.260 AI and 147 ELD-M powder selection??

[codyadams]

After some more analyzing...I think I'm just going to see how much will fit before getting seating depth variations. The 147 is going into the case a significant amount seated at 2.865...and the powder is at the base of the neck with 50.5 grains. I may only get to 50.8 or maybe 51 grains, but wherever I get to, I'll load up to that in .3 grain increments and look for pressure.

I want to find out if I'll pressure out or run out of capacity first with RL26 in a .260 AI, mainly for educational purposes for the next guy that wants to do this, I searched all over the internet, emailed Hornady as well as Alliant powders asking if they had any data or suggestions, and as I suspected they replied saying they have no data or even a suggested starting point...not that I was surprised, this is not a commercially produced cartridge, a new bullet, and this powder hasn't been around for a long time like h4831, for instance. And as the 260 AI is gaining popularity, and I'm sure this bullet is going to be popular in this chambering, and if 150+ fps over H4831 is going to be normal with RL26...I'm sure more guys will be looking at this, and I wanna throw em a bone.

If anyone has any suggestions or questions, just ask me. I'll report what I find next time I can get some bench time.

 

[Deleted member 25294]

Very interesting thread, you are getting some amazing speed with the 260AI.
I've been wanting to build a 6.5 that will get me over 3000 fps with the 147's, and have been seriously considering the 6.5 SAUM.
That being said if I could reach 3000 fps using 10 grains less powder over a SAUM then the 260 AI is looking like a it could be a good option, maybe even a 6.5x55AI..
Have you tried reloading a few of the cases multiple times with your hotter loads?curious what kind of brass like you're getting.

 

[codyadams]

Very interesting thread, you are getting some amazing speed with the 260AI.
I've been wanting to build a 6.5 that will get me over 3000 fps with the 147's, and have been seriously considering the 6.5 SAUM.
That being said if I could reach 3000 fps using 10 grains less powder over a SAUM then the 260 AI is looking like a it could be a good option, maybe even a 6.5x55AI..
Have you tried reloading a few of the cases multiple times with your hotter loads?curious what kind of brass like you're getting.

I have not tried it with these bullets, I'm interested as well to see how long the brass will last, and I plan on finding out. I will keep this thread updated as I go along. My load that I have fired 3 or 4 firings of in this brass is with H4831sc pushing a 140 at 2930, which is a full grain under my max with that powder/bullet combo.

If you wanted to do 3000+ with a 147 for sure, I would go SAUM...I was blown away by the velocity, I certainly was not expecting it. But once I find a load I'm satisfied with and have played enough with it, I will do trajectory validation as well to confirm my velocity readings.

I know equipment can fail or be wring...but I should add that on the same range session, prior to shooting the 147's, I also shot a 5 shot string of my tried and true load with the 140 Bergers, that I know and have validated to produce 2930 at 65 degrees, as a control, and my average of the 5 was 2921 with 9 fps E.S., which seems right considering it was 20 degrees, 45 below where I chronoed it going 2930. So I believe the speeds I was getting are accurate...

 

[NovaHunter]

This is a very interesting thread. I built a 260AI in October of 2015. My current load is:

Primer: Fed GMM Large Rifle
Brass: Lapua, formed
Powder: 44.2gr of RL17
Bullet: 142SMK

Barrel is a 28in Pac-Nor Super match 3 groove 1in8 twist. I get 2980 fps at the muzzle with this combination and have just had a ton of fun shooting it.

I am intrigued with the RL-26 and 147-ELD. I have about 700 SMK's and 8lbs of RL17 right now, so might need to try this combo once those are done.

 

[Santiam338]

I thought I would add my 2 cents.. My 260ai load is 47.3 gr's of IMR 4831 with fed primer under a 140 Berger vld. This gets me a average of 2940 fps with a 26" barrel..

Just for fun I loaded up 3 with 49 grs of RE 26 with all else the same..Stepped out back and fired them through the chrono..

2932

2944

2930

So pretty darn close to my load I have now.. I will have to wait until I can get up on the hill to see how it groups,but so far I haven't seen anything that might want to cause me to change.. While I may be able to up that charge,there is not much room left..

The weather sucks right now,but if it breaks I might get out..I will report back when I do.

 

[codyadams]

Ya, I'm waiting on weather as well...hopefully this weekend I will be able to get out

 

[codyadams]

I loaded some more today around the area I got the lowest e.s., I loaded 4 each of 49.3, 49.6, and 49.9; hopefully I will find a half MOA or less shooter, with the low e.s. that I want.

I tried something different, as I'm changing my bottom metal to a AICS type, I will be able to seat longer (up to 2.965") in the Alpha type II mag. I loaded these up just off the lands, somewhere between .005" and .010" off. I also took some pictures to show how much compression I'm getting with these loads. The picture is of the 49.9 grain load, then a bullet next to the loaded round seated at 2.908".

 

[AKSavage]

I should add my experience with RL26 here.

