I have settled on Speer Gold Dot for my 11.5 SBR, and bought a good amount of 55gr already.  It seems from reading threads here that the 64 gr is the favorite for SBRs, but the 75 gr is getting some positive reviews.  PSA has been running good sales on all three weights, but at different times.  So, specifically for an 11.5" 1/7 barrel, general purpose HD, SD, SHTF, which would you all select and why?  

64 grain GD for me out of a 10.5 and 12 inch barrel for HD.

I chose that based on the HD ammo recommendations here on the forum, which noted that the 55 grain load wasn't a stellar performer...for which reason, I can't remember.
I like that the 64 grain retains a bit more velocity over the 75 grain and would also be closer, trajectory wise, to my 55 grain range ammunition than 75 grain.

Of course, the 64 grain was less expensive than 75 grain at the time so that factored in too.

You really cant go wrong with any of those, but I would use the 75gr.  Good barrier performance, excellent terminal ballistics.

I was able to see all three in a recent gel shoot. I like the 64, then the 55, then the 75.

64gr version in my 10.3"

Do you recall the barrel length and distance from muzzle to block?

64 grain for my MK18

There were 11.5" and 14.5" Colts about 10 feet from the block.

The 55s and 64s expanded nicely, the 75s. The 75s ice picked a little.

They didnt expand fully at all, or just had a longer neck?

The 75s didn't expand as much from the short guns. They also over penetrated some. I'll try to dig up some results.

ETA:  Through sheet metal, the 64 penetrated 12.5" and expanded to .409. The 75 penetrated 20" and expanded to .275. It looks like that was the worst one.

Further reinforcing my choice of the 64 grain load.

Speaking of 64gr GD, PSA has it on sale again (expires at noon EST tomorrow) for 10.99 for 20 rounds with free shipping for 10+ boxes.  $1 more per box than the last time, but still a good deal for this ammo.

64gr

Yep, I am probably about to add 200 rounds to the 700 in storage I have now.

Looks like it performed just fine out of 11.5" SBRs in this test, even through auto glass.

75gr Gold Dot

Just ordered 500 of the 64gr from PSA. Free shipping is a good deal.

Just ordered 400rd of 75gr, gotta say, some of you all are making me nervous about not having gone with the 64gr! I have two 10.5's I'd love to use these with but now I'm a bit concerned that their lower velocity will lead to underwhelming results.

dont worry too much. its better than throwing ball ammo at a bad guy.

just seems there is inconsistent reports form this bullet but chopping blocks gel test is positive. i think he uses properly calibrated gel?

Those LE shoots show all kinds of data. If anything, it just re-enforces "P for Plenty", because every bullet and every slab of meat/vehicle/building is going to react differently. That said, I went over some of my notes from LE shoots, and saw that the many of the gold dot's offered "variable" expansion diameters (high highs, and low lows).

I strongly suspect that the round you saw which expanded to .275 suffered petal shearing and there were significant frags in the gel.

It is my THEORY that the heavier 75gr does not shed velocity as fast, when traveling through medium (gel/animal/person) as do the lighter rounds, and thus once the petals are fully expanded, while they are identical in size to those of the 55 and 62/64gr, they are subjected to more stress due to higher retained velocity mid-target, and thus are more prone to shed.

I'm not at all averse to this. I have talked to numerous hunters both in America, and those who hunt in Africa, and by and large, the consensus is that on thinner skinned game, cup and core bullets that retain 55-80% of their weight, and still penetrate sufficiently, kill game the fastest, as opposed to TBBC, X-bullets, etc.

I am personally taking my AR after deer and smaller, and in extremis, self-defense against bipedal threats. These things are thin-skinnned, of course.

It is my understanding that none of the departments who have switched to 75gr Gold Dot who formerly used 62/64 are regretting it, now that "a few" OIS's have occurred and they have had a chance to see how it does.

As always, P for Plenty, YMMV, blah blah blah

I would agree that 75 gr will retain velocity after impact better than the lighter weights, however, I am highly doubtful that they can overcome the higher impact velocity the lighter pills have.  

