Need a little education on bullets.

andy41567 · Jan 3, 2019

So I have 2 ar-15 's both shooting 5.56 one with a . 223 16" Wylde barrel and one with a. 223 18" Wylde barrel. Both are 5r 1.8 twist.
I have alway used store bought ammo and right now it's Winchester 55gr.
What I would like to learn is a little more about what is good to shoot through them barrels. From what I understand and I am not very educated in bullets/ cartridges, is that certain barrels are good at shooting certain ammo.
I know some things but I just need some help to better understand it all so I can make some good ammo decisions.

Overboost44 · Jan 3, 2019

I have 1:7, 1:8 and 1:9 barrels. For the 1:8, I would go with a 62gr-70gr bullet for the best stability. My 1:8 with a .223 Wylde White Oak barrel loves the 62's. Heavier for 1:7 (in the 77gr range) and lighter for the 1:9 (55gr) for the best accuracy. I am sure others will be along to comment.

Melnic · Jan 3, 2019

Others will want to know:
Are you reloading? (this is the reloading section so I was assuming so)
Are you trying to get better accuracy for paper punching? Distance(s) you will shoot?
What size groups are you getting now with the 55gr Winchester.
What AR/Barrel is it?
Sights you have on the AR.

John from MD · Jan 3, 2019

I have a small assortment of different twist barrels. IMHO, you will never get great accuracy shooting 55gns in a 1 in 8 twist barrel. If you are just shooting paper or three gun, fine, no problem. However, if you are shooting NRA matches, you need to get 62 to 70gn bullets for best accuracy.

Biggfoot44 · Jan 3, 2019

Oversimplified :

There is a relationship between Twist Rate and optimal Bullet LENGTH .

Often , but not always , there is a relationship between Bullet Weight and Bullet Length .

As rule of thumb , bullets are a lot more tolerant of spinning faster than needed, vs slower than needed . [ Too fast gives somewhat larger groups , until self destructing in flight . Too slow, and will tumble , and pattern like a shotgun ].

To flip the discussion around , what kind of groups are you getting with your current 55gr ? Is it meeting your requirements and reasonable expectations ? Have you determined that current ammo is your limiting factor ?

andy41567 · Jan 3, 2019

Melnic said:
Others will want to know:
Are you reloading? (this is the reloading section so I was assuming so)
Are you trying to get better accuracy for paper punching? Distance(s) you will shoot?
What size groups are you getting now with the 55gr Winchester.
What AR/Barrel is it?
Sights you have on the AR.

Ok see this is my I needed the help.
No I am not reloading. But was unsure where to post such a question.

Yes accuracy for paper punching. Trying to get proficient at a hundred yards.
My groups now are terrible at 4". But in my defense I have never done this beforeand when I come down to 50yds I can do 1" groups.
Ar-1 is a Faxon 16" heavy 5r 1.8 twist with EOTech 3-4 and 3x magnifier.
Ar-2 is 18" rock river arms hbar ss 5r 1.8 twist with Trijicon ch31-ah cross hairs.
I think i got all the specs right. Don't have them in front of me.

andy41567 · Jan 3, 2019

Biggfoot44 said:
Oversimplified :

There is a relationship between Twist Rate and optimal Bullet LENGTH .

Often , but not always , there is a relationship between Bullet Weight and Bullet Length .

As rule of thumb , bullets are a lot more tolerant of spinning faster than needed, vs slower than needed . [ Too fast gives somewhat larger groups , until self destructing in flight . Too slow, and will tumble , and pattern like a shotgun ].

To flip the discussion around , what kind of groups are you getting with your current 55gr ? Is it meeting your requirements and reasonable expectations ? Have you determined that current ammo is your limiting factor ?

Yes that's what I am thinking... Its the ammo. I did not understand the correlation between the ammo and the type of barrels that I have. So that's what I was trying to get a better understanding of I know I don't have the best barrels for the highest quality barrels. I also know I don't have the best skill. So what I was trying to get a better understanding of was what could I change. And it looks like the ammo would be the most likely culprit but I just didn't know if I go up or down in green and that's what I was trying to learn.

Biggfoot44 · Jan 3, 2019

Splurge for a box or two of Federal Gold Medal Match ( FGMM) , and test in each rifle with best practices techniques ( presumably either a proper bench rest, or prone with sling )

The ammo will be capable of well under 1 inch , to establish a baseline to either set future goals, and/ or show what is needed for rifle/ aiming equipment/ shooter technique .

John from MD · Jan 3, 2019

You really need to put a scope on the gun to see what the rifle can really do. Even a cheap 3x9 will give you better than the EOTech and magnifier. The EOT was designed for MoP shooting, not MOA. Minute of Person that is. :lol2:

Uncle Duke · Jan 3, 2019

John from MD said:
You really need to put a scope on the gun to see what the rifle can really do. Even a cheap 3x9 will give you better than the EOTech and magnifier. The EOT was designed for MoP shooting, not MOA. Minute of Person that is.

