45-70 Plain base velocity

[elrotundamundo]

I just bought a box of 250 HSM brand .459 405 grain RNFP-BB, labelled hard-cast. After some research, I believe these are re-branded and actually made by Rimrock Bullets. Rimrock lists the BHN as 22, and says the lube is Magma brand. There is only one lube groove.

The bullets measure .459 as stated and I want to load them for deer and elk hunting with my Henry H010 45-70, which slugs at .457 bore diameter.

I understand that all guns are different, but need a starting point. Would I be likely to get leading at, say, around 1400 FPS? I normally use IMR4198.

[44MAG#1]

No. But this will turn out to be a many post thread all in the wind up saying give them a try to find out. There will be many ways people will tell you that. But, no matter which way you travel from point A to point B you still wind up at B.
Try them.

[runfiverun]

I'd back them down a click from the 1400 area.

[Toymaker]

Every rifle is different and there's no real way to tell other than giving them a try. That being said here are the results of two loads I worked up using a much softer bullet. These are 5-shot groups at 100 yards off the bench. The 500 grain Hoch was pushed to 1400 fps and the 405 Lyman was pushed to over 1700 fps. The "filler" in the Lyman load was a 1 inch piece of biodegradable packing peanut. Some people have expressed concern about recoil. I found the recoil very manageable and have used both loads in 40-shot competitions (plus sighters and any shootoff). However, I tend to be relatively recoil insensitive in spite of my 3/4 of a century :).
There was no indication of leading with either.
176265 176266

[NSB]

I load all my 45-70 bullets to around 1400fps and those are not even close to being "warm". They're mild to shoot and will completely shoot through a deer from end to end. I get my best accuracy at those speeds. I think you're in a great place to start and I'm betting you'll be perfectly satisfied with the results if you shoot an elk or deer with that weight bullet at that speed. Good luck.

[Ballistics in Scotland]

I just bought a box of 250 HSM brand .459 405 grain RNFP-BB, labelled hard-cast. After some research, I believe these are re-branded and actually made by Rimrock Bullets. Rimrock lists the BHN as 22, and says the lube is Magma brand. There is only one lube groove.

The bullets measure .459 as stated and I want to load them for deer and elk hunting with my Henry H010 45-70, which slugs at .457 bore diameter.

I understand that all guns are different, but need a starting point. Would I be likely to get leading at, say, around 1400 FPS? I normally use IMR4198.

I think that is just about the velocity you will get by at. The bullet sealing the bore is important with that hardness, which may not expand quickly enough to do so. But a modern barrel is most unlikely to be over .459in.

You won't be short of powder space with 4198, so why not use a wax cookie between card wads? You can float a layer of beeswax about 3/16in. thick on top of hot water, and cut out discs with am amputated case body when it solidifies. It is a long time since I shot a .45-50, but I have some high temperature wax sheet I bought from McMaster-Carr, self-adhesive on one side. It is about as soft as beeswax, but melts at a higher temperature if you think that matters.

[17nut]

I shoot the NOE 185gr collar button cast 97/3 and push it to @1625fps easy.

Proper bullet fit is paramount!

No BHN short of jacketed will compensate for bullets that is to small and the resulting gas cutting.

[Ballistics in Scotland]

Quite the reverse of compensating. Escape of hot gases will blast atomised lead ahead of the hardest lead-alloy bullet there is, but a softer one is more likely to expand and seal the bore. Lyman knew all about antimony and type metal when they devised their #2 alloy.

The question asked was about leading. There is no doubt about the impact effectiveness of a 1400ft./sec. cast bullet on just about anything non-African, and someone who chooses a .45/70 is unlikely to be desperate for the last inch of flatness of trajectory.

[longbow]

I used to have two .45-70's ~ Marlin 1895 and a converted Siamese Mauser. I used to load the Lyman 457124 (385 gr. RN PB) to "J" bullet levels with no problems at all in the Marlin with 22" barrel. I don't recall the powder charge but these were right up to 1895 Marlin max. loads for "J" bullets and looking at load data for the .45-70 and likely powders IMR3031, IMR4198 or IMR4895 starting loads all run about 1800 FPS and max loads 1900+ FPS.

Same loads in the longer barrel Siamese Mauser gave a bit of leading near the muzzle. Not sure if the boolit was running out of lube, whether fit wasn't quite as good or what but it wasn't serious leading. My solution (which I am sure will get some comments) was to add a .410 fiber wad which filled up the powder space and protected the base of the boolit. That solved the problem with no apparent pressure signs.

Nowadays being a lot older, and I hope a little smarter, I would likely reduce the powder charge until leading stopped or go to a gas check boolit.

I'll add that accuracy was quite good but being young guy (40 years ago) and more or less an avid plinker I was not shooting competitively or shooting targets to determine best bullseye accuracy. I could consistently hit the steel gongs at the range and pop balloons at 300 yards with the Siamese Mauser and a Williams peep sight. Good enough for me at the time.

