25-260AI

[Hoodoo]

This is a new project I've been working on this winter. I've been shooting a 260AI with 140ELD-M's for several years now in PRS and NRL Hunter. I've been very happy with it, and won a lot of matches over the years.

However, my only complaint has been that the 260AI is a slightly long cartridge in a short action, and I have to seat the 140's in a little deeper than I'd like to fit in my MDT short action mags. I’ve wanted to try the 147 grain ELD-M’s, and 153 A-Tips but I never have because I’d have to seat them in even further. With the 25 caliber becoming popular again, and bullets becoming available, I decided to play around with this cartridge this winter.

Based on past experience, I knew I’d like to settle somewhere around 2825-2850 FPS with the 138’s. This is from past experience with my 260ai. I had one barrel that ran the 140 ELD-M’s at 2930 really well, until I shot a match at S3 in Montana in 2022. It rained horribly all day, and I was blowing primers on every stage. Lost around 100 pieces of fire formed brass that day. After that, I backed it down to 2830 and have been running that velocity ever since.

I’ve got the following bullets to try, but to be honest if I can get the 138 A-tips shooting the way I want, I probably won’t play around too much with the others.

138 A-Tips
135 Berger Hybrids
134 ELD-M

Build Specs.

Defiance Elite Short Action
Lilja 25 caliber 3-groove, 1:7 twist 3-groove 26" finish. Taper 22 contour. https://riflebarrels.com/wp-content/uploads/taper22.pdf
ZCO ZC527 5-27 and Nightforce ATACR 5-25
KRG C4 chassis
Thunderbeast Magnus-S-RR w/ RecoilX brake
Triggertech Diamond

H4350
138 A-Tips
Lapua 260LRP
CCI200’s
(I've also got a good amount of Alpha SRP, but I'm going to try and run this whole barrel on Lapua.)

My previous load in my 260ai was 43.0 grains in a couple barrels would give me 2830. My last barrel was a little faster, and 41.8 grains of H4350 gave me 2830. So I decided to start a ladder test at 42.0 grains.

42.0 2833
42.1 2831
42.3 2831
42.4 5827
42.5 2850
42.6 2837
42.7 2865
42.8 2856
42.9 2873
For some reason I didn't do anything from 43.0-43.5
43.5 2890
43.6 2906
43.7 2912
43.8 2931
43.9 2940
44.0 2937
44.1 2937
44.2 2942
44.3 2952
44.4 2962

I really liked the node around 42.0, but this barrel only had about 25 rounds on it and I thought with it speeding up over the next 100 rounds or so, I'd end up a little faster than I wanted. I did have some pressure around that 44 grain mark, but because I didn't want to be that hot I never shot anything more that hot.

At this next load, I had around 40 rounds on this barrel as I'd done a ladder test from 41.0 to 42.0. For whatever reason I can't find my notes for that test.

I loaded the following 4 shot groups.

41.5 2794
41.8 2814 (This one I did a 5 shot group, and had a ES of 9 and SD of 4.)
42.0 2837

I've done this shooting over the last month or so, weather depending, and I shot this last load above on December 11th. That 41.8 group was a very tight group, so at this point I'm going to load around 20 rounds and some 5 shot groups. If that holds, I'll go shoot it out at distance. I'm still expecting the barrel to speed up a little more, as I've got about 40 rounds on this barrel so far. I'll update this thread as I go.

 

[Hoodoo]

Shot several 5 shot groups at 100 today, December 12th. I started on a clean barrel, and each group got better as I shot. This was the last group I shot. I'm going to load up around 40 rounds at this load and go shoot at distance.


Snuck out and did some testing out to 930 yards. It was too muddy so I didn't get a chance to drive out and take a picture of the steel plates, but overall I was very happy with that load. There's a match in three forks in early January. If weather is decent, I'll drive over and try it out.

Shot on Saturday. Little rusty as I hadn't shot since the NRL Hunter Finale in August. Jared Miller took this pretty awesome picture. I'm going to work up the load a little bit, 41.8 grains settled at 2790FPS, which is a little slower than I had wanted.

 

[Hoodoo]

Saved.

 

[DHuffman]

Thanks for putting it out there.

 

[Tangent]

I've been wondering about this combination. Would this be a 260AI reamer run into a 25cal barrel?

 

[Hoodoo]

I've been wondering about this combination. Would this be a 260AI reamer run into a 25cal barrel?

You can't use a 260AI reamer, you have one to one made for this specific chamber. I had Manson make me a reamer, and I'm more than willing to provide the print to anyone that wants it.

 

[X-Caveman]

Lil off topic, but how important to you is the panning on your ckye pod? I ask because I just got my Gen 3 only to discover that they did away with that feature. I called and they said it was by request of their top comp shooters. Trying to decide if I’m going to keep it.

 

[STOMP442]

The .260 Ackley will always have a place in my safe. Most will say the juice ain't worth the squeeze but most would also say they have never ran one. I personally think it gets that 140 class bullet right where it needs to be while being extremely efficient doing it. That being said necking it down to 25cal with the new bullets would be sweet as well. I find it interesting your velocity is so low though. My brother built a 25 Creed a couple of years ago and he was able to get over 3000fps with the 131 Black Jacks and Reloader 16. The 25 Ackley should be able to do the same and then some.

 

[Hoodoo]

The .260 Ackley will always have a place in my safe. Most will say the juice ain't worth the squeeze but most would also say they have never ran one. I personally think it gets that 140 class bullet right where it needs to be while being extremely efficient doing it. That being said necking it down to 25cal with the new bullets would be sweet as well. I find it interesting your velocity is so low though. My brother built a 25 Creed a couple of years ago and he was able to get over 3000fps with the 131 Black Jacks and Reloader 16. The 25 Ackley should be able to do the same and then some.

100% agree, .260AI is an awesome cartridge.

So, if you read the original post, I had a barrel that I was running at 2930 with 140ELD-M's. It shot great, but I shot it at a match and it rained all day. Ruined 100 pieces of formed AI brass that day.

Since then, and over the subsequent years, I've changed my opinions on FPS. I'd rather run a little slower node these days. Again, just my personal preference.

Also, I'd be willing to bet your brother had more pressure than he realized. 3000 FPS in a 25 creed regardless of the powder is crazy fast.

 

[Hoodoo]

Lil off topic, but how important to you is the panning on your ckye pod? I ask because I just got my Gen 3 only to discover that they did away with that feature. I called and they said it was by request of their top comp shooters. Trying to decide if I’m going to keep it.

Not important at all. In fact, I think one of the best things about the Gen 3's is that they got rid of the pan.

I want the rifle to be square to both the target, and my body/shoulder. I would rather pick up the rifle and reposition, rather than pan to the next target.

 

[17VLD]

Beautiful spot to test a new 25 cal rifle. Thanks for sharing your piece of heaven. I'm trying to decide on a 25-284 and the 25-260AI. My straight 6BR does it's best right near that node that you like. I am thinking your really on to something here and for long for caliber bullets slowing down may be the way.
Matt

 

[JFrank]

@Hoodoo
Thanks for the great read Carson, I’ve enjoyed it very much and good luck this season.

Jim

 

[Hoodoo]

Beautiful spot to test a new 25 cal rifle. Thanks for sharing your piece of heaven. I'm trying to decide on a 25-284 and the 25-260AI. My straight 6BR does it's best right near that node that you like. I am thinking your really on to something here and for long for caliber bullets slowing down may be the way.
Matt

I couldn't agree more.