IMR 4064

[markm]

4. 6.5 creedmoor has proven to be a little tricky for me to work up loads. I think I read that Markm had the same sentiment.

ABSOLUTELY!! And when I get a successful load, the next weekend it's barely MOA. To your velocity issue... do you see the chance to go over published max safely??

I say this because I've had batches of 4064 (as mentioned) where the velocity changes dramatically.

[archad]

I have 6.5 Sig Cross. 1st time loading I had sig new 6.5cm brass and 8208 and 107 SMKs from loadind for my 6.5 Grendel. I had sd of 19 and average velocity was 2935 and sub moa

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[archad]

Results

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[Krazykarl]

Markm,

Thank you for the reminder, yes there is still some room left to experiment with using IMR 4064 and 123 SST. I went as high as 38.0 gr. It measured 2608 fps but precision suffered opening to 2.0 inches. My digested recipe sources are:

1. 35.0 min - 38.0 max = 2882 fps
2. 36.0 min - 39.0 max = 2900 fps
3. 36.2 min - 39.2 max
4. 38.5 max

Maybe this week I can get back out and try a few more. But, if the precision does not improve from the trending 2.0", there is no point.

As far as the IMR 4350, I will repeat the 44.0 grain load using the 123 gr bullet. With the well documented temperature sensitivity of this powder, I really don't want to try for the published 44.4 maximum charge.

[turnburglar]

Can someone post any links to documented IMR4350 temperature stability?


I have been shooting a bit of it and I feel like I notice my DOPE change even when its a 10-15* difference.

It's getting to the point where I want a different powder. Anyone know if BLC2 or Staball 6.5 is actually stable? I just want predictable dope. I need to know my misses are marksmanship.

[Krazykarl]

https://www.handloadermagazine.com/r...re-sensitivity

[markm]

Maybe this week I can get back out and try a few more. But, if the precision does not improve from the trending 2.0", there is no point.

No joke. One of Pappabear's Bergara 6.5s shot a 3 inch group with a load of 150 Sierras last week. I was like... this gun is effed up.... then we tried a different load of 140 ELDs and it shot 1/2 MOA. Some barrels just refuse to like certain combinations of components no matter how good they look on paper.

[Krazykarl]

Went to the range yesterday for some more testing. It was not fun. I was the only one out there with the RO. 10 above with an unknown wind chill. Cold enough that my ohler required a fresh battery rather than a good used battery to measure velocity. Always have a fresh battery....

The take away notes:

1. Like Markm, I duplicated my IMR 4350 load of 44.0 gr with 123 SST. 2693 fps first day and 2688 fps yesterday. 1.0 inch group first day miserable 2.0 inch yesterday. Fickle...

2. I can safely push the velocity with 39.0 gr IMR 4064 and 123 SST. 2730 fps from the 18" bbl. But group size was 1.2".

3. Interesting velocity nodes exist with my 18" bbl 6.5 creedmoor shooting 123 SST. For this rifle to be 1 MOA or better, keep the velocity between 2594 and 2693:
A) IMR 4350 = 2693
B) Varget = 2673
C) IMR 4064 = 2594

In the 142gr bullet I found a much more narrow node from 2403 to 2461 fps:
A) IMR 4350= 2403
B) Varget= 2418
C) IMR 4064= 2461 day 1.
D) IMR 4064= 2418 day 2.

Any velocity for the 123gr SST higher than above produced a rifle that is no better than 1.2 MOA. For the 142 SMK, anything higher than above produced a 2 MOA rifle.

The take away? My rifle likes the 123 SST the best in the 2650 fps range. Reminds me of my 762 Nato M21, keep the 168 bullets in the 2550 fps for best precision.

[markm]

I was working on my oldest lot (4 or 5 years old) of 4064 with 69gr RMRs in .223/5.56. Max load shows compressed at 24.0 grains. I started there and didn't notice much compression/crunch, and the velocity was only in the low 2800s out of a bolt gun 20". I bumped it up to 24.3 gr, and I was getting a little crunch on bullet seating. The velocities were still just mid 2800s but the brass looks to be starting to show some light swiping.

It doesn't seem that 4064 is optimal for getting velocity out of .223. At least in this lot and with my sample of one.

[grizzman]

I’ve used quite a few different powders in .223, but never had any desire to try 4064. It works great for my .22-250 and 30-06 M1 load.