260AI roll call

[Fast14riot]

Thanks. It's a slow process for me with a non published AI cartridge with HBN and a long freebore. That's why I only went .3gr increments.
I wouldn't have guessed it but n160 is behaving as slow as I imagined H4831.

This is exactly why I started this thread. To be a repository of data for a cartridge that seems a lot of people shot for a few years and left or are just discovering. I love the cartridge and do not forsee not having one. Those of us very familiar with it can help new shooters to the cartridge with historical data and software predictions to keep things safe and groups small.

I'm actually considering putting a 260AI barrel on my XTC gun and using it strictly for any/any comp. I have a 7.5tw, 30" medium Palma 260AI kreiger sitting on the shelf waiting for me to burn up my 6x250 barrel. If I do, that one will be 140s just for recoil management in the sling. Probably go back to the 140VLDT.

 

[Bill Norris]

This is exactly why I started this thread. To be a repository of data for a cartridge that seems a lot of people shot for a few years and left or are just discovering. I love the cartridge and do not forsee not having one. Those of us very familiar with it can help new shooters to the cartridge with historical data and software predictions to keep things safe and groups small.

I'm actually considering putting a 260AI barrel on my XTC gun and using it strictly for any/any comp. I have a 7.5tw, 30" medium Palma 260AI kreiger sitting on the shelf waiting for me to burn up my 6x250 barrel. If I do, that one will be 140s just for recoil management in the sling. Probably go back to the 140VLDT.

Yea, I don't fore-see me being without a 260AI no time soon for sure. It just tunes easy and with the E C V 2 tuner I can keep it there very easily.

 

[Heman]

This is exactly why I started this thread. To be a repository of data for a cartridge that seems a lot of people shot for a few years and left or are just discovering. I love the cartridge and do not forsee not having one. Those of us very familiar with it can help new shooters to the cartridge with historical data and software predictions to keep things safe and groups small.

I'm actually considering putting a 260AI barrel on my XTC gun and using it strictly for any/any comp. I have a 7.5tw, 30" medium Palma 260AI kreiger sitting on the shelf waiting for me to burn up my 6x250 barrel. If I do, that one will be 140s just for recoil management in the sling. Probably go back to the 140VLDT.

Funny you said XTC I originally was going to go with a 260AI for course, but decided with 75% of the match at 300 and in not really needed especially when a 260 with 123s works really nice at 300 and 600. Also it was an AR-10 and while Medesha said he could do one, he was concerned about feed from the mag.

I have mine already to go, going to slide it in the 308 palma tube gun kit (making my own tube gun kit for it just not done yet) and work up loads. Mine will be a 1k Any rifle also.

 

[Fast14riot]

I've been shooting F Class with the 260AI. I have my own reamer with a tight neck and .210 free bore. I use a Whidden hydro form die instead of fire forming. Right now I use Hornady 153 Atip over 43.5 gr of reloder 16 at 2870. Could go faster but this load is very accurate.
Ron

I've considered a hydroforming die in the past. Discounted it because I could shoot a mid range match and not drop any points due to fire forming. However with everything getting even more expensive and scarce, I'm thinking about it again. Is your HF die long in the shoulder to push it back for better formed or just a straight chamber replica? I was thinking of ordering one .007" or so longer so I can size it down to give a sharper shoulder and better form.

 

[Fast14riot]

Funny you said XTC I originally was going to go with a 260AI for course, but decided with 75% of the match at 300 and in not really needed especially when a 260 with 123s works really nice at 300 and 600. Also it was an AR-10 and while Medesha said he could do one, he was concerned about feed from the mag.

I have mine already to go, going to slide it in the 308 palma tube gun kit (making my own tube gun kit for it just not done yet) and work up loads. Mine will be a 1k Any rifle also.

My xtc gun is currently in a single shot 40x rimfire stock. So, not an xtc gun anymore. But still have the McMillan prone stock and magazines if I ever want to torture myself again, lol! I prefer to lay there for 22-30 minutes and take my time single shot.

I guess turning 40 has really made me a lazy shooter!

