Help with Pedersoli Rolling Block loading - HELP

[ckpj99]

First off, this is my first post here. I've been posting for answers to this question in other forums, and I just haven't gotten any solid information. The little info I have found was in previous posts on this site so I signed up. I hope you all can help.

A little background - I've been loading 45-70 for several years. First for an original 1884 Trapdoor, next for an H&R Buffalo Classic.

I recently purchased a 1986 Pedersoli Rolling Block. It's apparently a Calvary Model in stunning condition. It has a 26" octagon to round barrel. I've never handled a rifle with a barrel profile this heavy. I'm really excited to shoot it, but I'm not sure about my reloads.

This will probably be kinda of a long post, so I apologize, but I'm desperate.

I've had really good luck using 510 grain "Hunters" brand hard cast lead bullets. They are advertised as 15 Brinell hardness and .459 diameter, but I measure them at .460 at the widest point on the driving bands using a micrometer. (I've attached a photo showing the other measurements of the bullet, but it has a .449 nose diameter)

Using these bullets in my H&R, I was able to seat the nose of the bullet into the barrel/throat and get the rifling to hit the first driving band.

However, when I tried these bullets in my new Pedersoli, the nose would not enter the barrel.

Next, I slugged the barrel. It has a .458 groove diameter and a .446-447 land diameter. Given these diameters I was expecting the nose of the bullet to at engrave on the rifling, but no amount of thumb pressure would get the bullet to enter the rifling. As an experiment, I kept seating the bullet deeper and deeper into the case until it would chamber. The overall length ended up being 2.550 (which weirdly is the OAL of flat point 405 grain cartridges).

I attached a photo showing my normal seating depth vs. the experiment. If you look carefully, you can see the ring on the deeply seating bullet where it is contacting the barrel.

Ok, so here my questions:

1) I'm assuming that the profile of these bullets makes them completely unsuitable for use in my Pedersoli. Is that correct?
2) I'm also assuming I can use any .459 to .460 diameter bullet in the rifle so long that the profile allows it to be seated to an appropriate depth. Is that correct?
3) Lastly, I'd really like to find a hard cast 500-530 grain bullet (commercially available until I get the space and knowledge to start casting myself) that will work well in this rifle. Any suggestions?

I do have a .457 sizing die that takes hard cast bullets down to .458 due to spring back, so I could potentially use that. I'm dying to know what you guys think.

[rfd]

i've used close to a dozen different profile and weight alloy bullets in my pedi rolling blocks, never had a problem. from what you've typed, and from my perspective, the alloy is way too hard (antimony). cast with tin:lead @ 1:20 or even 1:30 and all should be fine - maybe ... yer bullet shape has very little nose taper.

as to the oal, it would be good to check that first, using whatever bullet will be used, and find the max (where it engages the rifling). then load as appropriate, depending on whether black or white powder will be used. not sure, but i think the older pedi rollers were meant solely for black powder.

curious - what's yer prime purpose for the rifle, hunting or targets?

[JSnover]

I wouldn't call them unsuitable, you'll just have to reduce your charge, assuming you're unable to compress the powder any further. I had a similar problem with one of my molds and solved it by sizing the nose .005" This allowed me to seat it a bit further out and reclaim some space in the cartridge.

[country gent]

SIzing the driving bands down wont get you what you want. A nose sizer needs to be made to size the nose down to the appropriate dia for these bullets. Buffalo Arms company has cast bullets that should work in your rifle cast from 20-1 alloy and lubed with SPG. I would look at the lyman 535 grn postell also. Id be willing to bet Baco can tell you the nose dia of thier bullets also so you will have an idea if they will work. My Pedersoli SHarps long range in 45-70 will take noses to .449 dia easily. The other route is to shoot it a bunch and burn the lead out in the chamber to where they will chamber LOL

[ckpj99]

Thanks so much for the help, folks!

So, based on what you're saying, those 500 grain bullets are ok to shoot? I typically load them with 25 grains of 5744. That super deep seating depth does not compress that charge of powder. I suspect with the significantly decreased case capacity, I'll still want to reduce the charge to keep the pressures from spiking.

Just to clarify a couple things based on the comments. I have an email directly from Pedersoli that the previous owner received while researching the rifle. Pedersoli verified the year of manufacture, the importer, and said it safe to shoot with factory smokeless ammo up to 29,000 PSI.

I also may not have made it totally clear that I'm not set up for casting yet. I plan to, but it's just not in the card yet.

My goal for the rifle is accuracy. I mostly target shoot, and I'd like to get a 45-70 to consistently shoot 2 MOA. I was getting there with the H&R, but I couldn't pass up the Pedersoli.

Any suggestions? Should I size the 510 grainers to .458 before I run them? Any idea how much my pet 5744 load needs to be reduced?

