6mmBR

[bustin]

20" 6BR test today
95gr SMK loaded to 2.3"
32.5gr H4895=3032fps
32.5gr Varget=2950fps
32.5gr RE15=2890fps
33.5gr 2520=2960

75gr Vmax
32.5gr H4895=3158fps
I think more is possible here with a slightly faster powder so that should make a good varmint round.
I should be able to get 3100 with the Barnes 80 and 85TSX so for deer and hogs it should work just fine.

The 6mm shoots pretty flat, it's pretty accurate, the 20" barrel on the AR15 platform makes the rifle pretty light compared to the 308. It should work just fine as a walking varminter so I can go shoot some varmints, yotes and a deer or hog if I want to and still be accurate enough to punch holes in paper.

 

[Tx_Flyboy]

Re: 6mmBR

You either suck at math, don't know wtf your talking about, or both.

 

[bustin]

Re: 6mmBR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tx_Flyboy</div><div class="ubbcode-body">You either suck at math, don't know wtf your talking about, or both. </div></div>
I've been shooting 308s for about 30 years and probably built more 308 ARs than you have ever seen. Crank up quickload/quicktarget and check the vel out of a 20" 308 AR with the 155 amax and see for yourself. Maybe you should read and shoot more and post stupid shit less.
Z at 300yds. Factory Hornady ammo. We ran this test about 3 years ago at the range the 95SMK has a higher BC and is faster than a 155amax out of an AR with the same length barrels. The poi is much higher and does not drift as much. E is a calculated by QL/Qt
using the actual vel we saw on the oehler there was an extra O if thats what you're talking about you should have known it was a typo.

 

[Tx_Flyboy]

Re: 6mmBR

Bustin,

You claim to have been shooting 308s for 30years, well, apparently you dint learn anything about physics while you were at it.

You bash me for posting stupid shit, and then turn around and do the same thing...your rebuttal is to "play with quickload" instead of giving hard numbers from YOUR rifle...typical.

To your point, all "high speed" cartridges .243winchester, 6mmBR, .22-250, et al will have less drop than a 308, but that's because they are launching a smaller bullet faster(less time for gravity to act on them)...some bullets such as the 115DTAC, and the 105AMAX, and other high BC 6mm bullets will exhibit even less wind drift than the 308 because of the combination of their speed and high BC.

All that being said, NONE of the 6mm BR bullets will carry MORE energy downrange that a 308 shooting 155s at 2850ft/s without launching the 95gr SMK at least at 3,530ft/s...your 6mm BR will not be capable of achieveing this level of velocity...whilst 2,900ft/s is easily obtainable in a 20" 308.

Additionally, when you substitute more modern, higher BC 30cal bullets such as 208AMAX (.649 BC), 178HPBT (.530 BC), Berger 185s, the gap btw the 30cal and 243 increases dramatically...again.

Therefore, my comment that "you wither suck at math or dont know wtf ur takling about" stands.

That, unfortunately, was an unprovoked attack on you, and my apologies. But nothing irkes me more than ppl making wild claims about their new sweet hearrt cartridges.

 

[bustin]

Re: 6mmBR

The 308 factory loads produced no where near 2900fps from a 20" AR10.
How about this to keep from ruffling your feathers.
The 6mm shoots pretty flat, it's pretty accurate, the 20" barrel on the AR15 platform makes the rifle pretty light compared to the 308. It should work just fine as a walking varminter so I can go shoot some varmints, yotes and a deer or hog if I want to and still be accurate enough to punch holes in paper.
I have 3 308 ARs (1 Pacnor, 2 tight bore Kriegers)and a 6.5x47 Bartlein, don't shoot the 308s much now though, I don't think I'm a sniper so I'd rather use the caliber that works best for what I want to use them for.

 

[Tx_Flyboy]

Re: 6mmBR

Bustin,

Dint mean to bust ur chops.

There are several factory loads in 308s that produce 3,000fps in 24" barreled 308s, and by extension about 2,900fps or more in 20" barrels. Nosler makes a 150gr load that achieves 3,025fps & Hornady's superformance load makes makes 3,000fps...granted, these are 150gr bullets, not the 155gr bullet you made ur initial point with.

But as a relaoder, you know that you can duplicate and often exceed the box velocities on factory loads safely in your own rifle.

Alliant's new powder, the 2000-MR makes a published 2,990ft/s from a 24" barrel shooting 150s or 155s IIRC...same thing with Hodgon's CFE223 powder. These new powders for 308s, coupled with the newer, high BC bullets bring the 308s into the next century IMHO.

I'm achieveing 2660fps from my 20" gas gun shooting 178AMAX.

As to your point about the AR-15 being lighter than an equivalent set-up in an AR-10 platform, you'll get no argument from me about that. Yes the AR-15 is lighter, but only by about 1.0-1.5 lbs total. The difference will be the weight of the BCG & reeicver....the barrel weighs less for the 308, (if you use the same profile, the bigger bore means less metal), the reciever is only slightly heavier for the 308, and the BCG contains the majority of the weight delta.

Btw, my favorite caliber to shoot is my .243 winchester...It shoots flatter than my 308, but felt recoil is more (its a bolt gun vs my semi-auto, braked 308), and i dont have any illusions as to which caliber carries the energy farther....the 308, hands down.

I have hunted with both, and both have their roles. I love not worring about hold-overs with my 243 (because of the flat trajectory) where i hunt.

Once again, my apologies for bashing you first before engaging in a civil conversation.