 

[Ron Gorski]

I've considered a hydroforming die in the past. Discounted it because I could shoot a mid range match and not drop any points due to fire forming. However with everything getting even more expensive and scarce, I'm thinking about it again. Is your HF die long in the shoulder to push it back for better formed or just a straight chamber replica? I was thinking of ordering one .007" or so longer so I can size it down to give a sharper shoulder and better form.

With the Whiddon system, you must headspace the brass with a FL sizing die or body die.

 

[Heman]

I've considered a hydroforming die in the past. Discounted it because I could shoot a mid range match and not drop any points due to fire forming. However with everything getting even more expensive and scarce, I'm thinking about it again. Is your HF die long in the shoulder to push it back for better formed or just a straight chamber replica? I was thinking of ordering one .007" or so longer so I can size it down to give a sharper shoulder and better form.

I have a HF die sent them the reamer specs and also had dies made to the reamer also. What I've done for years with my 280 Rem (using -06 brass) and what I did with the 260AI was to screw the die out and blow the should past where it needs to be. Then I come back with the seating die and set it back where I want it. I know you can fire form but got a bad taste in my mouth trying to fire form 280 brass and in my mind if I'm wasting barrel life I want it to be with the actual load not fire forming stuff.

40? LOL, I'm 46 and I've had more fun the past 3-4 years shooting course than before. Optics and ETS has made it more fun, but also shooting consistent low/mid 190s in OH and shooting in the 780s also makes it more fun. When I was happy with 740 or 750 it wasn't as much fun. Go figure......... I look at it like cross training, need to do different stuff than shooting prone all the time otherwise I get tired/bored and you work different skills. Shooting OH keeps my reaction time up.

 

[Fast14riot]

I have a HF die sent them the reamer specs and also had dies made to the reamer also. What I've done for years with my 280 Rem (using -06 brass) and what I did with the 260AI was to screw the die out and blow the should past where it needs to be. Then I come back with the seating die and set it back where I want it. I know you can fire form but got a bad taste in my mouth trying to fire form 280 brass and in my mind if I'm wasting barrel life I want it to be with the actual load not fire forming stuff.

40? LOL, I'm 46 and I've had more fun the past 3-4 years shooting course than before. Optics and ETS has made it more fun, but also shooting consistent low/mid 190s in OH and shooting in the 780s also makes it more fun. When I was happy with 740 or 750 it wasn't as much fun. Go figure......... I look at it like cross training, need to do different stuff than shooting prone all the time otherwise I get tired/bored and you work different skills. Shooting OH keeps my reaction time up.

I do shoot some specialty and fun matches to keep on my game. But, I do try to keep up on the game I choose to play.

My fire forming load with 130gr smk pulled bullets shoot 1/2 moa with no load development. Also, I do not need to fire form very often. I've been shooting the same batch of 75 pieces of brass over 10 firings now. Have another 75 with 3x on them ready to go if needed, and lots more as back up, so its not a hassle, just cost of components.

Were not that far apart in age either...

 

[Skedaddle Shooter]

I've considered a hydroforming die in the past. Discounted it because I could shoot a mid range match and not drop any points due to fire forming. However with everything getting even more expensive and scarce, I'm thinking about it again. Is your HF die long in the shoulder to push it back for better formed or just a straight chamber replica? I was thinking of ordering one .007" or so longer so I can size it down to give a sharper shoulder and better form.

I had Hornady build me a hydro die. I didn’t form a sharp shoulder. It was rounded off like a Weatherby. It still needed to be fireformed even after the hydro forming. I had an older 260AI barrel in the shop so I turned it into a fireforming barrel and like that much better. I can start load development right after fire forming. I’m using seconds bullets and some old 4831 to do the fire forming, so saving my good bullets for load development.

 

[Fast14riot]

I had Hornady build me a hydro die. I didn’t form a sharp shoulder. It was rounded off like a Weatherby. It still needed to be fireformed even after the hydro forming. I had an older 260AI barrel in the shop so I turned it into a fireforming barrel and like that much better. I can start load development right after fire forming. I’m using seconds bullets and some old 4831 to do the fire forming, so saving my good bullets for load development.

I fire form with 130smk pulled bullets and some old surplus H4831 as well. I bought several hundred of these pulled bullets for about $0.19/ea many years ago. The H4831 was purchased for about $10/lb and my keg is nearly done. Those pulls and surplus powder can make 1 ragged hole at 100y from 50 rounds pretty easily. If shooting a 600y match i fire form with 140 match bullets. If its a new barrel I use my final match bullets and do a seating depth test while fire forming, no wasted data.

