug" because the die alone will not seat a round or flat nose bullet correctly. Where do I find a "seater plug"....I have been on RCBS website and cant find anything. Also he stated that when firing ammo in a Marlin a heavy crimp is needed. I am going to be reloading mostly plain lead bullets, but I am unsure of the size yet....maybe 405 gr or 525 gr beartooth. What kind of die wil give me the crimp I need? Should the crimp be done at a seperate stage on the press or will a RCBS press do it while seatng the bullet? Any info will be appreciated. Thanks in advance.
  2. Ridgerunner665

    Ridgerunner665 Well-Known Member

    The seater plug comes with the dies (cowboy and regular)...but RCBS only has a 1 seater plug with their 45-70 dies...it is for round nose bullets. The seater plug for flat nose bullets from 45acp pistol dies can be used in its place. Call RCBS...they'll know what you need when you say seater plug for flat nose 45-70 bullets...or just ask for one for 45acp flat nose bullets.

    Crimp...there are 2 reasons for a good crimp in Marlin rifles. 1 is to keep the bullets from getting pushed deeper into the case during recoil. 2 is accuracy...in my experience with the 45-70, it likes to be crimped good.

    I crimp cast bullets that have a crimp groove with RCBS dies...in a separate operation, not while seating the bullet (its more consistent that way, and doesn't damage the bullet).

    For crimping bullets like the Remington 405 (no crimp groove) or similar...the Lee factory crimp die is a must have. Some bullets that can be used in the 45-70 have a crimp groove, but its in the wrong place...the Lee factory crimp die will make its own crimp groove in the bullet as it crimps.
    Last edited: Mar 31, 2010
  3. Ridgerunner665

    Ridgerunner665 Well-Known Member

    And...you can use the round nose seater plug with flat nose bullets. But its not the ideal situation...as it may booger up the edges of the meplat on flat nose bullets, which won't do accuracy any favors.

    The cowboy dies may have a different seater plug...but the plain RCBS 45-70 dies, only have the one for round nose bullets.
  4. Mullins81

    Mullins81 Well-Known Member

    Thanks for the clarification....I have found a place here in Canada that makes cast bullets


    They make a 450 gr cast bullet...it is a round nose flat point with 4 lubricating grooves and a beveled base...it measures .459 in diameter which is what you recommended to me last night....would you have a look at the wesite and let e know your opinion on this bullet....I can get these REALLY easy....overnight...lol...
  5. Mullins81

    Mullins81 Well-Known Member

    When you get to the site click "price list" on the left to see the bullet selection
  6. Ridgerunner665

    Ridgerunner665 Well-Known Member

    I'd get the 420 grain 45-70 RNFP GC TLG if it were me...you'll need that gas check in my opinion.
  7. Mullins81

    Mullins81 Well-Known Member

    What is the purpose of the gas check, just seals the bullet better?
  8. rcmodel

    rcmodel Member in memoriam

    Protects the bullet base from gas cutting when running high pressure/velovity loads.
    Also helps to prevent heavy bore leading by sort of scraping out the previous shots lead the next shot.

  9. Ridgerunner665

    Ridgerunner665 Well-Known Member

    Yes...and it also serves to clean some of the lead out of the barrel with each shot.

    If you are gonna load that 45-70 to its potential with those bullets (appx. 1,850 fps), you'll need the gas checks.
  10. Mullins81

    Mullins81 Well-Known Member

    ok thanks...all this is starting to make more sense now....thanks guys...when you looked at the site did they look like "decent" bullets....I noticed the 420's only have 3 lube grooves...also will i still need the lee crimper or will the RCBS set of 3 dies do the trick?
  11. Ridgerunner665

    Ridgerunner665 Well-Known Member

    They look good to me...I didn't look to see if the hardness was listed on there. (Edit: the hardness is 25, thats plenty hard enough)

    The 3 lube grooves will be fine...just be sure to check them before loading them...sometimes you get a bullet with grooves, but no lube. (usually one or two per box)

    The RCBS dies will crimp those just fine....size and flare the brass, trim it to 2.095"...then seat the bullet until the top of the brass is even with the top of the crimp groove in the bullet (do this simply by looking at it). This is to ensure that brass is crimped into the entire groove...and not just barely crimped.

