6.8 Upper Recommendations

[Tomcat088]

Zak, my apologies if I appeared to say that you were full of bull, or something even worse. It is obvious to me that you definitely know what you’re talking about when it comes to ballistics and shooting; and that you definitely know more about this particular cartridge than I do. I merely wanted to say that a lot of what surrounds some of the cartridges that I mentioned is hype and that some people are using the legitimate data you provide and making some other crazy claims about it. I know the claims you make are legitimate, I have just seen lots of people claim that overall the .300 win mag can’t even touch the .260, and I believe that to be false, I’m pretty sure that you’d agree with me that that isn’t the case. I merely wanted people to do more research on the subject and know A LOT more about what they’re getting into before they purchase a particular cartridge that some reloaders and long distance shooters are into and have convinced some others how much “better” it is. The truth of the matter is, it probably won’t give them much of an edge or fit in their budget, and a more conventional caliber would probably fit their needs just as well. Again Zak, I in no way meant any offense to you or the numbers that you presented because I agree that they are legitimate, I just had some doubts about how some data was presented. I now know from your response that you were being unbiased in your approach, and it was some of the sources that I heard quoting this article that had been misusing the information; my apologies for making the assumption that you were too. I’d like to welcome you to the forum and also apologize if I almost “taunted” you to come on. You are most welcome here and we can ALWAYS use someone of your expertise and knowledge here. I look forward to see you around and seeing more of your data.

P.S. as you can tell I’m a little partial to the .300 win mag and I will not at all claim that my preferences are not unbiased. Oh and thanks for the links I’ll be checking them out.

[John A.]

Originally Posted by Tomcat088

Just a word about the link that ichy posted. I'm not saying that the man's uppers aren't good or nice [Dtech], but do a little research on those barrels.

It's pretty obvious you know quite a bit about bullets, but as for Dtech, he's one of the premier custom shops in the country. He is a second generation gunsmith and wildcatter himself. He's probably forgotten more about AR's than most people know.

Matter of fact, he was the one who designed some of the WSSM AR's to begin with. I'm not talking about the guy who thought the idea up, but the guy who actually did it.

There is only one other person in the whole country I trust with my equipment besides myself, and that's Mike.

Using Shilen barrels is only a recent thing also. He has more flexibility with chamberings and countours from them. Until lately, he's used a ton of Olympic Arms broach cut stainless ultra match barrels, which honestly are some of the best over the counter barrels out there where accuracy is concerned but the inavailability of them at times and lack of alternate chamberings are is a primary reason he has switched to Shilen.

Squaring of reciever faces is just one of the steps he uses when building a true competition rifle so there is an even amount of pressure on the barrel nut/reciever.



In not so many words, if you're wanting a "real" match gun or upper, Dtech is the guy to talk to.

[Zak Smith]

Hey, I accept your apology. It was kind of hard to let a post that said my article was "hype and complete bs" pass, however.

There's nothing "wrong" with the .300WM; however, my thesis is that when compared to other long-range cartridges, it does not have compelling advantages.

I agree that the factory load of the 190 SMK @ 2900 is a mild load. For a though experiment, here is a table of max full-house loads for various calibers, and some of these loads will not be achievable in some/many guns chambered in the caliber:

_Bullet_           _BC_ _MV_         0     250     500     750    1000 | YARDS
338LM 300         0.77* 2800 >    0.00    2.57   10.84   25.81   48.71 | wind (inches)
300RUM 240SMK     0.71* 2950 >    0.00    2.59   10.95   26.13   49.48 | wind (inches)
338LM 250         0.675 3050 >    0.00    2.61   11.05   26.44   50.13 | wind (inches)
7RM 180           0.698 2900 >    0.00    2.71   11.46   27.38   51.87 | wind (inches)
300RUM 210        0.631 3100 >    0.00    2.73   11.64   27.97   53.30 | wind (inches)
7RM 168           0.648 3005 >    0.00    2.78   11.83   28.39   54.03 | wind (inches)
6.5-284 140       0.628 3000 >    0.00    2.89   12.29   29.55   56.39 | wind (inches)
243 115 DTAC      0.585 3100 >    0.00    2.96   12.68   30.65   58.82 | wind (inches)
300 210           0.631 2900 >    0.00    3.01   12.84   30.89   59.01 | wind (inches)
260 140           0.628 2860 >    0.00    3.09   13.17   31.72   60.64 | wind (inches)
300 190           0.574 3050 >    0.00    3.10   13.28   32.15   61.84 | wind (inches)
308 210           0.631 2550 >    0.00    3.62   15.48   37.40   71.49 | wind (inches)
308 155           0.508 2950 >    0.00    3.71   16.06   39.38   76.73 | wind (inches)

