260 Load Data with Mag Friendly COALs???

[Dutch260]

I’ve been scouring the other 260 Load Data threads on here and have noticed that most of the data here consists of loads with bullets seated way out towards the lands and that are considerably longer than what the run of the mill SA mag length will allow. Therefore, the limitations of the mag length leaving some (myself especially) with a considerable “jump” to the lands.

It would be great to see some load data related to shorter (< 2.840”) mag friendly COALs. Especially with the newer 6.5 projectiles we are seeing and with some of the new powders that have come out recently (RL-26).

I personally haven’t had much success yet in finding a winning combination of projectile/powder for my gun with the bit of load development I’ve done when loading to a COAL of 2.840” or less.

Setup:
Remington 700 5-R Gen 2 .260
24” Factory Barrel 1:8 Twist
Factory H&S Precision Stock (Pillar Bedded/Aluminium bedding block)

Tested Projectiles/Mag length resulting bullet “Jump”:
-127 Barnes LRX (.050 to Lands)
-129 Accubond LR (.075 to Lands)
-130 Berger AR Hybrid (.050 to Lands)
-130 Berger VLD Hunting (.095 to Lands)
-135 Berger Classic Hunter (.055 to Lands)
-143 Hornady ELD-x (.090 to Lands)

I haven’t given up on finding that perfect load yet and still have plenty of additional testing to do as I have not played with seating depths moving further away from the lands for shorter COALs. And I understand that every rifle is different and likes different things but I thought it would be good to hear from others with similar experiences/limitations who have found accurate loads when loading to mag length limited COALS resulting in considerable “jumps” to the lands.

Interested to see what others have found to be successful for them so let's hear it!

 

[the_accuser]

I've pretty much found any 139 - 142gr bullet with 42.0gr H4350 loaded at a COAL of 2.800" in my .260 will shoot sub moa easily.

 

[Dutch260]

UPS just delivered my two boxes of 139 scenars today so that is what I will try next. I've read and been told they are incredibly forgiving regarding seating depth.

Have you found any hunting bullets that have showed similar results or mainly just the scenars?

 

[XTREM HTR16]

43.5 H4350 with 130 VLD at 2.81 worked in my .260


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[Laseredge]

I've pretty much found any 139 - 142gr bullet with 42.0gr H4350 loaded at a COAL of 2.800" in my .260 will shoot sub moa easily.

My experience too. 139 Lapua Scenar, and 142 Sierra MK don't mind a a longish jump. The Lapua 144 FMJBT I have to load to 2.760" . They all shoot really well.

 

[sharac]

RL17 (RS60) - 42.8gr
140gr Hornady hpbt
2,835" coal
26" Lothar speed is 2850ish

RL17 - 42.5gr
136gr ScenarL
2.840 coal and speed is 2930

 

[the_accuser]

UPS just delivered my two boxes of 139 scenars today so that is what I will try next. I've read and been told they are incredibly forgiving regarding seating depth.

Have you found any hunting bullets that have showed similar results or mainly just the scenars?

One bullet I tested was the Hornady 140 ELD-M. You could probably get the same results with their 143 ELD-X.

 

[Dutch260]

One bullet I tested was the Hornady 140 ELD-M. You could probably get the same results with their 143 ELD-X.

I did do some load development testing with the 143 ELD-X & H4350 loaded to 2.830" COAL but I just couldn't get the velocities I was hoping for. My Quick Load data was showing I should have been getting close to 2750 at my max load and it is usually spot on but I was getting easily 100 fps less than what Quickload was telling me. I think the barrel only had around 120 rounds through it at that time so maybe I haven't realized that "barrel speed up" I've heard about.

However I've also got some 143s loaded up with some RL-26 ready to go I just need to find a calm day to hit the range and see what they'll do. The little bit of experience I've had with the RL-26 has been impressive velocity wise with the heavier boolits.

 

[Dutch260]

RL17 (RS60) - 42.8gr
140gr Hornady hpbt
2,835" coal
26" Lothar speed is 2850ish

RL17 - 42.5gr
136gr ScenarL
2.840 coal and speed is 2930

How do you like the RL-17?

I've got a pound of it but haven't gotten to test it much. Looks like it has the extra velocity factor too.

 

[sharac]

It really does i would estimate around 60-80fps easily. The max i went was with 130gr Norma (hBN coated) and i got 3090fps out of 28" barrel but this was probably already above max pressure (primer pockets lasted for 3 firings and then primers would leak) and i got no accuracy at these high levels. Now i load them with 42.8gr and get 2920 (26" barrel and 2,866" COAL a bit under max for my AICS mag) and get basically under .5MOA.

