.45-70 / NOE 400gr / Alliant 2400 = questions

[Rick R]

I'm sure this has all been covered before but my search fu must be weak. I have two Marlin Guide Guns and last year purchased a used H&R Buffalo Classic rifle for more than I should have paid, but it's a cool old rifle you don't see on the for sale rack often. I added a Williams target knob rear sight and a slip on neoprene recoil pad/cartridge holder. Basically I see the Buffalo Classic as a range toy. My area ranges are limited to around 300 yards and I'd have to change the front sight to use a 500gr boolit.

I normally use an NOE 360gr Ranch Dog bullet in the Guide Guns at a bit over 1,900 fps, they shoot sub 2" groups at 100 yards, slay deer and work pretty well in several friends guns too. I tried that load in the H&R and it hurt. Shoots decent groups but it makes my .458 Lott seem gentle. I then tried some 405gr bullets from a Lee mold and they shoot pretty decent groups (approaching 1" at 100 yards) over 24 grains of Alliant 2400. Life is good right?

When do we ever stop with "good enough"? I decided that I needed a better grade of 400gr bullet so I ordered an NOE 400gr mold and it drops purty boolits. They make real thumpers in the Marlins loaded over Varget, accurate and probably enough for Jurassic Park. They work well in all rifles using the 24gr/Alliant 2400 recipe except that when they are seated into the crimp groove as they should be for the Marlins they're too long for the throat of the H&R. It makes the gun hard to close and occasionally the round will get stuck in the chamber hard enough that the ejector won't eject the loaded round. The edge of the boolit nose shows where the leade begins to engrave as the action closes. Loaded short the NOE boolits do shoot better than the Lee boolits which don't engage the rifling when loaded to the crimp groove.

1) Should I have the throat of the H&R lengthened to accommodate rounds loaded for the Marlins? Or just segregate for each rifle?

2) Does it cause pressure problems if the boolit is jammed into the rifling at ignition or should it get a running start?

3) When using Alliant 2400 in the .45-70 I've seen advice to use a poly filler and then I've seen that it's not needed. What does everyone think of that? And can you substitute a half cotton ball for the poly fill? I hate the smell of burning plastic when I shoot.

Thanks in advance for any advice.

[fredj338]

Rethroating, your call.
yes jamming the bullet into the rifling raises pressures, so backing off a bit is advisable.
I have always used poly filler with small charges of handgun powder in the 45-70. Try both ways, see if it improves vel. Cotton instead, never tried it bit it takes very little over powder wad to hold powder in place.

[Larry Gibson]

If you want to use the same ammo in all 3 rifles then throat the H&R.

No, jamming a cast bullets will not raise the pressure to any degree. It is barely measureable and many times not measureable. That is based on measuring the pressures in my own rifles, including the 45-70, not conjecture.

If you can use H&R specific ammo then seat the bullet deeper so it chambers normally in the H&R. No need to crimp in the crimp groove with a SS rifle. Taper crimp just enough to close the case mouth flair. I suggest the use of a 1 gr Dacron filler over the 2400. Use it as a filler and do not tamp down as a wad. I use the Dacron filler with 350 - 413 gr cast over 2400, 4227, 4759, 5744 and 4198. The benefit comes in keeping the powder position in one place against the primer when shooting at all angles and from all carry positions. That improves consistency of ignition and burn giving better accuracy with less vertical string at 100+ yard ranges.

Larry Gibson.

[2ndAmendmentNut]

1.) If you are getting 1" at 100yards I would simply segregate your rounds. One load to work in all guns is convenient, but will not necessarily result in the best accuracy across all the rifles. If you really must have one load for all I would recommend having the H&Rs chamber lengthened.

2.) In a single shot with cast boolits I personally think contact with the rifling is ideal. If you are having issues with closing the action and ejection of live rounds you should probably consider a boolit with a different style nose or lengthen the chamber.

3.) Fillers with smokeless is a no in my books. Sure a lot of people do it, but I'm not going to recommend it. Besides I have never noticed 2400 to be position sensitive in any of the various calibers I have used it in. Do you get inconsistent velocities? Personally I like powders that take up more case capacity in the 45-70, such as RX7 or real black powder. 2400 in the 45-70 used to be an old standard load, but my current load manuals have no data on it. I would use up to date load information.


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[Tenbender]

I have a Knight 4570 . Single shot break action. My loads are left a bit long with no crimp. That pushes the boolit back in the case when chambered. That way it touches the lans and is not jammed in.

[Rick R]

Gentleman,
Thanks for the words of wisdom!
Since it's shooting so well I believe I'll leave the throat as is for the time being. I plan on loading fifty rounds for the H&R and segregating them for it alone.
Next is try some with filler to see if the occasional flyer is the shooter or the ammo. Maybe I'll learn something that translates to my other rifles along the way.