what powders are you using?

[320pf]

Originally Posted by charles357

Anyone shooting subsonic loads need to try Accura 5744. The powder is the least position sensitive of any powder I have used. I put 10.7 grains behind Sierra 220gr. Sierra match bthp. This load has killed many deer. I have set up guns for local game management personnel and they have all been pleased with results. Shooting in hot summer I have found I need to drop load .5-1.0 grains because about 20% of loaded ammo cracks. I have used 240 gr. Sierra but the accuracy was not as good, but since I have a bunch of these bullets I am going back and try them again.

Charles357,

Thank for the heads up on AA#5744. I have shot AA#9 and I really like the powder. With AA#9 the velocities almost always have small standard deviations and the loads usually shoot tight groups. So I would like a bit more information on AA#5744. I am seriously thinking about trying it.

Since this is not one of the usual 300-221 Fireball powders can you tell a bit about it? For example is it a single base, ball or flake, and how course are the grains say compared to H110 or W296

Have you tried AA#5744 for super sonic loads.

Thanks,

320pf

P.S. you might want to try AA#9 with those 240 gr Sierra's if you can not get that particular bullet to work with AA#5744

[kurtz]

went to the range today to shoot a couple loads.....24" 1:11 CZ527

H110 20gr Sierra 110gr HP 2650fps
H110 20gr Speer 125gr TNT 2520fps
H110 20gr Hornady 110gr VMAX 2670fps

IMR3031 18gr Hornady 110gr VMAX 1550fps (just a comparison load)

no signs of high pressure, bolt lifts easy, primer looks good.....

83 degrees, 80 % humidity, sea-level +6......

kurtz

[320pf]

Kurtz,

Intresting data! I have load data for H110 and Speer TNT from both a 16-inch and 20-inch AR platform:

300-221 fireball AR15 16-inch 1:8 twist
1) H110 20gr Speer 125gr TNT 2290fps*
2) H110 20gr Speer 125gr TNT 2332fps**

300-221 fireball AR15 20-inch 1:10 twist
1) H110 20gr Speer 125gr TNT 2420fps (~75-80 deg F)

* these data were obtained in Feb-07 at an indoor range temp 60-65 deg F
** these data were obtained in May-07 at an outdoor range temp 70-75 deg F

16-inch = ~2300fps
20-inch = ~2400fps
24-inch = ~2500fps

With the caveat that these data are from different barrels and different actions obtained under different weather conditions; It looks like there is an increase of ~20-25fps/inch of barrel. This is a bit more than I would have expected, but not too crazy.

I could not fit much more powder (H110) into the cases. Different bullets and powders might give you a bit more or less but unless some new wonder powder comes along, I would say that for 125gr bullets... this is about the most one can get from the 300-221 Fireball.

What do you think?

320pf

[lemmethink]

Sorry I don't have all the details but I started shooting the 300/221 last winter when I lived in Alaska. I was using 2400, velocities of various loads were somewhere in the range of 900 and 1150fps with a SMK 220gr. It was quite cold, 15F degrees. I was amazed at how each different load would move up or down vertically but would group 10 shots in less than 3/4 inch at 100yds.

Since then I have moved to Nevada and with the 2400 at 95F to 100+F degrees I get lots of variation in velocities resulting in some big vertically stringing groups. I'm talking maybe up to 8 inches and more from top to bottom.

I started working on some loads using AA#9 and my groups have tightened up nicely. If it weren't for the occasional flyer the AA#9 groups at desert temps would be just about as good as the 2400 at cold temps. I am still trying to sort out the flyer issue but I am much happier under these conditions using the AA#9.

Anyone else notice big changes with temperature, or better yet not notice much change at all with a particular powder?

Regards-
David

[kurtz]

320pf

I think the 20 to 25fps per inch of barrel is right on the mark.....I have an old old old article from a guns and ammo or sports afield or something concerning barrel length....the test started out with a .30-06 and 400 rounds of ammo...they cut the barrel off in one inch increments down to 10 inches (article was probably done way before NFA SBR laws)....for each inch of barrel removed they would shoot 20 rounds of ammo and take the average....don't remember what method they used to chrony the rounds....the published info showed an average of 20 fps difference per inch....neat old article....

I agree that 20gr of H110 is pretty close to max volume in the 300-221....I wanted to make sure I didn't have any pressure problems with the 125's at 20gr then I was going to creep the powder level up into the neck a little more, maybe 20.2 or 20.3 grains....but I'm not sure if the little bit of velocity increase would out-weigh the possible pressure problems....2500fps was really the target velocity I was trying for with the 125's and I hit it with 20gr of H110....



lemmethink

I have not had a chance to use AA#9 yet but it is on my short list of powders to try, I know other members have had really good luck with it....let us know how it goes....

The Accurate 1680 seems to be pretty temp stable in my super- sonic loads (40 to 90 degrees) but the velocity is a little lower than say H110...

[gary0529]

Does anyone have any additional information re: Accurate Arms powders for the 300 Whisper?
I have been loading AA #7 @ 7.8 gr. w/ 220 gr.Sierra HPBT Match bullets and the accuracy is spotty, always seems to be a flier or two in a 5 shot grouping. These chrono at 1025 +/- 15 fps at 82 degrees over an Oehler chronograph.
Gun is rock solid heavy barrel(Lilja) 1:8 twist, bedded and is quite capable of one hole groups with the right combo.

Have also tried IMR 4227, Blue Dot, and H-110 with less than stellar results.

Will throw this one out to the forum.
Thanks in advance.
Gary

[320pf]

Gary

Try this URL. If you going to try these loads in an ARa5, AA#5 and AA#7 are too fast and may not cycle the action.

I recently tried 8.5 gr of 2400 with good results. The velocitiy was 1040 fps ±38 fps but the groups were about 1/2 inch at 25 yrds with open/iron site... so I would guess that this load would shoot about 1 inch with a scope at 100 yrds. This load cycled the AR action... bolt stayed open on last round.

http://www.accuratepowder.com/data/P...0page%2076.pdf

320pf

[kurtz]

went to the range today to shoot a couple loads.....24" 1:11 CZ527 300-221

19.0gr Accurate 1680 Barnes 130 Triple-Shock X-Bullets 2060fps
19.5gr Accurate 1680 Barnes 130 Triple-Shock X-Bullets 2110fps

no signs of high pressure, bolt lifts easy, primer looks good.....can fit a little more in the case.....

The accuracy/grouping I have had with the Barnes bullets is OK, a little over 1 MOA, still experimenting with distance to lands....the Speer and Sierra bullets that I have used produce tighter groups to this point, less than 1/2 MOA but are 125gr....

was wanting to try the 130 X-Bullets as a 100 to 150 yard small body white tail round, any experience out there?

78 degrees, 80 % humidity, sea-level +6......

kurtz

[21contender]

has anyone tried 180-200 gr. lead bullets with trail boss powder for sub sonic loads? I have a ssk 21" contender barrel with 1-8 twist. seems like you should be able to just about fill the case with powder and still be sub sonic.

21c