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medlem |
I heard a friend of mine was planning to sell some guns at a garage sale last weekend, so I went to see what he had. I ended up walking out with a NIB Remington 700 VLS in .223 with a Weaver Grand Slam 6-20x40 scope for $800 total. He had bought the setup in the winter of 2002 for a groundhog thinning with some friends in Montana when things warmed up. A blight of some sort came through and decimated the population before the trip, so it just sat in his safe until now along with a similar 22-250 with a Bushnell Elite 4200 6-24 scope. He was asking $900 for the 22-250, but in the end, I went with the .223 due to the 1:12 twist vs the 1:14 for the 22-250 in hopes that I could stabilize some heavier bullets. I brought it to the range this morning and put 26 rounds of PMC Bronze through it before work mostly just to see how it felt with the 26" heavy barrel. I picked up some 53gr V-Max's from Walmart to load up, but haven't quite got to it yet. Does anyone have any experience with a longish barreled 1:12 .223 and how heavy of a bullet it will stabilize? My range is at 5,500', so I'm hoping that makes some small amount of difference. I have a couple hundred 69gr SMK's here, but I'm not holding my breath on those grouping well. Maybe 60-62gr? | ||
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Member |
Nice score. I have no direct experience with 1:12 barrels, so I'm going by second hand info. You might be able to stabilize 68 or 69 grain loads, but maybe only on hot days. A box or two is worth a try. Bullets below 65 grains are more likely your ticket. Hornady's 60 grain Vmax is a good bullet -- factory loads are hard to find. 55 grain plastic tips are good. Hornady Vmax and Sierra Blitz-King (ADI). I don't find Hornady's superformance ammo to be that accurate. Maybe the 53 grain will work for you. 52 grain HPBT is good. Black Hills makes a good load. Hornady's 40 and 50 Vmax bullets are good. | |||
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Freethinker |
Interesting question that prompted me to turn to the Miller Stability Formula that Bryan Litz discusses in his book Applied Ballistics for Long-Range Shooting. He says that the Miller formula is much more accurate for bullets of the SMK type than the ancient Greenhill formula. Using his data for the 69 grain SMK and a couple of assumptions, I came up with a stability factor for the bullet out of a 1:12 inch twist barrel of 0.95. According to Litz, good stability requires a factor of at least 1.4; 1.0-1.4 is marginally stable; and under 1.0 is unstable. The basic Miller formula is based on a muzzle velocity of 2800 fps, and higher velocities (which might be true of many loads from a 26 inch barrel) increase the factor. I assumed an air temperature of 60°; higher temperatures would increase stability, and lower temps would decrease stability. More important for your situation is the 5500 foot range elevation. With that as a correction (and still at 60°), the stability factor goes to 1.16, which would be marginal, and therefore it’s possible the bullets might stabilize, especially at higher velocities. All that is of course based on theory—good theory, but theory nevertheless. I’d be curious to see some actual data from others. And although you didn’t ask, I wouldn’t rely on the 69 grain SMK for varmints, or anything other than paper or steel, no matter how well they perform for you. For varmints I’d go with lighter bullets of the types mentioned by fritz, and that are designed to expand. Perhaps you already know that, but if not .... ► 6.4/93.6 ___________ “We are Americans …. Together we have resisted the trap of appeasement, cynicism, and isolation that gives temptation to tyrants.” — George H. W. Bush | |||
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Member |
These blue box Black Hills in 40 and 50 grain Vmax shoot very well in my Winchester 70 heavy varmint from the early 90’s that is a slow twist. Smokes a prairie dog pretty well too. http://www.black-hills.com/pro.../factory-reman-ammo/This message has been edited. Last edited by: dusty3030, | |||
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medlem |
Great information! I saw that book advertised on sale at the longrangehunting forum and went to pick it up, but it was out of stock, of course. I work with spreadsheets all day and am a sucker for data like this, which is probably why I love reloading so much. The Hodgdon site shows the 69gr SMK at 3,000 fps out of a 24" barrel with Varget. A couple inches more barrel might get me to 3,100, so it would seem possible to stabilize on warmer days. That would certainly make this rifle more versatile for shooting steel at the range with the longer bullets. Thanks for that info. You can bet the powder scale and brass will be sitting on my desk all day tomorrow while working. | |||
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Freethinker |
You are welcome. According to the Miller formula, increasing the velocity to 3000 fps would raise the stability factor by 1.023, or increase it to 1.19. At 3100 fps the correction would be 1.034, and the new factor (at 60 degrees) would be 1.20. If you try the 69 grain bullet, please post your results and the atmospheric conditions. It would be good to compare theory with actual performance. ► 6.4/93.6 ___________ “We are Americans …. Together we have resisted the trap of appeasement, cynicism, and isolation that gives temptation to tyrants.” — George H. W. Bush | |||