Gotta agree with John.

If OP is currently putting 4 inch groups into man sized targets with generally random and inexpensive ammo at 100 yards, that’s arguably what many would call complete victory, for that particular purpose.

Now if OP is looking to do something significantly different, he’s looking at defining his new and different game, and he’ll be looking at different rules and likely different equipment.

Melnic · Jan 3, 2019

andy41567 said:
My groups now are terrible at 4". But in my defense I have never done this beforeand when I come down to 50yds I can do 1" groups.

What distance for the 4" groups? 100yards?
1" groups at 50 yards with how many rounds?

As John mentions, it could be the optics affecting groups.
Good trigger?
Shooting off front and rear bags?

If you are Shooting at 100 yards and getting 4" groups, the target you are shooting at and your ability to find the center w/ your optics may be partly the issue.

whenever I'm looking at my accuracy, I have at least 9X on a scope, front and rear bags. I know others who will go to more trouble to stabilize the gun and eliminate the human factor.

andy41567 · Jan 3, 2019

Melnic said:
What distance for the 4" groups? 100yards?
1" groups at 50 yards with how many rounds?

As John mentions, it could be the optics affecting groups.
Good trigger?
Shooting off front and rear bags?

If you are Shooting at 100 yards and getting 4" groups, the target you are shooting at and your ability to find the center w/ your optics may be partly the issue.

whenever I'm looking at my accuracy, I have at least 9X on a scope, front and rear bags. I know others who will go to more trouble to stabilize the gun and eliminate the human factor.

Ok at 100yds both guns laying down with sand bags at front piled high enough that no part of the gun contacted the ground.
That is the 4" groups. Now with the Trijicon they are a little tighter probably more like 3" and that is the gun with the 18" barrel.
I always loaded 10 mags with 4 rounds. I will aim for bullseye first mag, then the "7" to the right second mag, and then "7" to left 3rd mag. If that makes sense. Usually have 3 targets set up. Saves on the running back and forth. My buddy will call out my shot and I will adjust.

Now the 1" groups have been standing, on a knee, sitting and laying. I seem to do really good there with bith guns.

Trigger is a rise RA-434 3.5lb in the 16" gun with the EOTech but I have since switched it out the a 4.5 2 stage GS2. The 18" gun is stock trigger with some light work done with about a 6lbs pull.

Also what I guess I need to do is make a decision as well. The EOTech gun was kind of my home defense gun. So maybe I should not be so concerned about 100 yards and farther. Where as the 18" gun I kinda planned the gun for more of a distance gun depending on my skill. But I knew I had to figure a few things out about the Optics and bullets

alucard0822 · Jan 3, 2019

There is the Greenhill formula, random experiences, and general observations, 1:9 is good from 40-62, might stabilize up to 70, 1:8 is good for 55-70, might stabilize up to 85, 1:7 is good for 62 and up. Thing is different bullets and loads might work better than others outside of the "ideal". My Mega 18" 1:8 I put together for 3 gun is a tack driver with Hornady FMJs, usually 1" or better for 1/2 a mag at 100 yards, shoots them better than 1:9 and 1:12 rifles I have, but slightly cheaper Xtreme or Berrys 55gr FMJs don't shoot anywhere near as good out of it, in other rifles there isn't as much of a difference between the 3 brands of 55 FMJs. In most everything 1:9 or faster, I usually get the best(or nearly so) groups with 69gr SMKs, same as loaded in federal Gold Medal Match. Ammo can make a big difference, 4" out of a mid-price build and low-power optic with cheap 55gr is average, maybe even good, 2" out of a premium build from a rest with optimized handloads might be dissapointing, much depends on your needs, your setup, the weather, and your ammo.

Blacksmith101 · Jan 3, 2019

andy41567 said:
Ok see this is my I needed the help.
No I am not reloading. But was unsure where to post such a question.

Yes accuracy for paper punching. Trying to get proficient at a hundred yards.
My groups now are terrible at 4". But in my defense I have never done this beforeand when I come down to 50yds I can do 1" groups.
Ar-1 is a Faxon 16" heavy 5r 1.8 twist with EOTech 3-4 and 3x magnifier.
Ar-2 is 18" rock river arms hbar ss 5r 1.8 twist with Trijicon ch31-ah cross hairs.
I think i got all the specs right. Don't have them in front of me.

Are you completely new to shooting sports? Have you taken any training? Do you have a coach/mentor that can watch your technique and critique you?

A coach/mentor can also help sort out the amount that ammo, equipment, and shooter are each contributing to group size.

