Kimber 243 to 260AI

[spencerhenry]

I've got a Kimber in 243, a very nice trim little rifle for carrying in high remote country. But, I can't seem to get it to shoot well. I have tried 100gr Hornady, 100gr sierra, a couple powders, it just wont group better than about 1.25" at 100 yards, often not even close to that good. I have tried other lighter bullets too, but at distance I'm not liking light bullets for deer.
I've been thinking about having it rebarreled to a 260AI. But, then I wonder about magazine length. Or other issues.

I had a Kimber in 300wsm years ago that was similar, shot "ok", but not great. I sent it down the road.

Suggestions?

 

[Bill Norris]

If you a

I've got a Kimber in 243, a very nice trim little rifle for carrying in high remote country. But, I can't seem to get it to shoot well. I have tried 100gr Hornady, 100gr sierra, a couple powders, it just wont group better than about 1.25" at 100 yards, often not even close to that good. I have tried other lighter bullets too, but at distance I'm not liking light bullets for deer.
I've been thinking about having it rebarreled to a 260AI. But, then I wonder about magazine length. Or other issues.

I had a Kimber in 300wsm years ago that was similar, shot "ok", but not great. I sent it down the road.

Suggestions?

If you are planning to go with a barrel twist to work with the heavier class longer profile bullets you may be correct on an issue with COL. If not probably won't be a problem.

 

[Fast14riot]

140s in a 260AI can usually be loaded to 2.9 or so and shoot great. 130-135gr bullets will do anything a 105gr 6mm bullet will do and be going 3000fps.

 

[NZ_Fclass]

Why not the 6.5mm SLR? Plenty of performance with 140g, easy to tune and no fire forming. I'm getting 2870fps with 43.5g of H4350 in a 26in barrel. Feeds well from a mag (AICS). Dies are available from Whidden or sometimes Redding. You can use up your existing 243 brass too.

 

[STOMP442]

The 260AI is probably the best chambering for a short action high performance round in 6.5. Just my opinion. I have two 260AI currently, one in a heavy bench gun on a long action throated to seat the 144s just above the neck shoulder junction. I can't remember the OAL off the top of my head but I do know its longer than a standard short action rem bdl magazine. I am getting 2957fps out of a 28" Krieger pushed by 43gr of H-4350. My other rifle is a trued up 700 short action set up as a hunting rig. That one is running a Berger 140 at mag length and I am getting 2935 with 43.5gr H4350 out of a 26" Shilen. Both rifles shoot fantastic at that 2930-2950 node. My point is mag length is not necessarily a bad thing and I don't think that should stop you from choosing the 260AI. The 260AI is everything the 6.5PRC tries to be and does it much more efficiently. The only downside really is the fire forming, and even that will give you hunting quality accuracy.

 

[spencerhenry]

I already have a 264 win mag, so maybe stick with 6mm, but make it a 243AI? Looks like 100gr is about the limit for hunting bullets. I have plenty of good choices for an elk rifle, this is for deer, wolves, antelope, maybe sheep and goat.

 

[Shutstr8r]

Spencer
I’m of the thought that your rifle has a 10 tw barrel. Recutting the chamber to 243ai isn’t going to make a bad shooting barrel shoot good, not without a barrel set back. Have you tried running 90gr bullets? I don’t know what your intended target is, but 90’s will take from mule deer on down. If you are ok with a re-barrel and you are wanting to run the heavier bullets in a 243ai, an 8tw will work but I think a 7.5tw barrel would work better.

The 260ai 40deg would be an ideal cartridge and, as has been already suggested, loading 140’s out to 2.9” is very doable. And yes I have one of each.

Just my opinion. YMMV.

—Darrell

 

[Walt Krafft]

I would check the twist of your barrel. If it is a slow twist, you will have to shoot lighter bullets in it. I would explore getting it to shoot before rebarreling. How is the bedding? How is the ignition? Have you cleaned and lubed the firing pin and spring? Lots of things can make a rifle shoot poorly. Once it is shooting ok with the existing barrel, then you can decide to rebarrel or better yet, get another rifle. If you can not get it to shoot, I would send it down the road.

 

[spencerhenry]

I have no intention of working with the existing barrel. I had another Kimber in 300wsm years ago, could not get it to shoot. After numerous loads with different powders, different bullets, I sent it down the road. I like the size and weight of this 243, its a great platform for way off the beaten path in steep rugged country. But, in country like that its even more important that it shoot well. I'd like to have a rifle that I can have a reasonable expectation to kill a wolf at 500.
The purpose would be a hunting rifle only, the heavier bullets seems to me to be target bullets only. So, I'd most likely run 100gr bullets. I have plenty of varmint rifles, I never take a 243 out for coyotes or smaller targets.

 

[Idaho-Lefty]

I've got a Kimber in 243, a very nice trim little rifle for carrying in high remote country. But, I can't seem to get it to shoot well. I have tried 100gr Hornady, 100gr sierra, a couple powders, it just wont group better than about 1.25" at 100 yards, often not even close to that good. I have tried other lighter bullets too, but at distance I'm not liking light bullets for deer.
I've been thinking about having it rebarreled to a 260AI. But, then I wonder about magazine length. Or other issues.

I had a Kimber in 300wsm years ago that was similar, shot "ok", but not great. I sent it down the road.

Suggestions?

You Might TRY,.. the 87 gr. H-VLD or 95 Grain, Classic Hunter BERGER Bullets, Before "Scrapping" the Barrel as Your TWIST might Not be, exactly "Right" for, the other Bullets, you used,.. "Possibly" ??
We used N-160 Powder at, a Little Bit Under, Max in our 1-10 Twist, Tikka .243 Win., to Shoot, SUB 1/2 MOA Group's
AND the 87's will FOLD Up,.. Big, Heavy Bodied, thick Horned, Idaho Desert Mulies,.. just, Fine !
My grandson Has got, 2 of them,.. One at, 268 yds and the other at, 287 Yards So Far and BOTH,.. DRT !
N-160 @ 3,185 ave, FPS !