My thinking with a hydro die is to have it form the shoulder 0.010" long, then crush it back sharpening up the shoulder a bit, getting closer to final capacity. Though I wonder if I would need a 3rd set of load data or if its close enough to stay in the groove.

I have an old barrel if I ever need to FF a bunch of brass at one time, but I've been shooting the same 75 pieces of brass over 10x now and still going strong.

 

[Skedaddle Shooter]

I fire form with 130smk pulled bullets and some old surplus H4831 as well. I bought several hundred of these pulled bullets for about $0.19/ea many years ago. The H4831 was purchased for about $10/lb and my keg is nearly done. Those pulls and surplus powder can make 1 ragged hole at 100y from 50 rounds pretty easily. If shooting a 600y match i fire form with 140 match bullets. If its a new barrel I use my final match bullets and do a seating depth test while fire forming, no wasted data.

My thinking with a hydro die is to have it form the shoulder 0.010" long, then crush it back sharpening up the shoulder a bit, getting closer to final capacity. Though I wonder if I would need a 3rd set of load data or if its close enough to stay in the groove.

I have an old barrel if I ever need to FF a bunch of brass at one time, but I've been shooting the same 75 pieces of brass over 10x now and still going strong.

That was my plan as well, I had the die built .007” long on the shoulder. Even when I ran it thru the sizing die it wasn’t sharp. I just fit a FF barrel and ran 500 pieces of Alpha small primer brass thru it in a couple settings. This was enough for me and a few friends who wanted one. I’ve been shooting a 260 AI for deer and antelope for years. It’s my favorite cartridge the those hunts.

 

[Fast14riot]

That was my plan as well, I had the die built .007” long on the shoulder. Even when I ran it thru the sizing die it wasn’t sharp. I just fit a FF barrel and ran 500 pieces of Alpha small primer brass thru it in a couple settings. This was enough for me and a few friends who wanted one. I’ve been shooting a 260 AI for deer and antelope for years. It’s my favorite cartridge the those hunts.

Never hunted with it, as much as I love the cartridge. My hunting guns are God's caliber of .30-'06, peoples choice of 6br Norma and gentleman's choice of 6mm Rem.

I've just never had a hunting barrel spun up for it. Even though I have my own reamer. Maybe I'll make a 20" barrel with it, just to keep velocity up. We'll see. I build a rifle just about every year anyway.

 

[Bwknives]

I have a Whidden hydro die and it seems to push the shoulder out well but it still has a slight radius to the shoulder. I’m in the process of switching to the 140 hybrid. Both H4831SC and H4350 shot great ladders with a couple obvious nodes. I chose a node with H4350 and printed some great groups. I need to test further but it looks promising without much effort. Build is a SA and jumping about 0.050” to fit in the magazine. 26” Hawkhill at 3865 fps. Not very hot but adequate for a range rifle.

 

[Bill Norris]

WOW 3865 is smoking. Are you sure the chrono is correct?

 

[SVT_Tactical]

A 140?? At 3865!!!???

 

[Greg Y]

That's got to be 2865. I've pushed 140s to 3100 with rl26 and it was obvious that I was about to get my face removed in short order.

 

[Bill Norris]

That's got to be 2865. I've pushed 140s to 3100 with rl26 and it was obvious that I was about to get my face removed in short order.

Yea 3000 is about all I want to see with the 140s

 

[Bwknives]

WOW 3865 is smoking. Are you sure the chrono is correct?

‍ 2865…. My typo

 

[Fast14riot]

Lol, thought we were talking about .20's there for a second with those numbers! 3000 is about functional max for a 140.

 

[46and2]

Predicted velocity was 2913fps. I'd be curious to see what it is when you finally get to chrono it. Cool to see nice groups matching up with the predictions!

47.1gr of n160,
2906 fps
17 es
4 sd. For 20 shots.
__________________
I'm up to 47.7gr today with nothing that resembles pressure signs. I might give it another .3gr and leave well enough alone.
200yard groups.

This might be a .2 moa or less load with a better shooter and better equipment. Seriously.