does firing a 38 out of a 357 cylinder change the ballistics?

Not significantly or even predictably, so don't let that be the deciding factor.

One of the most accurate .38 Special revolvers on the market used for competition was the Colt Python, chambered in the full .357 Magnum, so that extra freebore is not anything to worry about either.

The only three concerns I can see is that the .357 Magnum version will cost more money, so figure if you will really want to punish yourself with that SERIOUS amount of extra recoil when you use the magnum loads.

The Magnum version is a TINY bit longer, though it probably won't make the difference in whether or not its small enough to hide well. It still will be.

Shooting .38's through the gun will leave a residue inside the chamber that must be cleaned out before shooting the magnums, or the cases will stick and be very hard to remove.

As said by others, yes there is difference. But not that much. Since you are not going to target shoot with a LCR, no big deal. The LCR in .38 is a beast with +P ammo. The LCR in .357 is a monster. The one shooter I saw with one shot shot it 10 times and said that was enough. I am a big fan of .357s and shooting 38s in it. Just not in a pistol so light. I would save the extra cash for the LCR .357 and buy the .38.

I don't see any reason not to get the .357, because even if you don't intend to use .357; you will at least have the option to down the road.

However, I am told that you will lose about 100 fps shooting .38 out of a .357 chamber; but this typically isn't viewed as anything major.

I read an article on this about 20 odd years ago in some shooting magazine. I believe it said there was a slight loss of accuracy due to the length of bullet jump between the cylinder and the barrel cone where the rifling started.

They were comparing similar pistols with one pistol chambered for 357 mag versus another chambered for 38 special. The difference was measured by the increase spread of bullets on target, and the difference was about an inch at 10-15 yds.

The difference might be significant for a target shooter, but wasn't enough to matter for defensive shooting.

If there is a difference you would need sensitive machinery to see it.

The difference in the length of a .38 cylinder and a .357 is minuscule. Way way to little for the bullet to even notice on his trip out

To be honest I don't know about your first question but I do think the difference would not be felt on either end of the gun. I can't think of any reason not to get the revolver in 357 mag. except cost. Resale would justify that.

yes. But will be so small you would need a doppler set up to detect it. it will not really effect practical applications. get the 357 as you have a greater selection of ammo.

The cartridges do have different ballistics if that is your question.

Yes getting a .357 to use both 38special and 357 is a win win.