What do you guys think about using hollow base bullets with and under bullet wad in 45-70?

I and thinking of using hollow base 405gr bullets in my trapdoor. I'm just wondering what will a .060 gasket material wad do under the bullet. Will the bullet skirt still expand whent fired? is the wad neccesary with the HB bullet? I really want to get an accurate load for this rifle so I can bag some deer with it next year.

I am using 777 powder and spg lube and getting 1270fps with a 450gr flat base bullet and a .060 wad with a standard deveation of 7.48fps using 60gr of hodgedon 777 bp substitute. The only issue I'm having is that the bullets are key holing. I posted about this before but my bore is mirror shiny with only a few patches of pits. I am sizing them to .457 and the bore is .458 or so. I am using range recovered lead so I dont think the hardness is and issue. So I think that a .459 HB bullet will help. I just dont know about using a wad with them.

I'm no black powder shooter, but I shoot a lot of cast. You do want to be .001 over grove diameter I think, but what is the purpose of the wad?

Lead that is too hard might be an issue. A hardness tester is a good idea if you are shooting a lot of cast. I'm using an old one that has been out of production so I can't recomend you one though there are at least a few modern one on the market.

You want to make sure your bullet weight is also right for the riflings rate of twist.

Let us know how it works out after you do some more tests.

The wad as I understand it is to prevent gas blow by causing the melting of lead and lubricant. The lead should be in the ball park of correct hardness based off the fact that it is recovered bullet lead. But I have considered buying a lee lead hardness tester.

The rifling in my trapdoor is supposed to have been desinged around a 500 gr bullet as used by the army at the time so the 450's shoudl stablize fine.

I'll post my findings in the future.

I'd be concerned the wad would be stuck in the hollow base of the bullet.

With black powder (I don't know about 777) you want the bullet quite soft. I use a 30 : 1 mix of lead : tin. This gives a BHN of 7-9. Most cast lead you find in the backstop of your range will be the "hard cast" lead of 16 BHN or higher. This super hard (for black powder) lead combined w/ the undersize bullet would likely cause a bunch of gas cutting. Did you have any leading in the barrel?

The other thing that is very important in shooting BP (I don't know about 777) is the bullet lube. It must be very soft and of the correct make up to keep BP fouling soft. I use a simple 50:50 mix of beeswax and peanut oil. It's roughly the consistancy of lip balm.

Yor standard deviation #s tell me you are doing most of the loading correct there's just one critical element missing. I hope it's as simple as bullet sizing and/or alloy. Good luck.

the wad getting shoved into the base was my concern too. the lead I have been getting from the range is fairly soft compaired to wheel weights but I would like to get an actual bullet tester of some sort like the one that lee sells to find out. I am using SPG lube which is great and there is always a ring of it on the muzzle that indicates that enough of it is being deposited through out the bore. the leading I have gotten is very minimal. only one or two small flakes of lead on my lewis lead remover. its about what I see in my enfield musket shooting pure lead bullets.

I also did some checking last night and measured the slug I made of the bore as well as a sized bullet. the grove dia is about .458 the land dia is about .452 the bullet dia is .456-.457 so that would be part of the problem. it is difficult to get accurate bore dimentions on a 3 groove barrel however,

Heres a cheap way to measure hardness:

I've used this with good results

ETA: I use the ball bearing method descibed in the article.

I haven't reloaded for a black powder cartridge rifle.

But I too shoot a lot of cast lead bullets, both in handguns and modern minnie balls in my ML rifles.

I've seen a lot of keyholing when I start pushing soft lead bullets too fast.

I've also gotten terrible accuracy using the hollow based modern minnie balls and 777 powder. If I use pyrodex charges of the same amount or drop the powder charge down a bit I get very good accuracy.

I think you might be pushing those hollow based bullets too hard and blowing the skirts off of them.

Very possible but... He isn't using the hollow base bullet yet and 1270 fps is right in the ballpark of what I shoot my .50-70 w/ the 30:1 lead tin alloy. (I got 1258 fps w/ std. dev. of 9 using real BP last time I chronographed it this fall.)

Now his problems could be something particular to 777 but I've never used the powder so I can't comment in any way.

Understand that he hasn't used hollow based bullets yet. I was just relating problems I had with hollow based bullets and 777.

After I've thought about it some more I think he's going to have another problem with hollow based bullets and a wad between them. If you think about a flat wad being pushed up into the cone shaped hollow base of the bullet, it's going to pull the edges of the wad away from the edges of the barrel leaving the lead at the edges of the skirt exposed. I don't think it's going to hurt anything, but I think it effectively negates the use of the wad.

IF he's using soft lead, like I am, then I'm not surprised he is getting key holing at 1,250 FPS. I get it at around 1,000 FPS in the .38 special with soft pure lead.

I think the key holing he is seeing is related to the hardness of his lead and the velocity he is shooting at. I don't think a hollow based bullet will help him at all.

He also is sizing smaller then his bore size, he should be sizing .001 larger then the bore size.

