Picked up a 25 Bob this week. I've never owned one but did assemble some loads for a couple 20 years ago or so. I see reg 257 brass and some designated 257 +P.

A. What is the difference?
B. Can you run +P data in non+P marked brass?
C. Is Nosler brass really worth $1+ per case?

I plan to run my Bob at 'modern' pressures (+P data). 25 Bob brass is a bit pricey so don't want to screw up my brass purchase.

Any good Bob data with 100 TTSX and/or 110/115 Nosler PT?

Thanks.

You don't need +P, reg brass works fine. If you can't find 257 Roberts brass (I can't) then get some 7x57 Mauser and neck down.

Lots of load data available.

I've looked for Winchester +P or Remington Bob brass since before Sandy Hook. If you don't have or can't find brass, then the Nosler for $1.25/ea may be well worth it.

I just bought some Nosler .257 Roberts brass. Seems good. It's about on par with the latest WW +P brass I bought a few years ago and the loads seem interchangeable _so far_.

I killed both my deer this year with the 110 grain Accubonds over 45 grains of RL22. This is off max but gave the best accuracy in my gun with that bullet, 2.35 inches for a 5 shot group at 200 yards.

I didn't have any particularly good luck with 115s, neither partitions nor ballistic tips. I know my gun shoots very well with 100 grain ballistic tips and 48 grains of H4831, regular or SC. It hasn't done well with 100 grain partitions. I have a box of TTSX-s but haven't tried any yet.

At the moment I'm trying to find a box of 120 grain partitions. They shot well in testing IH414) but that used up all I had so I can't confirm their success. If it shoots them well I'll keep it, if not I'm going to sell or rebarrel it. I hope I don't have to wait too long to find out.

Tom

bwinters,

Quite a few different powders work in the .257, but I have loaded for around a dozen rifles and around 46-47 grains of either IMR4350 or H4350 with 100-grain bullets, or around 44 grains of the same powders with 115's, have been accurate in just about all. Or at least I can't remember any rifles where those loads didn't provide sub-inch accuracy.

Some +P brass is heavier than standard brass, but I don't know if all is. Dunno why they made it heavier, because the standard brass from Winchester was always plenty strong for even very warm handloads.

I have had some recent Remington brass that was so soft the above loads (which aren't much more than +P, if any) resulted in difficult extraction. Never had that problem with Remington brass in the past, but there it is.

My wife and I have killed several pickup loads of big game from pronghorns at 400+ yards to cow elk with various bullets from the .257. For average deer-sized the 100-grain Ballistic Tip works very well, but for anything bigger the 100 TTSX and 115 Partition provide plenty of penetration. In my experience the 115 Partition kills quicker than the 100 TTSX, on average.

I've loaded for the 257 Roberts since 1982, starting with a Ruger 77R. For a long time, my one all-purpose load was a 90 grain Sierra BTHP over 49 grains of IMR 4350, but I decided that the bullet was too fragile, so I changed over to the 100 grain Partition. I also like the 110 grain AB in some rifles.

I couldn't find brass for mine either, but factory ammo was on the shelves locally, so bought a couple boxes of Hornady. In addition to the already mentioned 4350 loads, mine shoots really well with 48 grains of RL19 and the 100 TTSX.

I've had great luck with 117gr. SGK's and 43.0 gr. of H4350. 2800 fps and 3/4" groups does the job to my standards.

Hey TOM - I'd be curious how the 120 NPT shoots in your rifle. I envision this rifle as an eastern deer rifle - long/steep hikes to far flung deer spots to treestands and 50 yard shots. As such, I don't need the absolute flattest shooting load combo.

Please let me know how your load development goes.

MD - I was hoping you'd chime in - I've read your articles on the Bob in the past. I also recall your grandmother, I think, shot a Bob.

Good info to know about regular and +P brass. I was a bit confused because the Bob is built off the 7x57 case - and I've shot lots of +P 7x57 loads in several commercial and military M98's. I never had an issue.

