My 91/30 could shoot these MOA @ 100 yds.
My 91/30 isn't run of the mill so to speak. It is shimmed and pressure point bedded and has a Huber trigger that Mr. Huber and I fine tuned together in my basement when I lived in WI. The rifle is a refurb so the barrel was basically new when I bought it during the wave/flood in the 90's.
Geez I am going to miss those bullets.

 

I still have a couple of boxes of the Hornady 174 gr .312" bullets. The box is labeled ".303" and "Graf's" since this was a special run made for Graf's. My No 4 Mk1. likes it.

 

So the .312" Hornady 174 grain bullets are not being made any longer and won't be made again, right?

 

Not likely, unless Graf's or some one else can get Hornady to make these .312" bullets again.

The Sierra 174 gr .311" MK mikes closer to .3115" so it might work as a substitute. However, I'm not a fan of Sierra MK's any more owing to their jagged meplats and weight variability.

 

Ammolab: it may be possible to use an 8mm bullet:

The Prvi Partizan B-350 - 175 gr HPBT - may be usable. It has a lead core so it will squeeze down to bore diameter. Of course, due consideration to pressures is called for. I suggest this because a range club buddy regularly shoots Serbian M30 - military version of Prvi Partizan 7.62x54R 182 gr FMJBT - in his FinnM28/30, which has a .3085" bore caliber. He also knows never to use steel-core milsurp in this rifle. However, the heavier 198 gr B-022 FMJ BT may be a safer bet. With the open base, the core can extrude to the rear, while the HPBT will force the core to extrude forward and thus distort the ogive.

 

Never knew they made those. Too bad they stopped.
I have a mosin I built with a UK59 barrel. Turns out it has a .312 bore (I slugged it). No wonder I could not get good accuracy with even .310 bullets.
I tried the hornady 150gr soft point 312's with ok results. I have not tried the 174gr round nose.

I thought about trying to resize some 8mm bullets, but I hear that resizing bullets that much can lead to poor accuracy from them.

 

Never knew they made those. Too bad they stopped.
I have a mosin I built with a UK59 barrel. Turns out it has a .312 bore (I slugged it). No wonder I could not get good accuracy with even .310 bullets.
I tried the hornady 150gr soft point 312's with ok results. I have not tried the 174gr round nose.

I thought about trying to resize some 8mm bullets, but I hear that resizing bullets that much can lead to poor accuracy from them.

This 180gr .311” flat base bullet might be a good one for you.

SIERRA 303(.311)180gr SPT BULLET PROHUNTER 100/bx - Graf & Sons

These bullets utilize the nominal 30 caliber dimensions common to the martial arms of several foreign entities. Most of these have found their way to the United States as either war trophies or were imported as military surplus in recent years. These include the British Lee-Enfields, the...

www.grafs.com