[Glock72]

I'm looking at Federal hydra shok 180 grain or Federal HST 155 grain ,opinions and recommendations appreciated .

[Nyckid211]

From my understanding, the lower the grain count (135-155) compared to 180, the less the 'snappiness' that some users report. So in essence, it really depends on the application. If I were looking for a SD round, I'd go with a lower grain, because it's suppose to fly faster, translating to high energy impact, and expands more then a heavier, slower bullet( read: 180 grain).
If you are looking for practice ammo, 180 should be fine. I read an article online that articulates what I told you slightly better, I'll try to find it for you.
Here is a list for comparison of the Muzzle energy of various rounds, i believe also including the two weights you asked about if not very similar rounds of the same brand and weight:
http://www.ballisticsbytheinch.com/40sw.html

[sgtcowboyusmc]

I carry 230 Gr Hyda-Shok in 45 and still believe them to be one of the best rounds made even though the design is 20 yrs old. I will not argue with those who disagree I can tell you from Cops I personally know have been in shoot outs with it and swear by it even though their Departments went to newer HP. They have also said that they do not believe that the new round is as good even though they have had only a few shootings. I also know those whom I respect who swear by CorBon DPX! But I have never shot them and know no one who has been in a shooting with them but I know several who are carrying them. I am a Bigger Bullet the better camp. So if I was carrying a 10mm or a 40 S&W it would be a 180 gr but one of the things I tell anyone who asks is Test the rounds on your Pistol! ALL GUNS ARE DIFFERENT! I have 2 Glock 21's and they shoot different with the same ammo, same box, same lot! So pick the ones you like the best and buy 2 boxes each (At Least 2 boxes) and see how they preform out of your Gun! If you have any hiccups then I say 5 boxes more of that round at least before you even attempt to carry! I like the new HST's and I am shooting them to test them but I use way more than 2 boxes before I carry them! I have shot 3 boxes of 20 so far but will not be sure until 200 rnds are through my EDC gun.

[iShoot]

I assume you are asking about stopping power? Which is generally a highly debated subject. Most believe the heavier bullet is best for self defense, I've heard arguments between 165 gr and 180 gr. Speer and Federal are popular for self defense. In my opinion any bullet will get the job done, if you do your part. If recoil is a consideration, try a couple weights and see which shoots best "for you". The G27 is pretty jumpy with two fingers on the grip while firing in rapid succession. You can find a lot of ballistic tests online and on YouTube.

[Blades]

Go with the HST.

[Lucian_253]

I use Hornady Critical Defense. Speer Gold Dot, and Federal Hydra-Shok are all good rounds too. I would stay away from 180-gr. though.

[G29EDC]

If your looking for a self defense round, I always recommend a bonded bullet, no chance of a jacket/core separation and the jacket staying with the intended target while the core passes threw and hitting something or someone. Plus if you have to shoot threw barrier the bullet is more likely to stay intact. I personally use Winchester PDX1 165 Gr in .40 S&W and in 10mm I use 165 Gr Speer Gold Dot's loaded by Double Tap.

But ammo is like anything else, you have to find what works for you and what works with your equipment.

Also, as tnoutdoors on YouTube always says, it is your responsibility as a law-abiding citizen to research and test the ammo you will carry.

[loneranger]

maybe I am wrong for asking this but I have been shooting a very long time... The 180 g is Grams of powder behind the bullet.. Not the actual weight of the lead coming out... So upwards from 180 will propel faster but still pull apart more during travel. A .40 or upwards will weigh more and pull apart faster than a .45 because of lead weight vs that of a .40??? If my math is on par??? I don't know for sure...

[G17XJ_BS]

That number is bullet weight, not powder weight.

[ZombieNinja]

Originally Posted by loneranger

maybe I am wrong for asking this but I have been shooting a very long time... The 180 g is Grams of powder behind the bullet.. Not the actual weight of the lead coming out... So upwards from 180 will propel faster but still pull apart more during travel. A .40 or upwards will weigh more and pull apart faster than a .45 because of lead weight vs that of a .40??? If my math is on par??? I don't know for sure...

It is the actual weight in grains of the lead and copper slug. Powder is waaaay lower number. Like 4-6 grains