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Posted: 11/25/2012 5:33:31 PM EDT
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First things first, I am NOT a long range shooter. My local range goes to 300 yards. I am starting to reload for a Remington 700. I will probably have the opportunity once or twice a year to shoot out to 1K and can shoot at my family's land a few times a year to 500yds. I am not the "push the limits and go 30 grains over max" reloader. I find my comfort zone with mild loads that shoot sub MOA at 100 yards (for example 42.5gr varget over 168gr SHPBT). My concerns are, would I be able to effectively and accurately utilize a slower load (under 2,700fps) for targets ranging from 600 -1k yards. More bullet drop does not bother me as I have PLENTY of range on my scope to adjust. I just want accuracy. I don't want to waste my well-waited-for range time and money on a class by discovering my reloads will be no use. I also understand each rifle acts differently, but as a general rule would I be able to pull this off or should I rethink my plans and go closer to the 2,800fps range? Thanks in advance for any advise.
M1barker |
| Don't use the 168smk for long range. You might get it to 800 but it will almost certainly but tumbling by 1k. If you have adjustment and know the trajectory velocity Isn't a big deal. Load where you are comfortable and with the knowledge of what the round is doing what you want is doable. |
| I will tell you that 168s can shoot to 1K with out any problems. I done it along with about 40 other guys at a sniper school in the late fall months when you could see your breath. You don't have to push them overly fast to do it. I will say the 175/178 are better for long range shooting as they stay super sonic longer and don't require as much of adjustment out to 1K. The 175/178 will do everything a 168 can but the 168 cant. If it were me I would go with the 175/178 but if you are stuck on the 168 don't worry you can shoot to 1k with no problems it's just not ideal and you will be on the edge of that bullets range. I know a couple of guys who shoot the 175s out to 1250 or so... |
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The alternative to the 175, if you have a 1/12 or 1/10 twist barrel, is to shoot the 190 gr Sierra MatchKing. They are an excellent bullet and work well in all rifles with a fast enough twist.
42 gr IMR4064 Federal 210M primer Winchester case 190 SMK seated 0.010" off the lands This yields about 2600 fps in my 24" barrel and stays supersonic well past 1,000 yards. The |
Responding to Teerex. 168s will work but 155 palmas would likely work better. I'm switching after the last of my 208 A-Max cartridges are gone. Not that there's good reason too since the 208s hold sub-moa at 600 yards. 155s are performing well enough to want to switch. 
Am pushing 208 A-Max past 2550 fps from a custom chambered 26.5" Shilen heavy barrel. Groups 2" verticals on my high blood pressure days at 600 yards and 2" groups on low blood pressure days. Problem is past 800 yards, velocity really falls off. Have almost everything together for .300 Win Mag, Rem 700, AI chassis bolt gun. Son questions my logic, pretty simple deal for me to figure out. I'm gonna load down most of the time and take advantage of case capacity when needed at 1000 meter range. Essentially what I'm saying is load for application. If 600 yards is all you have for distance, load accordingly. No sense in using yourself and the gun up if you don't have too. Your logic is pretty much in line with my own. By the way. Son's an ex-army sniper who's known for his remarkable skill set. M118LR is what he used for a kill shot at 1200 yards. Of course, killing steel doesn't count. My point is he worked his dope and judged the wind shooting a 175 grain SMK hpbt seated on top of 42 grains of Reloder 15 flying just under 2600 fps. Yes, you were just given the components for M118LR. 168 A-Max will work well out to 800 yards. Past that its pretty much on you doing an exceptional job of marksmanship. |
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Quoted:
The other way to go, if you have a 1/12 or 1/10 twist barrel is to shoot the 190 gr Sierra MatchKing. They are an excellent bullet and work well in all rifles with a fast enough twist. 42 gr IMR4064 Federal 210M primer Winchester case 190 SMK seated 0.010" off the lands This yields about 2600 fps in my 24" barrel and stays supersonic well past 1,000 yards. That's my old load. Best of the West range in Liberty Hill, Texas retired that one, replaced with 208s and IMR-4064. |
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A few thoughts...
The concern with the 168 gr Sierra Matchking is that it does not transition to subsonic flight as well as the longer 175 gr MK. The M852 match load with a 168 gr Sierra Matchking only had a MV of 2600 fps and it still did not go subsonic until about 925-950 yards downrange. It was superb at 600 yards but it was problematic in a 1000 yard match. However if 95% of your shooting is going to be 925 yards or less, I don't see a 2600 fps velocity with the 168 gr MK as an issue. The transonic issues are not a case of it darting off wildly in random directions at 1000 yards, instead it was just a bit less accurate with a bit more spread than either the same bullet pushed a little harder to stay supersonic, or a slicker bullet like the 175 gr MK that stayed faster and transitioned better. If you push the 168 gr MK to about 2800 fps it will stay supersonic out to about 1025 yards. My favorite .308/168 gr MK load uses 43.0 gr of IMR 4064 in an LC match case and develops an average velocity of 2787 fps in a 26" barrel. It's about a grain and half more than I'd put through an M14, but in a bolt gun, it's not a particularly hot load. The original 173 gr M118 Match (pre-1983) and the M118 Special Ball (1983 and later) rounds had performance similar to the M852 round - an MV of 2550 fps and it also went subsonic at about 925-950 yards. At the time the M118 was developed however that was not an issue as the engagement ranges for it were normally 500-800 yards, but as a match round it left a lot to be desired at 1000 yards. Even at 600 yards it was never quite as accurate as M852 given the FMJ design, but it still had good accuracy. However when they stopped loading it as a match round with H4895 and switched to WC846, accuracy and consistency suffered and it stopped pleasing anybody. The current M118LR round uses the 175 gr MK and has a 2700 fps MV in a 24" barrel. With the greater velocity and the slicker bullet, it stays supersonic out to about 1150 yards and the bullet also transitions better to subsonic flight. The whole idea of the M118LR was to push the effective range for the 7.62x51 from about 800 yards out to 1000 yards and it does that nicely. M118LR uses something roughly equivalent of canister grade RL15, but I prefer still IMR 4064, in part because I've used it for 20 years, but in part as it has been more temperature stable for me with only moderate changes in velocity at different ambient temperatures. Finally, the speed of sound is determined primarily by temperature. Altitude has almost no effect. At 100 degrees F the speed of sound will be 1159 fps. At 72 degrees it will be 1130 fps, at 32 degrees it will be 1086 fps and at 0 degrees it will be 1050 fps. Looking at the above numbers in rough terms, you'll see you can just start with 1130 fps at room temp and figure a 1 fps increase per degree increase in temp, and a 1 fps decrease per degree decrease in temp, and you;ll be close enough for government work. |
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