257 Roberts and 257312.

[RBHarter]

I've done some research but nothing really helpful came from it . I pounced on the 257312 because it's a 4C and there are just so few 25 cal moulds available .

The rifle is a 95 Mauser saved from the scrape pile , it's pretty soft . It shoots a 100gr Game King over a minimum charge of 4350 to 5 shot figure 8s . I figure that makes it a perfect cast candidate .
The information ,some from Ben and others here , says that the bullet comes in 80-90gr ....... I haven't cast any yet in this mould . The AB bbl is a 10 twist and should manage the 260-120 FP NOE well also for the heavier stuff .

There is a void of data for the 257 , it's either wide open or gallery loads .
I'd like to be somewhere in the middle . Maybe 21-2300 with the light bullet and 2000-2100 for the heavy .
I have some 4831 ,lots of 4350 and H322 and of course Unique .
I'm sure the 322 will be well beyond what I want to shoot in this platform .
I have small quantities of others but they are also in the 322 range .

I intend to stay with a blanket alloy that has shot well and expanded rather than splattered in similar calibers at similar speeds . I don't expect this to be a kill it all bullet but it would be nice to wreck everything under 90# .

Disclaimer , I know we'll the limitations of the caliber , I'm a clean hunter first ,every round I load is tooled in that direction .

 

[RBHarter]

Well I got a handful cast and I learned that clamshell handles aren't really all that great . Apparently brand new Lyman handles are also very stiff . I'm not impressed with needing 2 hands to get the mould open . I now also have a mould that will absolutely require the doghouse on the hot plate to get even close to temp before I start pouring .

The 257312 is on the left and a couple of 266s from singles on the left . The bullets seem fat to me at .261-2 from a random sample across the parting line and 94.5 to 95.5 gr . Story of my moulds they almost all cast fat and heavy . I think I like the profile . I am surprised they are so heavy though that is way outside of the typical description .

 

[Intheshop]

RB,I have a 257242 ,2 cav Lyman.Got any dope on it's applications?

One of those,got the mould...need rifle sort of things?

The 257 Roberts along with 250 Savage has always been on my radar.So very interested in your progress.BW

 

[RBHarter]

I think that may have been a single in the lot this mould came from . This is my first foray into 25 cal cast although I've run a 222 , 223 and a 6.8 this is the first really small cast I've actively worked it seems to be well better matched for moderate pressures than the small calibers/cartridges . R5R has suggested a light load with H322 so I will I guess get a feeling for it with a few loaded with Unique then run a few with the too slow to get hurt powder in a full case . If it behaves then I will pull out the pillow stuffing and see what happens . That's my usual routine anyway . I think I have some 4198 left I wonder if that would be a good one here using 100 gr jacketed data ?

 

[Intheshop]

My 700V,6mm Rem,which is the little bros of the Roberts shoots 1 hole,10 shot groups with medium doses of 4759...dacron filler,with nose bumped RCBS 95.

A cpl weeks ago,got a MINT,6-18 5 star Redfield with target turrets.Have been jacked to "revisit" this rig.Got 6#s of 4759...and for reasons,have been on a search the last few years looking for a replacement powder.

Enter 4198....Having 5744 as it's backup once the former has been fully examined.4198 with filler has been love/hate IME using it in certain cals.The 7-08 SPS Remington likes it,and feel I tested pretty well.5744 is next up for this rig,just like the 6.

What I've been doing with this powder is,load 20 at old Lyman CB book starting load....shoot,record data.Add a gr,repeat.Until the system,says stop.Then back down 1/2 gr,test.Keeping bullet fit,oal,lube constant.

Once backed into a sweet spot,then revisit the "fit" and oal.So with the 6,I haven't found the limit,yet.The 7-08/4198 rig is funny in that,it likes to be dry mopped about every 10 rds.But I don't know if it's the 4198 or the cheapy Lee,not soupcan 135?It's not a problem,unless you forget...doh.And it strings them in windage,NOT elevation when buggered up.Something I've never experienced before.

As an aside,the new Redfield is the first scope I've ever had that you can read mirage with.

 

[Intheshop]

Watching finish dry on a pce of furniture....

21 g 4198 was the limit on the 6 RB.Dropped 1/2g and just cut a <1" ,10 shot group @150 yds.Off our custom heavy BR rest.The ejector has been removed,so consider it a single shot."if the cases ain't flyin,you're dying"....is the notion that once the rig is riding the bags,kill it hard during a condition.So,that was 10,no foulers,as fast as I can work the bolt,pluck,reload,shoot.

I can probably do better....need practice.The firing process can improve a bit.Working the bolt is disturbing the "set" a little.Not a "hard" bolt lift,but I'm just not used to the sequence....yet,haha.Ya'll have a great weekend .

 

[Teddy (punchie)]

257312 Lyman mold

257312 Designed for high velocity in the .25-20 single shot and repeaters. Also good for other 25 calibers. (GC, FN, 89 – TP is 420)

I'll have to find older data on this as the new cast manual (s) are not showing anything.

Maybe a day or so, I'm sure I have data for you. As I have a 257 I need to work on loading but not sure it is going to be a good cast shooter.

 

[RBHarter]

Thanks !
I have some stuff loaded and have shot some moderate to full throttle Unique loads . I used 100 gr jacketed data as start data for the slowest powders . The 25 cal is new territory for me but the Unique loads were amazing . I need to get it on paper but steel is fun with it .

 

[300BLK]

257312 (85gr GC) 257 Roberts data from Ideal #39

15-16gr 2400 1900-2025fps
17gr 4227 1950fps
14gr 4759 1850fps
25gr 3031 2000fps

257464 (97gr GC)

20gr 4198 1900fps
25gr 3031 2000fps

257464 (89gr GC #2 allloy) 257 Roberts data from Lyman 46th

14-17.5 4759 1584-1933fps
14.5-19gr 4227 1584-2034fps
16-21.5gr 4198 1646-2063fps
14.5-20 RX7 1497-1981fps
18-24.5 748 1468-1959fps
17.3-23 H335 1544-1954fps

Yes, there is a discrepancy in weight of the 257464 between the old and much newer manual

 

[RBHarter]

My 312s weigh in at 90 gr -.2+.3 . Just one session and trying to get settled with an iron 4C .....
Looks like good data !

 

[Teddy (punchie)]

300 Thanks For the data I knew the older manuals had some.
And Yep Lymans number system got to love it.


Just posting darn eyes of my and Meds I'm on, I always double check.

What a time with old eyes and a light mark on a mold. now what number was that ?


257454 A fine H. Guy Louverin design for the .257 and other 25 caliber cartridges. (GC, RN, 92 – TP is 463)



257464 An excellent bullet of H. Guy Louverin design. Very accurate at target up to 500 yards and a good game bullet. (GC, RN, 89 – TP is 463)

Just in case, yes they made a :

257463 A very fine lightweight bullet. An H. Guy Louverin design. (GC, RN, 75 – TP is 463)