Loading 45-70 for Ruger #1 anomaly...

[Nathan]

So, every loading manual in the world and the crimp grooves on my bullets say 2.550" OAL. Funny thing is....2.505" is touching the lands.

What is your experience in 45-70, especially the RUGER #1?

I loaded to -0.030" off the lands as I normally start or 2.475" OAL. Your thoughts? Bad barrel? Normal for Ruger?

Bullet is Oregon Trail 405gr laser cast.

[steveno]

I don't know about that cast bullet but I loaded the Remington 405 grain soft point in the first cannelure from the nose and it is quite a bit more than 2.550. that bullet and loaded length will not work through a marlin guide gun. I have loaded a number of different cast Lyman bullets and never had any problem with oal. if you go back a number of versions of the Speer loading manual the wording for loading the Ruger #1 it seemed to indicate that at one time or another Ruger had two different chamber lengths.

there is always the chance that your rifle has a short leade.

I tried a number of different cast bullets and the only cast bullet that shot good was a Lyman bullet that weighed 395 grains and had a gas check. I bullet number was 457483 and I don't think it is made anymore. you might find one at a gunshow. all other cast bullets with a plain base really sucked.

[Paul B.]

I've heard here and there on the net that Ruger shortened the throats on the 45-70 because people were seating bullets farther out than standard and loading hot ammo. My #1 45-70 is an early one with a throat long enough to accept the original Lee 500 gr. cast bullet seated to the normal crimp groove. My friend who has a much later #1 says the bullets I gave him to try jam hard into the rifling. Just may be some truth to the story. A competent gunsmith can make a chamber cast and determine what the situation is with yout particular barrel.
Paul B.

[NoSecondBest]

Try a different bullet. See if you can get a Rem 405g JSP to try. I own several 45-70 rifles and the only ones I've owned with short throats were all made by Miroku under the Winchester name. Nothing wrong with the rifles, if you look it up the original factory specs on the 45-70 cartridge called out practically no lead at all. Miroku makes them to the original spec. As far as I know, Ruger always had a longer throat in their guns. I know Pedersoli has a longer throat as well. I've used Oregon Trail in my guns and had to seat the bullet deeper in order to get them to chamber without having to "cam" them into the gun. Your Ruger shouldn't have that problem. It's easy enough to check though. Seat the bullet without crimping it and chamber it into the gun. Remove the cartridge and measure the OAL. What can cause a problem is a bullet with a very large ogive which will not enter the chamber as far as one with a smaller ogive. I've found the Rem jacketed to be a good bullet to test with. If the leade/throat is too short, it's an easy fix. I had my Mirokus lengthened and they now accept all bullets with no loss to accuracy.

[noylj]

Those are very hard bullets. Have you slugged the bore to determine the actual groove diameter of the barrel? Those hard bullets really need to be at least 0.001" larger than groove diameter and 0.002" would probably be better.
You find the COL that works in your rifle and then start loading at the lowest starting load you can find.
I like my lead bullets to be touching or nearly touching the lede/rifling. For single shots, I always have the lead bullet touch the lede.
Try your rifle before you worry about it.

[steveno]

I remember when I first got my Ruger #1s 45-70 the bullet I used was the Speer 400 grain soft point with the two crimp grooves. I loaded them using the bottom crimp groove. I reread the Speer manual in the notes about the chamber length so I loaded a round and it wouldn't chamber so I reseated everything to the upper crimp groove and it chambered fine. I should have made a dummy round first and that would have saved a lot of trouble. I'm not sure if a person can have enough of the dummy rounds of various bullets

[44 AMP]

I have loaded and shot the Oregon Trail Lazercasts in my No.3 (also my T/C Contender), loaded normally, never any issues about length.

I used to have a Marlin, where the crimp mattered, but it doesn't in a single shot.

Maybe your No.1 had a short lead, but, so what? The proper OAL is the one that fits your rifle. No matter what the book says.

[Unclenick]

Nathan,

The SAAMI spec for cartridge length compatible with standard .45-70 magazines is 2.490-2.550 inch COL. Longer or shorter can jam a lever gun magazine, in particular.

Since the bullet has a crimp groove designed specifically for .45-70 and you are jamming despite using it, I would mark a bullet seated that way all over with a magic marker, jam it in by thumb pressure, then pull it back out and look at the shape of the mark on it. If it is marked by the rifling, then you do, indeed have a short throat. However, if the mark is just a ring around the bullet, it is sized too wide for your rifle's freebore, and you probably want to get one of the inexpensive Lee sizer to bring it down to fit. You should first slug the throat with pure lead by tapping the slug in from the breech end until it just starts to find the rifling, then tap it back out with a dowel rod. That will let you measure the freebore diameter, which is the maximum you want your bullet to be.

Finally, even silver alloy cast bullets are softer than jacketed bullets, making them prone to swaging into the rifling while retaining any degree of misalignment they may have at the start of firing. In other words, they often aren't strong enough to straighten out if they carry a slight tilt going in. This is a major cause of lower accuracy some cast bullet shooters experience. However, if you intentionally load them to seat in full contact with the throat, that can help them retain their alignment. Because they are softer than jackets, this has less affect on pressure than it does with jacketed bullets. Just start your load work up that way, and you should be fine.