When I developed my Hornady 140-grain loads for my Savage 110CL I created a dummy load by smoking a bullet and then making adjustments back from the lands I settled on 3.35 inches. The published maximum over all cartridge length for the .270 Winchester is 3.40 inches. As I recall this is at the very bottom edge of the cannelure on the bullet. I did not crimp these loads.
My initial loading efforts with the 140-grain bullet were with H4831 which I had been very successful with 150-grain bullets, and 130-grain bullets. My goal was to safely work up to 58-grains of H4831. As I approached 58 grains I had to back off. I settled on 57.2 grains of H4831. This development was just after Hornady put their 140-grain on the market and I did not have a Chrony at that time.
H4831 had been a pet powder in the .270 Winchester but I was not satisfied with the results. It killed deer and provided fair accuracy. My load development continued with the now discontinued WW785 ball powder. I used data published by Lyman and Hornady and spent a lot of range time developing my load. This developed a safe maximum load and then dropped back. In my testing accuracy improved as I approached “my” maximum. In my Savage when tested at 6700-foot elevation which replicates the elevation I hunt the load produced 3030 fps velocity. It also produced small groups. I still hoard a couple pounds of WW785 to support this load.
I purchased some WW 140-grain Silvertips that had been discontinued. I loaded these for the Savage 110CL and the Remington 700. I seated these bullets at 3.25 inches so that I could just catch the crimping groove in the initial loading. I used now discontinued WW WMR Ball Powder. I shot a 3/8 group with this combination.
Going back to where I started, I suggested that if you want to play with bullet length create a dummy cartridge and smoke the bullet with a candle or use a magic marker to color the bullet. You can chamber the dummy and work until you get a cartridge that is off the lands in “YOUR RIFLE.” Not only does it have to safely chamber in your rifle, but it needs to feed from the magazine. I understand that early Ruger M77 barrels came from different contractors. Some produced good results and others did not. My Ruger M77 in 7MM Remington Magnum was purchased new in 1979. It is the most inaccurate rifle I have ever owned when firing factory ammunition from Remington, Winchester, and Federal. It is an accurate rifle when using near maximum charges of H4831, H870, and AA8700. It was a rifle I was ready to trade-off because of the accuracy issue. Handloading saved it. I have given the factory ammunition the unscientific shake test. The result is there is a lot of unused space it the factory loaded case.
You did not say what weight bullet you are loading, but from the charge weight you have given I suspect you are loading a 130-grain bullet. I have had good results with Hornady, and Remington 130-grain bullets using H4831 charges from 59.0 to 60.0 grains in the .270 Winchester.
But I must bring up a different point. Seating depth at the lands varies with the bullet design itself, any time the design and weight change expect a difference in seating depth. The difference in the Nosler Ballistic tip in comparison with Remington C-L, Hornady Spire Pt., and the Barnes TTSX may generate different safe overall cartridge lengths.
Loads that would function in my 270 Remington M760 would not function in my younger brothers M760 Remington which was a good thing. It kept the rascal out of my ammunition.
Looking for accuracy in the .270 Winchester, try 140-grain bullets. I have found them to be slight more accurate and offer better penetration. That is a very general statement because I have only tried two brands of 140-grain bullets, and six different 130-grain bullets.
