260AI !!!

[kev77]

Who has a reamer print or or number to share also current load data. Going to spin one up . Thanks all in advance
Oh, also coal if you got also

 

[Fast14riot]

I'm on my second barrel and bought my own reamer. Mine is a no-turn neck (0.298) and works well with Peterson and Lapua brass. My freebore is lengthened separately so I don't have an actual number for it. I just send a dummy case with bullet seated where I want.

Fire forming, its really hard to beat 44gr H4831 under any 130-140gr bullet. It just shoots well and is plenty to form the brass. This is a known accurate combo for standard 260rem.

Formed, typically ends up around 47.5-48gr of 4831 under a 140. Drop 1/2-1 grain for RL23. H4350 typically ends up around 44-45gr. All of these should be between 2925-3000fps from a 26" barrel.

My rifle is single shot, so I just find the best jump/jam for the particular bullet with the boat tail seated just above the neck/shoulder junction.

 

[STOMP442]

The .260AI is amazing. I am using a Manson reamer just the standard one they have on hand. I want to say it has a .100" freebore but can't remember for certain. I also bought a throating reamer if I needed it but I don't think I will. a 144gr Berger seats perfectly at the neck shoulder junction with a .025" jump from the lands. My fireform load is 42gr of H4350 with the cheapest 140 I can find. My latest build is a 28" Krieger and I am running 46gr of R23 and getting 2950fps and one hole accuracy with Peterson brass and CCI 200 primers.

 

[Bill Norris]

Agree, the 260AI has to be one of the most amazing chamberings out there. Accuracy, easy to work up loads and no-trim brass are the attributes I like most.

 

[6MMsteve]

.050 jump in my 260ai was best accuracy for my barrel Krieger 30in 4 gr 140 berg BT's

 

[kev77]

I'm on my second barrel and bought my own reamer. Mine is a no-turn neck (0.298) and works well with Peterson and Lapua brass. My freebore is lengthened separately so I don't have an actual number for it. I just send a dummy case with bullet seated where I want.

Fire forming, its really hard to beat 44gr H4831 under any 130-140gr bullet. It just shoots well and is plenty to form the brass. This is a known accurate combo for standard 260rem.

Formed, typically ends up around 47.5-48gr of 4831 under a 140. Drop 1/2-1 grain for RL23. H4350 typically ends up around 44-45gr. All of these should be between 2925-3000fps from a 26" barrel.

My rifle is single shot, so I just find the best jump/jam for the particular bullet with the boat tail seated just above the neck/shoulder junction.

Thanks very much

 

[kev77]

The .260AI is amazing. I am using a Manson reamer just the standard one they have on hand. I want to say it has a .100" freebore but can't remember for certain. I also bought a throating reamer if I needed it but I don't think I will. a 144gr Berger seats perfectly at the neck shoulder junction with a .025" jump from the lands. My fireform load is 42gr of H4350 with the cheapest 140 I can find. My latest build is a 28" Krieger and I am running 46gr of R23 and getting 2950fps and one hole accuracy with Peterson brass and CCI 200 primers.

Good to hear thanks

 

[AckleymanII]

sounds like this case should go on a long action?

 

[deadidarren]

sounds like this case should go on a long action?

Yes it is ...... I did mine on a rem700 long .

 

[Fast14riot]

sounds like this case should go on a long action?

Mine is on a SA, but its single shot. My 140 loads in my old barrel were 2.985" COAL, so they may work in an AI magazine.

 

[paw]

Is the ai 260 any less likely to have donuts?

 

[Bill Norris]

Is the ai 260 any less likely to have donuts?

I have not noticed any at all with either of my 260AIs.

 

[Fast14riot]

Is the ai 260 any less likely to have donuts?

I haven't noticed it on mine either. I did have some brass that was fired a few times as 260rem that I then fireformed to AI and it had donuts, but the virgin brass never showed signs of it.

 

[Fast14riot]

Just a little something to get you excited about the 260AI, this is my fire forming load! My formed load I don't normally shoot at 100 yards, so I don't have pics of tiny little groups for that, I primarily shoot it at 1K, but have won my division a few times at Sacramento club matches with the 140gr load. I'll be switching over to 153.5 Berger for this new barrel, running right around 2850, I'll be within 1 moa of drop compared to my 140gr load running 2975.

 

[Liven The Dream]

Had Prone Rifle Built on a Pre-64 Action 30" Obermeyer Barrel
H4831 SC Winchester .243 Brass ,142 Sierra back then 2008 .
Won the State Long Range that Year .
Lot of Guy didn't believe that 260 Ackley was much back then ?
As I think back Barrel Life was a Little short ? Fire Forming and all.

One Tip I found out : Fire Form with R-19 at 600 yard Matches and Win .
R-19 would not work well after Cases where Fire Formed ?

 

[Bill Norris]

To add to your excitement of the 260AI with a well built rifle and good handloads and good driving skills you should be able to get this kind of accuracy.

 

[1lessdog]

A 260 I built for my Wife. Really likes 129 gr Nosler Partition

 

[DocDoc]

1less, do you or the wife shoot it more? Good job to get/keep her involved.

 

[1lessdog]

1less, do you or the wife shoot it more? Good job to get/keep her involved.

She shot two Mule Deer Does with it this fall. Two shots 2 deer

 

[46and2]

She shot two Mule Deer Does with it this fall. Two shots 2 deer

Whats your load and velocity, if'n you don't mind me prying?