I have the opporunity to pick up a 257 Roberts barrelled action. The guy selling it is a cast shooter I met at the range he claims the rifle will easily do 1" moa at the hundred with jacketed rounds, but claims he could never get good results with CB's. Is there really an issue with this caliber and cast bullets, or has my friend just not found the right combo of mold, size, alloy, and powder. TIA

A 10 twist barrel can be quite iffy in any caliber for cast boolits. A 12 twist would be better, but a 13 probably would be best. But, who has a barrel like that? ... felix

rikkit, I've done quite a bit of cast bullet shooting with a 257 Roberts. It's not any harder to get one to shoot well than other calibers. There are some bullet designs that work better than others.

Pursell, I don't think that is exactly right. I belive the faster twists and especially with the smaller bores are more difficult getting to shoot.
I've got alot of rifles in various calibers and from military to commercial configuration that I got shooting cast extremelly well. I just built a 260 Rem on an Arisaka action and it drills holes with jacketed bullets, but I'm having a hard time getting it to shoot decent groups with cast. I've tried three different bullets, all three different in shape and grooves as compared to one another, two being about the same weight, the third being heavier, and can't get them to shoot. I've been working with Buckshot from CastBoolit board using some of his suggestions and still no luck. I didn't build the rifle to mainly shoot cast but as a deer rifle. I though I would shoot a bunch of cast through it to smooth up the bore before developing my jacketed load for it. The twist is 9 1/2 and Buckshot told me that with the 6.5's he has that you can't push the bullet too fast...something like don't get over 1600 fps with them. I tried slowing them down with no good results. This is the first rifle and caliber I haven't been able to get to shoot what I concider decent groups, especially for a scoped rifle off a bench. I've gone through all the bullet seating depths, different powders, etc., with not much of a change. I have notice that I get absolutely no leading in the bore when I do try to shoot cast. The bore is buttoned rifled and is very smooth. Since nasty weather has set in I'm giving it a pause for now.
Joe

Starmetal, I don't understand. Are you saying a 257 won't shoot CBs?

No, I'm not saying that at all. Just saying that I think the smaller the bore and the faster the twist the harder they are to GET to shoot.

Aladin, I wasn't the one that posted about the 10 twist being iffy, that was Felix. I'm talking about twists down in around 9.5, 9.0, 8.5 etc bracket. What I define as "shoot" I mean 2 or less inches at 100 yards. I have a Sako 7m-08 with a fast twist and it shoots a ragged hole under an inch with of all bullets a Lyman 150gr Loverin and I say that because the throat of that barrel is very short and a good portion of the bullet ends up way past the neck. My eyes popped out the first time I tried that bullet as previously I had been shooting the 135 gr Lee in in it and the base of the Lee bullet didn't go past the base of the neck. I couldn't believe the 150 out shot and to boot with no barrel leading.
Joe

rikkit....I've been shooting a Roberts for a couple of years now with cast. It likes the lighter bullets for some reason.

No more ticklish to shoot than any other caliber as far as I know.

I do agree that the smaller the bore, the more closely you have to inspect bullets. Seems as if the larger stuff like .375s and .45s are more forgiving as far as flaws and you have to be very careful sizing the smaller stuff as you'll bend and distort the nose if you don't.

Now, I like the Roberts as a cast caliber. I'd grab that one, clean the copper out of it good and shoot it. Sometimes that's all that's needed especially with small bores./beagle

beagle, that's true what you said about the smaller the bore the more perfect the bullet have to be. The 260 I started with was new and didn't have copper in it and I've tried heavy and light bullets in it and at fast/slow velocities. Sometimes it seems like it wants to shoot good by grouping 2 to 3 bullets in nearly one ragged hole but then goes on to end up with usually a 4 inch nice round pattern group. Those 2 or 3 don't come an any particular sequence in the barrel heating up too. I'm shooting off a bench, front rifle rest, and rear sandbag. The action is glass bedded and at first the barrel was free floating. Then I put a pressure pillar up near the tip of the forearm. This was done because it walks jacketed to the right as the barrel heats up, and that is perfectly level to the right. After I put in the pressure points she cuts holes no shifting.
Joe

The possible accuracy damage to a boolit is based on the circumference of the boolit, assuming the same land/groove configuration, when discussing different bore sizes. Shooting a 30 caliber versus a 25 caliber at a 10 twist would appear quite different on paper at a hunnert. ... felix

rikkit, I've used four different cast bullets in my 257s. Lyman 257420 didn't do well, Lyman 257464 did better but is a bit difficult to cast, RCBS 25-100 and 25-120 both shoot very well and cast easily. The Lyman molds are both gone.

As far as powders, 2400, 4227, 4759, 4895 and Varget have produced velocities from 1800-2100 fps with the RCBS bullets. Accuracy is less than 1" to 1.5" depending on the load.

This is one cartridge that I've not weight sorted bullets for, just visual inspection. Maybe it would do better if I did weigh them but it does well enough the easy way. Being a shiftless-layabout, I tend to choose the easy way.

Rikkit/M Purcell...I haven't tried the 257420 in mine. The 257312, 257464 and both of the RCBS bullets do all right with the 100 grainer the best.

I have a 257418 being HP'd right now. It's a DC and I'm only doing one cavity. The regular bullet shoots pretty good in the Roberts and I have high hopes that the HP version will do even better.

Not a bad little cast rifle./beagle

Hardest part was getting a sizing die to fit the throat. Mine was .260 and I custom ordered it from RCBS. After I got the copper out ( took days) it shot great with the NEI 120g DD bullet. wrg-inc