338LM 300         0.77* 2800 >   -0.00    2.36    8.56   16.11   25.08 | drop (moa)
300RUM 240SMK     0.71* 2950 >   -0.00    2.03    7.66   14.60   22.95 | drop (moa)
338LM 250         0.675 3050 >   -0.00    1.84    7.13   13.73   21.72 | drop (moa)
7RM 180           0.698 2900 >   -0.00    2.15    8.02   15.29   24.07 | drop (moa)
300RUM 210        0.631 3100 >   -0.00    1.77    6.96   13.53   21.59 | drop (moa)
7RM 168           0.648 3005 >   -0.00    1.95    7.48   14.43   22.94 | drop (moa)
6.5-284 140       0.628 3000 >   -0.00    1.97    7.57   14.66   23.39 | drop (moa)
243 115 DTAC      0.585 3100 >   -0.00    1.79    7.11   13.93   22.47 | drop (moa)
300 210           0.631 2900 >   -0.00    2.19    8.23   15.85   25.27 | drop (moa)
260 140           0.628 2860 >   -0.00    2.29    8.53   16.41   26.16 | drop (moa)
300 190           0.574 3050 >   -0.00    1.90    7.45   14.60   23.60 | drop (moa)
308 210           0.631 2550 >   -0.00    3.20   11.25   21.41   34.07 | drop (moa)
308 155           0.508 2950 >   -0.00    2.17    8.42   16.71   27.56 | drop (moa)

338LM 300         0.77* 2800 >    2800    2518    2254    2005    1773 | velocity (fps)
300RUM 240SMK     0.71* 2950 >    2950    2636    2344    2071    1815 | velocity (fps)
338LM 250         0.675 3050 >    3050    2714    2400    2110    1842 | velocity (fps)
7RM 180           0.698 2900 >    2900    2584    2290    2017    1764 | velocity (fps)
300RUM 210        0.631 3100 >    3100    2738    2402    2092    1807 | velocity (fps)
7RM 168           0.648 3005 >    3005    2658    2336    2039    1766 | velocity (fps)
6.5-284 140       0.628 3000 >    3000    2643    2313    2008    1730 | velocity (fps)
243 115 DTAC      0.585 3100 >    3100    2710    2351    2022    1723 | velocity (fps)
300 210           0.631 2900 >    2900    2552    2230    1934    1663 | velocity (fps)
260 140           0.628 2860 >    2860    2513    2193    1899    1630 | velocity (fps)
300 190           0.574 3050 >    3050    2657    2296    1966    1666 | velocity (fps)
308 210           0.631 2550 >    2550    2228    1932    1662    1427 | velocity (fps)
308 155           0.508 2950 >    2950    2517    2125    1771    1465 | velocity (fps)

I included .338 Lapua Magnum, 7 Rem Mag, 300RUM, 6.5-284 Norma Magnum, 243WIN, 300 Win Mag, 260REM, and .308 Win. Again, it's sorted best to worst by wind drift @ 1000 yards.

With regard to .260 vs. .300WM specifically, look at how close the wind drift performance numbers are at 1000-- the 300 shooting the 210's has 59.01" and the 260 shooting the 140's has 60.64". There is less than 1 MOA difference in elevation required to get to 1000 yards. This is virtually identical performance!

So why would I want to shoot the .300WM when I can shoot the .260 with 57% less recoil, 48% less powder, and about 14% less cost per bullet? Not counting recoil, the 300WM is 31% more expensive to shoot than the 260 round for round. If you're willing to accept an extra 0.163" wind drift per mph cross and 0.9 MOA more drop @ 1000 yards, the only thing the 300WM gives you is more mass on target and 33 fps more impact velocity.

