Another amazingly thorough article from MD !
Is that ‘53 Fwt 308 built your year & month of birth ? 🥴

Makes me want to rebarrel my SA STS Classic to the Bob or better Bob .

What twist for the new .25 bullets ?
Or is that strictly a LA proposition ?

I was born in December of 1952, so no. But I did once own a Model 94 carbine in .32 Special that left the factory in my birth-month!

I haven't yet fooled with any .25-caliber bullets that require a twist faster than 1:10, and probably won't. Any lead-cores up to 120 grains do fine, and even the 115-grain TSX is designed to stabilize in a 10 twist.

Glad you liked the article!

Just skimmed it for the first pass ! I like to re-read for better retention.
I don’t have any 1/4 bores, but I’m watching the trend towards longer bullets and tighter twists with some skepticism.
If people try them in a 10” and they fail, what response are they going to get?

Not much, which is one reason very few .25-caliber bullets that require a faster twist than 1:10 have been introduced.

The other reason is that so many 6mm and 6.5mm barrels (including those on very "affordable" factory rifles) have faster twists for longer, heavier bullets there's really no point in fast-twist .25 barrels, unless somebody just likes to shovel sand against the tide.

.
I had a .250 Savage and a .257 Improved built a few years back but I use nothing heavier than 115-120 grain bullets in eithere
I had Krieger build the .250s barrel with a 1:9 twist barrel but the .257 has a 1:10 twist barrel. both stabilize 115-117 grain bullets but not sure if the .257 will handle 120s or not. I really don't know if I care or not because it kills just fine for what I built it for with 115 grain NBTs.

Filaman,

Yes, the 1:10 .257 will handle 120s very well.

About the longest 120-grain made is the Nosler Partition, at 1.175 inches. Have never had any trouble getting them to shoot well in any 1:10 .257 Roberts.

You might want to try using a good twist/stability program before assuming so much. The Berger program gives the 120 Partition at 2900 fps a stability rating of 1.42 in standard conditions (59 degrees F. at sea level), which is pretty tough for stabilizing. At higher elevations, such as my part of Montana (4000' minimum) the rating is 1.56 at 35 degrees. At a rating of 1.0 bullets will stabilize, but 1.5 is considered VERY stable. Obviously the 120 Partition is stable in a 1:10 in almost any conditions.

The 115 Barnes is a little longer, and has a lower BC of .335. But even then it's stable under standard conditions, and at 35 F. and 4000' gets a rating of 1.33.

Over the past 2-3 years I've had a hard time understanding understand why so many people assume that the standard 1:10 twist in .25-caliber rifles isn't enough for standard .25 caliber bullets these days. But believe I am finally getting it: Apparently 1:8 is the Magic Rifling Twist for any cartridge these days, no matter the caliber. Well, here's the deal: A "fast" (or "slow") twist is in proportion to the caliber of the rifle, the bore/groove diameter. Thus a larger caliber doesn't require as fast a twist to stabilize even long, heavy bullets, the reason the standard 1:10 twist in .30 calibers will stabilize a very long 210-230 grain spitzer boattail. It's also why the standard 1:14 twist in 9.3mm will stabilize even 286-grain monolithic bullets. Which is also why a 1:7 (or 1:6 or 1:5.5) twist is necessary in .224-caliber rifles to stabilize many of today's heavier, longer bullets.

Also, one thing you might discover when using such programs (which have proven to be very accurate) velocity has FAR less effect on bullet stability than most shooters believe.

Very succinct, “ likes to shovel sand against the tide” 👍

My next question, is where do the heavy / long 270 bullets sit ? Another caliber with a traditional 10” twist
Why swim against the tide when 6.5 and 7 mm have established the quicker twist standard. I don’t believe there’s much to be gained within reasonable hunting ranges.

John,
I have owned several .257 Roberts but not a lot of killing experience with them. My question is... which bullet seems more effective on game: 120 Partition, 100 Hornady Interlock SP, or the 100 gr TTSX?

PS: in your Rifle Mag article you state that Winchester never offered the .257 Roberts in a Featherweight. I owned a M70 XTR Featherweight built in the ‘80’s.

Thanks Mule Deer. When I had the .250 built I had several So Called Experts telling me I needed a 1:9 to stabilize 120s and at the time I had planned the .250 around them. But when I shot some I wasn't impressed with the MV so I tried 117s and 115s and was much happier with their performance, especially the 115s. Then when I used them on game I saw I was correct in using the some what lighter bullets. So when I had the .257 built I went with a 1:10 due to my experience with the .250 and 115 and 117 grain bullets.

That seems to be the case with those old black powder cartridges with the big bore, long heavy bullets with a twist of 1/22-1/38.

Barnes claims a 1-in-9" twist is required.

I have a gain twist which finishes at 1 in twelve and shoots the 120 Speer very well. It's not a particularly long bullet though. GD

If I were to build then I'd have the choice so I'd go 9" instead of 10". For my purposes there's no downside to a bit more twist.

