Page 1 of 1

40 70 SS favorite loads

Posted: Sun Apr 07, 2019 1:29 pm
by kenny s
In my 40 70 SS, I'm going over from PP bullets, that work just fine,,,to the GG which will start me all over again with load, length etc.

my load is now 63 , 2fg, one plastic wad, two paper wads over that and a 400 grain BA GG bullet with the first three bands reduced.
I had the mould cut with the final bands .408 to match the groove diameter. I'm hand lubing with SPG. hand seat and factory crimp a tad.

some great targets, some not so great. blow tube x3 after each shot, clean after 5 .

bullets and loads are each weighed.

SO....what is your favorite load for the 40 70 SS?

Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 2:04 pm
by gunlaker
I would suggest losing the crimp.


Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 3:23 pm
by TAA

If you are using Hornaday 405 Winch. cases that were trimmed to exact length, and the case mouth has not been deburred, a slight crimp might be needed so the rounds can be chambered. Maybe think about a Lee factory crimp (special order) if you keep crimping.

Some of us think we need to crimp to keep the bullet from falling out of the case. But if your ammo box lets the rounds stand upright, you may not need to crimp, if you handle the ammo carefully at the range.


Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 3:47 pm
by kenny s
sorry guys. I was not clear. I AM using a custom factory crimp die. never use a hard crimp.
I just 'tweak' it enough by feel to hold the bullet in place.

I'm using JBA marked 40 70 SS cases. (I was lucky to buy a bunch when the gun was on order a year ago)

What I'd like to know is.... do you seat it out enough to engage the rifling slightly. I do that now.
or.. seat it deeper with less powder and not engage the rifling?

and, how much compression do you think with the 2f. I'm doing 1/8 approx now.

just thinking......Ken

Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 4:42 pm
by Clarence

My experience with that bullet in a .40-65 is that it likes to be seated long, with 2 of the reduced bands well-engraved. Since they are reduced, chambering is not long even with that engraving. One caution: [b][b]you may not be able to remove a loaded round form the chamber. My use is strictly for target shooting.[/b][/b]

My .40-65 load is 3.170" OAL. Assuming a similar throat, that would translate to 3.517" for the .40-70 SS.

I don't crimp, and I use a 0.408" expander plug, so have minimal neck tension, just enough to hold the bullet in place. Engraving the bullet gives consistent ignition. I've shot the same load without sizing the brass and it works just as well.

My rifle likes this bullet shot fast. My recollection is that muzzle velocity is near 1350 fps. Use the wad of your choice, start with enough Swiss 1.5 Fg powder to get 0.060" compression, and change the powder by 1.5-2 grains until the load tightens up. I found a sweet spot in my rifle, and with my previous lot of powder, at almost 0.200" compression. I don't weigh powder, so can't give you a starting spot, but a few trial dumps will get you that info.

I do my testing at 250 meters, and expect an acceptable load to have less that 1 MOA vertical dispersion under ideal shooting conditions.

Be aware that different lots of powder may require more compression--my current lot needs more compression to get the accuracy.


Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 5:07 pm
by gunlaker
I shoot the same bullet in two .40-65 Shilohs, but .409" in diameter. I run it into the rifling as deep as I can while still being able to easily close the breech block. I actually shot this bullet for a couple of years where it was seated out so far I had to use a Steve Rhoades seater tool to chamber the cartridge. It worked very well that way too.

62gr of Swiss 1.5 makes for a nice load in the .40-65. If I had a .40-70 I would use more powder :-).

As far as crimp goes, I'd suggest a touch of neck tension instead. I partially size the case and expand with a 0.408" expander for a 0.409" bullet. The cases are annealed to be relatively soft leaving some neck tension, but not much. This load in my two .40-65's shoots extremely well.

Basically I'm doing almost exactly the same thing as Clarence.


