MidSouth Shooters SupplyLee PrecisionWidenersLoad Data
Titan ReloadingReloading EverythingRotoMetals2Repackbox
Inline Fabrication
Results 1 to 6 of 6

Thread: .256 Win Mag loads using 4198

  1. #1
    Boolit Master pertnear's Avatar
    Join Date
    Dec 2014
    Location
    Heart of Texas
    Posts
    661

    .256 Win Mag loads using 4198

    I have a Martini Cadet chambered in .256 Win Mag. It has turned out to be "bug-hole" accurate with a 87gr Sierra & H4198 powder load. Most of the older data I have lists "4198" as a good powder in this caliber. So does 4198 means "H4198" or "IMR4198" in these older manuals? My problem is that my H4198 canister is almost dead empty while I have 2 lbs of IMR 4198 ready & waiting. As everyone knows its not so easy to just go out & get some powder. Is the load data between the 4198's interchangeable (assume starting at min loads)? I have several bullets 60,70,75,87 gr that I would like to try.

    Thanks in advance for any comments or info!
    Hard times create strong men, strong men create good times, good times create weak men, and weak men create hard times.

  2. #2
    Boolit Master Jedman's Avatar
    Join Date
    Nov 2014
    Location
    Lenawee County , MI
    Posts
    1,324
    I also have a 256 Win. that has a 1-10 twist barrel and shoots very accurately. I have used I 4198 as that is what I have. I always here warnings that the I and the H are not the same so I would not start at near top loads when switching from one to another but hope you get the same accuracy when you switch.
    I have loaded 75, 87, and 100 gr. with mine and it likes them all. One thing I noticed is I reamed my single shot rifle where the rim recess was just deep enough to close the gun but after firing several loads that my RCBS dies were pushing back the shoulder at least .009 farther than needed. When setting up my sizing die now I use a .009 feeler gauge so when the ram is all the way up and the shell holder has the feeler gauge pressed up against the bottom of the sizing die snugly but able to pull the feeler out with some effort.
    To me it seems like I want the case shoulder as close in headspace as the rim so I am not overworking the brass everytime it’s resized.
    I also have a Zeller martini action that I am chambering in 256 WM with a 1 - 14 twist green mountain blank.
    The Zeller has double set triggers and a one piece stock similar to a schuetzen rifle but mine will have a scope on it when finished.

    Jedman

  3. #3
    Boolit Master Rapier's Avatar
    Join Date
    Sep 2020
    Location
    NW Florida
    Posts
    1,450
    The same numbers IMR and H have slightly different burn rates, similar but different. They are know to shoot the same group sizes with slightly different loads. I would take the H 256 load, reduce it by 10% and then try one IMR round for OP signs. If no signs, work up to a one hole group with IMR.
    The 256 shoots many powders, many bullets and is not a picky cartridge. The little Martini is a strong action, the 357 mag based 256 case is 50k so you should be working with a good safety net, if you start well below a max load.

    I have owned 12, a full dozen, 256 Mag Guns, four were Hawkeye guns.
    “There is a remedy for all things, save death.“
    Cervantes

    “Never give up, never quit.”
    Robert Rogers
    Roger’s Rangers

    There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.
    Will Rogers

  4. #4
    Boolit Master Jedman's Avatar
    Join Date
    Nov 2014
    Location
    Lenawee County , MI
    Posts
    1,324
    I know now is not the time to go looking for new powders but sometimes you can find some oddballs at gunshows cheap, like a year or so ago I bought several 1 pound bottles of AA powders for $ 10 ea. They were AA no.7 and AA 2015 BR, I found the 2015 to be a good powder for the 256 also. It is a very small grained ball powder and is quite dense and meters great. I didn’t do any chronograph of the loads I developed but they were all well under MOA with the heavier bullets so it’s a good powder also.

    Jedman

  5. #5
    Boolit Grand Master

    Wayne Smith's Avatar
    Join Date
    Mar 2005
    Location
    Hampton Roads, Virginia
    Posts
    13,617
    Pertnear, if you have time to play with the numbers get the Serria loading manual. In many loads they give separate data for IMR and H powders. Check their loadings of similar cartridges of each in 4198 and you have some numbers with which to work.
    Wayne the Shrink

    There is no 'right' that requires me to work for you or you to work for me!

  6. #6
    Boolit Master
    Join Date
    Feb 2014
    Location
    North of Palacios about 1400 miles
    Posts
    570
    Sierra manual copy right'ed in 1971 lists IMR4198 start of 13grs to max of 15grs for 87 gr SPP ..

    75gr is 14.5grs to 15.6 grs..... Those are only 2 bullet weights listed..... Todd/3leg

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