Pedersoli 45-70 Sharps breech loader

OK guys what are you loading your 45-70 with? Here's my problem. I just started casting a 500 gr spire point bullet (Lee 90577) for this rifle because it has a better BC over the 405 gr flat nose bullet. (.255 vs. .433).
Anyway when I drop 70 gr of FFg or FFFg down the tube it fills the case up to about 3/8" from the mouth. Then I add a .060" veggie wad to protect the base of the bullet. That leaves me with 1/4" of space for the bullet without compressing the powder. I have to seat my bullet 1/2" for it to chamber into the rifle (max OAL).
Now the bullet will seat to that depth but the seating plug leaves a noticeable ring around the olgive of the bullet which will more than likely affect accuracy.
I'm not sure if I can load this bullet with 60 grs without the same result. Any solutions or should I just stick with smokeless powder?

PLEASE BE CAREFUL AND REALIZE THAT I CANNOT BE RESPONSIBLE FOR YOUR PARTICULAR SITUATION.
Although I’m far from being an expert I can tell you what works for me.
1st thing I did was to select the bullet I wanted to use and using a Hornady OAL gauge I measured the OAL to the actual contact dimension with the rifling. Mark that dimension down as your reference for that bullet /case combination.
2nd step is to measure the height of the bullet and base wad that you want to use. Record this dimension and subtract it from your OAL. This dimension will be the height of your powder charge and having your bullet just kissing the lands.
3rd step is to make a small wooden , plastic or brass dowel to use as a measuring gauge. The actual length is irrelevant however a nice convient dimension helps to keep thing simple.
4th step is to trickle your chosen black powder in until you get to the height of the required powder charge. NOTE: This height is without powder compression and will not necessarily be your final dimension however it’s a starting point. Some bullet / powder combinations require powder compression of varying degrees depending on your particulars.
5th step is to measure this amount of powder to establish a base line and try multiple loading scenarios to see how consistent you are at the height. I would highly recommend using a drop tube and you will be surprised at how consistent you can be.
6th step would be to add your base wad and ensure that your OAH doesn’t exceed what you can chamber. If you can size a bullet down to .454 diameter and identify it as a test specimen it will simplify things however I made a test slug out of brass and use that.
7th step is to add some compression to the powder. I use a tool that I made specifically for that however with a bit of ingenuity you can figure out a way to use your loading press and a wooden dowel to compress the powder. I would start with .050 thousand and try that. Basically this would also give you a .050 jump for the bullet also. A SHORT JUMP BUILDS PRESSURE QUICKLY SO BE VERY CAREFUL. If you feel unsure about the jump either use less powder or add more compression.
There are a lot more details that could be added however I should mention that I’ve had the best results using 1.5 or 2 F black powder and I have NEVER used anything other than that in my gun.
BE CAUTIOUS AND LOAD SMART.

My advise is to buy a few books from buffalo arms and read up and also get advise from knowledgeable folks. I shoot 45-90 pp so I'm not gonna be much help but from what I got from your post is your using ffg and fffg I would think you would try 1.5 and 2f you'll probably get best results with those.

Dido. Be sure there is no air space within the cartridge. Each rifle chamber and load/ bullet configuration will be different. Therefore read the number of books on black powder cartridge rifles and the number of magazines out there. Hope you can find a nearby mentor to coach you. Just be carefull. And may all your shots be center.

Perhaps I wasn't clear. I have shot this rifle with BP loads in the past using 405 gr bullets, veggie wads to take uo any space and FFFg Goex. But these 500 gr bullets are a spire point and even when seated to a max OAL I am still seriously compressing the powder.

I suggest, take a empty case, seat the bullet and gently push into the chamber. When you can feel the bullet ogive reach the lands and the action closes without forcing, this is your maximum loaded cartridge length for the rifle/ cartridge bullet combination. Bring the powder/ wad level up to where the base of billet is located on the dummy round. Dosent matter the number of grains the charge is. 54gr?, and the wad? Again I believe the ring on the bullet is from over seating the soft bullet as a compressor thus swelling the nose/ of ogive diameter thus not being able to chamber. If you wish to compress the charge, do this with a compression plug in the die first before seating the bullet. Buffalo arms sells them. As I said previously, every bullet design is going to be a different over all loaded cartridge length. Again don't get hung up on powder charge. I've loaded these with charges which are barely 1150 fps and had very good accuracy. Hope this helps and good shooting.