For target shooting on paper or steel, this is a non-issue. For hunting, it can make a difference in terminal effect; however, I submit that you can get better long-range performance from cartridges other than 300WM at ranges where 260 might not be sufficient (and I consider it competent on thin-skinned game to 600-750 yards based on the fact that it has more terminal potential at 750 than a .30-30 does at 250 yards, which is certainly within its capable range).

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.

Sure, there are others that have similar performance. But do we get to count the drawbacks and disadvantages of those other calibers as well? That's what the whole problem is about. I've shown that with full-house loads, the 260 and 300WM have very similar performance for wind and drop @ 1000 yards. The downside of the 300 is over 2x more recoil and 31% more cost per round fired if you reload.

Let's compare both to the smokin' 243WIN load, using the 115gr DTAC @ 3100 fps. This beats both the 300/210 load by less than an inch and has 1/3rd the recoil. It's also about 3 MOA flatter at 1000 yards. What's not to like? Barrel life will be about 1/3 - 1/2 that of either 260 or 300WM. A high-quality barrel (chambered, installed, and finished) might cost about $650. A caliber which burns barrels out in 2500 rounds is $0.13 (or about 20%) more expensive on a per-round basis than one that lasts 5000 rounds with top accuracy.

Now if we're already thinking about shooting the 300WM, why use the 7 Rem Mag instead? The case is actually a little smaller, but don't think of it as a downgrade. The 7RM shooting the 180 VLDs has 12% less wind drift @ 1000 (the 168's have 8.5% less), both are a little flatter @ 1000, and the 180 has 27% less recoil, and marginally cheaper component costs (10gr less powder, bullets a few cents cheaper).

What about the 300RUM shooting those heavy 240gr SMKs? Or the 338 Lapua Magnum with the 250 Lapuas or the 300gr SMKs? Again, you are making big steps up in recoil (the 338/300SMK load has 90% more recoil than the 300WM/210 load), incremental steps up in component cost. Between the 300RUM shooting the 240's and the 338gr shooting the 250's or 300's, the 300RUM will have dramatically less barrel life than the 338 because of the large bore and barrel pressure bearing area. The general rule is that it's easier to shoot larger caliber high-BC bullets faster with more barrel life simply because there is linealy more bore bearing area (circumference) and there is more bullet base area on which to apply the same force with less pressure.

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).
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

This stipulation was merely to compare apples to apples. If you want to talk oranges (lathe-turned solid bullets), the same technology can be applied to any caliber, 6.5mm as well as 7mm or .30 or .338 (or .408 or whatever). All of these will have higher BC's than the normal jacket/core technology bullets.

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.

Actually, the 210's have to go basically 2900 fps to exceed a 260/140/2860 by about 1.5" per 10 mph cross @ 1000.

(continued)

[Zak Smith]

so why would you spare the price difference between lathe turned bullets if that\xe2\x80\x99s what gets you there consistently?

Besides comparing apples to apples, I discount it because $2.00 bullets are out of economic reach for virutally all long-range shooters. The most important aspect of long-range shooting is shooter skill, which is attained through diligent and voluminous practice. That kind of volume is probably not possible at approx $2.50 - $3.00 per round (reloaded).

If you want to keep things in a little closer and are shooting paper (so you\xe2\x80\x99re not worried about the kinetic energy) the .243 put up great numbers, and is MUCH more conventional.

Not really. Look at the numbers for the 70gr Nosler BT load in my original set of data. That's a conventional .243WIN load and it has terrible long-range performance compared to even .308. To get that great long-range performance out of the .243 Winchester requires special high-BC bullets such as the Tubb 115gr DTAC and barrels with faster twist than any factory .243 barrel I am aware of. That's not conventional-- that's exotic.

. Most of these guys aren\xe2\x80\x99t rolling their own, and aren\xe2\x80\x99t going to be able to deal with the .260 the way they would the .243.

