While attending the NRA Annual Meeting & Trade Show yesterday, I dropped by the Starline booth and picked up a couple of samples of Starline .45-70 brass with the intent to compare it to some new Remington & Winchester. I also have 100 pcs of new Starline .45-90 that came with a rifle I bought for resale some time ago. I’ve never had a chance to check the brass out closely. Starline has a reputation of making high-quality brass which is significantly cheaper than either Rem. or Win., at least from the sources I buy from. So, after checking the Starline out a few comments are in order.
The Starline is very nice looking brass. The primer flash holes are uniform with no rough edges which is evident in both Rem. in Win. Since I predominantly use Rem., deburring the flash holes is a normal step in my new brass preparations, which would not be necessary for Starline. Measuring the primer pockets depth, the Starline .45-70 samples were 0.132". My Rem. comes in at 0.128" +/- 0.0015" as does the Win. What I found interesting is the Starline .45-90 is a very consistant 0.128". Therefore, if one uses LP primers as do many BPCR shooters, the Starline .45-70 is on the verge of being too deep. BTW, the rim thickness measured an average of 0.065" +/- 0.001, the same as my Rem. & Win. The next step was to check out the neck wall thicknesses. I used 0.5” as the neck length measurement limitation since I never seat bullets any deeper.
Measuring with a tubing micrometer around the perimeter of the neck area, the average thickness varied from 0.010” to 0.0105”, for an overall variation of 0.0005”, which is about half the variation of Rem. & Win. Measuring from the lip to 0.5” into the case, the wall thickness did not vary or taper significantly, contrary to the tapered walls of the Rem. & Win. which thicken 0.002” & 0.001” respectively.
One can debate that tapered case neck walls are a positive or negative depending on the dimensions of the rifle chamber. My Browning .40-65 rifle chamber has a well defined (constant diameter) 0.5” long neck. Therefore, striving for uniform neck tension, I believe the ideal case necks should have no taper for this rifle, so I outside neck turn the Rem. cases. When fire formed the necks will conform to the chamber dimensions, resulting in a constant ID (no taper). The chamber in my Browning .45-70 tapers all the way to the transition step, so I believe that an ideal case should have a taper that matches the chamber taper, resulting in fire formed cases with a constant neck ID (no taper) & uniform neck tension. So I do not neck-turn the Rem. brass for this chamber.
Wayne