[Kraschenbirn]

+1 on 'too-hard' alloy. My favorite boolit for my Pedersoli RB is a 440 grainer from an old Ohaus mould with a nose diameter of .449-.450, seated to an OAL of 2.850 which requires just a bit of thumb pressure when closing the block. Alloy for smokeless is 2 parts range scrap to 1 part PB with 1% Sn added to improve fill-out for a BHN of 9.2-9.5. Shooting BP, I go with straight 30-1. Both boolits are loaded 'as-cast'. I also shoot the Lee 405HB (30-1) loaded to the same OAL without any chamber issues.

Bill

[JSnover]

Sorry, I assumed you were shooting BP. I still won't call them unserviceable but it might be simpler if you can find more of a bore-riding design. My main issue with seating them into the rifling was that once in a while a boolit would seat a little bit snug, making it difficult to remove an unfired cartridge.

[montana_charlie]

Should I size the 510 grainers to .458 before I run them?
You don't seem to realize where your mismatch is.

The 'bore diameter' of your barrel is .446 - .447. The 'groove diameter' is .458.
The bullet dimension at the grease grooves is .458, so that fits your barrel properly.
If the bullets are (even as much as) .460, they will still do okay if they chamber easily.

When using a smokeless porpellant, you want the bullet diameter to be slightly larger than the groove diameter of the barrel.
The reason for this is the fact that smokless powder doesn't bump up a lead bullet as quickly as black powder does, so the bullet must seal the bore before it is fired.

Using a 'hard alloy' also retards bump up, so it is doubly necessary that bullets be as fat as possible.


But, your problem is the nose of your bullets.

The diameter of your bullet nose is .449.
This is where your mismatch is.
The .449 won't slip into the .446 - .477 bore.

It would be complicated to size just the nose of your bullet down to .446, but that is what's needed to make your current bullets fit the gun.

When buying new bullets, specify the nose diameter that will slip into your 'bore diameter', and stay with .460 in the driving bands if that will chamber freely in your rifle.

[ckpj99]

Montana C - thanks for clarifying. Yeah, when it comes to matching bullet size to a bore, I'm learning the basics here. I probably won't run these 510 grain bullets in the new Pedersoli because they have to set back into the case so far (even though I literally have over 250 of them). I'm basically just trying to learn so I know what's safe to use, and I don't waste money with my next purchase. Thanks again!

[rfd]

i would check with pedersoli for shooting smokeless in that rifle, just to be safe.

25 grains of 5744 under a 500 bullet is a classic .45-70 modern load for trap door speeds. there is no compression involved at all (better not be!) with smokeless. set the oal down as need be for the bullet in question to just touch or miss the lands, and look for signs of pressure issues because you'll have decreased the case air volume. tin:lead alloy is really best, along with a better bullet mold such as the lyman 457132 or 457193.

[ckpj99]

rdf - I have an email directly from Pedersoli stating the rifle is safe for factory smokeless loads up to pressures of 29,000 PSI.

[johnson1942]

please check your p/m messages

[Jedman]

Try to find some 500+ grain Postell bullets they have a tapered nose and should work in your rifle.

Jedman

[flashhole]

Interesting thread, I can't add anything but I want to follow the dialog.

[ckpj99]

I went ahead and ordered a box of 535 grain bullets from Buffalo Arms. http://www.buffaloarms.com/Detail.aspx?PROD=157340&CAT=4135

They are 20:1 and they are made on the Lyman 457132. They have a much more tapered nose. I hope that with the softer alloy will make for a round that chambers correctly. I was also able to find accurate reloading data for that specific bullet. As most of you probably know, finding exact reloading data for heavy 45-70 bullets is pretty tough. But the Lyman 48th manual lists that exact bullet with a 20:1 alloy, so that's one less thing I need worry about.

[rfd]

that's a Classic .45-70 bullet, a good alloy, and just what ya needed. it will work quite well in yer pedi roller - i cast and shot that same bullet for nearly a year. there is no 'exact' load data; that will require your testing/trialling, in your rifle. finding a good white powder load data range is relatively easy, particularly if yer using aa5744 and lyman's is a good source for that. good luck, enjoy!

[EDG]

ckpj99

If you would like to try some bullets that will fit I have a few that you might consider.

Background
There was an older guy (maybe early 70s) at a gun show that was advertising hand cast bullets. He was from out of town so I paid him and sure enough in 2 weeks I got 100 of what looked like Lyman 457125s cast from early mold. The bullets were well cast of a soft alloy but I found that the nose was too small for my modern 45-70s.

The bullets are .440" dia on the nose and are .460 on the body. They will chamber in your rifle but even your rifle is a little large for the nose of these bullets. You can imagine what they might be like in a modern rifle with a land diameter of .450 to . 452.

They have been in a styrofoam tray in a box for the last 30 or so years and they are very clean. But they are not lubed so you will have to pan lube them or used a lube sizer on them. The .460 body does not need to be sized. They will shoot through a .458 bore without a problem.
I still have 40 of them left and you are welcome to them for the cost of a small flat rate box.