Since I didn't know much about boolit fit at the time I will have to say I lucked out and either got a Lyman mould that cast large or a Marlin with a tight bore because it shot well and didn't lead.

On that note... what 17nut said about fit! Good fit is very important. Best to have the boolit at least a thou or two over groove diameter in my opinion.

As long as fit is good I doubt you'll have any issues at 1400 FPS. Wouldn't hurt to start lower and work up though.

Longbow

[elrotundamundo]

I loaded twenty rounds using 31 gr. of IMR 4198 and went to the range. Afterwards, there were a few tiny flakes of lead but nothing I would worry about. Quickload said I should get 1317 FPS from my 18 1/2" barrel and that would be close to average on my Chrony. I didn't record them all and do the math, but the high was 1394 and the low was 1296 with most around 1315. From the extreme spread of velocities, and what I read on the forum, I think IMR4198 might be showing position sensitivity and this load would benefit from some sort of filler to hold it in place. Would that be a correct assumption?

176309I am including a photo of the target at 100 yards, showing 19 shots. Discounting the two fliers, it looks like vertical stringing from the velocity spread.

[Bird]

elrotundo,
I run a different brand of 405 grain plain base bullet to just below the point of leading, 34 grains of IMR4198, with no case fillers. It shoots tight groups in my rifle.
It looks like you have a 4.5'' or so stringing. If you have a velocity spread of 100fps, and a 100yd zero, you should see not much more than 0.5'' vertical stringing......in theory.
Try pointing the muzzle up before each shot, and see what happens to the stringing
You sight picture will also vary from group to group, depending on lighting conditions. Alternating bright to cloudy conditions can also affect your shooting with regards to how you view your front sight in relation to the target. Try shooting at different times of the day, and you will see different points of bullet impact.
Check all the screws on the firearm. Make sure you have the same grip and support for each shot.

[runfiverun]

a filler would help.
the vertical stringing is a dead giveaway of the velocity variations.

[NSB]

a filler would help.
the vertical stringing is a dead giveaway of the velocity variations.
That vertical stringing can easily (I believe most likely) be caused by the way you're putting pressure on the gun while shooting it in a rest. Leverguns and single shot rifles are "bridge" designs when it comes to support in the middle of the gun. I've spent a lot of time at the bench shooting these types of guns and I can make dramatic changes in POI vertically simply by applying the minutest change in pressure on the stock with my cheek on the gun, and/or moving the front bag forward or rearward by even an inch or two between shots. It could be also be velocity variations as mentioned, but I always look at what I've mentioned first. It often solves a problem like this and changing the load wouldn't have made a difference.

[44MAG#1]

What NSB said. Get some Polyfill and use some as a filler. At least 1.5 gr of it. Adjust the filler amount so that the charge is held well back in the case.

[elrotundamundo]

I will definitely get some Polyfill and try it. In the interim, I dug out some 1/8", .45 cal dry felt wads from my muzzleloader box. Two of them take up the empty space just right.

As to the rifle rest and hold being inconsistent, that is probably the case. I was using a "U" shaped padded rest under the forearm, and a small sandbag under the heel of the stock. The Henry has a 3-9 Nikon Prostaff on it that was set at 9X. The inconsistency was in my cheek position on the stock and how firmly the gun was against my shoulder. The scope lightly caressed the bridge of my nose twice, so I am thinking I didn't have the stock properly against my shoulder every time.

[44MAG#1]

The funny thing about Polyfill (I get mine from Wal-Mart) is the cases stay clean, the bore stays clean and the gun stays cleaner to a worthwhile degree.

[elrotundamundo]

I went to the range yesterday and today and tried the same load as per my original post, with the addition of fillers. Yesterday, I loaded and tested with two 1/8" dry felt wads that I normally use in my .45 cal. flintlock under a patched roundball. The two wads take up the empty space between the powder and bullet with slight compression and add 10 grains to the payload.

The wads increased the average velocity by 100 FPS and reduced the extreme spread in velocity to 58. The load was very accurate, just under 3 inches for 12 shots.

I loaded up ten rounds using polyester batting, which I tried to cut uniformly, using a piece 1/2" x 1/2" x 2", which weighed 1 1/2 grains. I tried to be consistent in how I put it in the cases, poking it in so it was firm against the powder.

The results were disappointing. Velocity ranged from 1302 FPS to 1522 FPS and the ten shot group measured five inches.

I am very pleased with the load using felt wads and will be using it for my hunting load this fall. I was surprised that the polyester filler didn't work for me since many shooters do well with it.

In the attached picture, the target on the left is no filler, the center one is the felt wads, and the right is polyester batting.
176459

[44MAG#1]

I use polyester fill that is in a big ball in the package. Not batting. I just pull off an amount and weigh it. Roll it around in my fingers and stuff it into the case. Have had very good results with it.

