257 Bob

[reloader28]

I have a custom 257 that we bought from a guy. 1/14 twist 26" barrel. Was shooting the 257418 thru it last spring with half way decent results.

I bought the RCBS 120 SP thinking my groups would get better. Never thought about twist.

Makes a very nice boolit, but at 50yds, I getting 15" groups and every boolit is hitting the target sideways.

I've heard of this happening, but never seen it. I finally found twist rate stuff at that LASC site and near as I can figure, these RCBS boolits need like a 1/9 twist. Am I figuring this all right? Boolit is 1.022 with the gas check.

It would be a shame to have to throw this gun in the garbage and find one to fit the boolit.

[warf73]

If it comes to throwing it in the garbage PM me. I've always wanted Bob just never got one yet.
How fast are you pushing the boolit, sometime more speed will help.

[docone31]

Paper patch it, and push the envelope!

[reloader28]

I dont remember what my loads were. This was about a week ago and I cant find my notes on it. They must have been on the targets that I threw away.

Seems like the speeds were around 1800-1900fps. Now that I think about it, I ran some hotter heat treated boolits threw it and they didnt seem to tumble as bad. The grouping was good, so I tried something else. Maybe I'll have to try some hot stuff. I still have the heat treated ones. Maybe some hot loads with the soft boolits would be better?

I've never tried paper patching, but I've thought of it in 30-06.

I really like this gun and this is frustrating.

[AZ-Stew]

Standard twist for .257 Roberst is 1:10. I believe mine will stabilize the Hornady 120 gr HP, which is a pretty long bullet. With a 1:14 twist, you'll have to move that boolit right along to spin it up fast enough to fly straight.

I'm guessing the person who had the rifle built was using it for a varminter, shooting very light (short) bullets and wanted the slower twist for best accuracy with them. Just speculating, but I suspect I'm close.

Regards,

Stew

[x101airborne]

I have 3 "bobs", my wife shoots a winchester 70 xtr bob, and my son shoots a custom mexican mauser in a bob. All of them with J-bullets gave me accuracy fits at first. I did not start getting consistent results from them until after 150 rounds each. After that, things seemed to "come together" easier. IMO, the bob is easy on barrels than most and takes a lot to break in. H322 powder gave the best results in the 100 gr. region maxed out. just under 3200 in my wifes and around 3100 even with my son's. As to the long, heavy cast boolits, I just dont think you can push them fast enough to stabilize. Even if they come close to stability, they will probably yaw like crazy. Just to try it, take some of your boolits and cut around 1/4 of the base off with a dremmel and gascheck as normal. Load over a normal charge and fire at range. If they hit straight, get a different mold. If they dont, you can throw the rifle in my trash. Remember, not looking for group. Just straight holes.

[reloader28]

You guys are to late. The gun is cut in half and in the trash can. What a piece of garbage.




Just kidding. My wife found it for me at a garage sale about 6 years ago while I was off turkey hunting. I think she paid around $200 for it with a pile of brass. Free floated bull barrel (I forget which brand) Timney trigger and mounted on a 03 Springfield action. We call it the Heatseeker. Whatever you point it at, no matter what range, its getting blown in half with 75gr V-maxes. No problems shooting wild cats and other small varmints at over 300yds.

I'm going to crank up the speed more on these and see what happens. If I remember right, they shot a little straighter when faster, but I didnt go terrible fast. I got about 100 heat treated left.

Airborne, I dont think I can cut the base straight enough to make that work. I aint tried it, but dont think I can. I thought about shortening the nose tho. I might even be able to put a little nose shape back on it. I was waiting about 6 months to finally get around to getting this mold, and now it wont work worth a darn. Have to try it in my Dad and brothers 25-06's.

If I do trash can this gun tho, I will make sure to send each of you boys a part of it, just so nobody feels left out.

[mroliver77]

You might be able to shorten the boolit a bit by forcing the handle on a lyman/rcbs sizer to squish boolit a bit. I use flat tpop punch and have "bumped" some boolits successfully to flat nose and lost a fair amount of length. You can ruin a boolit too but experiment and see what you can come up with. Theres more than one way to skin a cat.
Jay

[georgewxxx]

I've got Roberts rifles, one a Ruger #1, the other a 722 Remington and both handle anything from the still available 257420 65 grainer to the old 257306 115gr boolits. Obviously they're both faster twist, and handle lead slugs easily. If it were me, I'd be looking for a used 257454 or 257463 Lyman mould, both are Loverin designed. Other than custom mould, very few regular light weight .25 cal. moulds are offered anymore. You might want to consider a Ranch Dog TLC258-80-RF.

[376Steyr]

Check out the Group Buy section, look for "25 Cal heavy wt GB" which recently started up. You can get a NOE mould in 120 gr. GC, 100 gr. GC, and 85 gr. plain base. Downside is it probably won't be shipped until May or so.

[HORNET]

You might be able to find a 257312 (89 Grain FPGC) on FleaBay or somewhere. Lyman made a LOT of them and they're real good in 14" twist barrels in a wide variety of calibers. It'll probably give better groups than that 257418. Classic .25/20 heavy boolit.

[beagle]

My 1-10 bob stabilizes the 25-120-SP RCBS just fine. The 257312 might be an answer in that 1-14. I had a 1-14 twist .25-20 and it marginally stabilized them. Now, with a little more velocity that you could go to with the bob, it might shoot all right./beagle

[reloader28]

Hey, thanks for all the tips guyes.

I'll have to see what I can come up with for a mold. I may even find somebody that would sell a handfull of boolits to try before I buy another mold. The wife is starting to think I got to many. Till she starts shooting again anyways.

The Ranch Dog mold is a good looker, but I aint never done any tumble lubing. It looks like a messy pain. Would this boolit work in a lube/sizer?