Hornady .308 150 gr SP accuracy disappointing...

[PowderMonkey]

So on the purchase of my second Hornady LnL AP I selected the only .308 in the free bullet offer - qty 500 of .308 150gr SP bullets. They are lead nosed soft point or spire point. I’m finding out they are not nearly as accurate as the Hornady 168gr HPBT match type bullets out of my 20” Stainless Barreled target Armalite AR-10.

Last night was my third nite now shooting these two batches (150SP/168HPBT) of ammo back to back on two seperate fresh targets so my conclusions are made.

The 168 grainers match type bullets are making one ragged hole seven shot groups at my local 100 yard rifle range when I do my part – that load is a Varget fueled copy of Federal Gold Medal Match. The 150 grainer lead nose soft point loads are more like 4” groups. They dance around the bull and then throw filers high, low, left, right. Not cool.

OAL length is basically the same between them, both are all in F-C brass trimmed the exact same length etc. Same load other than a touch more powder given the lighter bullet.

Is it the bullet weight that just doesn’t agree with my barrel / twist rate or is it the inconsistent kind of blunt / non-pointed noses, or a combination of the two?

Is there any direction you would suggest I go in with my loads to try to help these 150gr SP shoot better? Load em longer, shorter? They are not at max either, so more or less charge?

Else what the heck am I gonna do with all these crappy shooting projectiles?

 

[Naterater]

sounds like they aren't agreeing with your barrel. Have you tried working up loads?

For me, I test ALL of the powder rates from min to max charge at a certain OAL, then I take the most accurate group and write down the powder weight of that group.

After that, I use that powder weight and test different OAL's. The bullets have different ogives, so the same OAL doesn't mean the same distance off of the lands for different bullets. Make one shorter, some longer--about 10 different OAL batches (5 cartridges a piece). You should find a few more accurate groups in there.

You can always fine tune if you have the resources by testing minute variations.

With a range of velocities and OAL combinations tried, you should find one that harmonizes with your barrel. And yes I said harmonizes, as in little vibrations that send the bullet straight every time.

There's no telling what's best for you in your gun. I hope this helps!

 

[longdayjake]

By "a touch more powder" what do you mean? There should be at least a couple grain difference.

 

[cag215]

I'm with Nate.....Ladder your load with the 150's until you see some improvement. At that point you can adjust your COAL and tweak the load.........I make ladder adjustment by the .3 grains.

Soft points get buggered being slammed in the AR platform, try shooting groups from the left side of the mag or the right side only....

I've also had guns that like a sightly fast powder when you lower the bullet weight....My guess is a powder that fills the case completely under the bullet, but maintains safe pressures.

 

[jmorris]

I've done better than 4" with them but there is a reason they are the ones they give away. My 1919 doesn't seem to care. Likey one of the few that gets fed soft points.

 

[rsrocket1]

I have the same bullets and love them in my 788. I use faster powder (H335) and find that as I changed the loads from 38g to 43g, the group moves around but stays consistent at about 1 MOA which is good enough for me. I've tried the 168g HPBT's and they are more accurate, but are way more expensive ($.23 each vs. free).

 

[zeke]

semi auto, soft nose bullets. Have had good accuracy with them in bolts and levers, not neccessarily seat to cannulur. Have better luck with SST's in semi's, when wanting accuracy and expansion.