It's the twist rate of the barrel, not the length that produces stability. I don't shoot them myself, but I have seen several members post that they use them. The barrel twist rate for the 1895 is 1:20" which was likely selected for the 405gr bullet.

Strictly speaking, it is the length of the bullet, rather than the weight, that requires faster twist. However, heavier bullets are longer than lighter ones, so it is shorthand to just say "heavier". And it is the imparted rate of rotation to the bullet that imparts stability. For instance, bullet shot at 1000 fps through a 1:12" twist barrel would be rotating at 1000 revolutions/second, or 60,000 RPM. If it were shot at 2000 fps, the rotation would be 120,000 RPM.

Is a 1:20" twist rate enough to stabilize a 500 gr bullet from your Marlin? You'll have to try it to see. A lot will depend upon what you want it to do. If you want it to stop a charging grizzly at 20 yards, no problem. Stability won't be an issue. If you want it for silhouette or target at 200 meters, maybe not. Somewhere between? It may be ok for your purposes. Buy some and have a go at it.

Bullet diameter may be an issue also. FWIW my 1895 will keyhole 405gr bullets that size 0.457 at 50 yards. However, it does fine with 405s sized to 0.4595 or larger. Shooting cast bullets can be an adventure. You should slug your barrel so you know what you're dealing with. General wisdom is that for best results, the bullet should be 0.002-0.003" larger than your barrel's groove diameter.

 

A few years ago I shot 535g postel bullets in a 1:20 twist 45-70. I used started at about 1,100 fps and slowly reduced the powder charge. The bullets started to keyhole right at 900 fps.

BB

 

My GG loves the 500 gr cast bullet.. I push them 1325 fps in a ballard rifling.

vid was a bad attempt to show the test was real... but ain't no one who has a YT that has pushed a bullet further that I know of.

 

ME,

Excellent video. Also, proves my point that normal purchased hard cast bullets do not expand at mid velocity ranges. Here is a 30-1 cast 365 gr PBB moving at 1,450 fps taken from a soft sand back at 110 yards.

It retained around 80% of the original weight and expanded to 82 caliber. As you can see, this bullet is a target design not a hunting meplat bullet. I would think a bullet with a 33 to 36 cal meplat would be an even better combo for hunting with 30-1 alloy.

The soft alloy transfers much more energy with fast deceleration due to expansion. Hard cast, unless shattering bone creating more projectiles, is a clean through and through wound unless the bullet impacts at over 1,700 fps creating hydrostatic shock.

This is one of the oldest conversations/debates I remember. Fat, Slow, Flat Point bullets vs. Slim, pointed, high speed bullets. The best news about the 45-70, you can have them both with bullets in the 300-350 gr range in a modern rifle!

 

The picture shows how finicky my 1895GS is with Beartooth's 525 grain Piledrivers and different charges of Reloader 7. Inaccurate to accurate. I would suspect you'll experience the same in your hunt for the right load combination working toward to the fps goal you set.

 

The picture shows how finicky my 1895GS is with Beartooth's 525 grain Piledrivers and different charges of Reloader 7. Inaccurate to accurate. I would suspect you'll experience the same in your hunt for the right load combination working toward to the fps goal you set.

View attachment 684049

Nice! I’ve got some 525gr Piledrivers and plan mae some loads with RL7. Can you share more details on your loads? Do you think there will be any issues using Winchester Magum Large Rifle primers?

 

I cast a nice NOE 530gr and they shoot well.

[HR][/HR]$103.00460-530-FN RG2 cavity GC (45-500-FN RCBS)
[AE3]

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460-530-FN RG2 cavity GC (45-500-FN RCBS) Comes with HP, FN and Cup Point Pins

 

fortyshooter,

Here is a link to a twist calculator. If you know the bullet length and desired velocity, it will calculate the minimum twist rate needed for stable flight.

Barrel Twist Calculator

I think you will find a bullet up to 1.1" long will stabilize well in a 1 in 20" twist rate at 1,000 fps. Depending on the design, say a wide meplat design, around 460 gr is about the limit. A longer rounded nose in the same weight will be longer and be too long.

Most of the black powder shooters using 500+ gr bullets have at least a 1 in 18" twist rate.

Additionally, if you plan to use for hunting, the typical hard cast bullets will not expand at subsonic velocities. You will need a lead-tin alloy in the 25 to 1 or 30 to 1 range for positive expansion.

You are on the right track for velocity expectations with the heavy bullet option. If you cast, here are a couple of designs by Accurate you may find useful. Look through Tom's catalog for many many more design options for the .458-.460 caliber. I have more molds for the 45-70 family of cartridges than any other. (240 gr to 535 gr )

 

That video is neat. Gallon milk jugs or 2 liter coke bottles full of water and capped tight are my favorite reactive targets. When our youngest daughter was going through her divorce, she liked to pound them with a 12 gauge from about 25 feet. She could make standard field loads launch them into orbit at that range. hahaha

 

Right from the getgo I assumed my 1895s ROT to be ideal to stabilize the generic 405 gr gov't issued bullet so I set my upper limit at 430 grains for hardcasts.
Even the 430s started to wander after 40 yards.
My 390 grain hardcast load is accurate out to 100 meters.
If other people want to fire 'car batteries' from their 1895s by all means be my guest and go for it.
If I didn't think the 390 grain hardcasts I'm using couldn't drop any game in North America I'd get a 460 Weatherby or 505 Gibbs.
You won't read my range reports on either the 460 or the 505 because I don't need either of them.

 

I haven't tried the 500gr but I shoot the Accurate mold 465gr and it works extremely well out of my SBL. If you give it a whirl get back to us and let us know how your load development is going and the accuracy results.