I just purchased a new No.1 in 45-70 and have read bits and pieces here and there that Ruger has shortened the throats on this caliber.
What exactly does this all mean? I got dies,brass and 405gr. Rem JSPs on the way and plan to load some up as soon as the stuff gets here.But I'm fairly new at reloading and was wondering about this short throat thingy???

I usually get best accuracy by seating the bullet a few thousandths of an inch from the rifling. A long throat will allow you to increase the over all length of the cartridge when using longer, heavier bullets. This prevents the bullet from intruding into the case and diminishing the powder capacity. Short throats do not allow you to increase the OAL, thus the amount powder you can fit into a case is reduced.

rws2

I went through the questions a while back and learned the following.

Bill Ruger gave the original #1 45-70s a little longer throated than SAAMI specs, probably to allow the full strength of the #1 action to be realized by using more powder for hotter loads.
Later, Ruger switched the #1 45-70 back to standard SAAMI lengths. As a result, hand loaded ammo for the earlier rifles will not fit the newer models and you can't get quite as much velocity out of the newer rifles.

I asked the Ruger factory people exactly when the change was made in terms of dates and serial numbers. Guess what, they don't know! Apparently serial numbers are not slapped on as they leave the line in exact time sequence, so their best answer was that the the change was made sometime in -- if I rightly recall -- 1980.

I guess if you want a longer custom throat, a competent gunsmith could do the job for very little cost. The action will certainly safely take the extra load because the earlier #1s did it w/o any problem. 1B

rws2. I have a Ruger #1 in 45/70. You will find that to find the correct OAL you will have to chamber the loaded round and ensure that you can close the action. Do this at home, not at the range because otherwise you won't be able to shoot it! I have found that bullets have to be seated deeper than standard OAL's. In particular, you will find that some bullets will have to be seated deeper than the crimping groove would indicate. This is not a problem as there is no need to crimp anyway. With all the different powders available, I suspect that unless you are a real masochist you will easily find loads that are more than adequate. The higher velocity loads are not very comfortable to shoot from a Ruger unless you are the kind of person who says "look what a man I am , I can getxxx fps from my 45/70".
Peter.

Thank You Everyone!!!
Thats answers my questions.

Have the throat lengthened for a little cost if you desire to get more out of it. For me, it is more than enough to load a 405-grain Remington SP to around 2000 fps with the standard COL. By the way, with the factory chamber, you will likely to have problems with those Speer 400-grainers so you may to seat the projectile a little deeper. Good luck.

Thanks Mingo,
I just plan to load the 405gr. bullets @ 1600-1700fps. I'm not wanting to push it to hard,sounds like I'll be fine with the 405s
A 100yd. woods gun is what I'm after,if I need something more I'll take my 338WM. Thanks Again! rws2

An example of this is: The Speer 400 grain flat point jacketed bullet. This bullet has two crimping cannelures. According to the Speer book- The early #1 rifles would accept the bullet seated out to the longest cannelure. Then, they switched throat lengths and the bullets had to be seated to the shortest cannelure. However, the current Ruger #1 rifles will not even accept these bullets seated to the shortest cannelure. I had to seat mine below the shortest cannelure (to 2.495" max) and obviously could not crimp it.

Peter: Chamber the loaded round at home? Have you ever heard of making up a dummy round? No primer, no powder, no chance of accident.