I thought I would post this here as a follow up. I have reached the maximum load in the Hornady manual, hornady 180gr btsp over 54.5gr IMR4350. My chrono shows 2580fps on average. It is a 22" barrel and I use a light crimp. Hornady folks suggested not going with more powder when I asked them why the Lee manual lists more for the 180gr. I am actually questioning the accuracy of my chrono because this group landed higher on the 100m target. Hornady manual lists this load at 2700 with 24" barrel. I suspect the group size is my fault more than the rifle but I am sure bullet speed is not my fault lol. I am wondering, where do I go from here? And, should I really worry about a bit more speed for under 300 yard moose and deer purposes? The other powder I have is varget and H4350. Any advice would be appreciated.
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Pheroze, a few things:
1) if you take the general rule that for each inch of barrel, you get around 25 fps gain in velocity, that'd get you around 2630 fps from your loads in a 24 inch barrel, everything else being equal....which is a big assumption. Now that's not a hard and fast rule for sure, and whose to say that your load in a 24 inch barrel would reach 2630 fps, but all in all it's not that far off from 2700 fps which is the "standard" 30-06 Spg velocity for 180 grain pills.
2) you'll find that reloading manual's velocity figures are often generous, and their powder charge maximums are very conservative often times. Having said that, I'm not advocating disregarding their maximum loads, but I've found many times that I can load a little more powder (0.5-1.0 grain give or take) without getting the classic pressure signs (flattened/cratered primers, sticky bolt, loose primer pockets, etc).
3) Also, you will start to see the approach to "maximum charge", when you see a diminishing "return" in velocity for each subsequent investment in grains of powder. When you start to see this, it's time to be very careful. That's why chronographs are so vital to accurately reloading. If you chart velocity vs powder charge, you'll often see the slope in the line start to flatten out. Again, time to back off. Of course unless you have barrel strain gauges, etc., you really don't know what kind of chamber pressure you're generating with your loads. I suspect it's often significantly more than what we think, and before you will see any of the classic signs. There's been loads written about this, and some of the reloading software like QuickLoad is really eye opening. The real key is to start slow, and err on the side of being conservative until you have more experience as to what too much is. Even then, I've seen and heard of "experts" ruining perfectly good rifles by trying to hot-rod cartridges.
4) Powder/component manufacturers are never going to tell you to go above and beyond what their ballisticians have published in their reloading manuals, especially in the U.S.A.. Attorneys would have a field day......
5) In using the Newberry OCW method I detailed above, he suggests utilizing the slowest powders that are possible, and I've found that to serve me well. Also, Nosler's "most accurate" powder seems to be a good starting point often, in my opinion. Maybe look at IMR 4831, RL 19, and even RL 22 as they're a little slower burning than IMR 4350? Just a thought. May give you more accuracy and/or velocity, and then again it may not.
6) You often will find that you're most accurate load will not have the fastest velocity, and may be off by as much as 50-100 fps from the maximum velocity. However, you have to ask yourself will an animal (that is appropriate to harvest within the parameters of a given cartridge) really notice the difference between 2600 and 2700 fps? My guess is no, as long as the bullet is suitable for the animal it's being used on (i.e., not using a 22-250 Rem with varmint bullets to try and harvest a Cape Buffalo.......
).
7) I'm not sure that velocity is as important as it used to be with the advent of laser rangefinders and bullet compensating turrets. Even without those tools, if you know your "dope", and the bullet is traveling at sufficient speed (> 1000 fps) when it impacts the animals vitals, it should do the job on most animals that a 30-06 Spg is appropriate for........having said that, I still find myself getting caught up in trying to wring a few more fps out of my loads, and have to frequently remind myself to cool it.
8) Velocity is pretty important in long range shooting, but I fall into the camp of getting as close to the animal as feasibly possible before taking the shot, so again, I don't really mind if I'm not getting the fastest speed possible out of my cartridge as long as it's appropriate, accurate, and consistent.
Just my $0.02 worth.........and I probably wouldn't give you a nickel for that..............