My .260 rem is throated long, so I can seat 140 grain bullets with the boat tail right at the neck/shoulder junction, with a COAL just under 3". (Gotta love the long Savage SA magazines!) This allows me to get 49 grains of RL26 into the case (case is full to base of neck) with only mild compression. I used to shoot 142 SMK at about 2800fps using H4350, and with 49g of RL26 Berger 140 VLDs leave the barrel just shy of 3000fps, and SD and accuracy are as good as I've had with ANY other powder/bullet combination. This is with ZERO pressure signs and a 25" barrel. I'm very impressed. I think you'd run out of capacity if you couldn't seat the bullets long, so really RL26 is a touch too slow for a standard 260 Rem. I actually wish I had a touch more case capacity (260 AI is *perfect* for RL26), but I'm happy with the substantial gains I did get.

I tried 140 Berger Hybrids too, but the 140 VLDs grouped best. I did not try the 147 ELD-M bullets in my 260 Rem because it's a 1-8.5 twist and wouldn't stabilize them. At sea level even the 140VLD is marginally stabilized, but close enough not to lose too much BC to stability degradation, only about 2%.

RL 26 is maybe a TOUCH too fast for a 6.5 SAUM shooting 147 grain ELD-M bullets, meaning that I ran into pressure with plenty of case capacity left. I tried RL33, but it's too slow...I ran out of case capacity before I reached decent speeds. Never the less, I got 3100+ fps using RL26 (24.5" barrel, 1-8 twist), with equal accuracy to what I was getting with Retumbo, so I went with it.

RL26 was awesome in my 7 Rem Mag too. 162 grain ELD-x bullets at 3200 fps from a 24" barrel. I never could find an accurate node though, so more testing (seating depth, etc) is required. I'm starting to think the factory barrel may have gone south. This has made me think it might be time to upgrade to a new 26" barrel throated for the long 180+ grain .284 bullets, and RL33 would be the first powder I try.

 

[codyadams]

I do have to agree, RL-26 is awesome in my .260 AI. my load I settled on is the 147 with 49.5 grains going 3050ish, depending on temp, still zeroing in on temp variation, and my e.s. is around 10-15, and after 3 loads, primer pockets are still tight and no pressure signs. I really like this load, it's amazing for the .260 AI capacity. And so far, out to 900 yards the bc of the 147 is right on.

 

[5280yotes]

I do have to agree, RL-26 is awesome in my .260 AI. my load I settled on is the 147 with 49.5 grains going 3050ish, depending on temp, still zeroing in on temp variation, and my e.s. is around 10-15, and after 3 loads, primer pockets are still tight and no pressure signs. I really like this load, it's amazing for the .260 AI capacity. And so far, out to 900 yards the bc of the 147 is right on.

 

[Santiam338]

Thought I would update..Pretty much switched to RE 26 exclusively in my 260ai..I didn't go up in bullet weight though,but went down...Got some of the new 135 gr classic hunters in 6.5 and boy do they shoot..I think they just work better for me and my Rem 700 short action...

50 gr re 26 is getting me 3100 fps with the Bergers with excellent and consistent accuracy..It was the consistent that was giving me problems before... I was able to take two deer this year with the load..One was a bedded blacktail doe at 316 yards and she didn't get up...The other was a big bodied mule deer buck at 433 yards with the same results...

I embedded a short clip of the buck..They don't go down much harder than that.

Rem 700 short action

26" Shilen select match

6x SWFA Super Sniper

 

[Schnyd112]

Thought I would update..Pretty much switched to RE 26 exclusively in my 260ai..I didn't go up in bullet weight though,but went down...Got some of the new 135 gr classic hunters in 6.5 and boy do they shoot..I think they just work better for me and my Rem 700 short action...

50 gr re 26 is getting me 3100 fps with the Bergers with excellent and consistent accuracy..It was the consistent that was giving me problems before... I was able to take two deer this year with the load..One was a bedded blacktail doe at 316 yards and she didn't get up...The other was a big bodied mule deer buck at 433 yards with the same results...

I embedded a short clip of the buck..They don't go down much harder than that.

Rem 700 short action

26" Shilen select match

6x SWFA Super Sniper

Well played. I have some I am going to run in a 300 wm and my .260 now that hunting season is over.

 

[codyadams]

I ended up going back to the 140 Bergers with RL-26. After a couple humdred rounds with the 147's, I just wasnt seeing the consistency I get with the bergers. Too bad, that bc is fantastic. My current load is:

140 VLD
Lapua brass
CCI BR-2 primer
49.1 grains RL-26
2.900" OAL
3090 fps

I got them up to 3170 fps....that is where i saw max pressure. I ran them at 3115 for a while, then backed down to 3090 because they have a little lower e.s. and are stupid accurate. This year, that load accounted for 5 antelope and a 6 point bull elk, ranging from 340 yards to my 6 point elk, at 715. All of them were 1 shot kills....it's like a shoulder fired lightning bolt. Love it....

 

[MudRunner2005]

Varget or CFE-223