What’s it for?
Plinking = Whatever’s cheap.
SD/ Duty 1/7 = 62 or 75 grain Gold Gots (55s are good, too), 62 grain Fusion, or 62 grain TBBC.

 

62 grain Gold Dots are like unicorns - I am down to 100 rounds + what I have loaded in mags -

I can't find any in stock at any price starting to wonder if they even exist.

The 100 rounds I have would most likely last a long time so I am not in a rush.

 

What’s it for?
Plinking = Whatever’s cheap.
SD/ Duty 1/7 = 62 or 75 grain Gold Gots (55s are good, too), 62 grain Fusion, or 62 grain TBBC.

Done. Answered on the first post!

 

OP, I would shoot both of them and find out which one shot the best with
the different loads, then sight both in for your best loads and put the best
one away and save it for emergencies, or till you shoot the barrel out on
the less accurate one.

If you shoot both of them a lot one day you may not have one for
emergencies.

Barrels are not much money, so you can get an extra or two for later, we
may not be able to get things in the future.

I don't know how much you know about working on ARs, it's not hard,
changing a barres does not take long and the tools are not costly.
I would lap the upper if you change the barrel, it's easy.

You can learn what will fail on your AR in this thread,
High round count AR/M4's (over 100,000 rounds) and how they have handled on our range - Page 1 - AR15.COM

This is another good thread that will probably start some chitt,
.223 for bear, deer, elk and moose. | Rokslide Forum

 

OP, I would shoot both of them and find out which one shot the best with
the different loads, then sight both in for your best loads and put the best
one away and save it for emergencies, or till you shoot the barrel out on
the less accurate one.

If you shoot both of them a lot one day you may not have one for
emergencies.

Barrels are not much money, so you can get an extra or two for later, we
may not be able to get things in the future.

I don't know how much you know about working on ARs, it's not hard,
changing a barres does not take long and the tools are not costly.
I would lap the upper if you change the barrel, it's easy.

You can learn what will fail on your AR in this thread,
High round count AR/M4's (over 100,000 rounds) and how they have handled on our range - Page 1 - AR15.COM

This is another good thread that will probably start some chitt,
.223 for bear, deer, elk and moose. | Rokslide Forum

I really like your idea of finding which works best, then saving it, while plinking and practice with the other.

As far as tinkering goes, I love to tinker, but have yet to actually assemble an AR. I do own most of the tools though.
If I ever shot out a barrel, my mind would be wondering how much life is still in the bcg and the upper. What say you?

 

For the reloaders out there,


22 Caliber .224 Diameter 55 Grain Full Metal Jacket Boat Tail With Cannelure 5000 Count by Berry's (midsouthshooterssupply.com)

Ramshot X-Terminator Spherical Powder 8 lbs (natchezss.com)

Shooters World AR Plus - 8lb (natchezss.com)

 

Edit: @happie2shoot beat me to it while I was typing.

@warbow150 post #2 has the info I've seen on what bullets a 1:7 inch twist like and purpose.

As far a sighting, you'd have to experiment. Different weight and style of bullets will usually shoot differently even from the same rifle.

How far do you think you will be shooting both rifles? Will the distance be short enough so that any point of impact change between bullet weights/types is still acceptably accurate?

If the rifles have easily-adjustable sights (like turrets with markings), you could sight for each bullet type on each barrel, noting the zeroed number on the turrets. You could then adjust for the bullet you want to shoot. Or if you don't want to have to fiddle in an emergency, split the difference on the 2 settings and you might be 'accurate enough' to handle situations fairly close.

 

Edit: @happie2shoot beat me to it while I was typing.

@warbow150

How far do you think you will be shooting both rifles? Will the distance be short enough so that any point of impact change between bullet weights/types is still acceptably accurate?

Probably inside 200 meters, so I don't know if POA=POI for 55 & 77 "decently" enough. My guess is it probably would be.

 

This is a good zero for 55gr and 62gr,

M855_vs_M193_16_inch_barrel-1301924.jpg (614×390) (ar15.com)

Many other zeros here,
AR-15 Zeros and Trajectories - AR15.COM

Reloading For The AR-15: Molon's Accuracy Node Detection Technique | Sniper's Hide Forum (snipershide.com)

You can learn much form MOLON,
Collected posts by MOLON (ar15.com)

 

im real pleased with the 62gr barnes TSX in my 1-8 twist

 

I never thought about it this way, and I suppose it's because while I was in the army, every bullet was fmj. I never considered the need for a hollow point like, a Gold Dot.
To answer your question, it would be for practice, then self defense in shtf.

Rifle caliber Gold Dots are bonded soft points, not hollow points.

Others to look at are the Federal Fusion line - same projectile as the Gold Dot.

 

Please, how do you edit, things on this forum have changed?

Not sure of your question. I just put that in because I changed the original content. Sometimes I get unlazy, have a flashback to my work days of having to accurately log changes. Maybe I should have said 'edited' or 'changed'.

 

I can't find the edit icon to click on,
when I post and want to go back to
change something, I can't.

I just figured how to reply, I thought quote
worked but was wrong. ??????

 

I can't find the edit icon to click on,
when I post and want to go back to
change something, I can't.

I just figured how to reply, I thought quote
worked but was wrong. ??????

Ah. left-click the 3 vertical dots (Site Navigation) in the upper right of your post. Dropdown should have 'edit' as top choice.