Biggfoot44 · Jan 3, 2019

Either you shoot a rifle of known grouping , or have shooter of known ability shoot your rifle(s) .

andy41567 · Jan 3, 2019

Blacksmith101 said:
Are you completely new to shooting sports? Have you taken any training? Do you have a coach/mentor that can watch your technique and critique you?

A coach/mentor can also help sort out the amount that ammo, equipment, and shooter are each contributing to group size.

No I'm not completely new two shooting. But an AR-15 platform years I'm only 6 months old. Now with that said over the last 40 years my shooting is always been sporadic probably doing fact to my wife popping out kids all the time. As a kids were young Couldn't Shoot as much when the kids got older I could shoot more. Most of my experience is with bold action wild going hunting. But this time round in all honesty it's probably been a good five years since I've picked up a rifle again.

As for coaches yes I have only military friends so basically they're going to pretty much show me the military way. Most of my close friends are Marines and Navy. And yes I have been getting some help from them.

andy41567 · Jan 3, 2019

Biggfoot44 said:
Either you shoot a rifle of known grouping , or have shooter of known ability shoot your rifle(s) .

So you kind of suggest having someone else with greater ability than me shoot the rifles and see what kind of groups he can shoot.

Rockzilla · Jan 3, 2019

andy41567 said:
So you kind of suggest having someone else with greater ability than me shoot the rifles and see what kind of groups he can shoot.

Variables.... remove the "operator" either replace or use a solid rest
eliminate the operator.

You need to get into your "groove" find your zone,discipline, call your
shots or as was done to me many moons ago Colonel Bartgis at the
Linganore Range (long gone) would load my M1A clips with a mix of live
and dummy rounds, to see if I was flinching, had me call my shots. Anyway swap out shooters, some one known to shoot good, that's one variable.

Get a solid rest bolt / clamp it to the bench, then shoot some 5 shot groups
try different ammo, bullet weights, etc. notice groups. Could go on...

anyway twist rate calculator
http://www.bergerbullets.com/twist-rate-calculator/

Bullet Weight: The Ideal Rate of Twist

So to simplify this for you, here is a chart you may want to print:

Bullet Weight Twist
40-Grain 1:12
55-Grain 1:9
62-Grain 1:8 or 1:7
77-Grain 1:7 or 1:8
80-Grain 1:7

or

.224 CF from Shilen Barrels
- 7" for bullets up to 90 gr.
- 7.5" * Ratchet rifled 4 groove
- 8" for bullets 80 gr. and under
- 8" * Ratchet rifled 4 groove
- 9" for bullets up to 70 gr.
- 10" * for bullets up to 65 gr.
- 12" for bullets up to 63 gr.
- 14" for bullets up to 55 gr.
- 14" * Ratchet rifled 4 groove

if you are into the "math" of it...
http://www.jbmballistics.com/ballistics/bibliography/articles/miller_stability_1.pdf

Greenhill .....
https://en.wikipedia.org/wiki/Alfred_George_Greenhill

http://www.accurateshooter.com/cartridge-guides/223rem/

-Rock

Blacksmith101 · Jan 3, 2019

andy41567 said:
No I'm not completely new two shooting. But an AR-15 platform years I'm only 6 months old. Now with that said over the last 40 years my shooting is always been sporadic probably doing fact to my wife popping out kids all the time. As a kids were young Couldn't Shoot as much when the kids got older I could shoot more. Most of my experience is with bold action wild going hunting. But this time round in all honesty it's probably been a good five years since I've picked up a rifle again.

As for coaches yes I have only military friends so basically they're going to pretty much show me the military way. Most of my close friends are Marines and Navy. And yes I have been getting some help from them.

Since you have experience but may be a little rusty these may help get you back to the fundamentals:

CMP Coaching Resources
http://thecmp.org/training-tech/coaching-resources/

USAMU SERVICE RIFLE MARKSMANSHIP GUIDE
http://www.nfga.org/highpower/pdfs/basic_highpower_info/SR_Shooting_Guide_AMU031204.pdf

FM 23-9
https://www.bits.de/NRANEU/others/amd-us-archive/FM3-22.9(03).pdf

Rifle Marksmanship Diagnostic and Training Guide
https://apps.dtic.mil/dtic/tr/fulltext/u2/a544533.pdf

andy41567 · Jan 4, 2019

Awesome guys. Thank you so much. I got a lot of reading to do and going to order up so ammo and back to the range Saturday to try some new techniques!

Need a little education on bullets.

The #1 community for Gun Owners of the Northeast

Member Benefits:

Active Member

6th gear

Ultimate Member

American Patriot

Ultimate Member

Active Member

Active Member

Ultimate Member

American Patriot

Ultimate Member

Ultimate Member

Active Member

For great Justice

Grumpy Old Man

Ultimate Member

Active Member

Active Member

Ultimate Member

Grumpy Old Man

Active Member

Users who are viewing this thread

Log in

Forum statistics