Re: 40 70 SS favorite loads

Posted: Sun Apr 07, 2019 7:53 pm
by kenny s
this is just what I'm doing guys. thanks.
I guess having it engrave the rifling is a good thing as long as it chambers ok. and it does.
I'm using 63 and 65 2f OE as my powder compressed the same.
more testing, but my question was answered. thanks..Ken

Re: 40 70 SS favorite loads

Posted: Mon Apr 08, 2019 1:40 am
by Randy Bohannon
The best consistent shooting GG bullet I have used in my Shiloh 40-70 SS was a .410” Lyman Snover with 65 grs of Swiss 1.5 compressed enough to seat bullet with about a half of a grease grove exposed and lightly engraving rifling. I have tried the Paul Jones Creedmoor bullet and could not get more than 62 grs. of 1.5 without bulging annealed cases. It shot well just ran out of gas at the ram line and was unstable not to far from that. I have a bullet mould similar to your reduced band @.408” and it shoots no better than anything else I have tried. I am contemplating another mould for this rifle and I think a reduced front band and a fat lower @.410”/410 gr . and a full 70 grs of E.O. 1.5 would do well in my rifle.
I bought a Steve Brooks Pointy Bullet (510grs.)mould off of eBay for $70.00. It cast .460”at the bottom and reduced first two bands. It allowed me to stuff 80 grs of O.E. 1.5 in my 45-70 and shoots lights out. This tells me both of my Shilohs prefer a full .002” over bore bullet somewhere in their design. I could be all wet, my observations say this is a good direction to go.

Re: 40 70 SS favorite loads

Posted: Tue Apr 09, 2019 6:00 am
by John Bly
I can't understand a 40/70 shooting 62 grains with a 400 grain bullet running out of gas at the ram line. My son shot a 40/50 SS for 5 years with a 416 grain bullet and 47 grains of Swiss. He rang one ram in 5 years. It had enough gas. I would think 30% more powder would be good to go. Barb Walters shoots a 40/70 at 1000 yds and she is the Nat'l record holder for women.

As Clarence says, start with about .050 compression, load in 2 grain increments with increasing compression. Let the target tell you what is the best load. Every rifle is an individual and some elses' load may not be the best for your rifle. Only your rifle can tell you what's best.

Re: 40 70 SS favorite loads

Posted: Tue Apr 09, 2019 7:02 am
by Clarence
I've shot several bullets in the .40-70 and .40-65 over almost 30 years, and have experienced "running out of gas" with only one. That was the Lyman spitzer, that shot very well at 200-300 but began to run out of gas between 300-400, with excessive drop and more affected by wind.

I am currently testing my grandson's new Highwall (.40-65 (Bartlein barrel, Zimmerman chamber) with a Gunn modified design and the BA Postell (the same as the Lyman Snover, which I believe to be one of the best designs for all-around 40 caliber use), and it is again reminding me that my best loads normally come with the bullet engaged into the rifling enough to center it and the powder charge/compression adjusted for best accuracy. Testing at 250 meters, vertical dispersion under ideal shooting conditions (for me, the last 1.5 hours before sundown, when mirage and wind generally are minimal here), begins under 2 MOA and tightens to less than 1 MOA as I approach the sweet spot.


Re: 40 70 SS favorite loads

Posted: Thu Apr 18, 2019 7:06 am
by kenny s
as a followup to the testing of the BA .408 greaser. first three bands undersize.
chambers easily . 3.54 total cartridge length

I was not getting the groups I wanted, cleaning every 5 shots. blow tube after each shot.

so....I started cleaning after each shot yesterday. Like I do with PP. One wet one dry.

Groups at 100 were all inside the 2 1/2 inch least 3 dozen rounds. one flyer 4 inches out and called out.
8 shot test groups measured 1 1/2 to 1 1/8 inch.

So, it likes to be shot from a clean barrel
Hold is two hand very tight shoulder hold. My 74 likes this with all bullets.

barrel is on the pewter tip in a heavy rest.

load is 65 2f, 397 BA Greaser, 1 in 16 cast, bullets and charges are all weighed. one poly, two newspaper, SPG hot mix type, hand lubed.

All this in front of a bunch of guys saying..Hey that's the Quigley gun, huh?
nice day....Ken