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Bone 4 Tuna |
Handsome rifle. Circa 2002 puts it in a far better place than the current sad state of Remington. Range report when you're able, please and thank you! _________________________ An unarmed man can only flee from evil and evil is not overcome by fleeing from it. - Col Jeff Cooper NRA Life Member Long Live the Super Thirty-Eight | |||
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Member |
I have a Remington 700 lvsf with a 1:12 twist in .223. I've not had much luck with 62 gr. bullets. Some of my best groups were with Sierra 53 gr. Match Kings (stock # 1400). Hornady Vmax does OK too. | |||
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Sigless in Indiana |
I always had stellar results with Vmax bullets in my 220 Swift with regard to accuracy. I would give the 60gr a try if I were in your shoes. I always used the 50s because they seemed almost magical in their ability to just turn coyotes off. Boom, drop. Shooting ARs with bulk 55 grain ammo, they seem to do fine out to about 550 yards, which is as far as I have spent any significant amount of time sending them down range. How far do you plan to shoot? | |||
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Member |
Oh yea, 68 grain Hornady BTHP shoot just fine. I have a fluted R700 Varmint .223 in 1/12 twist. A few thousand gophers and prairie dogs have been victims of 40 and 50 gr Vmax's. The first 2-3K bullets were moly coated and accuracy was awesome. I have also used 14-15 grains of Blue Dot under 40 gr VM's at about 3250 fps. Very cool running load, takes twice as many shots to get hot compared to H335. Enjoy your new rifle | |||
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medlem |
Thanks for everyone's input. Sounds like it may take a broader assortment of bullet weights than I originally thought. Lots of trial and error in my future it seems. I think the main reason for buying it was to get some higher volume trigger time at various ranges cheaper and less punishing than with my deer/elk rifle. I've seen a few coyote around here, and have heard stories about prairie dogs, but people are pretty tight lipped about the locations. For now, I'm going to see how many solid loads I can come up with for each occasion; small critters, coyotes, and as long of range steel shooting as a high bc bullet can take me. | |||
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Member |
What are you expected target distances, especially for steel? | |||
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Member |
I've also found most 55 grain bullets work best (for me) with 1:12 twist 223's. | |||
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medlem |
I expect out to 300. I'd like out to 400. I'd be thrilled with, but not expecting, 600. It's not the caliber I'm questioning, it's the twist rate and what it will let me stabilize. | |||
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Member |
These are reasonable distances, especially if the wind in your area isn't bad. The data I list below is for my 18" AR-15, using JBM figures for 7,000' DA -- a cool day for your elevation. From this rifle I get muzzle velocities of 2930 fps with Hornady factory 55 Vmax and 2630 fps with Federal factory GMM 69. Figures are in MOA for drop and drift (for a 10 mph crosswind). 55 VMax 300 yards -- 3.2 MOA drop / 2.9 MOA drift 400 yards -- 6.0 drop / 4.1 drift 500 yards -- 9.4 drop / 5.4 drift 600 yards -- 13.6 drop / 6.9 drift bullet velocity of Mach 1.35 at 600 yards 69 FGMM 300 yards -- 4.3 MOA drop / 2.6 MOA drift 400 yards -- 7.7 drop / 3.6 drift 500 yards -- 11.6 drop / 4.7 drift 600 yards -- 16.2 drop / 5.9 drift bullet velocity of Mach 1.38 at 600 yards Velocity should be above Mach 1.25 or 1.30 for best results, so I'm in the ballpark for these distances. Your MV will be higher, therefore your drop and drift figures will be lower for both bullets. At 300 yards it makes little difference in wind drift which bullet I use. By 400 yards the SMK 69 shows 2" less wind drift for a 10 mph crosswind. At 500 yards the SMK has a 3.5" advantage in the crosswind, increasing to 6" at 600 yards. Again, your wind drift figures will be a little less than mine. Accuracy will depend upon your barrel, but my gut tells me the 55 may shoot consistently better than the 69, due to your being on the lower limits of stability with the 69. My 18" 1/7 twist barrel really likes the SMK 69 -- its best 5 round groups at 100 yards are in the .70" to 1.00" ballpark. It does just fine with 55 Vmax -- the best 5 round groups at 100 yards are in the .95" to 1.20" ballpark. Ultimately your gun will tell you what works best, but for only 300-400 yards on relatively generous steel you may not see a huge performance difference between the two bullets. | |||
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medlem |
Thanks for the numbers fritz. I guess if I'm keeping the distances short (300ish yards), the bc means less than I thought it would. At my current skill level, the difference is probably within my margin of error. I'm looking forward to getting out to the range with some regularity to increase my skills to the point that a higher bc bullet will make a difference for me. | |||
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