45/70 Accuracy Issues

[huntingsgr8]

A friend of mine has a a nice Marlin 1895 CB with a 26" barrel, he loads for it using Varget, 4198, and home cast 405-459-hb bullets from a Lee mold, lubing with Alox. His lead is very, very, very, hard, I suspect pure Linotype, it will not lead his bore even in the absence of lube. I've slugged the barrel, the bullets are coming out the right size, bullets recovered from a snow bank show no signs of skirt blowout. 55grs of Varget behind one of those bullets, and it will only do about 8" at 50 yards. I fired that group, then with a 50gr load of 4198 and 405gr Speers instead of cast, I printed one of about 1.5". So, in my mind there's something up with the bullet. Is it possible for a bullet to be too hard to shoot well? I'm out of ideas, I shoot cast in most of my handguns, cast bullets aren't unfamiliar territory to me, but this has me baffled. Could it be that the bullet just doesn't want to perform at this high of a velocity? Weight variation of a random 10 showed 3gr of extreme spread, all average around 396-397gr.

[waksupi]

Make them softer, and lube them.

[huntingsgr8]

I will experiment with softer ones, they are being tumbled in Alox as it is.

[Grmps]

55grs of Varget is a bit hot try backing that off . Lyman calls for 42.0 to 46.5 grns varget for that boolit weight

Just curious, does he want to get a big bang and kick or be accurate

I agree with waksupi the boolit is too hard, try 12 - 15 bhn

[Hickok]

I would back the velocity down and start from there loading up until the boolits start to scatter. Start at about 1200 fps and work up. The Lee hollow base boolit is not meant for high velocity. Like Wasupi said, soften up the alloy.

I have an 1895 Marlin 45/70 and it is amazingly accurate with cast boolits.

[waco]

My Marlin shoots best with a .460" boolit. A softer alloy will help too.

[country gent]

With the mentioned load the skirt may not be blowing off but worse it may be deforming flaring and destroying accuracy. I would also recommend casting them softer ( My 45-70 bullets are cast from 20-1) Lighten the load down to trap door levels mid or just below and work up to point of accuracy for the rifle bullet combo. Another thing you might try is to finger lube a few with spg instead of the alox tumble coat. Use your finger to pack the grooves with SPG and then cut excess off with a fired case mouth. You might give some solid based bullets a try also.

[44Blam]

I cast with range scrap about 6:1 linotype and I get nice hard boolits. If it's ww lead, I'll make it more like 7 or 8:1.
I resize them to .460 and I shoot two designs. Both are NOE molds with the flat/cup/hollow point and one is 350 grn and the other is 405 grn. They are also both gas check designs. I shoot them pretty stout - the 405 grn boolit I load around 52 grn of varget and the 350 grn is about 56 grn. This is under the max by a few grains but are right under my threshold for recoil. I just powdercoat and gas check them. I get reasonable accuracy and I don't have any leading.
I chrono'd 5 of the 405s the other day and they were doing between 1803 and 1831 fps.

[Walks]

I use the LYMAN #457193 - 405gr FBFP over 44grs of IMR3031. Cast of #2, I've used this load in my 1895CB and older 1895 for a Looooong time. Given good accuracy of 2" at 100yds, 3 shots with Peep Sight.
Doesn't seem to matter if Micro-groove or Ballard rifling.

Forgot to tell Ya the bullets drop at .460 and I size .459 for both have .458 bores.

[huntingsgr8]

I forgot to mention that as cast the bullets are .460-461, the bore slugs at .460.

[kungfustyle]

May want to go .462. You could powder coat to get another .o1. You didn't mention if they were gc'ed. Soften the lead up to about 12 to 15 gc and size to .462 and re-work up the load. If its a pb boolit keep it at 15 or so and stay under 1400 fps or so. You may want to try a different lube too, never had great results with just alox. I had a 45/70 that wanted to be driven faster than a pb'ed boolit wanted to go. Good luck to you.