Big downside to this powder is its temperature sensitivity especially in the extremes (below 5°C and above 25°C) which prevents me to load xy amount of ammo and use it all year long. I use correction of around 3fps per degree C and load three loads summer load is 42.5 (above 25) and winter load is 43gr (below 5) and as said 42.8 in between.

 

[NovaHunter]

I have been using RL 17 alot in my 260 AI. Really like the powder.

My load is:
Powder: 44.2 RL 17
Case: fireformed Lapua
Bullet: 142 SMK
Primer: Federal GMM large rifle

My long range rig has a 28in Pac Nor 3-groove barrel on it. That load gives me 2980 FPS in 60 degree weather. Sub 0.4 MOA groups at 100 yards. This load is safe in my rifle, work up much lower as my AI has about 3.5% more capacity than the standard 260.

I've chrono'd the rounds on every 10 degrees from 50 to 80 degrees, and the change is pretty much exactly 1 fps increase/decrease for every 1 degree. Confirmed the 80 degree speed with my friends lab radar last weekend and it was spot on. I have this temperature sensativity data loaded into Strelok pro, and it automatically adjusts the speed based on the temp. Did my first PRS match last weekend as well. The first day was 50 degrees and rainy, 2nd day was 75 degrees and sunny. My app gave me consistent ballistics. I missed alot of targets for alot of reasons but didn't ever feel my vertical was one of those reasons.

Alot of people don't use RL 17 cause of the temp sensitivity. I like it so far, and I think I have enough data to account for that sensativity. The extra speed is great (100 fps more in my rifle compared to H4350). Additionally, since fewer people shoot it, I can find RL 17 MUCH easier than H4350.


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[zeroz]

142 smk
42.5 H-4350
cci-200
lapua brass
COAL 2.810
2666fps out of a 20"

 

[jambau]

I don't load anything that doesn't fit in it's intended rifle. I had a great load for my CTR when I was running the factory chassis and mag. When I dropped the action in the MDT chassis I discovered my loads were way too long for the MDT magazine. I started load development all over again and found another load at 2.790" COAL that shot just as well.

43.0 grains IMR-4451
Lapua 139gr. Scenar
Nosler cases (neck sized and turned)
CCI-200 Primer
COAL= 2.790"

 

[Ayoung1]

I don't load anything that doesn't fit in it's intended rifle. I had a great load for my CTR when I was running the factory chassis and mag. When I dropped the action in the MDT chassis I discovered my loads were way too long for the MDT magazine. I started load development all over again and found another load at 2.790" COAL that shot just as well.

43.0 grains IMR-4451
Lapua 139gr. Scenar
Nosler cases (neck sized and turned)
CCI-200 Primer
COAL= 2.790"

That is the main reason I want to keep the factory CTR mags, I'm looking at going with a Manners stock with the factory Tikka bottom metal. My rifle shoots .5 moa with .020 jump, my coal is 2.91. It shoots too good with this combo and the factory rifle to change anything.

 

[lash]

The 136g Lapua Scenar L loaded anywhere from SAMMI 2.80-2.84" CAOL are a pretty forgiving load using 42g H4350. We've shot them in all sorts of bolt and gas guns like this, using Federal 210 primers and always sub-MOA. If you want to tweak the load/length for your barrel, it should be no problem getting them much tighter. Mild enough load too, around 2750-2800 depending upon many variables, including barrel speed, chamber dimensions and free-bore.

Of course, I shouldn't be telling you this as it's not that popular a projectile what with all the higher BC latest whiz-bang bullets now out. That means that I can get them any time that I want with no trouble. Never had a problem getting them to consistently hit exactly where I want them to be out to 1200 yards. That is the limit of our normally available range and therefore as far as I've taken them. Shot literally thousands of them over the years and have seen no good reason to change yet.

 

[BoltRunner]

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Here is 2 separate 5 shot groups at 300yds with 2 separate 260's I shoot bottom target has a flyer on my part, both were shot off a bipod and rear bag only, both are mag fed AICS steel or Magpul AICS mags where about 2.855 they start to hit the mag and thats about as long as you can go. I load them 2.850 with Lapua and Remington Brass, Berger 140 hybrids, and I run IMR 4350. These particular groups were with 40.5g of IMR4350 and they chrono 2,650 FPS on average with less powder than H4350 takes me to get that speed. I know everyone and their dog run H4350 and im not saying IMR is better just my particular rifles seem to like it better, both of my rifles are 8.5 twist 24", one is Bartlein one is Benchmark and cant tell much difference between them. I can get over 2,900FPS with 140 Berger Hybrids pretty easy without seeing pressure signs, I just don't load that hot unless im really trying to get way out there. Hope that helps...

 

[wapiti16b]

I can't speak as to coal but a friend that competes swears by 4831SC , thought I'd list it since I didn't see it mentioned . I will follow this post as I'm torn between 260REM & 6.5CM for a re-barrel !