Full size vs compact size ammo

Huh? I have never heard of this and doubt there is any difference

Generally (and only very generally) the longer the barrel the higher the performance of any given ammo. Second, generally (and only very generally) a larger handgun will be heavier than a smaller handgun of the same make and model and so might feel less recoil.

So, there could be a noticeable difference between the same ammo shot from a full size handgun vs a compact handgun of the same model.

It could be the powder is optimized to burn more completely out of short barrels to provide the velocity trick bullets need to expand, and/or perhaps develop pressures needed to operate abbreviated slides reliably?

The self defense ammo made specifically for short barrels tends to use slightly faster burning powders than non short barrel ammo to help performance in the short barrels. They also frequently add flash suppressants to help reduce muzzle flash that is frequently present in short barrels.

I think it’s more of a velocity thing. Hollow points need to meet the threshold or they will not expand. Short barrel handguns lose more velocity than full size duty handguns due to the shorter barrel, therefore your more likely to see better performance out of full size handguns. Ammo companies develop bullets to expand at certain fps and if it’s designed to reach expansion at a high FPS then shorter barrels may not provide the performance they claim. Now whether or not it’s true you’ll have to do some test. I have some gold dot “short barrel” that performs identical to the regular gold dot. Seems to me it’s more of a market kind of thing. Now with Remington ammo maybe there’s some truth to it idk.

Nice idea, but seems like also another great marketing ploy to sell you 20 rounds for more than the price of 50.

Sort of like putting "lather, rinse, and REPEAT" on shampoo bottles.

There can be a difference in performance.

Check out the Ammo Quest videos by Shooting The Bull on YouTube. His videos are very well made and he tries to test five rounds in plain gel and five rounds in gel covered by demin.

His tests show that there is a need for the bullet to reach a certain velocity for expansion and desired penetration.

In compact 9mms I run 115 gr, in full-size I run 147 gr. (The difference probably isn't that dramatic.)

John Joseph said:

It could be the powder is optimized to burn more completely out of short barrels to provide the velocity trick bullets need to expand, and/or perhaps develop pressures needed to operate abbreviated slides reliably?

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This is what I've seen in a few, when the 'short-barrel ammunition' was starting up. Definitely advertised in a few reputable brands, lower flash was confirmed in a couple, doubt it's universal.
Also in one or two (Gold Dots, I think?) the hollow point was reshaped or larger, to encourage expansion with the less reliable velocities.

Otherwise, they'll just change something--different powder, +P to try and get it to velocity, using 115gr instead of 124/124 or 135 instead of 147--and chalk it up to marketing.

I don't know about the Remington but the Gold Dot .45 ACP Short Barrel has a different Hollow Point profile and tends to be just a bit faster in sub-4" barrels. I'm.assuming it's a little faster powder.

The HST Micro 9mm is a reduced recoil round optimized for.small pistols but I have no personal experience with it.

I personally just find something I think works in that barrel length and use it whether it's marketed for it or not.

The Remington I use out of a 3.3" Barrel is the Golden Saber .45 ACP +P 185 gr.

mljdeckard said:

In compact 9mms I run 115 gr, in full-size I run 147 gr. (The difference probably isn't that dramatic.)

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I shoot 115 gr out of compacts as well. I weighed a paper clip the other day and it weighed 15 gr. The difference between 115 and 124 is 9gr. I doubt whenever the 9mm hits the target it wouldn’t have a clue and I wouldn’t think you’d see any difference.

Would ammo designed for compact handguns have sub par performance from full size handguns or carbines? Since they hit max pressure so quickly would the longer barrels have a big drag on velocity?

BlueHeelerFl said:

Would ammo designed for compact handguns have sub par performance from full size handguns or carbines? Since they hit max pressure so quickly would the longer barrels have a big drag on velocity?

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The short barrel ammo would still perform better in a longer barrel but not as much better as ammo designed for a longer barrel.

Dramatically different gun but I think the example might help:
I was working up a 44 Mag load. I tried several powders and after getting two different powders worked up for the revolver to a power level I wanted (240gr @ ~1350fps). That in my revolver H110 (a slower powder) produced lots of muzzle flash and blast as some of the powder was burning out in front of the muzzle, since is was a bit too slow for the barrel length. The 800-X (a faster powder) produced noticeable less muzzle blast and no flash since it was burning completely before muzzle exit. They both produced basically the same velocity from the revolver. Now when I moved over to the carbine the faster 800-X powder only got a ~220 fps bump in velocity going from 6.5 inch to a 16 inch barrel were the slower H110 got over a 350 fps bump in velocity for the extra barrel length. -rambling

You would be surprised how much difference mainstream loads have when run in short barrrls.

230 gr standard pressure 45 ACP Loads can loose as little as 40 psi or as much as 120 fps dropping from 5" to 3".

I can certainly see where a load intended for short barrrls would not use the slowest of those powders.