.257 Roberts frustration

[robtattoo]

I'm about at my wit's end with this damn Kimber.
I was really wanting to shoot 100gn bullets, but it looks like that isn't in the cards. I've tried Partitions, Core-lokt & SGKs. I know there are others, but these 3 were what I wanted to work up for (pigs & bigger, range time & whitetail)
I've tried so many combinations around the 'magic' load with IMR4350 is not even funny. Nothing from 43 to 47gn will shoot under 3" whatsoever. I've dropped below book minimum to way above & nothing seems to do better than 3". I thought I'd found a happier spot at 46, but my last range trip slapped them all into 3" again.
I'm not seeing any group shift, all group centers are consistent (it's not the scope or mounts) it just doesn't seem to want to shoot 100 grainers.
Doing a bunch of online snooping, it turns out that this seems to be common, even with the 1:10 twist. They seem to like <90gn and >110gn. The mid weights don't get any love.

So. Has anyone had any success at all with 100gn bullets in the Bob? If not, what's the consensus on 80gn TTSX on accuracy & game? I've read a ton of very positive accuracy reports on the Barnes/4350 combo, but no dead stuff reports

 

[Salmonchaser]

I just bought a 257 Roberts. Only bullets I could find locally were 115 ballistic tips and 120 partitions. I’m hoping the 120s will work for gong ringers, buddy has some 100s he’s trading me. I’ll let you know what I learn. Rifle won’t be here until next week. Nothing down range yet.

 

[Mattyq17]

Remington 722 .257 bob, 44.5 grains of IMR4350, 80 gr TTSX, .5 MOA groups one shot dead deer for my son this year. Have some 100 gr TTSX but loading those in my 25-06.

 

[WKR]

Did you play around with seating depth at all?

 

[35WhelenAI]

If it shoots well in a rifle, 80 TTSX is a great choice, IMO. Light for caliber TTSX's in 270 Win, '06 and 35 Whelen AI have been superb medicine for elk in all 3 of those rifles for me. Allows them to be driven fast which they thrive on.

 

[robtattoo]

Did you play around with seating depth at all?

I've gone long, but I'm limited by the mag box. Tried to get a close to the lands as I could. It was pointed out to me earlier, on another forum, that I actually hadn't tried SAAMI spec. I need to give it a go & actually work outwards, rather than just going as long as possible (which has worked for me 9/10 times in the past)

 

[WKR]

I've gone long, but I'm limited by the mag box. Tried to get a close to the lands as I could. It was pointed out to me earlier, on another forum, that I actually hadn't tried SAAMI spec. I need to give it a go & actually work outwards, rather than just going as long as possible (which has worked for me 9/10 times in the past)

Yup I would try that before giving up. Some guns just like that big jump into the lands.

Have you tried heavier or lighter weight projectiles and had good results with this barrel?

 

[robtattoo]

Nossir, only the 100s.
I have a handful of 120s & 87s but I was totally set on the hundies.

 

[riversidejeep]

 

[robtattoo]

View attachment 392548

That'll do!

 

[Wrench]

My bob is new to me. I literally stuffed rl17 and a 100gr ballistic tip in it and it shot the first charge at about. 75". I quit there. Good enough for it's application in the line up.

 

[Jim1187]

I know its not one of your preferences but Speer's hotcores have been pretty good to me. The 87 in particular has been handy in getting a couple stubborn .25 cals to shoot and while somewhat splashy in the fast .25's, the Roberts shouldn't stress them.

 

[Sandstrom]

I may have missed this earlier, is the kimber new to you? Have you had any success with this rifle and other ammo, either factory or hand loads? Just wondering if it might be the rifle?
Ryan

 

[robtattoo]

I may have missed this earlier, is the kimber new to you? Have you had any success with this rifle and other ammo, either factory or hand loads? Just wondering if it might be the rifle?
Ryan

It's brand new to me. Essentially brand new. I'm 99.9% sure the previous owner never even mounted a scope on it. It's only the second 'new' gun I've ever owned, so I'm not 100% on how many rounds it'll take to settle down. I took the scope off to get another gun up & running, but the replacement should be here on a few weeks. In the meantime I'm going to de-copper the bore (just in case) & load up a few different trials.

 

[sndmn11]

I think I have a few kinds of .25 rifle bullets. If you are interested let me know.

 

[eaglemountainman]

robtattoo,
Is this a Montana or Classic Select? Have you gone through the Kimber checklist?

 

[robtattoo]

It's a Hunter.
Checklist? This is my first Kimber.

 

[.270]

My bob likes H4350, I use it with Speer 100 gr bt, Swift 100gr scirocco 2 and 110 eldx. I tried RL17 for more speed but couldn't get the accuracy like the H4350.

 

[Couescrazy33]

Make sure to let the barrel cool down.

 

[waitforit]

There is a "Kimber checklist" of things you can go through / verify for accuracy. I have a hunter in 7mm08 and it was a love/hate to start out. Most of what I've done is around my technique as a shooter using an ultralight rifle (my body alignment, using a bipod vs. bag). I also made sure the barrel freefloated "dollar test" all the way to the action and experimented a little with the action screw torque values (you can find info on this online). Finally, I lowered the trigger pull to about 2.5 lbs (I think it started at about 4+).

Honestly though this gun is not a benchrest gun.. but I think you should be able to nail down a 1MOA load.. My kid has a Ruger 6.5CM that is uglier, heavier, and far outshoots this kimber and it makes me feel better