A very good buddy of mine gave me a a Husqvarna 7x57 rifle. He said it had a very long throat and he had to load bullets "hanging by their toenails" to shoot accurately.

He gave me some examples of good loads he had with Hornady SST bullets and they have 5/32nds of an inch of bullet below the cannelure exposed.

The 150 grain Hornandy interlocks only have 9/32 of an inch from the cannelure to the base of the bullet. If I loaded to that same seating I would only have 1/8 of an inch of bullet in the case.

Is that acceptable?

How much depth is usually considered necessary?

The point is kind of moot anyway because my little Lee Classic Loader kit doesn't have enough threads to load that long anyway.

Well, the obvious solution is to give the rifle to me for proper disposal. Seriously, I have three rifles chambered to the 7x57. About the best I can give you is seat the bullet like he says and try it. I can get away, literally with murder on the Ruger #1 and it doen't have to feed from a magazine. The other two rifles I try to seat the bullet only as deep enough as I have to to hold them and still shoot accurately.
I stick almost strictly to flat based bullets as there is more leeway in seating them out.
I have also found I get better accuracy from the longer heavier bullets although the 140 gr. Nosler Ballistic Tips are accurate as hell in the M70 Featherweight. The most accurate bullet I have found in all three rifles is the long discontinued Sierra 170 gr. RN. The M70 will consistantly stay between ,375" and .50". A pox on Sierra for dropping them. The 175 gr. Hornady RN is a fairly close second place with most groups at .75" to one inch even. That bullet from my custom Mauser is a .50 to .80" gun. I just got some 175 gr. Hornady Spire points and Nosler 175 gr. partitions to try in a .280 Rem. for an elk hunt but will try them in the Mauser custom as well. Who knows, I just might use it for my upcoming elk hunt.
I've oly been playing with a 7x57 off and on but I'm thining of going more "on" than off. For a 120 year old cartridge, I have to say it's beginning to impress me.
Dunno about the lighter weight loads in factory ammo, but the batch of 175 gr. Federal ammo only did 2010 FPS, nowhere near the 2400 FPS advertised. The first time I had a rifle in 7x57, I was living in a small western town and the only ammo the hardware store had was that 175 gr. Federal stuff. Opening day I shot a nice Mule Deer with that load at about 8 in the morning. My wife and I searched for that deer until it was too dark to look any more. I did find what was left by the coyotes the next day by the birds.
I blamed the gun and sold it off. fast forwad to when I bought the M70. By then I had a chronograph. a partial box of 1973 issue Federal 175 gr. bullets and decided to chronograph the load. I picked p a fresh box of that same ammo to tst alongside to see if maybe the first box had a bad lot of ammo. Average velocity from both boxes, the old and the new as 2010 FPS. I've never decided as whether I should salvage the bullets and brass, use the loads for plinking or plain old practice. I do know that I will never use that brand and load for hunting ever again.
Many years ago, late 1950's to be exact I had a Husqvarna "Husky" in 30-06. I thought it was one cool rifle. today, if I found one in 7x57, I'm afraid my better half would pull a Loreena Bobbit on me if I bought it.
As I ungracefully age, i find that hard kicking rifles just ain'y all that much fun anymore. About the hardest kicker I shoot today is my .35 Whelen and that one not very much. It's the one i usually take fo elk but maybe this year it just might stay home. We'll just have to see.
Dunno what powders you plan on using but you might want to look at W760/H414, same powder just diffrent packaging. I'm getting some fine accuracy and damned good velocity using W760. My three 7x57s absolutely love that powder.
Paul B.

Rule of thumb is "one caliber deep". Seat it at least .284" into the neck. I'd stick with Barnes/Scirocco/GMX because they're longer and you can experiment much more safely...

[1 / 8 = 0.13 inches is NOT enough]

Wow!! more case capacity

I think BNagel is a little conservative. Yes, one caliber deep is prefered, but not necessary. The neck on a 300 Win Mag is only .264" long, or .044" less than one caliber. A 375 Ruger neck is .070" shorter than one caliber and it has lots of recoil, but you don't hear of bullets shifting in that cartridge.

Pick a bullet long enough that you can start it .015" off the lands (if that cartridge will fit the magazine box) that has at least .225" of bullet in the neck. Work up a safe, reasonably accurate load. Then keep the same powder charge but seat the bullets deeper in the case by .015" increments until you get the best accuracy.

FWIW,
over the years I've picked up modified cases to use with an OAL gauge for all the chamberings for which I reload. I then can get a reasonable idea of the max OAL for that rifle's chamber. On many commercial chambers, the max OAL is so long, the bullet will not touch the case.
I usually start from the other direction, going short to long. One can easily determine the max OAL of the magazine, if you want a repeater. If not you can load longer than the magazine, put one in the chamber and 1 in the mag.
Did you query your buddy whether he had actually sat down, started at SAAMI OAL for the 7 x 57, then loaded cartridges increasing the OAL, say .030 at a time and firing either 3 or 5 shot groups to see what it actually liked?. You might be surprised.
One more FWIW. I've encountered few rifles that would not shoot Nosler ballistic tips well.

Best
GWB