45-70 Starline Brass

[paborn]

Have had good experience using Starline pistol brass, so bought 100 brass 45-70. Used them to load light loads, primarily 405 Lee flat nose, flat base. Lapped the mold to cast .4585 diameter. Loaded 15 grains of Unique and 25 grains of 2400, which had shot very accurately with Winchesster brass. Got very erratic results. Played with the load to no avail. Yesterday I took fired brass and tried to insert both a .459 bullet that was fired in it, and a .457 diameter bullet. To my surprise, they would not enter the case. Measured the fired case and got a .4565 internal diameter. I think that these loads do not generate enough pressure to completely expand the brass at the case neck. Cases are not particularly dirty after fireing. Starline suggests neck annealing cases for blackpowder loads as they make hard cases for higher pressure loads. Looking at the fired cases, it appears that the case is not expanding enough to comletely take out the crimp. Based on the inside diameter of the fired cases, I think the hard brass is resizing my carefully sized bullets smaller, resulting in the erratic accuracy.

I will try expanding the brass with a larger M die for a not so tight fit, and if that doesn't work will anneal the brass, or both.

Any thoughts?

Paborn

[sqlbullet]

I would think you need to anneal that brass. Those are definitely light loads.

They will expand easier after annealing with that M die as well.

[paborn]

Both loads are light plinkers that would group about 1 1/2 inches at 100 yards in softer brass. They print about 10 inches lower than standard loads and drop about 30 inches at 200 yards with a 100 yard zero. Fun to shoot at the 100 and 200 yard gongs at the range.

[cajun shooter]

You need to anneal that brass! Be it for the fake or real powder. Have seen groups change by over 2 inches with annealing.

[44man]

Yes, for the rifle, anneal it.
I use Starline in my revolver, I need tighter brass so I need a harder boolit.
I just use Remington brass in my rifle.

[montana_charlie]

bought 100 brass 45-70. Used them to load light loads,

I think that these loads do not generate enough pressure to completely expand the brass at the case neck.

Starline suggests neck annealing cases for blackpowder loads as they make hard cases for higher pressure loads.

it appears that the case is not expanding enough to comletely take out the crimp.

I will try expanding the brass with a larger M die for a not so tight fit, and if that doesn't work will anneal the brass, or both.

Any thoughts?
My only thought is a question...

Even if you expand the brass to accept the bullet, the brass will still be too hard to seal the chamber. That alone will cause erratic performance.

So, considering the analytic progression evident in your post, why is annealing second on your list of things to try?

CM

[paborn]

Had your same thought...but...the cases are clean, indicating they seal somewhat, just not enough pressure to completely take out the crimp, hence my thoughts on resizing the bullets. I'm definitely going to anneal, but need to go buy a berz torch and until then have loaded some with a larger M die. Had been using a Lee factory crimp die and changed to a light roll crimp on the ammo loaded with the larger M die. Those light loads have a hard time taking out the crimp from the Lee die.

The one thing I should have done is inertia pull one of the loaded rounds to confirm that the bullets are being resized.

But I digress...I agree that the solution is to anneal the cases.

[jtaylor1960]

I recently shot some loads with both Starline and Winchester brass.The Starline came out all dirty and the Winchester was clean.The Winchester shot a tight group the Starline was much bigger.The load was 50.0 grs. of H-4895 with a 400gr. cast bullet.This isn't a light load but the pressure according to published data is very low with this powder.As mentioned repeatedly above annealing is called for.

[John Boy]

paborn ... with Starline brass:
* anneal
* 0.001 to 0.002 neck tension
* light factory crimp on the 1st GG band (single shot rifle, not magazine feed)
Your accuracy will improve