What am I doing wrong?

[Maverick1911]

I am reloading for .223 I use H335 22.5 grains with a 69 grain sierra hpbt....my 3 shot group at 100 was good so that's what I use....I have never used a chronograph but another thread was telling about the necessity of one for accurate loads. I am shooting from a "custom" AR 15 with a 20" stainless varmint Hart barrel, 1:7 twist that was matched to my bolt. I ask because I am trying to get my dopes out to 600 yards and am slightly frustrated....not sure if my bullets are sporadic because I'm still new to the long range scoped rifle game or if my bullet is not the best for my particular rifle? One can go nuts trying to figure out what the issue might be! I am not sure if it's the powder or just that my rifle doesn't like the round or powder charge, etc.? The rounds are made on my hornady lock n load and I have had no issues with the rounds themselves as far as function, etc. How do I hammer out a way to fix this so I know it's me and not my bullet, powder, etc.? I liked the 69 grain projectile because it gives me a good overall weight and I can use it in my other 3 ar's without being too heavy for the ar with a 1:9 twist. If a Chrony is the way...can someone tell me how to use it and what I should be looking for? Or am i missing something else..?

 

[ASP785]

What symptoms are you seeing that indicate a problem to you? A chronograph may not be necessary, but a 3 shot 100 yard group is simply not going to be an indicator of performance at 600 yards.

 

[Maverick1911]

My rounds are just hitting all over the place. I can't pattern a tight group or consistently establish a dope based on the data.....rounds are hitting high and low. Now. It could be me but geez....at 200 yards I shouldn't have an issue. All the powder drops are on the money as is the coal, etc. I did notice that I had to set my dope at 2 moa from 200 yards at I believe 5 moa at 300....seems like quite a drop, no?

 

[ASP785]

If we assume 2750 fps or so then no, your drop doesn't seem that odd.

What about crimping? Are you crimping your rounds?

 

[Maverick1911]

I am using a redding taper crimp...barely kissing the round...

 

[ASP785]

Here's the reason I ask, powder charge is but a small part in reloading accuracy. Neck tension and primer pocket uniformity play as big or bigger part in the accuracy of reloaded rounds as the powder charge. Crimping can affect the neck tension and thus the velocity of your reloaded rounds. Sometimes if there is not proper neck tension, the bullets may set back in the cartridge when they are chambered and then velocity will be all over the board. COAL should actually vary if measured from the cartridge head to the tip of the bullet. If you measure from the case head to the bullet's ogive, the distance between loaded rounds here should be about .001" or so with quality bullets (SMK). A chronograph will help you narrow down whether the problem is with your rounds or with your gear. If your rounds are consistently shooting a narrow velocity and your ES and SD are fairly tight, that gives you an indicator that the problem is elsewhere. Interestedly though, just because you find a round with a small ES and SD, that doesnt instantly indicate that it will be accurate. Without some more data, which a chronograph could provide, everything is just a guess.

 

[dennishoddy]

With a 1-7, try a heavier bullet.

 

[Maverick1911]

I wa thinking the heavier bullet but was hoping that wasn't necessary being I only wanted to load 1 round for my ar's. The others are just carbines.....but could that be the issue?

 

[Driller]

I've got several carbines and one AR that I wanted to be a tack driver. It has shown a strong tendency to prefer one particular bullet and powder combination over others (77gr. SMK with 24 grains Varget, match prepped brass).

As others have said, a chronograph will help sort it out as far as eliminating varying velocities in your load.

Can you accurately subtend your targets at 200 yards and beyond? If you are shooting at 1" round dots or squares, can you divide the target into four equal quarters with the crosshairs of your reticle and thereby get a precise point of aim for each shot? (Aim Small, Miss Small)

Most of it is just me, but I have significantly different results depending on how I am shooting the rifle. Using a bipod off of a hard bench doesn't work for me too well. Prone, with softer ground, and a bipod works better. Prone off of a bag, and using a rear bag, works extremely well for small groups.

Are you using a stock trigger? I switched my 308 to a Geissele and my grouping problems disappeared, all other factors being equal.

Just some ideas.

 

[Maverick1911]

All good points...just where to begin!? Lol. I am using a Jp 4-4.5 lb trigger...I have noticed I shoot best from the bipod in the prone position. Question about the chronograph....is there a range I should be in with regard to velocity? I assume it's just measured from the muzzle? I might end up changing by bushmaster barrel from 1:9 to a 1:7 if I find the 77 gr smk's perform better. If I was more of an experienced long range rifle shooter it may be a bit easier to narrow down te issue....I might just have had a bad day at the range. That woukd cut out half the guessing game. I was back and forth on using Varget simply because the grains are larger and was concerned about how they would accurately meter in my progressive. Has this not been an issue for anyone? I was out in the sun for hours with my rounds in a plastic ziploc bag. They got hot to the touch. Wondering if the H335 is that sensitive to temperature to effect results....