Home Forums Hunting & Shooting Ask The Gunwriters Question for John B. and others - Ruger M77 in .257 Roberts.

I have two M77's in 257 Roberts. the older one is a "Liberty" and only likes 100 grain Nosler bullets. It's taken 43 whitetail deer with one shot apiece. The newer one is a Mk II Ultralight that seems to like 120gr Speer BTSP bullets. Neither rifle is a tack driver. The tang M77 is a 1 1/2" rifle, the newer one is a problem seeking an accurate powder/charge. Both have long chambers so factory ammunition and standard seating depths don't work well.
The Ruger factory stock fits me better than any other, and the deer I hunt don't often stand still if I have to move my head around to see through a scope, so I tolerate less than prairie dog accuracy.

Thanks Norske,

Can I ask, you mention both your Rugers have long chambers (throats). Can a long bullet, like a 110gn Interbond or 115gn Ballistic Tip, be seated out to reach the lands, or just shy of the lands with enough bullet shank left in the case neck?

I'm hoping my rifle has a longer throat than my Hawkeye as I want to shoot 110gn bullets and heavier in it, but not so long that the bullets can't be seated near the lands.

Thanks.

According to my Hornady OAL measuring tool, my maximum length is 2.93". The magazine allows this. I'm still playing with OAL and am at 2.91" with my latest loads of H4831.

Norske,

2.93 inches isn't overly long. I should have it soon so I'll see how long it is.

My son's Ruger M77 257 Roberts from 1988 measures:

120 Nosler partition....3.22" to the lands
120 Speer ....3.15"

All with a Stoney Pt

I finally got the rifle and loaded up some test loads. A 120gn Sierra HPBT seated 0.030" off the lands measures 2.89 inches so the throat is not overly long. I doubt that a COAL of 3.2 inches or so would make much difference velocity wise. It would have been nice to use up some of that space left in the box magazine though.

Elvis, maybe a sleeker bullet eg the 115g NBT loaded near the lands would be longer in oal, allowing you to use more of the mag space and create more room for powder capacity?

I don't have any of the Sierra HPBTs here but I have it in my head they're not as long and pointed as some other bullets?

Have mentioned this before here and there, but seating bullets out further doesn't make all that much difference in powder room, especially in smaller calibers. In the instance of a .257 Roberts, seating a bullet out another 1/4 inch would result in about a 6% increase in powder capacity. This sounds like a lot, but any increase in powder space only results in 1/4 that much in extra velocity. So the gain would be about 1.5%, about 45 fps in a 3000-fps load.

Using a slightly different bullet would result in far less gain in powder room and velocity.