They never chambered the .257 Roberts in the pre-'64 Featherweight, and the article was about pre-'64s.

I have discussed this before. When bullet makers list a particular twist on their website, or a box of bullets, it's because they're afraid somewhere, sometime a customer will shoot in "conditions" where a bullet might not stabilize--say when hunting below zero along the shoreline of the Arctic Ocean for caribou. It does not mean that a slower twist won't work fine for all other conditions.

A good example is the .270-caliber 170-grain Berger EOL Elite Hunter. It has shot very accurately in two different 1:10 twist .270 Winchesters here where I live in Montana--and the two ranges I use are on the valley floor, 4000 feet above sea level--where its stability rating according to the Berger program is over 1.3, quite a way above the 1.0 minimum. It would be even more stable when hunting at elevations up to 9000 feet in the mountains above the valley--and according to Berger's own stability problem is "marginally stable" even in standard conditions of 59 Fahrenheit at sea level.

Yet Berger suggests a 1:8 twist. This is NOT just to stabilize the bullet, but to maximize ballistic coeffcient--which tops out at a 1.5 rating. With the 170-grain .270 bullet, shooting it at 2750 fps at 4000 feet reduces the bullet's "maximum" G7 BC of .339 to .323. Big deal.

I wonder? Just what twist rate did Winchester use in those mid 80's.257 Robt. XTR Featherweights? I haven't been able to the 120 gr. Speer to shoot worth spit in mine.
Paul B.

December 52? I beat you by 7 months :-)

I beat him by 12...December of '51. What day John? Mine was on the 20th. powdr

The 1st!

I had 3 of them, ROT was 1-10". The only post-'64 .257" bore rifles that Winchester and Winchester/USRA cataloged with a slower ROT was the 1986/87 70 Lightweight Carbine in 250-3000 that the rifled at 1-14" for reasons that nobody has ever admitted to.

Yeah, I had one of those for a while. It shot very well with 100-grain Speer Hot-Cors (as do a lot of 1:14 Savage 99s), which is the bullet I used in the rifle. It worked fine on deer, of course, but WTF?

Paul: FWIW my 1980s XTR FWT 257 shoots great with 120 Speer Deep Curls, which are longer than the 120 Hot Cores,,,

Gotcha by a month. Nov. 24, '51. Looking forward to JB's article. He's a pretty sharp kid.

Wish I could claim youth & vigour, but alas playing the cards dealt me. I’m December of ‘55

I was taught to respect my elders. Old age & Treachery and all that.

Most Especially, If they can make sense of all this twist nonsense, and present it in a manner that my youthful mind can oversimplify. Which you have done, at least for me.

Cheers

Say hello to the campfire dinosaur!

You may well have discussed it on this forum previously, but following these threads can get slightly convoluted going down all of the rabbit holes where people lead us. A detailed "Handloader" may be worthwhile. I know I'd read it.

You guys are just pups!

Any Olde Farts that can compare their birth date to the ‘36 M70 .257 Roberts in subj article ?
Any within a decade ?

This would’ve been the first hunting gun for someone born in the early Twenties !
Maybe someone born earlier and saved up to replace a WWI conversion. Or an old family heirloom lever.

What amazes me is how this design was so suited to its purpose, but evolved also.
Ergonomics improved, witness the wing safety evolving into the SideSwing design.
Allowing for low mounted scopes, Until Ocular, and more recently Objective lenses got too big for low mounting.
Stocks changed dimensions to follow market preferences.

An interesting glimpse of where we’ve been

Jackie Treehorn,

I did an article on bullet stability and rifling twist for RIFLE magazine, instead of HANDLOADER, long enough ago to expand it some as a chapter in the first BIG BOOK OF GUN GACK, published in 2015. It's chapter 4, "Rifling Twist."

I'll have to revisit that.

I like the 257R threads here and read them all. This one sure got weird.

10-1-1953 here.

I also devour any and all 257 threads and articles.
My son picked up a Roberts built on a Mauser action at a LGS about 3 years ago.
He has killed several deer with it. I have shot it extensively during load development and it is probably my favorite rifle in the stable to shoot aside from my 222’s.
It is a finicky rifle but it really likes 117 gn. Gamekings on top of IMR-4350. It is no problem to place five shots under an inch with this combo and they seem to kill well.
I would love to have a pre-64 Model 70 in a Roberts but in the the future will probably settle for any 257 I can get.
Really love the cartridge!

A friend had one so I got to see it. I was surprised at how heavy it was scoped.

what magazine was this 257 Roberts in ? thanks,Pete53

On my list of projects I'd like to do is a 257 Roberts in the fwt configuration on a pre 64 (fwt), as the factory should have done. Same list includes a 7x57 in the same config! Purely nostalgic vs. practical!