Accurate 4350: Low Velocities

[Huntfly]

I've got 2lbs of Accurate 4350 I picked up in April brand new from Midway.
I've loaded this powder in 6.5 Creedmoor and .270.

In the 6.5 Creedmoor I barely made it to 2600 FPS in a 24" barrel Tikka with 143 grain ELD-X.

Today in a 22" barrel Tikka .270 best I could get was 2750 FPS with a 130 grain Interlock at 55.5 grains. I was right on the edge of pressure signs.

SD and ES numbers were acceptable but this powder is awful for velocity. Did I get a bad batch?

Did you notice how dirty it was. I quit using it.

 

[General RE LEE]

Did you notice how dirty it was. I quit using it.

No I didn't but I will check next time.

 

[General RE LEE]

Accurate 4350 is nowhere close to H4350. That's your problem. IMR 4350 and H4350 are almost identical.

But H4350 is a burn rate of about .51 compared to way slow Accurate 4350 at .38 ish

Accurate 4350 is not at all in the same burn rate class as IMR 4350 and H4350

One thing I failed to mention when I started this post is Western Powders has data on the .270 for this powder and I'm coming in 250 FPS lower in velocity. Granted I am shooting a barrel 2" shorter than the test barrel but my results were nowhere near the load data. I'm not convinced this lot was a dud.

2764 FPS vs data attached below:

 

[Tagnbagem]

Just for reference, I get 3000 FPS using Berger 130 and 60 gr of RL 26, win cases, fed LGR primers. Just for reference. Case capacity makes difference.

 

[baldhunter]

You can send an email to Western Powders and let them know about your issues.Other people may have had those issues with that lot of powder too.I have been shooting Accurate 4350 for about ten years and have found it to be very consistent,even after changing from Accurate Arms to Accurate.I do know barrels make a difference,they are all different.I also know that chronographs can have issues too.What chronograph are you using? I ran into a chronograph issue at the range one morning.The range is setup shooting to the East.As the sun would rise it would change how the bullet was seen as it crossed over the eyes.I would sometimes see a 100fps difference in one hour.It only has to be off just a fraction of an inch to give you some wild readings.Went to a different range shooting to the North.The velocities are consistent during the range session and repeatable on different trips.I shoot over a ProChrono as well as a Magnetospeed.I have compared the two and my readings are very close to each other.

 

[Veteran]

One thing I failed to mention when I started this post is Western Powders has data on the .270 for this powder and I'm coming in 250 FPS lower in velocity. Granted I am shooting a barrel 2" shorter than the test barrel but my results were nowhere near the load data. I'm not convinced this lot was a dud.

2764 FPS vs data attached below:

Yes, your batch could be a dud. Lot to Lot, powder burn rate can vary 5-10% or it could be humidity and if you live in the southeast this could really be pronounced.

How does humidity affect powder?

You may have heard about a relationship between humidity and bullet velocity either in a book, on a reloading forum, or from a crusty benchrest shooter right after saying they get better ES/SD&#821…

chronoplotter.com

I also agree with Tagenbagem, if you are shooting different brass maybe than you've used in the past, take some of your fired brass and measure by weight the brass dry, and then filled to capacity with H20. Then repeat the same test with your old brass.
Even a slight difference in the volume of your brass will cause a big difference in velocities too, for the same charge weight and powder.

So check humidity, check brass, and maybe its just a dud batch at the end of the day. All are possible.

 

[General RE LEE]

Thank you

 

[Mike Matteson]

Accurate 4350 is nowhere close to H4350. That's your problem. IMR 4350 and H4350 are almost identical.

But H4350 is a burn rate of about .51 compared to way slow Accurate 4350 at .38 ish

Accurate 4350 is not at all in the same burn rate class as IMR 4350 and H4350

IMR 4350 isn't the same as H4350. IMR 4350 is very heat sensitive. The H 4350 is a very Stable powder. So depending on the weather or Temperature you hunt in, be careful with IMR powders.

 

[Huntfly]

IMR 4350 isn't the same as H4350. IMR 4350 is very heat sensitive. The H 4350 is a very Stable powder. So depending on the weather or Temperature you hunt in, be careful with IMR powders.

A 4350 is also very dirty too.

 

[Veteran]

Yes, although the burn rates are very close for IMR 4350 and H4350
the H4350 is an extreme powder by Hodgdon, so its a lot less temp. sensitive than IMR 4350

In the IMRs you have to go to the Enduron line up to get any claim of
temperature insensitivity.

Has anyone compared Enduron powders vs. Hodgdon Extremes for temp sensitivity? How do they compare?

 

[Huntfly]

Yes, although the burn rates are very close for IMR 4350 and H4350
the H4350 is an extreme powder by Hodgdon, so its a lot less temp. sensitive than IMR 4350

In the IMRs you have to go to the Enduron line up to get any claim of
temperature insensitivity.

Has anyone compared Enduron powders vs. Hodgdon Extremes for temp sensitivity? How do they compare?

Good luck finding any!

 

[Swinehunt74]

Hi there. I've been hanging around for about a year or so. Have had lots of questions, but finally decided to ask about one. I just started, like a lot of people, reloading last year just before the pandemic hit. Fortunately, I've been able to accumulate a decent supply of components, including a4350. Like several others it appeared to be closer to H4350 than what people are discovering. So, my question is whether using magnum primers rather that standard would help bring up the velocities, or would it cause pressure problems? Thanks for any answers and/or suggestions. Cheers! BTW - the rifle is a Remington 700 BDl 30-06 I purchased in '65.

57-59 gr A4350 behind 165-180 bullets is all i've shot in ''06 last 40 yrs. Too many animals to list have succumbed to this combo......Probably 5 different 3006's. Load it and good skill is all that's required to accomplish the mission.

 

[Jr600yd]

What he said! ^^^^^^^^

 

[Fedwell]

I

Well that stinks. A4350 advertised like another "4350" but it's too slow I guess. SD and ES numbers along with accuracy were good.

I might try IMR4451 in the 270.

have had the same problem finding H4350 so i bought a couple of pounds of A4350. It works really good in my 25-06. Working on a ladder test with 75gr. Hammer Hunters I am getting 3800fps . using standard LR primers.