Surprising results, 6.5CM / 147ELDM / H1000

[XLR308]

You speed demons can go ahead and tune out now this isnt one of those posts.
I went to the range today to put some rounds on two new barrels.
One is a Schneider 1-8 in 6.5x47 lapua and the one in question is a Bartlien M24 profile 1-7.5" twist chambered in 6.5CM with .198" FB finished at 23".
Just out of curiosity i loaded 10 rounds with H1000 and the 147ELDM at .018" of the lands in new lapua brass that was neck turned to 85-95% clean up.
The charge weight range was from 44.0 to 45.8 grains and started at a very mild 2460fps and ended at a still very mild 2534 fps.
Now the surprising part atleast for me anyway since these are the first two 6.5 caliber cartridges I have ever owned.
I have read many posts from people stating that the Magneeto Speed jacks up groups when attached but the first seven rounds went into a .293" group and I had a distinct second group once the velocity went over 2500fps that the remaining three rounds went into a .175" cluster that was .5" away only high and right.
So my question to those of you running the 65CM and the 147eldm is it normal to have such a wide accuracy node on the low end or is it maybe a consequence of the short stiff profile barrel I'm running with a slightly faster twist that's aiding with the accuracy I'm seeing ?
I shot a full work up with H4350 before hand but I was seeing two distinct groups in many of my charge weights which I attribute to me being out of form from not shooting near enough and the rifle needing an adjustable cheek rest since its on the low side to be optimal
Regardless of that it was averaging .625" - .5" five shot groups even though they were in distinct separate groups for five shots each.
Any input would be appreciated but I think I may still explore that lower node.

 

[MikeMcCasland]

A couple of thoughts...

1.) I've had lots of luck with 'slower' powders in .260 and 6.5CM. H1000 shot amazingly well in my .260s, albeit too slow a powder for optimal velocities. The same can be said for H4831sc in the 6.5CM; it's about 100 FPS slower than H4350, but the accuracy is tighter, and the SDs are lower (fill ratio most likely).

2.) Magneto Speeds do affect groups and POI; the extent to which depends on several different variables (barrel contour, factory vs. aftermarket (stress relief), barrel length etc.). Even though you're running a shorter/heavier tube, I still wouldn't do load dev with one attached. Think of them as a barrel tuner that is never attached in a repeatable/consistent position. As far as how they affect groups, I've had them make groups better, and I've had them make groups worse...the problem is in the field you won't be running around with an MS.


3.) The 147ELDM is a good bullet in my experience; I've shot 4-5 thousand so far, and they've been surprisingly very consistent lot-to-lot, and they have great BCs. That said, I wouldn't be shooting them if I wasn't pushing them at least 2650+. The whole point to them is their high BC to cost ratio, that and they're on the edge of what an 8 twist will stabilize. If you're informally plinking on steel or shooting short range stuff, then keep on doing what you're doing; if you're planning to shoot matches, you need to be pushing them harder to realize their real advantages.

 

[XLR308]

That's kind of what I figured just haven't heard or seen much data on them thats run through a faster than 1-8 twist.
I am just at the point of getting some rounds down the new barrel and getting some once fired brass to work with so really no telling were I will end up at.
I've never really been much of a speed demon with anything unless that's were I saw the most gain and accuracy first.
I'm guessing I won't notice much of anything by pushing these past the 2650 mark but will have to see were they settle in and if I see consistent accuracy in the. 250" range at or below 2600fps I will most likely stay there.
This caliber is new to me and don't see myself deviating from what has allways performed for me in all most all other chambering I've used.
I'm thinking if I want more speed and performance I could possibly have a barrel spun up in the 6x47 or 6mm Creedmoor variety just need to burn up the 1-8" 243win barrel I'm running now.

 

[MikeMcCasland]

I think it really just depends on what you're doing. If you're shooting for tight groups at 100, then it doesn't matter at all...push em at 1700fps.

If you start shooting at longer ranges (really out past 700) that's when speed really becomes a bigger factor. I do agree though, too many people go nuts for velocity.