[Wayne Smith]

It's a HB boolit, I doubt anyone added a gas check. My question is: Why that boolit? It's designed for BP and oversized trapdoor barrels, not high pressure Marlin loads. There are dozens of designs more appropriate to what your friend is doing.

[Bird]

Use starting trapdoor loads and work up.

[huntingsgr8]

It was just the mold he bought when he got the gun. The only 45/70 mold Amazon didn't want 60$ for. I have considered powder coating, as that's what I do with my 357 and 44

[Petander]

That was my first 45-70 mold some 20 years ago. Shot thousands of those,that was my main subsonic bullet.

My understanding is the hb design is for trapdoor / bp loads with softer alloy to obturate. I never tried to push mine hard, neither tried it with a hard alloy. There are many,many 45-70 molds for modern loads available.

[Larry Gibson]

As mentioned you are pushing that cast bullet way to hard (fast). Drop back to listed TD loads for use with that bullet. Otherwise if that level of velocity is wanted then a GC'd 400 +/- FN bullet would be the right answer.

The "HB" on the lee 405 bullet is not really a HB as is in a Minie' bullet. The Lee bullet is a replica of the 1873 bullet and the "HB" is actual called a "dish". It is there to regulate the weight of the bullet given consistent external dimensions. It is not there to expand into the grooves ala a Minie' bullet.

[MostlyLeverGuns]

No offense but Amazon has 2 Lee molds, a 340gr($27) or 405gr($22) for the 45-70 well under $60, just looked. If you run a hollowbase, you need softer lead, more lube and less velocity, like everyone has advised. A faster powder might help with obturation, but I think your bullet design is part of the problem.

[huntingsgr8]

They do now, they did not when the gun was purchased a year ago, keep in mind that being on the north side of the border things are a bit more expensive. The 340 is 34.55$, the 405 is 46.62$, the 450 is 37.52$. I believe he paid 32 or 34 dollars for the mold he has, he's still a full time student so he's on a budget, and more so after spending 1300$ on a brand new 1895 CB w/26"bbl. The next time he gets some time to himself, he'll come by with his gun and his gear and we'll experiment with the suggestions of reducing velocity, changing the alloy, and improving lubrication.

[a danl]

when was your gun made? was it made by marlin or later by remington? the problem of no accuracy ,, the first thing to do is examine the rifling on a recovered bullet to see if there is gas cutting , if there is then you almost have to start over with a different bullet mold. i believe the one you're using was meant to be used with softer lead and at trapdoor speeds around 1300 fps. if your gun has "jm" stamped it was made by marlin and that would be better.

[huntingsgr8]

It was made by Remington.

[longbow]

I'm betting that you are getting gas cutting at the heavier load. Check the outside of the bottom driving band and I bet you see smooth ripples from gas cutting. You may need a magnifying glass but I bet you see some smooth and shiny uneven ripples on that bottom driving band.

I used to shoot a lot of cast boolits through my converted Siamese Mauser back in the 70's and with the hottest loads (top end Ruger #1 and Siamese Mauser rated) I got just a bit of leading near the muzzle with PB boolits. My solution at the time was to add a .410 fiber wad and that stopped it.

I did not have the leading issue with my 1895 Marlin but of course was using Marlin loads for it so a little less poop.

As mentioned,using a boolit of 0.462" may help if there is some gas cutting. Slightly softer boolits may help too but also as mentioned, even with the thick "skirt" he may be getting some flaring now and even if not could well do with softer boolits. A flat base boolit would be a better choice for heavy smokeless loads... in my opinion anyway.

