Inaccurate powder charge Dillon 650XL 300 blackout

[bigwakes]

Need some help with my powder load issues. I'm loading 300 blackout 175 grain pulled bullets from David. The bullets weigh consistently 174-176 grains. I'm loading them as subsonic Plinkers trying to hit 1000 fps in my 9" AR so it will stay subsonic in my 16" Remington 700.

The issue is I chrono'd about 40 rounds and they were 960-1050 with one as high as 1500 and one as low as 750 with 10.8 grains of AA1680. One thing I'm going to do this week is cut the bearing spring for the auto indexing wheel to stop the indexing jump. I have noticed losing powder because of it. That doesn't explain the flier at 1500 fps. I only had one, but seems that a 100fps swing for the average would be a little much.

I have been reloading in small batches so I have not filled up the powder measure more then a couple inches of powder. Could that be causing inconsistent powder measurements? I do have some inconsistencies in the powder measure when testing random rounds. Could be as much as .2 grains off with a Hornady digital powder scale.

Any words of wisdom? I'm using the AK powder funnel.

[Hershmeister]

Inconsistent powder throws often are a result of not holding for a few seconds at the bottom of a full handle pull.

It may sound silly, but check to be sure that you're pulling the handle all the way down and ensuring all the powder drops.

[Photoguy67]

Is this a new press? I have seen a situation like this with a new press and I found clumps of powder sticking to the charge bar. Just a thought and maybe worth looking at.

[bigwakes]

Inconsistent powder throws often are a result of not holding for a few seconds at the bottom of a full handle pull.It may sound silly, but check to be sure that you're pulling the handle all the way down and ensuring all the powder drops.

Will give that a try.

Is this a new press? I have seen a situation like this with a new press and I found clumps of powder sticking to the charge bar. Just a thought and maybe worth looking at.

I bought it new about 8 months ago, but have just now gotten a chronograph to figure out why some of my subsonics run super sonic. I have only loaded about 300 rounds on it since I had a move across the state in those 8 months.

[Dolomite_supafly]

Try a different powder. I used A1680 in the begining as well, because everyone said to use it, and had some pretty miserable results. I would hand weigh each charge and I was having the velocities vary by over 100 FPS with subsonic loads. There are also a lot of rumors about AA powders not being very consistent from lot to lot. I gave up on A1680 when I seen a lot of posts about people having miserable accuracy when using it as well.

 

I have tried every single powder that is recommended as well as some that are not and the best I have found is Lil'Gun. I would start out at 10 grains of Lil'Gun then adjust up or down depending on where you fall in your FPS. I am shooting cast bullets that are hitting within a few inches of each other out to 150 yards using Lil'Gun. With A1680 I was lucky to get 2" groups at 50 yards. H110, H4227 are better than A1680 as well. Not sure if you are shooting through a can but Lil'Gun, H4227 and H110 will all be quieter than A1680.

 

1,000 FPS in a 9" gun may not remain subsonic in a 16" bolt gun. I would load to high subsonic in your bolt gun then see if they will cycle your AR.

[bigwakes]

That's too bad since I just got ahold of an 8 pound jug of aa1680. I have a few pounds of H110 to experiment with, but will start looking for Lilgun. I have a YHM Phantom QD 7.62 and definitely want to get them as quiet as possible.
That's a good idea to load to the 16" and then chrono in the ar. I have a CMMG and a PSA 16" ARs in 300 as well. I doubt they will cycle subs with these bullets though.

I have been looking at casting in the near future and just started the paperwork for a Liberty Mystic to shoot cast subs.

[Dolomite_supafly]

Before buying Lil'Gun I would try the H110.

 

The AR's with pistol length gas system should cycle fine. Carbine length gas system will never cycle with the lighter bullets at subsonic velocities.

[mikegideon]

H110 works real well in my supersonic loads. I haven't shot them over my chrony yet.

[R_Bert]

out of curiosity, do you have a baffle in the powder drop ?

 

I also leave a Downy sheet in my hopper, helps with static attraction .

[Dolomite_supafly]

I ALWAYS have a baffle. I found that single item reduced my variation more than anything else.

[bigwakes]

Does Dillon make the baffle or another company?

[Guest Lester Weevils]

I try to keep the powder measure more than half full (but dunno nothin about 300 blackout).

 

Also, after every full downstroke, I "tug" on the handle once or twice, hard enough to rattle the reloading machine and shake the powder a bit. Dunno if that makes any difference, but the idea is to encourage each entire load to shake loose and drop.

Edited May 12, 2013 by Lester Weevils

[bigwakes]

I try to keep the powder measure more than half full (but dunno nothin about 300 blackout).
 
Also, after every full downstroke, I "tug" on the handle once or twice, hard enough to rattle the reloading machine and shake the powder a bit. Dunno if that makes any difference, but the idea is to encourage each entire load to shake loose and drop.

I saw a guy on YouTube put an aquarium bubble maker on the powder to constantly vibrate the powder while reloading.

[ToysRUs]

The baffle I use is from UniqueTek. I mades a big difference.

Have you also put the bearing kit on your shell plate. Really smooths out the indexing.

http://www.uniquetek.com/site/696296/page/45029

[R_Bert]

I saw a guy on YouTube put an aquarium bubble maker on the powder to constantly vibrate the powder while reloading.

 

Nobody commented on this yet, but my gut reaction is bad idea.  The powder drop systems are designed for safe handling of powder, and depending depending on how this concept is implemented, bypasses several safety principles.  Induced static charges and airflow are not your friends in this system.

Edited May 13, 2013 by R_Bert

[Guest sbcman]

I had the same problem with a new 550. I noticed on the charge bar that there was a lot of play between the adjustment nut and the bar. The washer between the two was letting things move too much, so I put a small spring there to keep tension. Fixed it right up.