So decided to get into more long range, but I don't reload.  Tried several different loads and discovered my rifle (Ruger American Hunter, 20" HB 1:10) liked the IMI 175.  Bought a case of it.
Local range goes to 200 and I get pretty good groups.  Took it out to 1000 yards and, while I got hits, not consistently.  Some was wind, but the ammo wasn't performing as predicted.  So I bought a Caldwell Chrono.  Also had a collection of FGMM (168, 175 and 185) and fired some strings.
10 rounds for the IMI (as this is my go to round)
5 each for the others.
I know this is way too few to make a really accurate prediction, but it was enough to learn some basic facts.
IMI averaged 2400, which my dope predicted.  Dead on in fact.  HOWEVER, the SD was 58.8.  From a low of 2302 to a high of 2460.  That explains what I saw beyond 600Y
185 Bergers  2541 16.6
175 SMK 2522 11.8
168 SMK 2581 17.0

So I spent money so you don't have to.  Within 300 the IMI is OK.  It shoots a pretty consistent 3/4 MOA out to 200 in my rifle.  But the SD makes it irrelevant for long range.

My gun likes the 168s, but I know they don't do well beyond 600.
175s were Good.  Steady 1 MOA
My gun does not like the Bergers, but a 185 bullet going 2541 is nothing to sneeze at.  Work investigating if you gun likes it.

I may just have to bite the bullet and start reloading.

Anyway.  There is my data.  Go forth and waste ammo no more.

Make the jump, start reloading. You can load 308 ammo for probably close to half what you're paying for factory ammo, and you can make it more precisely.

Also once you have the press and accessories its a really short jump into niche cartridges that shoot better at 1000 yards than 308.

So some more follow up.  Because why not?
Bought some of the new(to me) Centerstrike FGMM 175s and Lapua 175 Scenars and kept shooting the IMI, because I have to do something with it.
15 shots of Lapua
average 2481.
SD 20.7
Grouped OK.  Verticle stringing.   1.5 MOA.

15 shots centerstrike
average 2438
SD 18.7
Grouped about like FGMM.  I honestly can't tell you the difference between the Centerstrike and the normal FGMM.  I see no reason to buy it over regular FGMM which can be had for cheaper.

IMI 10 shots
2491 average
28.8 SD.  

Grouped fine as usual at 100 Yards.   It was about 10 degrees warmer but still have an average almost 100 FPS faster than before.  All the same lot.  Don't know what to tell you.  Hyper temp sensitive maybe?

The good news is the Lapua didn't shoot better than FGMM.  So I won't be buying any more (I still have 35 rounds to mess with.)

More data for reloaders to ignore.

Do the polymer tipped 168gr SMK's have the same issue as the BTHP SMK's?

By better do you mean they don't have the issues past 600?  Or do they have the same boat tail design?

Thanks for sharing your findings.  

You're not alone in buying bulk ammo that just didn't shoot well though.

You could've already been reloading for what you have paid for ammo. Don't be afraid to buy a used press off ebay to save some money. I would also buy a used scale, powder measure and dies. You can save a lot of money. If you decide you don't like it you can send it down the road and get your money back.

Oh, I am aware.  But time and money both count.  I don't compete and don't really shoot that much.

Thanks.

Actually his post still kinda confuses me.

If the only difference in the two rounds is the tip, then the TMK retains the boat tail instability issues.  Its advantage is that the better BC extends to when that issue arises.  But the trans sonic issue should still be there.

So does the TMK fix the transonic instability or only extend the range before it shows up?

Ah.  Cool.  I have 40 rounds of the blackhills showing up tomorrow to test.

The SMK has a 13 degree boattail. The TMK is 9?
https://bulletin.accurateshooter.com/2014/09/practical-thoughts-about-transonic-bullet-stability-and-accuracy/

Attached File

OK.
A few more tests.  
Lapua 175s 10 rounds.  1.5 MOA
40 SD
2574 AVG.  Disappointment immeasurable on this one.  Shocked at how high the SD was.

FGMM Center Strike 175s  NO clue whats different between this and normal FGMM  1 MOA
12 SD
2475 AVG
Shoots like FGMM, just a little slower.  No reason I can see to buy this over normal FGMM, which is cheaper.

Blackhills 168 TMK.  10 rounds 1.25 MOA
25 SD
2638 AVG


So all this to say I still get the best groups out of IMI.  But the SD makes it worthless beyond 300Yards.
If I look around for sales I can get FGMM for 1.25 per round.  This will be my go to.  1 MOA with a very good (for factory) SD makes this the most consistent ammo for my gun.

I think my gun likes slow ammo, and the IMI is the slowest.

Great, great thread.

I tried reloading about sixteen years ago, hated it and now depend on manufactured cartridges. Were the IMI 175s their “match” version of the m118 bullet, or something else?

Thanks!