Both H & IMR 4350s have varied significantly over the years, but newer production Accurate 4350 is the 2nd slowest of all 4350s, beat in slowness very slightly only by Shooter's World 4350. It's actually much closer to IMR 4831 than it is to the other 4350s (except SW). Either judiciously add powder, watching for pressure signs, or get a more suitable propellant.
Low velocities with 6.5 Creedmoor
- Thread starter worrdogg
- Start date
Both H & IMR 4350s have varied significantly over the years, but newer production Accurate 4350 is the 2nd slowest of all 4350s, beat in slowness very slightly only by Shooter's World 4350. It's actually much closer to IMR 4831 than it is to the other 4350s (except SW). Either judiciously add powder, watching for pressure signs, or get a more suitable propellant.
AA4350 is much slower than H4350. Not even close to as slow as you're getting. You probably have a chrono issue
For lapua 6.5 creedmoor brass + 136 lapua scenars, this is what I get:
41.5 H4350 = 2800 FPS
41.6 AA4350 = 2630 FPS
42.86 AA4350 (all I could put in the case) = 2785
For lapua 6.5 creedmoor brass + 136 lapua scenars, this is what I get:
41.5 H4350 = 2800 FPS
41.6 AA4350 = 2630 FPS
42.86 AA4350 (all I could put in the case) = 2785
I think something is wrong with your chronograph. 2200fps is way too low for that load. I’m shooting 41.4g of H4350 with star line LRP brass and consistently getting 2830fps in 72F weather. Not the same powder you are using but should be very close.
Dave
Precisely. I’m getting 2830fps with 41.4g of H4350 in Starline LRP with Federal 210GM primers.
I was wondering about that on the full case with A4350, the 42.4 was getting close to optimum fill with seating a bullet
KMart
Gold $$ Contributor
What is your barrel length?
^^^^^^^^^^
Exactly, it is useless as a substitute for H4350 it is way too slow.
Ned Ludd
Silver $$ Contributor
For those that keep telling the OP to try another chronograph, he already tested commercial ammunition and the chronograph yielded velocities close to the box value (Post #18). The problem is likely not the chronograph. To the OP - I'd contact Accurate and see if they have any Lot-specific info on the powder.
I don’t know I think I’m going to get pretty close to the velocity needed for the 6.5 Creedmoor at 42.5 grains. The biggest plus is I have gotten 15 pounds of it at discounted prices. I hope it shoots like the Carolina load that people get with the 4831.
It all depends what you are looking for,
6.5 Creed, 43.5 gr of A4350 gave me 2750 FPS with a 140 except the load was compressed and seating depth consistency went to crap, so no point.
Same Rifle with 41.2 H4350 pushes a 140 at 2790 FPS and no seating issues, easy street.
25 Creed, 43.0 gr of A4350 gave me 2836 FPS with a 134 where with 41.6 gr of Reloder 17 has a 134 is running 2960 FPS.
No point in wasting my time with Accurate 4350 when other powders work much better for a particular cartridge.
My load "was" 42 grains of Reloder 16, BR2 primers and the 140 RDF
touching the lands. 2765 fps. No hint of pressure, easy bolt lift and a
good 1/2 MOA. My free bore was .205" and just a tad longer then SAMMI.
Jvance513
Gold $$ Contributor
That’s still slow you should be around 2800-2820 with 42grs and a 140.
That's a good free bore for the 130 gr bullets.
My 6.5CM load
Lapua SRP brass
CCI 450
140 ELD-M
CBTO 2.223 Jammed
H4350 (42.6 GR)
2853 FPS
No LRP won't help your problem, With the same charge weights i get more velocity using SRP brass and a 1.5mm flash hole over the LRP brass!
Jager
Gold $$ Contributor
A couple years ago I posted about a similar dilemma with markedly lower velocities than expected, using the very same AA4350 powder (https://forum.accurateshooter.com/threads/handloading-old-school-vs-new-school.4042201/).
It's a dilemma because if you take the chrono at its word and jump to the conclusion that the load manuals and QuickLoad or GRT or wherever else you got the load data are all wrong, and you still have lots of headroom to work with, you potentially are marching into the murky land of very high chamber pressures.
So validating the chrono results is absolutely the first thing you want to do.
But once you have confidence in that you can proceed, carefully, knowing that pressure = velocity. If you're truly seeing low muzzle velocities, with appropriate components and with comparable barrel lengths, you can reasonably assume you're also experiencing low chamber pressures.
In my example above from a couple years ago, I ended up extending the ladder considerably higher than "book." The issue ended up being a soft lot of AA4350.
It's a dilemma because if you take the chrono at its word and jump to the conclusion that the load manuals and QuickLoad or GRT or wherever else you got the load data are all wrong, and you still have lots of headroom to work with, you potentially are marching into the murky land of very high chamber pressures.
So validating the chrono results is absolutely the first thing you want to do.
But once you have confidence in that you can proceed, carefully, knowing that pressure = velocity. If you're truly seeing low muzzle velocities, with appropriate components and with comparable barrel lengths, you can reasonably assume you're also experiencing low chamber pressures.
In my example above from a couple years ago, I ended up extending the ladder considerably higher than "book." The issue ended up being a soft lot of AA4350.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.