257 Roberts DISAPPOINTMENT

[atr]

In answer to some of the questions:
1. Yes I did get the bore cleaned of the metal fouling from J's.....the patches came out clear of gilding residue
2. This rifle is VERY accurate with J's
3. The boolits I used were very hard....harder than lyman #2

I checked my older Lyman loading manual and it started with 14 grains of 2400....so I think I will reduce the charge and cast a few softer boolits.
I will keep you posted.
thanks all
atr

[jazzman251]

I have done some work with Roberts using cast bullets. When using cast bullets it's best to begin at the starting load and slowly work up. My Lyman 44th edition lists loads for 2400 with 100 grain cast GC at 12-15 grains of 2400.
For the record their accuracy load is 9 grains of Unique @1615 FPS.Hope this helps.

[docone31]

I paper patch my 25-06, and .243. I also had that dissapointment, but patching made all the difference.
I use a cigarette roller to make the wet patches tight. They load well, and are extremely accurate. I use start load data for 4895 for my patching. It took some fudging, but it does work.
Two wraps of computer printer paper. Wet them, roll them, let dry size them and off you go.
Works for me.

[aspangler]

16 Gr is a little hot for that boolit. Max is listed at 15. Reduce your load and try again.

[madsenshooter]

257418 appears to be a reduction of the infamous Squibb bullet. It likely shares the velocity limits of 311413 and the rest of the copies, like B&M's 311169. A little slower should help. I'd try a different bullet before giving up on the caliber, something that gives you more nose contact. I don't how deep the rifling is on a 25cal, but when I was shooting my 6x45, the rifling on it was only a couple thousandths deep or tall, depending on how you look at it, but either way, it's easy to loose your grip on the little things. I even went as far as painting lube on driving bands rather than lube in the conventional manner. Liquid in the bore when the rifling is so shallow is too much. My 6x45 would have lube literally dripping out the barrel after only a short string.

[texassako]

I think I would wait on being disappointed after you try more than one single load that happened to shoot poorly. The closest comparison I have tried is the 257388 with Unique in my .25-06. The relatively unsupported pointy bullets have always done better at slow speeds for me, <1600 fps or so. I have had much better luck with the 257325(NOE and Lyman) and have high hopes for the new NOE GB 258 120 FN when Al starts delivering them.

[FLHTC]

With a bullet that is a marginal fit, when the barrel expands, accuracy goes away. Fatter bullet. Deja vu!

The metal expands, not the hole. So the bore would get tighter with heat but not by much. The barrel expands in all directions, not just outward. The bore would become constricted with heat. Too much forend pressure will cause a warm barrel to shoot erratically. The forend acts like a heat sink.

[atr]

Attachment 129275

OK, I took some of your suggests to heart: I reduced the powder charge to 12 grains and used as-cast boolits with a 0.260 diameter.
The first shot #1 ....OK it was a cold barrel
the next 4...I started to get hopeful...a pattern was forming...................barrel getting warmer
then the ???...OK,,, maybe it was me and not the load/rifle.......................same
then 2....a tight group but nowhere near the group of 4..........................barrel warmer
the last 2....again a tight group but again nowhere near the group of 4....barrel warmer
Alright guys ....tell me what you think ...what do you see in this pattern?
thanks
atr

yes this was at 50 yards

[JWFilips]

Attachment 129275

OK, I took some of your suggests to heart: I reduced the powder charge to 12 grains and used as-cast boolits with a 0.260 diameter.
The first shot #1 ....OK it was a cold barrel
the next 4...I started to get hopeful...a pattern was forming...................barrel getting warmer
then the ???...OK,,, maybe it was me and not the load/rifle.......................same
then 2....a tight group but nowhere near the group of 4..........................barrel warmer
the last 2....again a tight group but again nowhere near the group of 4....barrel warmer
Alright guys ....tell me what you think ...what do you see in this pattern?
thanks
atr

What was the distance you were shooting at? What was the total spread of the shots? Possibly neck tension change?
Are you seating the boolits to touch the lands?
13 grains of 2400 shoots a tight group for me in a .243 Win with a 100 grain .246" boolit ..... maybe you should slowly move up to 15 grains.
"Feel" the boolit setting into the case...does it feel the same each time or do you feel a slight pressure difference?
I'm thinking you are thinking a change in the barrel warmth when it is more likely a loading discrepency you haven't picked up on

[leadman]

My normal work up for a cartridge is to start with a safe charge, in this case the 12gr charge would be good, then increase by 1 gr of powder with a case this size or larger. Smaller cases would be increased by .5grs.
I would weigh the load ready boolits and sort by .5grs into groups. Load to get the boolit just off the rifling if the magazine will accept it.
Shoot a group of 3 to 5 cartridges, let the barrel cool, run a bronze brush thru the bore, shoot a fouling shot then the 3 or 5 for group.