Longbow

[EDG]

What I found that seems to work in all .45-70s as long as rhe bore is decent. If you have tight spots at sight or magazine hanger dovetails you may have problems with cast bullets. You can have tight places in the bore if a banded fron sight or front sling band was installed too tight..
The following is what has worked for me.
1. Bullet metal is 20 to 1 tin lead = 10 brinell to clip on WW at 13 brinell.
2.bullet is .002 oversize. I have actually shot bullets as large as .004 oversize.
3. Velocity is regulated by the powders in the range of 2400, 5744, SR4759 and 4227. Do not use the similar burn rate H110 or WW296.
4. Powder charge of 5744 and SR4759 IS about 23 to 25 grains with heavy bullets.
5.i use only strong single shots so these loads may not be good for an old antique.
6. Bullet lube is 50-50 alox and beeswax.
7. No gas checks

Check your bore after each shot for unburned powder kernels.
If there are dozens of unburned grains you can increase the powder charge a grain or 2 in a strong rifle. The increased pressure will burn more of the powder. Having your cast bullets run over unburned powder is a good way to degrade accuracy.
Velocity should be somewhere between 1000 fps and 1300 fps.

I get groups near 1" at 100 yards with good bullets using aperture sights on Browning 1885 BPCR rifles in 45-70 using a 500 grain bullet.

I get similar groups using similar 312 bullets with gas checks in a .40-65 Browning.

[a danl]

something i have'nt seen or heard on this forum is something i have been doing for many years. i use a flat base bullet in my trapdoor with a 45cal gas check seated upside down in the case and i seat it with the bullet itself. it will only work in a straightwall case . the inverted gascheck acts as a wheel cylinder cup and expands to seal the hot gases . as i found out trapdoors have a wide variety of bore dia. it should be used as per example with a powder that is bulky like imr3031 that way there isn't much room for it to become lodged. i have never had that problem. doing it this way the bullet just slides out the barrel with absolutely no gas cutting.

[osteodoc08]

Slow it down, soften it up and use a better lube is my suggestion. I use a 405gr FN GC design with the levels of Varget you’ve mentioned and get superb accuracy. My go to is 50gr Varget. I’ve been able to shoot several sub MOA groups with that load if I do my part.

[GregLaROCHE]

My Marlin has always been very forgiving no matter what I feed it. However, I’ve only used solid based boolits. My alloy is pretty hard too. I would try some different boolits. You don’t have to buy a mold. Just buy some different cast boolits. There are lots of different ones for sale on the internet.

[hanleyfan]

what I use is a lead hardness around 12-13 and powder coated 405 boolit with 43 gr. of 4198 get right at 3 in.groups at 100 yards. I have gotten 3 deer with this load all pass through

[WHITETAIL]

+1 on softer boolets
and a flat base
But I also use a wax paper card.
I got a punch out of MID-WAY
and cut cards from milk cartons.:cbpour::holysheep

[GregLaROCHE]

+1 on softer boolets
and a flat base
But I also use a wax paper card.
I got a punch out of MID-WAY
and cut cards from milk cartons.:cbpour::holysheep

With those cards, are you shooting BP or is this something with smokeless, that I haven’t heard about?

[GregLaROCHE]

Have you verified that those micro grooves are all clean. No lead or copper in or around them?

[huntingsgr8]

It's "Ballard" rifling, not microgroove in this one. And I haven't got it on hand to check, but it grouped well with commercially made bullets, so I don't think fouling is to blame.

[dubber123]

I have the same gun, and it was a chore to get it to shoot well. I ended up with mid range loads, and cast and size large, (.462"). I have since gotten it down to sub 1" at 50 yards using the iron sights. If you get vertical stringing, check the mag tube for tension/binding. Mine had it and would string over 4" vertically until I fixed it. Good luck.

[WHITETAIL]

I shoot a Marlin CB and the load is IMR- 4198 with a wax card
under the cast 405 NOE boolit:cbpour:

[GregLaROCHE]

I have heard that the new .45-70s had issues with the full length tube. The original load tubes were produced with only enough for four. The heavy rounds would have an effect on accuracy as they were used up and affecting the balance and maybe harmonics of the barrel.

Maybe someone else can add to this. It’s just something I remember once reading.