In addition to my immediately prior comments about the suitability of various .243 loads for long-range use, there are no factory .243 loads which are suitable for great LR performance. In contrast, both Black Hills and Cor-Bon ship factory 139 and 140-gr loads in .260 near the cartridge's maxmimum potential (ie, not watered down much if any).

[rogerxd45]

24 inch barrels

and 16 inch barrels below


looks like the 6.5 grendel did pretty good

[Sharkbait]

This thread has gone the way of my thinking about the 6.8 SPC (right out the window). But it has gotten me thinking along the lines of a long range Elk rifle and I had been eyeballing the 300RUM intil i started reading about overbore, chamber pressures and barrell life. Do either of you guys know much about the .338 edge?

[Zak Smith]

I don't know about the Edge, but the 338RUM I've been playing with for about 5 months duplicates the loads I use in my 338LM.

[Sharkbait]

The edge is supposed to have a 3-5% case capacity advantage over the Lapua but I'm thinking that I'm not going to see any diff in the limited shooting that I do. I've been doing some reading on the 338RUM, 338WinMag and a few others. Still doing my due diligence before I invest that kind of money.

[Tomcat088]

Zak thanks for clarifying things for me. I see exactly what you're saying, and I just think that in order for things not to be watered down, you're going to have to reload the .260, the same way that you would for the .243. This puts them basically in the league that you gotta reload those rounds period, if you want to take them long range. Most long range shooters already know this, and so I don't know why it would be an issue. I know lots of serious long range shooters who shoots $2 a round, look at the .50 BMG guys, they're paying $5 a round for the "cheap stuff". I still don't disagree with you, and understand what you're saying. I guess I don't mind the recoil of a .300 winmag, and don't typically shoot over 50 rounds per range session, based on cost and recoil, and just how long I can concentrate/focus properly. The .260 might allow for more when in terms of cost or recoil, but I still think the average shooter would have problems shooting over 50 rounds the way they should be. I don't know that it would cost less because I haven't checked our brass prices, and the prices of the bullets that you're talking about shooting. I do see what you're saying in terms of the practicality of it, and maybe you are right. As I said before, I'm not real familiar with the .260. I suppose different strokes for different folks.

Sharkbait, about the .338 edge. I don't have any person experience with the .338 edge, but everything that I've heard about the caliber praises it. The .338 edge is a .300 RUM necked up to a .338. I know that it does have a bit more case capacity over the .338 RUM. I have heard that for the money, the .338 edge will give you near .338 lapua magnum ballistics for less. I really don't know a ton more about the .338 edge other than probably what you've read and a bit of the specs. I know that another long range caliber that some guys at thompson long range use for hunting is the 30-378, realize it's huge overbore, even more than the .300 RUM, but it's quite flat shooting for a .30 and delivers massive kinetic energy. If you're shooting paper, pretty much all of those are going to be way more than what you need. If you're shooting those kinds of calibers at paper, you'd probably need to be consider longer distances, more on the 1500 yard range, to see some differences. Sorry I can't help much more, but I don't know too much more. Best of luck to you and hope that this discussion has at least helped.

[Zak Smith]

and I just think that in order for things not to be watered down, you're going to have to reload the .260, the same way that you would for the .243. This puts them basically in the league that you gotta reload those rounds period, if you want to take them long range

Fact is that the shooters who bought the Black Hills .260 chronod it and it was right around 2800 - 2830 fps, the same as my reloads. The Corbon ammo is listed as 2750 from a 25" barrel.

If you want to mandate use of factory ammunition for comparison purposes, then we're back to the sub-standard performance of the 190gr Federal load in 300WM.

I guess I don't mind the recoil of a .300 winmag, and don't typically shoot over 50 rounds per range session, based on cost and recoil, and just how long I can concentrate/focus properly. The .260 might allow for more when in terms of cost or recoil, but I still think the average shooter would have problems shooting over 50 rounds the way they should be.

That doesn't make any sense. Lighter recoiling calibers are easier to shoot accurately, longer. Shooter fatigue and the resulting degradation of technique and accuracy comes in part from recoil and blast. Who says you shouldn't shoot more than 50 rounds in one day? Just as an example, a day of NRA High-Power shooting usually consists of at least three 20-round matches plus sighters (which are unlimited in F-class).