I've had issues in the past with the 25 cal TSX. I launched the 100 gr from a 25-06 at significant velocity and was less than impressed with their terminal performance. I've talked to Ty at Barnes and am willing to give the TTSX a try, mainly because the TSX versions have always shot very well in my rifles. I still always lean Partition.........

In my 25-06, I had a hard time getting 3 Partitions to stay inside 1.5". I'm leaning 115-120 Part for this gun running at 2850-2900 or so from a 22" barrel. SubMOA isn't really required but is always nice. I somehow managed to kill a decent 8pt with my 25-06 and 1.5" 115 gr Partitions the year I used it. I shot it laying down at ~ 60 yards. It never regained its feet. It flopped around for about 10 feet but was dead in short order. Partitions have always worked for me.

I've looked into factory fodder - but can't quite make myself buy a box of shells for $30 firing bullets I have no intention of using on game. I'll likely fork over the money for Nosler brass if I can't find any decent new or once fired. I like to have 200 cases of the same lot when I start a project.

I use old white/yellow Winchester brass in my 257Ackley at +P pressures, never had an issue. Supposedly, the regular non +P has a thinner web, but I've never had an issue with any brass I've tried. To date, I've got R-P, the Win I mentioned above, which is ww-super stamped, Hornady and PMC.
Never had a case separation, cases rarely need trimming and primer pockets stay tight. I do not hotrod it, even though I am running around 58, 000psi and never go above 60, 000psi.
The brass is too expensive to wreck it, I look after my brass.

Cheers.

I load for 12 of my 18 Bobs and have always used standard, not +P, Winchester/Olin brass. My shots are typically under 300 yards and both the 100 grain Partition and 110 grain AB shoot good groups and produce quick kills. The weakest actions in my service are a Savage 99 and a pre-WW1 Swedish military 1896. I load these a little lighter than the 1898 style Mausers, both large and small rings actions, and the commercial actions from Marlin, Remington, Ruger, Savage, and Winchester.

Unless the chamber in your rifle is over-size, I wouldn't worry about using good quality standard brass in lieu of +P brass with the maximum recommended loads.

You have more Bob's than I have rifles............

Lucky for you!

bwinters -

I had one box of 120 grain partitions when I bought the gun. I did a fast test with those last spring.

All brass is WW +P from the same bag o' 50, all groups were at 100 yards. The first 15 were 3 shot groups, the last with H4350 was a single 5 shot group which used up the box of bullets.

Fed 215M primers, H414

39.5 grains, 4.8 inches
40 grains, 1.67 inches
41 grains, 1.79 inches
42 grains, 1.26 inches
43 grains, 1.05 inches

Fed 210, IMR 7828

44 grains, 1.09 inches
45 grains, 0.93 inches
46 grains, 1.17 inches
47 grains, 1.12 inches
47.5 grains, 2.5 inches

Fed 210, IMR 4831

40 grains, 1.25 inches
41 grains, 1.76 inches
42 grains, 1.16 inches
43 grains, 2.19 inches
44 grains, 1.92 inches

Fed 210, H4350

42 grains, 1.84 inches

I've had two other .257s that also did their best work with 120s (Partitions and the now-discontinued Hornady FB HP) with 43 grains of H414 and a federal magnum primer. Based on that, plus this brief test, I hope to find another box of 120s and do some shooting on past 100 yards.

I haven't seen any more 120s. The 100s and 115s have shot poorly, 2+ MOA, in this gun.

My plan for it right now is to shoot the hell out of it as a varmint rifle. I've got a bunch of lighter bullets and a few Accubonds left. If I run out of bullets before I find 120 grain partitions I'll sell it, if the 120 grain partitions show up sooner I'll try them s' more and decide keep or sell based on what they do downrange.

Thank you for posting. I was thinking H4831 and 7828 to start. Anyone try the new IMR Enduron powders?

