Choice of Ammo can make a world of difference in accuracy

[bushmaster1313]

It is only relatively recently that I learned about barrel twist, bullet weight and "match ammo."

Today I had my first opportunity to shoot my new Ruger 5.56 American bolt action rifle. 16.125" target crown barrel with 1:8 twist.

The choice of ammo made a big difference. After firing two rounds to get zeroed in at 25 yards, I went out to 100 yards with a 4X Leupold scope.

The first four rounds at 100 yards were IMI 55 gr. 5.56 FMJ "Ball" ammo. 4" group in the large black target:

Then I switched to IMI 5.56 with 69 gr. Sierra Match BTHP bullets. The three rounds at the top of the target grouped just over 1"

Clearly, choice of ammo can make a big difference

 

[rockquarry]

It is only relative recently that I learned about barrel twist, bullet weight and "match ammo."

Today I had my first opportunity to shoot my new Ruger 5.56 American bolt action rifle. 16.125" target crown barrel with 1:8 twist.

The choice of ammo made a big difference. After firing two rounds to get zeroed in at 25 yards, I went out to 100 yards with a 4X Leupold scope.

The first four rounds at 100 yards were IMI 55 gr. 5.56 FMJ "Ball" ammo. 4" group in the large black target:

Then I switched to IMI 5.56 with 69 gr. Sierra Match BTHP bullets. The three rounds at the top of the target grouped just over 1"

Clearly, choice of ammo can make a big difference

Your results are fairly typical. I've sampled eight or ten cheap bulk ammos. If you have any interest in accuracy, such ammo is generally a waste of money. The 69 Sierra MK will usually shoot very well in most guns that have the proper bore twist. Good handloads can often shrink five-shot group sizes to well under 1".

 

[Nevada Ed]

You will finf that your 1:8 barrel twist should do better with 165 or heavier bullets.
The little 55 gr bullets will tend to do better with a 1:10 or faster twist barrel.
My 22-250 has a 1:12 twist and does very well with tiny 52 gr HPBT target bullets.

Enjoy that new Ruger.

 

[bushmaster1313]

You will finf that your 1:8 barrel twist should do better with 165 or heavier bullets.
The little 55 gr bullets will tend to do better with a 1:10 or faster twist barrel.
My 22-250 has a 1:12 twist and does very well with tiny 52 gr HPBT target bullets.

Enjoy that new Ruger.

165 gr in 5.56 ? Sounds heavy

Also 1:8 is faster than 1:12

 

[Paul in Nevada]

It is only relative recently that I learned about barrel twist, bullet weight and "match ammo."

It's not so much bullet weight as it is bullet length. I found this out when I started shopping for solid copper projectiles.


eta: 1:8 is the sweet spot for 223/556 unless you start getting into those crazy heavy/long bullets in the 70gr+ range. Most people who buy 1:7 rifles never shoot anything heavier than 55gr.

 

[pasound]

My M&P 15 is good with 55's, ok with slightly heavier 62 hollowpoints. Shotgun patterns with anything heavy.

 

[Nevada Ed]

165 gr in 5.56 ? Sounds heavy

Also 1:8 is faster than 1:12

You are correct.
My bad.

My brain got disengaged in my wording and thought.
When you pass 75, things happen.

PS;
here are your bullets...........

 

[rockquarry]

Twist rate formulas often apply, but they aren't absolute. If you suspect something may or may not work in a certain twist, it always worth trying if you have the bullets on hand.

Again, these may not work in all applications, but I've found a 1 in 7" twist works very well for 55 grain (Sierra Blitz) and 75 grain (Hornady Match), the lightest and heaviest I've tried. Same for a 1 in 9" twist, but add the the 50 grain Sierra Blitz, the lightest I've tried in a 1 in 9" barrel. I've never really seen much practical use for bullets lighter than 50 grains in any of the centerfire .22s, except perhaps the very small capacity cases.