Recording the data in a notebook with notes if you pulled a shot, etc. I would then load and shoot 5 to 10 of the best group to confirm the load. If it still shoots good load that group.

[Three44s]

Are these new slugs softer than the first ones?

Three 44s

[303Guy]

The metal expands, not the hole. So the bore would get tighter with heat but not by much. The barrel expands in all directions, not just outward.

Actually, the bore itself does expand. The metal expands in all directions, including circumferentially so as the circumference of the bore expands, so does the bore. This is how a sleeve is heat shrunk onto a shaft.

[atr]

finally got a day without rain....so I tried again.
I was VERY careful loading this last batch...make sure the cases were trimmed exactly the same, carefully measured the powder, etc. etc.
so here is the target result of 16 rounds.
I did notice that there was a slight keyholeing on many of the rounds
your thoughts are always appreciated
atr
Attachment 130141

[JWFilips]

I'm still voting for fatter boolits....Every keyhole problem I ever had was cured by that JMHO

[waksupi]

I'm still voting for fatter boolits....Every keyhole problem I ever had was cured by that JMHO

Yep, still agree. Someday he may try them.....

[35remington]

I'll echo some of the above.....larger bullet diameter and seating the bullet out to minimize jump to the rifling are the biggest "secrets" to getting cast to shoot. That and not overdriving the bullet with too much pressure.

Single loading to find accuracy with a seated out bullet is no handicap if the rifle shoots. A single hit makes the magazine reload unnecessary. Seat that bullet out if the rifle will accept a longer OAL. I can single load a bolt action rifle pretty fast.....and it's worth it if it shoots.

Skip these steps and the right to complain goes away. You're stuck with what you've got unless you try other methods.

Compared to these steps, case trimming and precisely weighing charges is an utter waste of time. 2400 throws superbly through a powder measure and is one of the least beneficial powders to weigh.

[JWFilips]

I'll echo some of the above.....larger bullet diameter and seating the bullet out to minimize jump to the rifling are the biggest "secrets" to getting cast to shoot. That and not overdriving the bullet with too much pressure.

Single loading to find accuracy with a seated out bullet is no handicap if the rifle shoots. A single hit makes the magazine reload unnecessary. Seat that bullet out if the rifle will accept a longer OAL. I can single load a bolt action rifle pretty fast.....and it's worth it if it shoots.

Skip these steps and the right to complain goes away. You're stuck with what you've got unless you try other methods.

Compared to these steps, case trimming and precisely weighing charges is an utter waste of time. 2400 throws superbly through a powder measure and is one of the least beneficial powders to weigh.

YES! Additionally : If I'm developing a load for cast Boolits I start development on the lands. This is not J-ville. All is reversed somewhat, in this cast boolit world.
All of my loads are developed "on the lands" and worked up from there. When I reach a point were I got something good happening only then do I play with backing off on col. Again please note this is JMHO

[largom]

I would try an non-sized, as cast boolit if it will chamber. Since you do not want to seat a longer OAL I would try a different lube.

Larry

[atr]

no key holing....still not as accurate as I hope to achieve...but some progress
Attachment 130660

[JWFilips]

no key holing....still not as accurate as I hope to achieve...but some progress
Attachment 130660

Ok Things are happening here! I would try a slower powder like Reloader 7, IMR4227 or even IMR 3031

Also looking like it wants to group....How stable is your shooting rest? Are you postioning the forearm on the same point for each shot? Everything screwed down tight? Some how I think there is a group there but something maybe changing during shooting ( you actually have 3 two shot groups that are not bad!) Something inconsistant is going on ...maybe in the let off???