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#11
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XDTalk 10K Member
Join Date: Jan 2004
Location: Dayton, Ohio
Posts: 10,366
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http://www.dtechsuperstore.com/Wildcat.htm
if you want an alternate upper, check this guy!
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#12 | |
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XDTalk 500 Member
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Quote:
Just a word about the link that ichy posted. I'm not saying that the man's uppers aren't good or nice, but do a little research on those barrels. Shilen is known for producing very accurate barrels, and lots of BR guys use them. Just realize that some of those guys change their barrels every 500-800 shots (not all of them, but some). Sometimes if they don't like how they're shooting, they change them before that. In the long term, there are many people that believe some of the shilen barrels don't quite last as long as "they should" when you compare them with other barrel makers like Krieger, Lilja, Hart, Bartlein, etc. Typically varmint hunters want a barrel that will hold up to some pretty rapid firing, or at least hold up for quite a long time. Not busting on Shilen, they make fine barrels, I'm just saying do some research on the matter before you jump on top of those. |
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#13 | |
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XDTalk 500 Member
Join Date: Feb 2005
Posts: 568
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Quote:
My thinking on a .223 compatible upper was that I could save the money for another upper long before I could save the money for an entire .308 AR. The more I weigh my options I am leaning towards just buying the >308 AR outright at some point.
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Red Ryder BB Gun Tom Mix pocket Knife A Bad Attitude A Seriously Disgruntled Wife |
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#15 | |
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XDTalk 3K Member
![]() Join Date: May 2007
Location: boise ID (its boy-see, not boy-z)
Posts: 3,592
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Quote:
if you shot a 7mm bullet at lets say 3000fps and then shot a 308 bullet at 3000 fps the 7mm would have LESS wind drift and less drop and would have a higher ending velocity. you can shoot a 22-250 at 4000fps but it looses its speed really fast but if you shot a 223 at 2800fps with a high BC bullet the ending velocity would be higher on the 223 (depending on distance to the target. the farther away it is the higher BC bullet with have a higher velocity at the end of its flight even though it started with a lower velocity) and the 243 is based on a 308 winchester and thats not an ar15 caliber so your comparing apples and oranges but i would choose a 7mm or a 30 cal bullet for a long range bolt action over the 6.5 any day but if i wanted a long range ar15 and NOT an ar10 i would choose the 6.5 im not saying the 6.5 is better then a 308 or 300 winchester mag (which i dont think it is) but i am saying its much better then the 6.8 spc Last edited by rogerxd45; 03-10-2008 at 04:53 PM. |
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#16 | |
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XDTalk 4K Member
![]() Join Date: Jan 2006
Location: Bikini Paradise
Posts: 4,963
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Quote:
Olympic Arms, Inc. - 16" 6.8 Remington/SPC Upper Conversion Unit Rock River Arms: 6.8 SPC CAR Upper Halves
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#17 | |||||
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XDTalk Newbie
Join Date: Mar 2008
Posts: 8
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Quote:
I am the author of that article. I'm not going to address the 6.5 Grendel at all; however, your characterization of the .260 is inaccurate. I know a thing or two about mid-size 6.5mm calibers-- I've shot over 5000 rounds at long-range targets through the .260REM, 6.5x47 Lapua,and 6.5 Creedmoor over the last 22 months (in addition to 5000 rounds of .308 and approx 2000 of 338 Lapua Magnum over the last few years). Painting .260 with the same brush as 6.8 SPC and 6.5 Grendel reveals a fundamental misunderstanding about those cartridges. One might argue that 6.5 Grendel and 6.8 SPC are comparable because they were both designed for the AR-15 platform (albeit for different purposes); however, the .260 Remington will not fit in an AR-15. It's a .308 necked down to .260, and in a different cartridge "class" than the 6.5 Grendel or the 6.8 SPC. Putting .260 in the same category as the 6.5 Grendel is like saying .308 and .30-30 are the same- it just doesn't make sense and ignores that 300-500 fps difference (in the case of the .30 cals anyway). Here is the quote from the article on 260 vs. 300WM, Quote:
The Case for .260 Remington: A Better Cartridge For Practical Long-Range Shooting (it's about 1/3rd of the way down) Quote:
Here are some facts about .308 and .260 loads: Code:
_Bullet_ _BC_ _MV_ 0 200 400 600 800 1000 | YARDS 243 115 DTAC 0.585 3050 > 0.00 1.92 8.09 19.24 36.28 60.31 | wind (inches) 260 139 Lapua 0.615 2820 > 0.00 2.04 8.58 20.38 38.36 63.65 | wind (inches) 260 123 Scenar 0.540 3050 > 0.00 2.09 8.84 21.15 40.11 67.10 | wind (inches) 308 155 Scenar 0.508 2910 > 0.00 2.38 10.15 24.40 46.58 78.33 | wind (inches) 308 175 SMK 0.51* 2650 > 0.00 2.79 11.94 28.88 55.48 93.43 | wind (inches) 308 168 SMK 0.46* 2700 > 0.00 2.98 12.98 32.15 63.10 108.09 | wind (inches) 243 70 NBT 0.310 3400 > 0.00 3.28 14.45 36.31 72.85 127.47 | wind (inches) 243 115 DTAC 0.585 3050 > -0.00 1.03 5.01 10.05 16.10 23.35 | drop (moa) 260 139 Lapua 0.615 2820 > -0.00 1.37 6.07 11.96 18.97 27.34 | drop (moa) 260 123 Scenar 0.540 3050 > -0.00 1.05 5.11 10.33 16.70 24.47 | drop (moa) 308 155 Scenar 0.508 2910 > -0.00 1.27 5.89 11.86 19.27 28.48 | drop (moa) 308 175 SMK 0.51* 2650 > -0.00 1.75 7.52 14.99 24.38 36.21 | drop (moa) 308 168 SMK 0.46* 2700 > -0.00 1.68 7.39 15.00 24.93 37.99 | drop (moa) 243 70 NBT 0.310 3400 > -0.00 0.80 4.68 10.45 18.73 30.74 | drop (moa) 243 115 DTAC 0.585 3050 > 3050 2739 2447 2175 1922 1688 | velocity (fps) 260 139 Lapua 0.615 2820 > 2820 2537 2272 2024 1794 1582 | velocity (fps) 260 123 Scenar 0.540 3050 > 3050 2714 2400 2110 1842 1597 | velocity (fps) 308 155 Scenar 0.508 2910 > 2910 2563 2242 1947 1677 1441 | velocity (fps) 308 175 SMK 0.51* 2650 > 2650 2315 2007 1723 1469 1261 | velocity (fps) 308 168 SMK 0.46* 2700 > 2700 2329 1982 1658 1374 1159 | velocity (fps) 243 70 NBT 0.310 3400 > 3400 2786 2246 1775 1384 1116 | velocity (fps) 243 115 DTAC 0.585 3050 > 0.00 0.21 0.44 0.70 0.99 1.33 | time (sec) 260 139 Lapua 0.615 2820 > 0.00 0.22 0.47 0.75 1.07 1.43 | time (sec) 260 123 Scenar 0.540 3050 > 0.00 0.21 0.44 0.71 1.01 1.36 | time (sec) 308 155 Scenar 0.508 2910 > 0.00 0.22 0.47 0.76 1.09 1.48 | time (sec) 308 175 SMK 0.51* 2650 > 0.00 0.24 0.52 0.84 1.22 1.66 | time (sec) 308 168 SMK 0.46* 2700 > 0.00 0.24 0.52 0.85 1.25 1.73 | time (sec) 243 70 NBT 0.310 3400 > 0.00 0.20 0.44 0.74 1.12 1.61 | time (sec) In direct contradiction to your claim that "are only talking about the very light bullets that the .260, 6.5 Grendel shoot, and comparing them to the heavier bullets that the .308 is shooting. ", note that it is the highest-BC bullets in the 260 which perform best at long range (which often means the heaviest but not always). High-BC bullets lose velocity at a slower rate and have less wind drift. Quote:
You can see this in the data. The 260/139gr starts at 2820 fps but slows to 1582 at 1000 yards. The 308/155 starts at 2910 but slows to 1441 at 1000 yards. Quote:
If we compare this "high BC" but heavy load in 308 to the 260/139, here's what we get: Code:
_Bullet_ _BC_ _MV_ 0 200 400 600 800 1000 | YARDS 260 139 Lapua 0.615 2820 > 0.00 2.04 8.58 20.38 38.36 63.65 | wind (inches) 308 210VLD 0.631 2450 > 0.00 2.42 10.21 24.31 45.81 75.71 | wind (inches) 260 139 Lapua 0.615 2820 > -0.00 1.37 6.07 11.96 18.97 27.34 | drop (moa) 308 210VLD 0.631 2450 > -0.00 2.13 8.57 16.51 26.01 37.34 | drop (moa) 260 139 Lapua 0.615 2820 > 2820 2537 2272 2024 1794 1582 | velocity (fps) 308 210VLD 0.631 2450 > 2450 2197 1960 1740 1539 1363 | velocity (fps) 260 139 Lapua 0.615 2820 > 0.00 0.22 0.47 0.75 1.07 1.43 | time (sec) 308 210VLD 0.631 2450 > 0.00 0.26 0.55 0.87 1.24 1.65 | time (sec) 260 139 Lapua 0.615 2820 > 0.04 -0.05 -0.18 -0.33 -0.52 -0.76 | drop per yard (inches) 308 210VLD 0.631 2450 > 0.05 -0.08 -0.24 -0.45 -0.71 -1.04 | drop per yard (inches) Continued in next post |
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#18 | ||
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XDTalk Newbie
Join Date: Mar 2008
Posts: 8
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Quote:
If you can get a 210gr VLD going fast enough, it can break even or just beat the best 260 loads. In my comparison above, I was using my load of the 139gr @ 2820 fps. I know 260 shooters who are using the 140gr VLD at 2860 fps which provides identical wind and drop performance to a 210gr VLD shot at 2850 fps from a 300WM. But now we're comparing a a moderate to hot load in a magnum case burning 80 grains of powder to a short-action cartridge burning about 40. The 300WM load has 2.2x the recoil and gives exactly the same trajectory performance. Quote:
Last edited by Zak Smith; 03-12-2008 at 04:20 PM. |
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#19 |
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XDTalk Newbie
Join Date: Mar 2008
Posts: 8
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Here are additional articles relevant to this topic, all backed by facts and experience:
article | The 6.8 SPC, Is it all that? [Shotgun News 60(21):4-16. July 31, 2006] article | Practical Long-Range Rifle Shooting, Part I - Rifle & Equipment article | 6.5mm Shootout: .260 Remington vs. 6.5x47 Lapua vs. 6.5 Creedmoor article | 6.5x47 Lapua Tactical TackDriver (6mmBR.com Gun Of The Week) |
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#20 | |
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XDTalk 500 Member
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Quote:
Howdy Zak, I’m glad to see that you were actually on the forum and are actually talking about the article. I believe that some of what I have said has been a bit misunderstood, as I have probably misunderstood some of what you have written. I have seen the article that you have written being used to totally “disprove” the use of the magnum cartridges for long distance shooting. I agree that the numbers on the .260 are pretty impressive, and I would definitely favor the .260 over many of the other cartridges that I previously discussed. I will start off by saying that I am not a fan of the .308, and only mentioned it in context of that the .260 doesn’t beat the pants off of the .308. I am fully aware of the differences in the platforms that the 6.5 Grendel, 6.8 spc, and the .260 and their differences, I merely mentioned these calibers because on this forum and a few others they are all mentioned to have “the best long range ballistics” and some data is over looked. When you talk about comparing the 190 grain sierra match king in a .300 winmag at 2900 fps, I consider that to be quite a moderate loading. Most of us that shoot the .300 win mag are aware that the benefits and the true pay off to shooting the caliber and suffering the downfall over the over bore is using the some of the heavier bullets and really pushing them. I have no doubt about the calculations you make with the numbers you provide, I merely don’t think that it’s comparing apples to apples either. If you are talking about using some of the heavier or best BC bullets of the .260, then it would also seem a valid comparison to compare the heavier bullets in the .300 win mag and it’s high bc bullets as well. I agree with you, that the .260 overall probably beats the heck out of the .308 as a long distance cartridge, but I would say the same for the .243. Sure it doesn’t quite deliver the kinetic energy that the .308 does, or even the .260 but it still has phenomenal ballistics. I did not have any intention to say that the .260 is useless or not a good caliber, I merely intended to get the point across that there are other widely accepted cartridges that will have similar performance to the .260. You could get a bit more velocity out of the .243 and have a lighter bullet and lighter recoil, and probably the same wind drift with less recoil. It’s just taking what you did to the .308, doing it to the .260 and taking it a step further to the .243. Now I do realize that when you want to talk about “optimum” bc, it definitely is favored towards the 6.5 and 6.8mm bullets over the 6mm, but I’m was merely saying that other cartridges will have similar numbers for the conventional user and be much more accessible. You show yourself in the numbers between the .243 and the .260 that the .243 has more velocity, and less wind drift than the .260 and it shoots flatter. I was merely stating that fact again to other users, that the if you want something that shoots flatter and has less wind drift than the .308, go with a .243 they’re easy to come by and you can buy amazing brass and have tons of bullets choices and the benefits (aside from some of the kinetic energy) that the .260 delivers. I agree with you 100% that in terms of wind drift and how flat they shoot, the .260 beats the crap out of the .308. If we really get down to it though, so do lots of other cartridges because the .308 is kind of “dragging ass” (pardon my language). You mention ignoring the lathe turned high BC bullets for the .30, so let’s consider that fact for a minute (we’ll come back to it). I know quite a few fellas that shoot the 210 VLD quite a good clip over 2450, so it’s not like it’s