Not a 308

[GStephen]

What are some things that I can check to help tighten up groups?  
I have a psa 556 that is not very accurate.  It had a 16” barrel and I changed to a 18” BA barrel and it really didn’t help.  Both 1:7    What type ammo should be accurate in it?  62 grain green tips are about 3 moa. 55 superx soft points are over 1.5 moa. I put the thermal back on my 308 and it’s sub moa at 100.  Put a glass scope on the ar15 and still no difference. The gun cycles perfectly and it would be nice if I could use it for coyotes.  I have an ar22-250 and a 308 that are both very accurate, but they are heavy AF

[shooterrex]

1/7 will shoot 69-77 gr bullets better than 55's

[98Z5V]

^^^   Right there.  The heavier, the better, in that range given. 

[GStephen]

I will try to find some ammo heavier, and try that 

thanks for your input 

[98Z5V]

1 hour ago, GStephen said:

I will try to find some ammo heavier, and try that 

thanks for your input 

Hornady loads it as the Hornady BLACK .223 75gr HPBT loaded ammo. 

https://www.hornady.com/ammunition/rifle/223-remington-75-gr-bthp-match-black#!/

Hornady also runs it in the Match line, product number 8026.  Looks like this:

Black Hills Ammunition loads a Sierra 77gr MatchKing as their Red Box .223 ammo - it's identical to military issued Mk262 ammo. 

Here's what you'd look for:

^^^^^^  That's just civilian packaged Mk262.  They also actually sell Mk262 direct to civilians now, as well:

http://www.black-hills.com/product-category/mk-262-mod-1-c-mil-pack/\

I doubt you'll ever find it in a store, on a shelf, but you can order it.  Comes in 460-round ammo cans. 

The ammo I listed above will shoot well through that gun you have.  You might be able to make a better handload, but you won't find anything from a manufacturer that will work as well as anything I listed above. 

The only thing different about the Black Hills Red Box and the Mk262 packaged ammo - is the testing (and lot number records) of the Mk262 ammo.  It's got a very high accuracy standard for testing, whereas the just load it up and package it, for the Red Box.

 

I've used this stuff, too, and it works well:

Edited April 2, 2023 by 98Z5V

[GStephen]

19 minutes ago, 98Z5V said:

Hornady loads it as the Hornady BLACK .223 75gr HPBT loaded ammo. 

I had already made an order from sgammo before you posted that, and I got 3 boxes of black coming with a couple others.   
I am looking forward to trying these.  

The gun doesn’t have a great trigger, but I have the same one in my aero m5 lower and can shoot sub moa easily with it in my large frame guns   4.5lb Ruger trigger.

 

[98Z5V]

You'll do fine, man. 

[shooterrex]

How snug did the new barrel fit the receiver? Any play? If so you can use locktite 609 to bed it in.

[GStephen]

9 hours ago, shooterrex said:

How snug did the new barrel fit the receiver? Any play? If so you can use locktite 609 to bed it in.

The LGS installed it for me, so I don’t know.  At same time he put in the plastic wedge to stop any slop between upper and lower.  It didn’t wiggle much there before that. 
I will try the different ammo before I do anything else 

Edited April 2, 2023 by GStephen

[GStephen]

all three new ammo were similar

The Hornady black with the 7.62 suppressor best group 

The same ammo without suppressor. It knocked off the red sticky dot 

 

my 308 loves the suppressor but the ar15 not so much.  I didn’t have any 55 grain ammo with me to try without suppressor.   I guess I won’t be using the suppressor on the ar15

 

 

[GStephen]

Funny thing is that my 17 hmr almost same hole with that suppressor on it

 

 

[shooterrex]

Glad it likes the new ammo better.

Cans don't usually make groups worse.

[GStephen]

10 minutes ago, shooterrex said:

Glad it likes the new ammo better.

Cans don't usually make groups worse.

My 22-250 did similar with the can. Although not nearly as bad as the 223

 It’s a rugged razor 7.62 and on my 308 is not a problem at all.  It’s sub moa even at 200 yds.
 

I probably won’t bother trying to get a suppressor for the 22-250 or the ar15.  

When I first shot it today with the new ammo, I was thinking WTF!  I thought barrel was loose or something.   Then I took off the can and it came together.  

 

[98Z5V]

That's massive success - walk away, give a mean look back at the crowd, and drop the gun on the ground - like you meant to do that.  Whatever that ammo was, it worked.  Buy more of it.