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- Pridružio: 09 Jan 2006
- Poruke: 1519
- Gde živiš: Beograd
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Čisto da malo dodam temi o 408 Chaytec-u. Pre jedno godinu i po naleteo sam na ovo i sačuvao jer je dobar opis onoga što jeste cela priča o snajperistici:
Citat:Okay, on to your specific questions (338 vs. 408). I am one of the original owners and partners in Cheytac, the builders of the .408. My job specifically was the field testing and development of the platforms for military use. I shot the groups that the guns in those days were capable of. Over the years, a couple of partners left Cheytac because of bad management and personality issues. I left originally in 2003, and again in 2005, after a stint as a consultant to work on their semi-automatic gun, and their .308 SASS semi auto sniper backup gun. After working those systems for a few months, I tried to tell them the guns needed a major re-engineering, that they would never work in their current design. They were incredibly accurate, but could not function well. These were due to engineering flaws in the design of the recoil and ammunition feed mechanisms of both guns, as well as their gas systems.
The .408 is a great cartridge, but the "management" now makes claims that they cannot substantiate. I say this as a direct observation as well as seeing the impact of their misrepresentations on the US military. We are at war, and for the sake of money, I will not be a part of any of their type of management. CheyTac doesn’t have the internal talent or engineering brains they used to have. Those people have left, and now they have marketing guys, with no knowledge of the these systems or how to develop them.
Why the .338 Lapua is better. In combat sniping, the ability to strike a target at great range is more about the ability to address environmental and meteorological factors than it is the gun. The .408 without computer support is no better at 2000 yards than a 50 or a 338 Lapua. It is guess work for any of those guns. The above things are intangibles, here is real data:
Bullets and the cartridge make all the difference. The .338 270 gr. Lost River Ballistic Technologies J40 match bullet is the best .338 bullet in the world. It has a 2000 yard supersonic range in a gun that can push it to 2850 fps. (At this point, I’d advise against the AI .338 Lap Mag, it's the least capable of any of the guns out there, but they have great marketing guys and good brochures). The 250 gr. Scenar Lapua bullet only has a super sonic range of 1600 meters at 3000 fps.
At 2000 yards, the flight time for a 750 gr. AMAX out of a .50 and flight time is 3.6 seconds. Velocity at 2000 yards for the AMAX is 1153 fps, just barely supersonic. This means the projectile at 2000 yards moves about 3.8” for every 1 millisecond of time and range.
At 2000 yards, the flight time for a 338 Lapua at 2900 fps (their best speed) and the flight time is 3.4 seconds. Velocity at 2000 yards for the 270 gr. LRBT J40 round is 1159 fps, also, just barely supersonic. This means the projectile at 2000 yards moves about 4.1” for every 1 millisecond of time and range.
At 2000 yards, the flight time for a 408 CheyTac shooting the 419 gr. at 2900 fps and the flight time is 3.5 seconds. Velocity at 2000 yards for the 419 gr. LRBT J40 round is 1213 fps, also, just barely supersonic, but a little better. This means the projectile at 2000 yards moves about 4.4” for every 1 millisecond of time and range.
SUMMAY OF ABOVE DATA:
750 GR. .50 BMG AMAX @ 2000 yards, projectile is 1153 fps and covers 3.8” for 1 millisecond of flight.
338 Lapua 270 gr. LRBT J40 @ 2000 yards, projectile is 1159 fps and covers 3.4” for 1 millisecond of flight.
.408 CheyTac 419 gr. J40/M40 @ 2000 yards,, projectile is 1213 fps (a little better but statistically and tactically insignificant) and covers 4.4” for 1 millisecond of flight time.
The reality is that at that range, none have any advantage and a flight time of 3+ seconds is too long for any realistic shot on a non-material target. As a professional shooter, I would challenge any CheyTac shooter to a head to head shoot against a .50 BMG shooting AMAX and any .338 Lapua shooting the 270 gr. LRBT bullet.
With the above things in mind. The .408 suffers the following real world disadvantages.
.408 vs. .338 on weight = you can get a .338 Lapua in at 17 lbs easy. Lightest weight for a .408 repeater is 26 lbs. They do make a single shot rifle that they can get down to about 17 lbs, but recoil management is a serious issue. You can make a gun too light to be good with it.
.408 vs. .338 on cost. = You can have a .338 Lapua from H&S Precision for 2100.00 in their HTR rifle. Dakota Arms, which is a very fine rifle, is 4400.00. The .408 M200 military gun from Cheytac is 12,000.00. (If they sold you one, right now, they like to claim military only, but no military is buying any.
