450 Bushmaster practical considerations

[Seanhagerty]

I have a spare lower I am looking at a build for a heavy caliber AR platform weapon.

I like the idea of having a longer range cartidge than I can reasonably reach with my .223 AR. So I am looking at several calibers- 50 bmg, 338 lapua, 416 barret, and now the 450 Bushmaster.

I dont see a lot of ballistic data for this round. What are the ballistics like for the 450 bushmaster? How accurate is this round at longer ranges? Should I look at this build in a different caliber if I want accurate distance capabilites?

[Hoot]

In my humble opinion. Despite the 450b's many positive attributes, I would recommend a different caliber for a long shooter. Consider a .25 WSSM or the non-proprietary version of the 6.5 Grendel. Hard to beat the 6.5 for optimum ballistic coefficient, which ultimately translates to a good starting point for a long shooter. A fellow Minnesotan, Mike Milli, of Dtech can set you up with a wide variety of calibers based upon the Winchester Super Short Magnum case. While Mike is a wizard gunsmith, his web site is a little tricky to navigate. Make sure you follow through all the links. His work is highly lauded on many forums. If you're more inclined to a larger caliber than .264, consider the .300 OSSM which can toss a 150gr .308 bullet at 3000fps.

Hoot

EDIT: Oops! Welcome to the forum

[BD1]

The ballistics of the .450B are much closer to the 45-70 than the .338 Lapua. Another consideration is that none of the other cartridges you mention will feed from the mag well of an AR 15 lower with the result that any upper you build for those cartridges for an AR 15 lower will be a single shot.

BD

[Seanhagerty]

I have had the hardest time trying to figure my way through this mess. I may end up going bolt action and building a 6.5 something or other (the 6.5-284 is flashy!!)

I will sit on my hands for a while longer and figure this out a bit more.

[wildcatter]

Sean, All these cartridges you are looking at have far different missions. You've got to define the mission and then the cartridge will emerge. For instance, if the mission is to stop trucks at 1.5 miles, then the BMG is the best bet. If woodchucks at 300 is your gig, then all that you are looking at could work, some slightly better than others. If however, the left ear of a mouse is the target, then indeed, that 6.5/284, might be the trick. You really do have to define what it is you want to accomplish and then start to look for a shooting iron that will do it. As for accuracy, over the intended ranges, this 450b will be hard to beat, assuming you need kinetic energy when you get to the intended target. I have maintained sub MOA at 600yd, with the 450b, but then again, most of your mentioned cartridges will do that and better, but then again, the 50cal cost 5 to 20 grand and at 10-20 bucks a shot, well let's just say, there are other options..t

[Al in Mi]

my wants, always out weigh my needs

[Texas Sheepdawg]

I would consider first, a 308. But as others have pointed out,
What task/mission do you want your future platform to carry
Out? There is also the 6.8mm SPC. If in reality, most of your
Hunts are presenting you with shots not exceeding what the
450 Bushmaster is capable of effectively reaching 250-300
Yards then by all means, I encourage you to consider the
"Thumper". With a velocity of around 2200fps and 2700 Ftlbs
Of energy, there ain't much on the North American continent
The 450B won't dispatch within it's effective range.
But one thing to remember is that the 308 and the 6.8 SPC
Require a lower with a mag well that will accept the magazines
For those cartridges. The 450B operates in most standard AR lowers.
And finding spare mags is a snap.

[BD1]

I'm a big fan off the 6.5x55, and own several old swedes for hunting and targets. I'm currently thinking of building a new 6.5. The .260 Rem, 6.5 Creedmor and the 6.5 lapua are all AR-10 platform cartridges that will basically keep up with, or exceed, the swede in similar length barrels, but at higher pressure with shorter brass and barrel life.

I'm looking more at the 6.5 Grendal ,which is an AR-15 platform. It's a bit slower than the swede, but is a very efficient cartridge offering long brass and barrel life. My "mission" for this is thin skinned targets out to 1,000 yda.
BD

[Hoot]

Due to their differing Ballistic Coefficients. The 6.5 Grendel shooting the Hornady factory load 123gr Amax has more downrange energy than the Hornady factory load 250gr for the 450 Bushmaster beyond 250 yards. That's according to ballistic calculators.

Hoot

[jsspss21]

Just a point of clarification...Texas Sheepdawg wrote

the 308 and the 6.8 SPC Require a lower with a mag well that will accept the magazines For those cartridges.

This is true for the .308, but the 6.8 SPC uses a standard AR-15 lower.