Bronko22000 wrote:Perhaps I wasn't clear.  I have shot this rifle with BP loads in the past using 405 gr bullets, veggie wads to take uo any space and FFFg Goex.  But these 500 gr bullets are a spire point and even when seated to a max OAL I am still seriously compressing the powder.

Depending on powder type I wouldn't compress more than 1/2 " if your compressing more than that lower powder charge or change wad thickness my 45-90 loads with 2f Swiss I load with no compression at all.

UFFDA I did that and I know I'm at my max length. Using this bullet there is no way to load 70 gr into the case. My gusstimate is that I'd have to drop all the way down to 50 gr and still be compressing the charge. Velocity would be pretty low.

I have a Pedersoli 1874 45/70 with a (special paper patch chamber) bore rider ,so OAL does not matter but I use a 32 inch drop tube and at the base (the cartridge rests) I have an electric razor attached ( for vibration) and set up will fit 81.5 grains of OE/Swiss 1 1 /2 a .060 poly and the PP bullet just inside the case taper crimped where the bullet stays but can be rotated (remember bore rider) . For you get a proper bullet mold from BACO ,tell them what barrel/twist and use and you will get exactly what you need and you can get 75+ grains using a drop tube ,think they sell the drop tubes too ./Ed

stikshooter wrote:I have a Pedersoli 1874 45/70 with a (special paper patch chamber) bore rider ,so OAL does not matter but I use a 32 inch drop tube and at the base (the cartridge rests) I have an electric razor attached ( for vibration) and set up will fit 81.5 grains of OE/Swiss 1 1 /2 a .060 poly and the PP bullet just inside the case taper crimped where the bullet stays but can be rotated (remember bore rider) . For you get a proper bullet mold from BACO ,tell them what barrel/twist and use and you will get exactly what you need and you can get 75+ grains using a drop tube ,think they sell the drop tubes too ./Ed

I made my own drop tube out of 3/8" copper tubing. I attached a 1x4x 24" board to a 8" section of 2x6". Screwed 2 1/2" eye bolts into the edge of the 1x4 and slid the tubing into them installing a small hose clamp between the eyebolts so as to adjust the height of the tube. I just use a reloading funnel on the top to pour the powder in. Works perfectly.
Its just that the bullets I'm currently loading are to long for a decent charge of black powder.

UFFDA wrote:I suggest, take a empty case, seat the bullet and gently push into the chamber. When you can feel the bullet ogive reach the lands and the action closes without forcing, this is your maximum loaded cartridge length for the rifle/ cartridge bullet combination. Bring the powder/ wad level up to where the base of billet is located on the dummy round. Dosent matter the number of grains the charge is. 54gr?, and the wad? Again I believe the ring on the bullet is from over seating the soft bullet as a compressor thus swelling the nose/ of ogive diameter thus not being able to chamber. If you wish to compress the charge, do this with a compression plug in the die first before seating the bullet. Buffalo arms sells them. As I said previously, every bullet design is going to be a different over all loaded cartridge length. Again don't get hung up on powder charge. I've loaded these with charges which are barely 1150 fps and had very good accuracy. Hope this helps and good shooting.

I already know what my OAL is. I don't want to be shooting a squib load! I'm just going to have to use smokeless powder to get any decent velocity for longer range shooting.

Or you could call Lee Shaver tell him your dilemma ,and send him the barrel and you will no longer wonder why 80+ grains is not a problem and again (BACO) has the bullet mold you (NEED) along with some advice on how / I'm done recommending (have fun shooting)/Ed

Stiks I appreciate the info but I don't want to sink any more $$ into the rifle. Its just a toy and I enjoy shooting it now and then. I've shot many 405 gr and 500 gr FP bullets out of this rifle with BP and have a loads that shoots great. I want to try this spire point because of the higher BC.