Skip to main content
Help Center Community Shop

45-70 grouping with different powders

vepr762
I have a Marlin 1895 Cowboy. I like to load the Hornady 300gr HP's to about 1800fps. I was getting good accuracy with 4198 at 100 yds, but when I switched to 3031 the groups REALLY tightened up. Is it because of burn rate, air space in the casing, or..?

Thanks
0

Comments

9 comments

Date Votes
  • nononsense
    vepr,

    Tell us what each load for each powder is and we can be of more help. Did you change any of the other variables? Did you change your rest or rest position? More information, please.

    Best.
    0
  • Throckmorton
    After reading zillions of posts on firearms boards,I'd have to say that ,yes,powder is part of the accuracy 'equation' on any firearm,and 3031 is a favorite of many rifle shooters.
    I know that in my handguns different powders are more,or less,accurate.


    Throckmortons' the alias,cas is the game.
    0
  • vepr762
    I load right out of the Hornady book. The 3031 load is about 25% larger than the 4198 load, for the same listed velocity. I shot off of sandbags, 3 five round groups per session, on different days. 4198 on Saturday and back Sunday with 3031. Weather was about the same, as was the time of day.

    Hope this helps.
    0
  • MIKE WISKEY
    IT MEANS YOUR BARREL LIKES 3031 BETTER THAN 4198, NO TWO BARRELS/RIFLES MADE WILL EVER ACT THE SAME. BARREL VIRATIONS, INTERNAL STRESS, BORE DIA., TYPE OF RIFLING, PHASE OF THE MOON, DEM. OR REP. PRESIDENT, ALL WILL AFFECT VELOCITY/GROUP SIZE/ACCURACY FOR A PARTICULAR RIFLE (DID I MENTION THE NUT BEHIND THE TRIGGER)[:D].
    0
  • vepr762
    Great! I'm having the action and trigger worked on by a smith that happens to be the former Oregon state CAS champion. Now I'm really gonna have figure out what I'm doing right and wrong. ;-)
    0
  • nononsense
    vepr,

    You're in that "Twilight Zone" of ammunition testing when you switch a component and all of sudden there is either a significant good or bad reaction to the change, from the firearm. Good changes are usually accepted with gratitude and no questions. Bad ones, everyone wants to know what happened?

    I had the opportunity to work up a load for a friend of mine who drew into a fairly thick wooded zone for deer. He wanted to use his 1985 because of the zone so I called Barnes for some back up information to what was written in their manual for the lever guns and the 45-70. I asked a question similar to yours but for a different reason. The answer I got proved itself to be true when I ran the test loads. IMR-3031 ran about 100+ fps faster than the IMR-4198 load at the same (approximate) pressure. There is a difference in the case volume also; the 4198 occupies about 75% of the case while the 3031 is up at about the 90% mark.

    My suspicion is that the additional velocity is in the "sweet spot" for your rifle while the lower velocity puts you on the outside of the sweet spot. It just means that the barrel vibrates in such a pattern that the bullets exits the barrel more consistantly or more repeatably. All of the good variables came together in your rifle to provide improved accuracy when you switched to the IMR-3031.

    Best of luck.
    0
  • vepr762
    Thanks NoNonsense. I guess we're also talking "barrell harmonics" if I only shoot single shot and not from a full mag tube, right? A full magazine would probably have different results.
    0
  • nononsense
    vepr,

    That's correct. Any change, in any variable, which includes the weight and the position of a weight on a firearm, will affect how the firearm vibrates, which will have some effect on how well or poorly it shoots. But the difference may not be significant.

    The Boss-cr is a good example. It's a weight out on the end of a rifle barrel, that is machined to allow very small, accurate changes in the position of that weight in relationship to the muzzle. These weight/position changes affect the barrel harmonics or wave pattern, allowing the shooter to "tune" his load.

    I'm not sure how much/little of a difference that you'll see in a lever gun especially with open sights. I haven't noticed any significant changes when working up loads as opposed to hunting with a full or nearly full tube. The shorter (stout) barrel may have more of an control factor over the harmonics than the magazine tube weight. I see more changes in groups from the position of a lever gun on bags than with the tube full or empty. But the change in the way the rifle vibrates will be affected whether it is significant or not.

    Best.
    0
  • chuck
    3031 Works great in my 45-70 Ruger #1 I can load it down to factory or up to 458 win mag, But on top end it HURTS.
    0

Please sign in to leave a comment.

Recent Activity