    When the bullet is properly crimped...the brass should butt right up next to the lip on the bullet...the lip on the top of the crimp groove.

    pic added for reference...

    Last edited: Mar 31, 2010
  12. rcmodel

    rcmodel Member in memoriam

    RCBS seating die will crimp it just fine.
    The ring around the bullet with no grease in it is the roll crimp groove.


    This bullet has no crimp groove so you would crimp over the shoulder of the front driving band. (For single-shot rifles with no magazine tube problem)

  13. Mullins81

    Mullins81 Well-Known Member

    Ok sounds easy enough...lol...you guys have been MORE than helpful...thanks a million...maybe seems like stupid questions but when you're a newbie all this is a lil overwhelming to take in at once.....I also bought "THE ABC's OF RELOADING"...it is a really good starter book. If I need ya again, I know where you are...lol...
  14. Ridgerunner665

    Ridgerunner665 Well-Known Member

    That ABC's of Reloading is worth every penny you paid for it and then some...

    We are here...when/if you need us.

    Just be safe...if you have doubts, ask first before proceeding because the only stupid question is the one not asked.
  15. Mullins81

    Mullins81 Well-Known Member

    which kind of brass is best??...i have my choice between winchester and remington...thats all i seem to be able to get my hands on up here in Canada....
  16. Ridgerunner665

    Ridgerunner665 Well-Known Member

    I prefer Remington...
  17. David Wile

    David Wile Well-Known Member

    Hey Mullins,

    I got a Marlin Cowboy back in May of 2001, and my first reloads were done on my RCBS Rockchucker using a real old RCBS 3-die set. I started with some commercially cast bullets, but they were not gas checked, and I did not like them. I bought two RCBS mould blocks: one a double cavity 300 gain gas checked bullet, and the other a single cavity gas checked bullet. Both bullet designs were exactly the same other than the lighter bullet was shortened enough to make a difference of 105 grains. I like my own cast bullets much better than commercially cast bullets, and I now make my own aluminum gas checks for the 45-70.

    After arriving at some loads I liked using the single stage press, I decided to start reloading the 45-70 on my Hornady LNL, but I found my old RCBS dies were not long enough to easily adjust in the thicker LNL press. I bought a regular 3-die set of Hornady dies in 45-70, and they work just fine with the LNL press.

    All my 45-70 cases are either Remington or Winchester, and I cannot tell any difference between them. When they were all empty at the same time, I sized them all, trimmed them all to the same length, and then chamfered all the case mouths. This process allowed me to set the seating and crimping die so that one operation with the third (seating & crimping die) would seat and crimp the finished round at the same spot on the bullet and without shaving any lead. If you have cases of different lengths, you will not be able to seat and crimp the bullet at the same place.

    Also for your consideration, once you trim and chamfer your cases to the same length, you will probably not have to trim and chamfer for a very long time since straight walled cases like the 45-70 do not lengthen over use like happens with bottlenecked cases. I cannot see why you will not like the Remington and Winchester cases.

    Best wishes,
    Dave Wile
  18. Mullins81

    Mullins81 Well-Known Member

    Thanks David, our advice is much appreciated. As much as I would like to cast my own bullets, I think I will wait until I am experienced in reloading before i attempt it...lol...that IS my goal though, eventually...I will probably go with the remington brass if it is just as good as the winchesters due to the fact it is a lil cheaper here.
  19. Mullins81

    Mullins81 Well-Known Member

    Also, how do I know what I am going to need for primers? There are so many different brands and they all seem to have their own "numbers" which i'm guessing means for different applications....any advice?
  20. Mullins81

    Mullins81 Well-Known Member

    i was thinking of using the CCI BR2 primer like ridgerunner recommeded....what is the difference between standard and benchrest??

Share This Page