 

[Steel head]

If I was to go that route I’d use H4831SC instead of H1000

 

[XLR308]

I think it really just depends on what you're doing. If you're shooting for tight groups at 100, then it doesn't matter at all...push em at 1700fps.

If you start shooting at longer ranges (really out past 700) that's when speed really becomes a bigger factor. I do agree though, too many people go nuts for velocity.

After comparing the ballistic data of my very mild velocity of the H1000 initial ladder to were I was originally thinking I would top out once I am done at around 2650fps with the 147eldm it's only a .8 mil difference at 1000 yards so not really a concern at 700 and beyond since I know it will easily exceed that mark.
This barrel is shorter than what most are running from the recoil lug to the muzzle it measures 22.25" but I don't think that is really a handicap since I had no intentions of all out speed to begin with or I would have gone with a 27-30" barrel.
Just to use as a baseline for comparison I ran two different types of factory ammo over the Magneeto Speed at the end of the day yesterday to see were this barrel compares to listed box velocity to actual on a shorter barrel than what is generally used.
The Norma match 130 grain averaged 2910fps so was an average of 60fps faster than listed from a shorter barrel but this barrel only has 75 rounds through it now and may speed up a little but I'm happy with it so far.
If I can get H1000 to run the 147 in the 2650fps range and it still hold accuracy around .250" I will stay with it as it definitely seemed to burn cooler and the barrel wasn't heating as rapidly over a ten shot string compared to the H4350 loads I was testing though I'm sure some of that was due to the velocity gap between the two.
I really need to send the stock off to @jducos to have the adjustable cheek rest done since I'm sure that would help with the issue of seeing two distinct groups from not having a consistent cheek weld.

 

[XLR308]

If I was to go that route I’d use H4831SC instead of H1000

I will have to dig through my powder stash to see if I have any H4831 left and run a ladder with it.
I also plan on running another 10 shot ladder with H1000 in the once fired Lapua brass but will run from 46.0 to 47.8 to see were it tops out and determine if it's even worth messing with anymore.
The remaining 150 pieces of new Lapua brass I think I will just fire form with H1000 and the 147 around the 2540fps mark but will stretch them out to 1000 yards or more to see if it holds similar accuracy at distance as a mild plinking load to form the new brass.

 

[Juggerxxx]

I’m glad you posted your results with H1000 as I had posted a question last week about using Retumbo with the 147gr ELD. As far as I can tell, H1000, RL26 and Retumbo have similar burn rates with Retumbo being the slowest. Densities and case fill will be different from those powders. I have some Retumbo loaded up with the 147eld and plan on testing it this weekend.

I have gotten excellent results with RL26 and the 147eld. I have a lot of data with it but to answer your question about group size for a larger charge range; below is what I found to also be a nice group for a slower powder over a large charge range. Maybe not as good as what you experienced but similarities that might suggest more flexibility for slower burning powders.

 

[XLR308]

Those are some impressive velocities and a nice group considering the velocity span.
I'm thinking that were I stopped with the first 10 shot ladder should have been my starting point but considering it was new brass and I had no published data I was kind of playing it safe.
I recently saw a one pound canister of RL-26 on the shelf at a local store but passed since its the only one I've ever seen anywhere and didn't want to work up a load with a basically non existent powder.
I had some very promising results with H4350 as well but didn't chrono any of them just shot some groups.
The wind conditions were less than optimal with 12-18 mph right to left but swirling due to shooting between two berms but the temps were in the mid 90's so feel confident in all of the upper charge weights I ran up to.

 

[russkim04]

I will have to dig through my powder stash to see if I have any H4831 left and run a ladder with it.
I also plan on running another 10 shot ladder with H1000 in the once fired Lapua brass but will run from 46.0 to 47.8 to see were it tops out and determine if it's even worth messing with anymore.
The remaining 150 pieces of new Lapua brass I think I will just fire form with H1000 and the 147 around the 2540fps mark but will stretch them out to 1000 yards or more to see if it holds similar accuracy at distance as a mild plinking load to form the new brass.

Did you test h1000 with the hornady 147? With my brass i can get 47.5 grains in my casings. I have an old jug from the 1990 that's almost empty- but still curious if it gives similar results as rl26. Ty