350 Legend

[Hickory]

Can I load .357 diameter jacketed bullets meant for a 35 Remington in a 350 legend without pressure issues?

[Coopaloop86]

I would almost certainly think not. Most every 350 Legend ive seen has been .355 bore. You would have to slug your bore to be certain but id gamble to say its in the .355 ballpark and not .357. You could however run those bullets through a push through sizing die of .355 diameter and make them work.

[NSB]

You’re asking if you can use .357/38 bullets in a 9mm. I’d think that could be a problem at the pressures in the 350 Legend round. You can run them through a sizing die and size them down to .355 to make them work as stated above.

[MarkP]

Mic the mouth of a loaded round and compare to the diameter of the mouth on a fired round. You should have about 0.003" difference to allow the bullet to release when fired. The fired case mouth should be larger than your loaded round. Starline 350 Legend brass is thinner at the mouth compared to WW brass. When comparing SAAMI chamber drawings the 350 L has the same Groove Dia as 357 Mag both at 0.355".

[MostlyLeverGuns]

The space needed to allow the case to release the bullet is probably the biggest concern regarding pressure, sizing a cast bullet down .003 is not the real issue. Long ago, P O Ackley published experiments he did expanding a 30-06 chamber to 8mm and .358 using the .30 cal barrel and did not experience significant pressure excursions. Many of us commonly shoot .311 bullets through .308 barrels. As always starting low and working up should let you know. Again if the cartridge chambers easily with a .358 bullet seated, things should be OK, but as always, start with lighter charges.

[Hickory]

I was look at the Winchester box for the 350 Legend and it listed a .357 diameter bullet their factory used. What gives?

[centershot]

I slugged the bore of my Marlin 1894c, .357 Mag. carbine a few years ago. Imagine my surprise when the mike read 0.3556" groove diameter! I repeated the process, same result. I was (and still am) shooting Hornady 158 gr. XTP's loaded over 16.6 gr. of #296/H-110 (from the W-W handbook) and I'm not having any pressure problems. As far as cast bullets, I'm using 160 gr. Lee RNFP-PB, as cast, with two coats of tumble lube, over 9.0 gr. of Blue Dot, around 1400 fps (haven't chrono'd this yet), not remarkable really except that the bullet is 0.360" OD, and still no pressure indications. So, R/T the OP's question, "You won't know until you do it!". I had no idea my bore was that small (had to have been the oldest button ever pushed down a barrel!) when I started loading jacketed rounds for it, in hindsight it's hard to believe it works as good as it does, but, it does.

[P Flados]

Having a bullet larger than bore diameter is really not that much of a concern.

However, for the 350L it is usually all about diameter of the neck for the loaded round.

Most available brass will not allow a round to chamber in a typical 350L gun with a 0.357" bullet.

Early on after the round was introduced, it was found that 0.358" jacketed bullets can be sized down to 0.356" to allow use in the 350L.

[MarkP]

321337

321338

Look at the attached SAAMI drawings; max cartridge and minimum chamber for both 350 Legend and 357 Mag. Both have the same groove diameter of 0.355" with a +0.002" tolerance. 350 L bullet dia of 0.357" with a - 0.003" tolerance

With Starline brass you will be fine with some of the early WW brass I had from 145 gr FMJ's loaded rounds you will probably be near SAAMI max at the mouth (0.378") with a 0.358" dia bullet.

Yes I realize this is a 357 Mag revolver chamber drawing but the groove dia will be the same as compared to a breech loaded chamber and the cartridge dimensions will be identical.