45-70 light load question I may have screwed up

[mdevlin53]

Yesterday I went to the range and shot some 45-70 PP loads. When I went to write the results in my book I saw what I had loaded and it just did not look right. I have a 400g paper patched slug over 30 grains of 3031. I went back to the lymans manual and it is way under the recommended load (about 15 grains low). the load for 4759 is 30 gr on the low end so I may have crossed them up. Question is, is this dangerous being under the minimum.
The load was actually pretty accurate and not bad on the shoulder either. It did not lack power either as it made it through a 5" oak log with no problem

[MtGun44]

IMR powders do not seem to do much bad with underloading. Not really
sure, but this should be fine as far as I know. Maybe somebody has a
good reason why this is bad, but my first thought is "no problem"

My biggest issue would be that powder costs nearly the same per grain
no matter what kind (Except Finn VV!) so I would do the same with
10-12 gr of Unique, 16-17 gr of 2400, etc - just to save money on powder.

Bill

[runfiverun]

3031 is pretty dang stable in reduced loads, it's as good as 4895 in most every case.
if it were me and I was gonna lose some sleep over it or was seeing some vertical stringing or excessive unburned powder i'd add a filler.

[RickinTN]

In my Lyman 4th edition Cast Bullet Handbook 34gr. Imr3031 with a 405gr. bullet is the recommended starting charge, so your not much under that. I've shot many loads with 35grs. of the same powder and bullet with excellent results. I'm wondering what Lyman book your using?

Rick

[mdevlin53]

The Lyman 49th is the same 34g for the 405 alloy boolit. When I wrote the OP I had just got done lookin at the IMR online load data and they have the starting load for a 405 at 45grains. I either use a Lee manual the lymans or the IMR website for my loads. Some times I may take some advice from members here but only if it is backed up by a lot of concurrence from other members.
I still have no idea how I came up with that load in the first place. I am in the process of reading through my load log and looking for any other loads that look off. Guess I dodged a bullet this time.

[enfield]

405 grain in the lyman is 24 to 26.5 gr 4759 max for TD. you didn't say what rifle you were using so I wouldn't say that 30 gr is on the low end.

[smokeywolf]

The Lyman #49 handbook doesn't give a load for 3031 using a 405 grain cast boolit. But the Ken Waters Pet Loads book mentions a range of 46 to 53 grains of IMR 3031 for "Group II (Moderately strong actions)". This suggested range does not mention a boolit weight. Other sources mention 45.5 to 48.5 grains of IMR 3031 as an acceptable load for most 45-70 actions.
I was shooting 47 grains of IMR 3031 under a 405 grain boolit out of a Model '86 Winchester "Nickel Steel" barrel 3 days ago and my shoulder is now very colorful.
I have seen loads of 3031 with a 400 +/- grain cast boolit as light as 34 grains. My shoulder now wishes that that's what I had been shooting last Wednesday.

smokeywolf

[mdevlin53]

The rifle is a Model 45 Husqvarna single shot bolt action. it is from the 1920s or thereabouts, I want to keep it in the trapdoor range not because of the action but because it is a fairly light gun and I like my shoulder.

[mpmarty]

If you don't stick one in the barrel and don't get squib loads you're OK.