On Tactical edge. The .408 can go a little farther supersonic, but both guns real world range is 2000 yards based on supersonic speed. The realistic max flight time for any shot is about 2.5 seconds. This is around 1500 meters for all three gun platforms.
At that speed, all three mentioned are about the same for flight time. 2.5 seconds for the 338 Lapua, 2.5 seconds for the 408 CheyTac and 2.6 seconds for the .50 / AMAX combination. I would challenge anyone to point out the edge of one of those cartridges vs. the other. .408 looses on weight, cost, and factory work on the guns, non-standard parts, etc. All things compared, cost, precision, range, flight time, etc., the .338 Lapua is the easy winner.
The .408 had the advantage, but Cheytac burned that away by changing a gun in ways they knew nothing about. They lost velocity over the original guns, which were all at 3050 fps and had a real advantage.
On my recommendation for a tactical 1500 meter gun is the .338 Lapua. Prairie Gun Works of Canada, Dakota Arms, one built by McBros, H&S Precision, personally, I build my own. I would use a Prairie Gun Works Timberwolf action, a Lawton barrel (made to my specs), a McMillan A5 stock. Install a cantilever metal block system instead of a conventional bedding job, put a suppressor on it, and use a Schmidt & Bender PII Marksman sight with 100 MOA of elevation, expensive, but nice. That setup will smoke a .408 all day long. The trick is you'll have to use the 270 gr. LRBT J40 match bullet, or you won't have the supersonic range the .408 has. If you use the 250 gr. Lapua Scenar bullet, you loose 400 yards of supersonic range and the .338 Lapua drops out of the race against the .50 AMAX setup and the .408 CheyTac.
I've been in the special operations sniping community on the operations side, training side and material development side. I shot the very first .338 Lapua when it was called the .338/.416 back in 1987 and have been seeing it mature since then. It's time now. I believe the .338 Lapua will be the new hot sniping round. It's been adopted in England, Canada, turkey, and several other countries as the standard sniping round. I think there will always be .308 guns; you couldn't run a training program on .338s alone. Barrels would not survive the heat generated by excessive shooting.
The more interesting setup is the .375/.408, using a LRBT built .375 projectile with a .930 G1 ballistic co-efficient at a speed of 3250 fps. Those are serious numbers.
Dakle, izjava jednog od ljudi koji su radili u firmi i to na testiranju. Bitni delovi priče su po meni ovi:
Citat:On Tactical edge. The .408 can go a little farther supersonic, but both guns real world range is 2000 yards based on supersonic speed. The realistic max flight time for any shot is about 2.5 seconds. This is around 1500 meters for all three gun platforms.
Citat:At that speed, all three mentioned are about the same for flight time. 2.5 seconds for the 338 Lapua, 2.5 seconds for the 408 CheyTac and 2.6 seconds for the .50 / AMAX combination. I would challenge anyone to point out the edge of one of those cartridges vs. the other. .408 looses on weight, cost, and factory work on the guns, non-standard parts, etc. All things compared, cost, precision, range, flight time, etc., the .338 Lapua is the easy winner.
Citat:Why the .338 Lapua is better. In combat sniping, the ability to strike a target at great range is more about the ability to address environmental and meteorological factors than it is the gun. The .408 without computer support is no better at 2000 yards than a 50 or a 338 Lapua.
Ili ti da taktički, a to je bitno za snajperistu na bojištu daljina preko 1500m nije nimalo interesantna, ne zato što ne mogu da je dosegu već je vreme leta preko tih daljina toliko da bilo kakvo gađanje neke mete, pogotovu pokretne je pre pitanje koliko ko može dobro da nagađa nego da pogodi cilj. Čak i na daljini 1500m to je nagađanje, vreme leta je 2.5 sec i za to vreme može mnogo toga da se desi sa ciljem (uapao mu kamenčić u cipelu, on se sagnui i eto, manji promašaj). Dalje, najbolje snajperke sa ručno punjenom municijom teško postižu i 0.5 MOA kao tačnost. Gde je tu vojna snajperka i vojna match serijska municija? Pa slabije rešenje sigurno. A to je rasipanje municije na daljini 100 m od nekih 15mm. Preračunajte to na daljjinu od 1000m, pa na daljinu od 1500m, pa zatim na famoznih 2100m. Pa metar u ruke, izvucite dotičnu veličinu, pa stavite dotičnu veličinu prema svom telu, i vidite koliki je to krug. I to za najpreciznije puške sa ručno punjenom municijom. U prevodu, matematika i balistika kažu u idelanim uslovima teško je pogoditi cilj. Sad, dodajmo i meteo uslove, pa dodajmo samog strelca, pa minimalne greške u upucavanju optike, pa .... Jap, snajperistika je malo zezn.... nauka  .
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