some super hot load. Sure it beats your shoulder up, but the bullet delivers more kinetic energy on target and if it’s going over 2450, like say 2700 fps or a bit more from a .300 win mag, it would have less wind drift than the .260. It’s funny to me that you want to ignore the lathe turned bullets and talk about long distance shooting. If you’re truly being serious about long range ballistics and talking about which high BC bullet will shoot better long distance, why would you discount the lathe turned bullets of the .30’s? You and I both know that shooting long range consistency costs a lot of money, so why would you spare the price difference between lathe turned bullets if that’s what gets you there consistently? It would appear to me that comparing apples to apples would be comparing the highest BC bullets of the .300 win mag at their moderate or even hot loadings and comparing it to the highest BC bullets of the .260 and it’s moderate and hot loadings. That would give us a pretty good idea of what the maximum of the .300 win mag is and what the maximum of the .260 is. I would much rather this approach than comparing a load that’s moving a pretty good clip with the best bullets available from the .260 and comparing it to a load that’s maybe only 85% of what the .300 win mag will do. Then saying well, the .260 has 17% less wind drift and 87% of the kinetic energy. People that shoot the .300 win mag seriously, shoot the heavy bullets and they shoot them hot, that’s what they got the .300 win mag for. They shoot the light bullets to play around, varmint with, and keep them somewhat up close, not to push 1K or more. So the .260 blows the .308 out of the water, ok, I’ll go with you on that. The .260 still doesn’t blow the .300 win mag out of the water using the heavier bullets (what it was designed for) and pushing the loads a little. So if it then doesn’t do what the .300 win mag will do at a distance, well then let’s take thing in a little closer, and the .243 will stay right up there with the .260. Sure the .260 has less recoil, that’s a given because it’s a lighter load, and it still won’t have the same kinetic energy as the .300 win mag. I agree with you that the .260 has its own place and it does pretty dang good at long range. I believe that if you’re being serious about it though, you’re going to use a larger and heavier projectile, and you’re going to just deal or compensate for the eating you take from that magnum. If you want to keep things in a little closer and are shooting paper (so you’re not worried about the kinetic energy) the .243 put up great numbers, and is MUCH more conventional. You said it yourself that the .300 win mag’s best loads will beat the bets .260 loads. I suppose that it’s like anything else, it’s all a preference thing and I’d rather have the extra kinetic energy and the heavier projectile. When you add in lathe turned projectiles into the equation, the .260 doesn’t measure up, and in the long range game, not many people spare many expenses if they’re serious about it. Why would you not spend the extra money to make your hits, flatter with less wind drift? The main point that I was trying to get across to most of the people on the forum is that there are more economical and reliable cartridges that will do what they need it do for A LOT less. Most of these guys aren’t rolling their own, and aren’t going to be able to deal with the .260 the way they would the .243. Realistically, most of them won’t even shoot seriously over 600 yards either. The ones that will, the .260 would probably fit them a little better, just like other cartridges might. For the practicality reason, and the benefits that most of these guys would get, the .243 is all they need if they want a lighter faster bullet. The .243 has at least 3 times as many choices when it comes to ammunition, and they’re usually WAY WAY cheaper. ALL of the ammunition for the .260 is around $1.50 a shot, with a lot of it being $2 a shot. You get onto the price of a .300 win mag and some of late turned bullets, but you could use the same argument against the .260 in favor of the .243 when it came to price. Continued in next post. |
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LinkBack to this Thread: http://www.xdtalk.com/forums/ar-talk/60568-6-8-upper-recommendations.html
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| Posted By | For | Type | Date | |
| ??? about the 6.8 spc round | This thread | Refback | 03-15-2009 04:20 AM | |
| lr .260h? over lr.308 - Page 3 | This thread | Refback | 11-04-2008 01:45 AM | |
| ??? about the 6.8 spc round | This thread | Refback | 03-10-2008 01:58 AM | |