The keyholing is a classic sign of undersized cast bullets.
Trapdoor Springfields are notorious for having larger than spec groove diameters. Also, the three groove barrels are impossible to measure accurately without a micrometer with a vee-shaped anvil designed for three lobed objects.
I'd try bullets sized .460" or .461", or maybe pan lubed and shot unsized.

I recommend the .459 hollow base 405 gr bullet using 20:1 alloy from Buffalo Arms. I load it that way in my Trapdoor with real BP with good results. No need for a base wad, the hollow base will expand to fit the grooves just like a mini ball. This is the recipe Spence Wolf worked up based what was actually used in these guns. I recommend getting a copy. Real BP like Goex cartridge is little different in cost from the substitutes and is easy to clean up. I am working up loads using Lee 405 gr HB bullets I recently cast.

45-70 book

As noted undersized bullets are a problem. Also as noted, best advice is to size the bullet .001 over groove diameter. In this case that means .459 with a .458 groove diameter.

I am a big believer in pure lead in a muzzle loader where the projectile needs to be undersized to facilitate loading (with a patch with a ball, or without with a minnie or maxi ball that either depends on an expanding skirt or partially engraves on loading). However, a harder alloy is vital in a breech loading rifle, especially when the velocities get over 1000 fps to prevent both lead fouling and to prevent the bullet from skidding and stripping in the rifling.

I routinely shoot both 45-70 and 45-90 loads in the 1100-1250 fps range and use a fairly hard lead alloy - at least compared to pure lead which has a brinnel hardness of 5 - of around 12-18 brinnel hardness.

The alloy used in clip on wheel weights varies a lot but averages around 1% tin, 2% to 3% antimony, 0.25% arsenic and a 96-97% balance of lead. they will normally have a brinnel hardness around 12 . For reasons of both practicality and availability it is not a bad idea to figure out how to work with wheel weights.

One of my favorite alloys in .45-70/.45-90 bullets is wheel weights with about 2% tin added to the resulting mix to make it very slightly harder (without making it brittle) but mostly to help it flow into the mould a bit better with no voids or wrinkles. This works well at the 1000-1250 fps velocities in question with a .001 oversize bullet.

If I want to use the bullet for hunting in a .45-70 or .45-90 where expansion may be important, I use 1/2 wheel weights and 1/2 pure lead with 2% tin added to make the final alloy. This provides adequate hardness with little or no tendency for the bullet to fragment as the antimony content (and brittleness) is reduced.

The arsenic and antimony in wheelweights makes the alloy brittle, but also allows the alloy to be heat treated, either in an oven (where you can get a hardness approaching 30) or just quenched in water when dropped out of the mold (where you can get a hardness around 18). In either case give the alloy about 3 weeks to fully harden after the heat treatment. When heat treated and used with a gas checked bullet, the resulting alloy works well up to 1800-2000 fps when drop quenched, or 2200 fps when oven quenched.

For comparison purposes, the old standby for 45-70 class rifle bullets is to use Lyman #2 alloy which consists of 90% pure lead, 5% tin and 5% antimony. This alloy will have a brinnel hardness around 15. So in effect, wheelweights, with some tin added to improve the moulding quality of the alloy will give you fairly comparable performance. A common substitute recipe for Lyman #2 alloy is 9 pounds of wheelweights with 1 pound of 50/50 (lead/tin) bar solder and this is another one of my favorite lead alloys for the .45-70 and .45-90.

I think I'll buy the lee .459 dia 405gr hb mold and use it with the same alloy I have been and just not size the bullets. I'll also not use the wad and I'll see what happens. This bullet also has deeper grease grooves which is also a plus even though the ones one the bullet I'm using are sufficient but who needs sufficient when one can have excessive? The other plus will be a flatter shooting round with less powder wich is good for the longevity of the action of my trapdoor not to mention the 121 year old stock.

Something not everyone considers is that the actual "as cast" diameter of the bullet depends on the alloy used.
Generally speaking pure lead results in smaller bullet diameters, higher antimnony content increases bullet diameter, and higher tin content increases bullet diameter.

So the same mold may cast a smaller diameter but heavier bullet in pure lead, cast a lighter but larger diameter bullet with wheel weights or number 2 alloy and cast an even lighter and larger diameter bullet with linotype. A .002 inch difference in diamter is not uncommon.

So.,..when you consider a mold, also consider it's intended purpose and the alloy it is intended to use. A hollow base mold could be fine for a BPCR like the .45-70 unless it is in fact intended to increase obturation and is consequently intended for use with pure lead. If that is the case, then the mold will end up casting a bullet with WW or #2 alloy that may be .460 or .461 rather than the desired .459.

It's been a few years since I have played with a Lee 459-405 HB in particular, but if memory serves it is intended for closer to a pure lead alloy (perhaps a 30 to 1 lead to tin ratio) and it will probably cast in the .460 to .461 range with a harder alloy more suitable to the caliber. In general, accuracy also tends to suffer with a hollow base mold compared to a flat based mold. It's a lot harder to get good consistency in the base with a hollow base mold compared to a flat base, and base consistency is very important to overall accuracy.

Also, the hollow base is great if you are trying to get a bit more powder capacity, but it tends to create issues if you want to use a base wad for any of a number of valid reasons.

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