[NSB]

Don't compress the poly filler. In fact, pluck about .5g of it and "loft/pick" it up so that it is simply a spacer between the powder and the base of the bullet. You should not compress this stuff when you use it. The purpose is to simply keep the powder from migrating inside the case.

[44man]

The goal of under 1400 fps for deer is good. Better at around 1300 for a hard boolit.
I shoot my 45-70 BFR revolver at around 1600 fps with a PB. It is miserable on deer and needs a soft nose. Boolit is a sharp stick and cost me several deer. A few recovered made 200 to 300 yards with double lung shots. My boolit is a WFN too.
My other calibers in the 1300 fps range are deadly killers even with 22 BHN.
I can't slow the 45-70 revolver or I could not hit anything past 20 yards.
4198 plain sucked in the gun and gave me excursions to 1800 fps. Had a few stuck cases. It worked with jacketed but not cast. Could be the short 10" barrel because no powder worked with the huge case until I tried 4759, ONLY thing to work and been down to 1/2" at 100 yards and 2-1/2" at 500.
Could 4198 give velocity changes in a rifle? I don't know. I do use a filler, garneted polyester fiberfill. The stuff does not melt, I found tufts in front of the bench, just dirty. Puts to bed the idea a boolit base will melt.
How fast can a PB be shot? VERY fast if the boolit does not skid past the base band. Once you skid the length or the boolit, you open gas escapes. If you think softer will seal, good luck, does not work.
Many think a GC protects the base from melting--NO, it protects the sides from gas leakage because they stop skid better then lead. I seen too soft a boolit skid so bad it exceeded the GC.
I wanted the stainless Guide Gun in 45-70 but the price tipped me over, over $800. BFR's were costly and I had to sell off guns. I have no more to sell.
The guide gun should do well with about anything, friend has one and he came to shoot with CA loads. It was super accurate.
One load had Star Line brass but never buy A-Merc, junk brass that will split at the first sizing.
I have always had to double think 4198, I found 3031 MUCH better and even less recoil for the same speed. It is my powder of choice in a rifle. Give it a try.

[elrotundamundo]

Thanks for the tip on 3031, I will get a pound and try it without felt wads. I also have some Varget on hand to try. Quickload shows that it fills the case much fuller for equivalent velocities. Haven't looked up 3031 yet for volume.

Been thinking about the felt wads and why they work for me. Always a guess on interior ballistics. The action is hidden from our sight and too fast to see, even if we could see in there. So, we have to form conclusions from data after the fact.

My guess is that the felt wads not only act as a filler, to hold the powder against the primer for consistent ignition, but also help seal the gas behind the bullet. Kind of a poor man's gas check, although the cost with shipping makes them just as expensive as buying gas checked bullets in the first place.

[NSB]

With felt wads you may be well on your way to ringing your chamber. You should do a little research here before you have a problem.

[44man]

Varget would be a very good try. It had done wonders in some of my guns.

[44man]

Felt wads can work but they MUST be on the powder and to the boolit base, NO air space.

[elrotundamundo]

After reading NSB and 44man's replies, I searched the forum for ringed chamber, and found enough there to concern me. As I understand it, when a wad is against the powder, but not touching the bullet base, it can, in effect become the primary projectile, begin moving as the powder burns and builds pressure, then run into the base of the bullet, which then acts as an obstruction, causing an unusually high pressure spike which can ring the chamber.

I could, i think, avoid this by making sure to firmly seat the felt wads, then double checking the depth to make sure the bullet base would slightly compress the felt. After thinking this over, it occurs to me that the one component that suffers from lack of consistency in manufacture is the felt wads. I have noticed the thickness can vary a bit. It wouldn't matter much in my flintlock, but could matter in my 45-70.

Ultimately, I decided that the elegant solution for me, was a powder that filled the case better. I bought a can of IMR3031 and will work up a load with that under the leading threshold for PB bullets in my gun. Quickload shows that at 1400 FPS with a 405 grain PB, the case will be around 85% full.

[NSB]

I spent a lot of time researching fillers and trying some out that were made of poly pillow filling, lofted up to take up the space between the powder and bullet. Using .5g of this stuff worked very well and my research indicated it would not compress and act as a projectile against the base of the bullet. That all being said, I found very few cases where accuracy improved enough to make it worth while. Most powders work the same with or without fillers. The 45-70 is the least fussy round I've ever loaded for. Many, many powders give excellent accuracy without any filler. I simply started using those powders and don't have to worry about it at all. I think your best course of action would be to try to find a powder that gives you good accuracy without fillers and go that route. I have a couple of guns that give me 1moa or less at 100yds without fillers and the loads are mild enough to enjoy shooting and still pass completely through anything I shoot with them....end to end even. Your gun, your journey, do as you please and good luck.