 

[lrrifleman]

OP,

Based on almost 34 years of competition, 23 using the AR platform, I've found the following concerning the 223/5.56 and twist rate:
1:10 to 1:12 rate will stabilize bullets up to 55gr to perhaps 300 yards and stay within 1 MOA.
1:9 rate will stabilize bullets up to about 72gr to about 500 yards maximum and group within 1 MOA.
1:8 rate will stabilize bullets up to about 80gr to about 600 yards maximum and group within 1 MOA.
1:7 rate or faster will stabilize up to 90gr beyond 600 yards and group within 1 MOA as long as the bullet remains supersonic.

 

[rockquarry]

OP,

Based on almost 34 years of competition, 23 using the AR platform, I've found the following concerning the 223/5.56 and twist rate:
1:10 to 1:12 rate will stabilize bullets up to 55gr to perhaps 300 yards and stay within 1 MOA.
1:9 rate will stabilize bullets up to about 72gr to about 500 yards maximum and group within 1 MOA.
1:8 rate will stabilize bullets up to about 80gr to about 600 yards maximum and group within 1 MOA.
1:7 rate or faster will stabilize up to 90gr beyond 600 yards and group within 1 MOA as long as the bullet remains supersonic.

That's impressive. I've fired lots of load development groups with Colt ARs, but never beyond 200 yards.

 

[AJ]

Your choice of ammo can make a world of difference. This group of three shots at 100 yards convinced me to buy this rifle. This is American Eagle Varmint & Predator 50 Grain @ approx 3325 FPS. It came with a Nikon 3-9X scope. Best ammo I have found for it.

 

[Nevada Ed]

With a little .22 bullet, FPS and wind can make or break good score when you are shooting parrie dogs out at 200 and 300 yards.

They are 3/4's of the size of a 12 oz. soda pop can, when sitting up and looking around.

A rifle with a good bullet and correct fps is a must for this game, to make, "Red Mist", past 150 yards.

 

[Paul in Nevada]

With a little .22 bullet, FPS and wind can make or break good score when you are shooting parrie dogs out at 200 and 300 yards.

They are 3/4's of the size of a 12 oz. soda pop can, when sitting up and looking around.

A rifle with a good bullet and correct fps is a must for this game, to make, "Red Mist", past 150 yards.

Ed, do we have prairie dogs in Northern NV?

 

[lrrifleman]

That's impressive. I've fired lots of load development groups with Colt ARs, but never beyond 200 yards.

Sir,
Before becoming disabled, I shot NRA High Power with first the 03A3NM, then an M1MkII, then my AR, all across the course (200-600 yards). I loved shooting Service Rifles. Now that I am disabled, I am shooting NRA F class mid-range (600 yards) with a custom AR in 223,and NRA F class long-range (1000 yards), first with a 7mm Rem Mag and now with a 224 Valkyrie. The key is to keep the bullet supersonic or better at the target.

As a note, I'm using the Hornady 88gr ELD-M for my 1000 yard + load. Currently shooting within 2 MOA at 1000 yards, and still developing the load.

 

[Nevada Ed]

Ed, do we have prairie dogs in Northern NV?

Yes we do.
There ar a few "Towns" around Reno but if you head east to Lovelock or even further east, the numbers increase in all the foot hills on the dirt roads, that are well away from the blacktop roads.

Lots of the shooting areas are on BLM land but you do need to be on the lookout for livestock in the area, since this is ranch & farm land, also !!
I also like to use a hill as a back stop in the desert, for safety, if possible.

Being in the "Ironworkers" and putting in box culverts and bridges from Reno to Elko, let me see a lot of the state and also where some shooting areas were.

In Battle Mountain we found a rancher that supplied us .22 ammo, to thin out the jack rabbits in the area, that were eating his crops.
The best shooting stared an hour before dark and at sun down we could not shoot fast enough and had to quite shooting from lack of light............. not rabbits.