Maximum Effective Range of an SBR

AR/M4 AR General Discussion
1

I was wondering if any knew the effective (the ability to knock down a BG)range of an SBR?:confused:

2

I asked this same question and pretty much got the answer that it depends on ammo, barrel length, and shot placement and that an SBR is designed for CQB and will be effective at those ranges.

I too was wondering 100yds, 200, etc. I havenā€™t found anything definative nor do I have the time, resources, or especially the $$ to do the testing on my own.

I was wondering if I went from a CQB environment like a house or other building, to outside and needed to engage a target at a few hundred yards, if I would be wasting ammo and need to move closer to engage, or if I would be GTG. I hope you get some useful info!

-RD62

3

Whatever constitutes butt-stroking distance for your body size.

4

There have been several members on this and other forums that have successfully used 10.5" SBRā€™s at 300m+ in Iraq/Afghanistan. Shot placement is key. Donā€™t let fragmentation range be your only guide.

As far as knocking someone down, youā€™ll find better info on the artillery forums. :slight_smile:

5

I guess the answer is that no one really knows. If they did they would have piped in their answer. From my limited knowledge and information I have been able to gather an SBR would be effective out to 200 yds. After that you would need a different rifle to get effective hits.
A .308 would be a nice addition to a collection if you need to shot out past 200 yds.
Or you can do like I have considered and get a .308 SBR and probably have an effective range out to approximately 400yds. This information is from what I have been able to gather and not diffinitve in any way.

6

Actually, Iā€™ve found that shorter barrels will decrease the effective range of larger calibers more than smaller calibers. A .308 SBR will basically give you a 7.62x39 with a heavier bullet. I like 5.56x45 SBRā€™s and full-size (16"+) .30cal rifles for that reason.

If I need more range than a 5.56, then it doesnā€™t make sense to handicap myself with a larger caliber CQB weapon.

7

Iā€™m SBRā€™n one of my lowers now for a 8in Piston upper. I know MV is gonna be low, but shot placement is key. FBI was done studys and, ready for this, have found it isnā€™t bullet size but shot placement. uh, Dah. I can hit a steel 10x10 plate at my range with my 1911 at 150 yards 4-5 times outta 10, bet Iā€™ll be doing better than that with the SBR. SBRs are not long range guns, but sometimes their whatā€™s at hand. Iā€™m gonna do some testing with mine asap out to 200 yards first, further when I can find a place to do so. Does anyone know where to get ballistic gel? Maybe Iā€™ll just go get some big chunks of meat to shoot at.:confused: Did I mention Iā€™ll be having a BBQ soon. ā€œOh donā€™t mind that, itā€™s just a piece of bone.ā€:smiley: Some Mil guys have tested the same upper in 6.8 and said it to be a killer at 300yards, and hits arent too hard. Mil testing 6.8, Humm:confused:

8

Figuring out the maximum fragmentation range is very easy. But that is not necessarily the maximum performance range since there are so many factors that go into it.

Just look at the MK262. The Maximum fragmentation range is around 250 yards, but there are guys making kills all the way out to 600 yards with it. It really is all about shot placement. A .223 may only fragment out to a certain distance, but it will still yaw and cause serious damage.

If you are looking for good ammo for an SBR, check out ammo like:

  1. Hornady:
    a. 55 Gr. TAP.
    b. 60 Gr. TAP.
    c. 75 Gr. 556 TAP.

  2. Federal TRU:
    a. 55 Gr. BT.
    b. 55 Gr. HP.
    c. 64 Gr. SP.
    d. 69 Gr. SMK.

  3. Winchester Ranger:
    a. 55 Gr. BT.
    b. 64 Gr. Power Point.

9

not trying to be a smartass here, but arenā€™t ALL M4s technically SBRs?

10

Technically, all M4s are select fire and issued to MIL/LE, too. However, Iā€™d say that the majority of ā€œM4 carbinesā€ owned by members here are semi-auto and have 16" barrels. :smiley:

11

sure :slight_smile: but my point is that with all the folks in iraq using m4s, I wouldnā€™t think the effective range would be a big mystery

12

Iā€™d bet that most members here are referring to the sub-12" barrels when referring to SBRā€™s. Most of the SBR discussions seem to center around the 11.5"/10.5" guns. Personally, I wouldnā€™t waste the time/money to buy a tax stamp for a 14.5" barrelā€¦but Iā€™ve spent a small fortune on tax stamps for the shorter guns. :slight_smile:

13

While you can use a mk18 effectively at longer ranges, ~400m that I am aware ofā€¦, its not the weapon of choice.

Bullet Placement is part of the equation - but at longer ranges, and the lower velocities the 5.56mm is not going to act like it does in close - so your .22 cal hole in AliBaba is a little less effective than a large chuck of fragmented chest.

Most SBRā€™s are not scoped for engaging out past 200m - bullet drop, wind and tgt detection and the adjustment of splash are going to come into play.

Lastly just cause you get a good result at long range (for a SBR) on one tgt does not mean its going to translate into the next tgtā€™s. SBRā€™s are chosen for a mission - units issued them tend to be DA specific - or at least use SBRā€™s when doing DAā€™s and use other weapons when doing other missions. Cardinal rule - use the longest barrel you can get away with to do the jobā€¦
I have a 10.5" a 14.5" and a 16" middy on my wall (plus a FN) and I carry the 16" since I can get away with is in my role. I dont like to be constrained into a SBR unless I need it.

  • if your using a chopped 7.62x51 - best bet is a 155gr AMAX.
    Doc Roberts can over more.
14

No rifle will ā€˜knock down a BGā€™ (unless it fires Mack trucks) otherwise it would also knock the shooter down (pure physics).