IOW, if a  55gr doesn't shed a petal, a 75 gr won't.  I've punched 55gr through multiple bones without shedding a petal.

I subscribe to the same newsletter. Shoot til you don't need to shoot any more. I wouldn't feel at all bad about carrying the 75s. It's just that on the day that we tested, the 64s were very consistent. We also have other considerations, like personally owned rifles that may or may not shoot the 75s well. That might not be a factor for an individual. YMMV and all that.

Good point rock, I would definitely recommend trying the 75gr out on an individual rifle basis.  A lot of guys think their gun will shoot heavy stuff just fine, only to realize after buying a case of the stuff that it doesn't.  Get a little of each and see what groups the best for you.

Shooting water jugs with both,  sometimes I see petal frags with 75. Rarely with 62, never with 55. The petals on the 55 stand out almost straight. The petals on the 75, even at 100 yards, fold and curl, sometimes tear.

Water is a heck of a lot harder than flesh/bone.

FBI gel data shows the same thing.
55gr petals stand out more, and the 55gr retains more weight, while the 75's fold back. Residual velocity post-expansion. View the bare and heavy clothing covered gel shots. Unless you have another explanation?
http://www.le.vistaoutdoor.com/ammunition/speer/rifle/compare.aspx?compare=24446%2C24475

Interestingly enough, hornady also chose a 75gr weight bullet for their TAP SBR load and it's also going about the same velocity as the 75gr gold dot out of a 14.5" bbl as tested by Molon. So heavy and slow shouldn't automatically mean bad in terms of SBR loads.

I'm not sure what is on that link that supports your position?

Here are a couple of pics of an actual 55gr gold dot, fired from a 16" tube, into a deer at 275ish yards.

Looks good! Sadly, I don't have a recovered 75gr from a 275y shot to show, and the one I have went through a lot of bone and was under 200 yards, so not very comparable.

The link I posted shows what I stated. Less weight loss % and larger expanded diameter of the 55gr.

That said, that bullet did great! What method was used to determine distance to deer?

I was planning on buying some 62/64 gr, and some 75 gr. Seeing that the 75 gr may not expand well at low velocities, and if I were to use it in a 16 in barrel, about how many yards would it be good for before it fell below the expansion threshold? I want something to work out to at least 250 yards.
I have a couple cases of 55 gr, but was wanting something a bit heavier for medium size hogs and deer. Should I just stick with the 62/64 gr for a general use round?

The distance is approximate, but I was on my shooting platform, and the deer was further than my 250 yard gongs.  It could have been 300ish.  I went back last week, but forgot my rangefinder, again.

My son shot a doe at about 100 yards with 55gr from a 16" tube, it broke a rib on the way in and out, and was stuck in the skin on the off side.  Roughly 14" of penetration, double lunger a little high.  I can't tell the bullets apart, no appreciable difference in expansion/shank length.  I was surprised the bullet didn't perform differently at what must have been drastically different velocities.

Shooting water jugs, I came to the same conclusion. These bullets are not super velocity dependant. The 64gr nosler bonded and 62gr tbbc, are much more variable based on impact velocity.

This is part of why I like the 75gr. At somewhere around 220 to 250 yards, the much higher BC begins to translate into the 75 moving faster. The higher BC and mass also mean better penetration, and higher velocity through three target, as well as about only 50% as much wind drift vulnerability as the 55gr.

I use the 64gr GD in my 11.5" BCM upper.

The stuff is pretty accurate too, I get 1" - 1.5" groups with it out of my 18" BCM upper.

I have a mix of 75 and 64. Should i stack one and then the other while loading mags or us that stupid?  Like the saying goes keep shooting so in theory sending a 75 then 64 then 75 then 64 should cover barriers and non barrier and anything else, correct?

Or is this one of those things that sounds plausible but is dumb?

You would probably be better off filling one mag with 75, and one with 64.  Used colored electrical tape to identify which is which, or just label them.

I don't have any pics, but the 75 grain gold dot shoots about as accurate as 77 gm in several of my guns. Great BC too.