I've used both IMR 4166 and 4451 in my iron sighted, 760 Remington. Both work quite well. They meter better than do 4064 and 4350.
Accuracy with the Barnes 80 gr. TTSX was outstanding, 1.3 inches at 100 ys. w/ 46-47 grs. of 4451. E

They are just things.

bwinters,

I've had excellent luck so far with IMR4451, using essentially the same loads used with the 4350's, in the Remington 722 that's always been one of my most accurate .257's. Haven't tried it yet in my wife's NULA .257.

Thanks John,

I called IMR last week inquiring about 4955, which should be ~ 4831 rate, and was told it hasn't been released yet. It looks ideal for the Bob with 100-120 gr bullets. Have you seen any yet?

I'm looking for these new powders locally without much success. I really want to try 7977 in my 270 - it looks impressive.

I dont have a Bob but have been shooting a lot of 250 Sav AI which is a similar beast.

I've just been using some old "non+P" 250 Sav brass along with resized 22-250 brass. Never seen any difference and I am running pressures in the 55-60k PSI zone.

Lots of luck with the 117g Interlock BTSP and the 115g NBT for accuracy and terminal effect. The 100g Hot Cor similarly so.

I also found the 87g Hornady SP held up surprisingly well on game and in wet newspaper tests.

Also find it loves R17 in all bullet weights and H4895 for lighter bullets.

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46 grs H 4350 and 100 grain Sierra Pro Hunters work well in mine.

I have a Model 70 Super Grade (South Carolina) in 257 Roberts and I shoot the 110 grain Accubonds in front of 47.1 grains of 100V. It will touch three bullet at 100 yds when I do my part. I have never run it over the Magneto V3 so I can't quote velocity. 100V is suppose to be temp sensitive but I only use this on pronghorn and plains deer so temperature isn't a factor.

Speaking of H100V, check this out.

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/10719797/6

DF

It appears to me that Hybrid 100V is headed for obsolescence like 4007. I notice that Graf & Sons has it for 124.99 per 8 pound jug. Usually and indicator of poor sales. To bad though as it goes through the measure like water and it gives good velocity and accuracy in several calibers. I have had good success with 100V in the 300WSM. 64 grains in WW cases with WLRM primers and a 180 TTSX gives 3030 FPS from my 24 inch barreled FN PBR

48.5gr of RL22 with 215M primers and 115gr Nosler Partitions
in my model 70 Winchester. Gives 3049fps. also very accurate.

I've found Ramshot Hunter & Win LRMs to do very nicely in my Bobs w/ 90 gr GMXs, 100 gr C&Cs, & 110 NABs.

My experience w/ brass is identical to JB's.

Plus right now it's REALLY hard to find.

When I was a younger shooter velocity was always THE goal: the more the better. Shot deer with the regular Roberts and an Ackley version as well. Built a very lightweight Bob for my wife but it took her years to want to use it on deer. Well, last year, she finally decided to try. Loaded her little 20" barrel Mauser with one of the lightest loads I could find: 35/4064 w/ 100gr. Nosler B.T. to keep recoil as low as possible. Now 2 deer later, she's had 2 quick one shot kills at 110 and about 45 yds. Both bullets exited and did much damage. So, even loaded very mild, the little .257 is a lethal killer.

I hunt with a M77 MkII in 257 Bob. Full length bedded, trigger slicked up and breaking around 2.75#, by Roger Ferrell.

Using MuleDeer's load of 46gr. of H4350 and the 100gr. TSX in Rem. brass, she generally puts 3 into around a .600" group at 100. And those TSX's work perfect. I've killed roughly a dozen or so deer with that load at anywhere from 10yds to 200 yds. The 2 that didn't drop where they stood ran maybe 80 yds combined. I pulled both those shots, just behind the shoulder. If I do my part and center-punch the shoulders, it's a thud and lights out. No tracking required.

Good luck and enjoy. I love mine.