107 SMK, Duramag & E-Lander

[KenC]

...500 box of Sierra 107 SMK's arrived and started initial prep work to load & test.  Measured for "touch point" in my barrel (20" BalAdv) and they averaged 1.7574" CBTO and a corresponding 2.30795" COAL.  I have to admit, the Sierra's had near perfect CBTO measurements, but the tips had COAL variation ranging from 2.303" to 2.310". 

I also tested just how long I could make them so that they still fit in my magazines.  I ended up having to seat them to a MAX COAL of 2.269"-2.270" in order to fit in both magazines with clearance for the tips, the E-Lander being just a tad shorter than the Duramag.  I tested by putting 3 empty cases in, followed by the dummy round in both left & right feed positions.  I also tested by loading more empty cases on top to push the dummy round down to and beyond the curve in the magazine, which is where binding could occur.  If the tip made a scratch mark on the mag, I'd adjust my seating stem down .02" then try again but on opposite feed side so if touching a fresh mark would be made. 

At this COAL they will be jumping 0.04".  Hopefully the alleged "jump tolerance" of the SMK line holds true with this bullet.  This will put the junction of the bullets boat tail & bearing surface right about at the casings neck/shoulder junction and base of bullet right at or just below the casings shoulder/body junction.  This is less intrusive into the powder column than the 108 ELD-M, 105 RDF & Berger 105 VLD.   I'll be testing these with Lever.  

I'll follow up once I am able to get out to test.

Was thinking it would be nice to have my 24" McGowen Precision throat reamed a little bit longer. With the 107 SMKs, I hit the lands at 1.708" ogive and set them at 1.698"(2.254"/2.244" COAL). With 28.3grs of LVR(hit a velocity node) was able to tune in .4 MOA at 2750 fps. I can put up to 2.297" in my ASC mag. I wonder if BA is reaming just too long? I am putting together a BA 16" 6.5 Grendel and a 123gr Hornady FMJ overall at 2.377" on the lands. Geez. I am in the middle of an RMA to have them look at it. With the FMJ in my 13" Sanders, the COAL is 2.244" and that is .020" off the lands shooting 3/4 MOA. After measuring the BA, I researched and apparently a few people are having inconsistencies with them. Just note: if you want to easily tune a round after you find a velocity node, get an EC Tuner/Brake. It just makes the task MUCH easier.