I'm planning to start reloading a Ruger M77 in 257 Roberts with H4350 powder and Speer 120 bullets which I currently have on hand. I will be using Winchester +P brass. The Speer manual does not have a load listed using H4350. I have seen suggested maximum loads in articles ranging from 42 grains to 47 grains which seems like a wide spread. Does anyone have any experience with this combination? Any suggestions would be appreciated.

I'd suggest starting at 43 gr & you'll probably top out around 45, because the max listed in an old Speer #12 lists 47 gr of H4350 as max for their 100 gr. bullets & that's a compressed load in the +P flavor... & good luck with that Winchester +P brass...I've just culled 7 out of 25 because the primer pockets aren't deep enough to fully seat the primers...I'm loading 80 & 100 gr. Barnes though & using ramshot hunter...also gonna load a dozen or so with Reloader 17 & see what I can get...good luck with the brass...


Edit to add...Just previous to starting the .257 loads, I loaded 50 rounds of 7-08 & Remington brass...not a single cull...I don't know if I'm just unlucky with Winchester brass or wtf is up...


2nd edit...Gonna chuck em all...2/3 rds are chit...
Ain't gonna shoot this chit in MY rifle...like I said, good luck with your brass...maybe you got a better batch...

MM, Thanks for the help with the reloading data and the tip about the winchester brass.
How does the Barnes/Ramshot Hunter perform for you?

seems like I am using 46.5 under a 100 grain bullet, I would think the 120 would want you to use a bit less. The 100's are kick arse in my gun, when I get thinking about 130'ish I whip out my 270 win. I fully admit when I first got my roberts that I thought that the heavier bullets were the way to go....and then I found that the Barnes 100 grain TSX thinks its a 165 grain 308 bullet.

I'm going to try both 100's and 120's. I tend to get shots 100 yards or less where I hunt. I thought the heavier weight in a traditional bullet would hold up better at closer range.
I've never tried Barnes bullets, I was thinking about trying a 100 grain nosler partition. Any thoughts on the partition vs barnes bullet?

If your worried about bullet holding up I would go with Barnes TSX.My gun shoots better with I4350,H4831,and R17. YMMV

So far so good. I just got this rifle out with a few other rifles last weekend for the first time & actually only burned 12 rounds...was loading them on the spot & did a 3 round workup to 50 Gr. with the 80 gr.TTSX, then shot three groups with none going over .75 The velocity was right at 3400.
I'm really bummed about the brass though...

What's the Reloader 17 doing??? Start? Ending charge? Velocity??? I had originally intended to spend the entire labor day weekend, shooting & doing load workup & had a can of Re 17 along with several others, but had other things more pressing so I was only able to spend a few hours up in the hills.

I'd 2nd your comment about the Barnes bullets...

48gr.max with 80gr TTSX,46gr max with 100 gr TTSX in my rifle and R17.As always work up to your max with your rifle.Do not have chrono yet but was getting 3/4 inch groups.Barnes tech stated 47 gr as max load with 80gr TTSX at 3390fps,but this is not +P load.

Miner get yourself a primer pocket uniformer from Sinclairs for about $10 and save yourself some money,brass, and a whole lotta grief. powdr

Thanks Hutch...I HAD figured on starting at 48...
powdr...I have a uniformer SOMEWHERE...probably in one of the boxes out in the shed. But IIRC I only have one for small rifle.

I could go on a small rant about Winchester brass of recent manufacture but I won't...rest assured this is not the first problem I've had with it...this recent purchase of .257 brass is likely the last I'll buy of Winchester though...I did buy some pretty old, "new" cases here on the fire a while back...about half of it was primed & the difference in quality between THEN & NOW is amazing...suffice to say, I washed, dried, full length sized then trimmed and chamfered every one of 100 pieces of .257 brass, only to find most of it useless unless I want to hand ream every primer pocket??? No thanks...it's now scattered up & down inside a big green garbage tubb that the garbage man will collect in the morning...

no doubt both will work fine, shoot what shoots best in your gun. I like the barnes 100 in case you want to bust shoulders.

FWIW-
I had the same problem with the primer pockets on a recent purchase of new Win 257 Roberts +P brass.

Man, a lot of you "hot rod" your 257R. I usually stick with 42.5 of H4350 for anything in the 115-120 range. I haven't chrony'd them but the 110 Accubond will go about 2820 with 42.5 grains. That is fast enough for me.

Hodgdon reloading site has 48gr. of Hybrid 100V moving a 100 grain bullet at over 3200 fps. That or something close to it is what I will be trying my next trip to the range.

Forty-eight grains of H4350 propelling a 120 gr. speer or whatever 120 gr. bullet is not going to be very good for case life no matter what cases you use. Good Luck
Mouse

Sorry to hear that but at the same time it's sorta comforting to know I'm not the only one...If you notice in my earlier post I said I "washed" them??? A previous batch of Winchester brass in .223 had really bad lube contamination in quite a few of the cases that I didn't notice until I was about halfway through charging them along with a half dozen that wouldn't fit the shell holder, they were so far out of spec....The lube prolly wouldn't have really bothered me too much if I had intended to shoot them all up within a week or two BUT I still have them in a drawer & they may not even get fired this year....

I guess I got lucky,I bought a 100 pieces of win brass and only threw away one that wouldn't fit in shellholder.As far as the best group I ever got was with 50grs H4831 and 100gr TTSX.One half inch group and I'm not a paper shooter.

It was not the primers. I pulled some and reseated them and fired them in an empty hull. They would go off. I don't know what the problem was with the pockets, or why they wouldn't work. I had a nice primer strike/dent, but no bang. I've never had that happen previously. After depriming and repriming, everything worked.

I use 44 grains for about 2850 in a 22" tube. Those 120 speer hot-cors really hold together well and penetrate at these velocities.