 

Thankyou

 

My knowledge on the subject is limited, but I think I would want a slightly longer barrel with a 1:7 twist and a rifle length gas tube. Maybe go Wylde with the chamber too. Again, I don't know what the heck I'm talking about, but a 1:7 twist should be able to handle heavier bullets better than the lighter ones if you're wanting better accuracy at longer distances.

Disclaimer: I know next to nothing about the subject. These are just theories and thoughts based on a few articles and conversations.

 

Military adopted 1:7 for many standard issue 5.56s. They issue 3 types of bullets (most often) - 556gr, 62gr, 77gr. Rank and file get the first 2, longer distance shooters get the 77gr.
I don't shoot 1:7/16" ARs so most I can offer is based on 1:8/various lengths - but bullet theory would say 1:7 would "like" the slightly heavier rounds for grouping/accuracy - and 1:9 (also something I do not shoot) would like the lighter weights.

I know most of my guns (1:8/14.5" - 20" seem "perfect" at 68 or 69gr HPBT (especially Black Hills - who is providing spec ops with ammo now). I use 18" barrel for 3 gun and we shoot 50m to 600m typically (although we have a few runs at 1,000m). I adopted 1:8 at first as a compromise twist, but stayed with it because I seem to get really good groups and consistency. (not trying to sell 1:8 over any other - but you deserve to know I am not presenting apples to apples results). In competition I shoot 68/69gr throughout the most of the runs, but 77gr for the longer distances. I keep a small data card on the inside of my optic cover so when I flip it up the data is right there to see - in case I forget what the "best" optics settings were for that particular gun at various distances.

I shoot a few Mini-14s on occasion that are 1:7/16" and they seem to do well with the same 68/69gr ammunition - but almost equally well with 62gr (at 50-150m). The bullet I prefer is the HPBT over the FMJ or Spire Point for accuracy. But, I would be the first to admit 1.5-2moa is good accuracy for a mini-14, and most of my ARs are sub moa accuracy (so take the mini data with a grain of salt).

If I remember correctly the original M16s issued were 1:12/16" and that twist was scrapped in the 2nd or 3rd year of issue due to inaccuracy. 1:7 seemed to run a bit tighter and provide reasonable accuracy with the 62gr (which became the preferred ammo for many).

Others may have different or even better data/experience with 1:7/16".

 

<snip>

If I remember correctly the original M16s issued were 1:12/16" and that twist was scrapped in the 2nd or 3rd year of >issue due to inaccuracy. 1:7 seemed to run a bit tighter and provide reasonable accuracy with the 62gr (which >became the preferred ammo for many).

IIRC the original AR-15 (pre-M16) used a 1:14 twist barrel, which the U.S. military changed to 1:12 twist in the M16/M16A1 to better stabilize the 55 grain FMJ bullet used in the 5.56mm M193 round. Switched to the 1:7 barrel twist when the M16A2 was adopted with it's heavier 62 grain semi-armor piercing (SS109) bullet (M855 round.)

 

I found this chart to be helpful.

 

You can not over stabilize a bullet so 55gr in 1-7 shoot just fine. The 55gr just spin faster.

 

No debate about it going downrange successfully. I agree in principle, but in practice my groups are measurably better with 62gr than 55gr, and best with 69gr (HPBT) - but I have only used Sierra and Winchester 55gr/62gr against Black Hills 69gr and 77gr ammunition for most of my shooting. 75m and under negligible difference, 100+ concerning difference (1/2" at 75m, and 3" bigger groups at 200m, 18" barrel). Curious if you have compared them and found something different? Or different ammunition?

 

Post #2 nailed it. Also that twist is perfect for the heavy bullets like 77gr SMK type. These bullets are made to be very accurate at longer ranges. But they are also very good in gel test shots for defensive situations.

 

Years ago we built and tested many ARs, 1 in 8 and 1 in 7 mostly,
we got reports back form customers that the 1 in 8 would under
.5'' at 100yds with 40gr nosler bullets. Back then all ARs we built
had very heavy barrels, they were made for ruckchucks and
whistle pigs at long range.

Many times with a 1 in 7 barrel, your best groups are with the
50 to 55 gr match bullets, they just don't hold up at the longer
ranges.

I have shot 3/4 MOA at 630 yards with a standard wt PSA
barrel, with 55gr bullets. Was using wc844 powder, 1-8
twist SS Wylde barrel. After that I dumped all my heavy
barrel ARs

The problem with the 40 to 55gr bullets in the faster twist
barrels is when you use the very thin jacketed varmint bullets,
like the ones made for the 22 Hornet.

With the extra speed and centrifugal force it would destroy
the thin jacketed bullet, many times you could see a smoke
stream to 75+ yards.

 

I only saw this with my 220swift shooting 45gr bullets at 4200fps.

 

You have a good selection grain-wise with that length and twist. I like 62gr for mine in that size but as noted above you have a few to choose from. Shoot a few from 55 up through 70’s to see which one your barrels like. Get better ammo for SD.

 

Yes, also when you test the 55gr use a good bullet, like a Hornady FMJ BT or a good SP.

Have had good results with these,
22 Caliber .224 Diameter 55 Grain SP w/Cannelure 500 Count Sleeve (5 Boxes of 100 Count) by Hornady (midsouthshooterssupply.com)

22 Caliber .224 Diameter 55 Grain FMJ Boat Tail With Cannelure 100 Count by Hornady (midsouthshooterssupply.com)

Have not used this version but I think they would be good too,
22 Caliber .224 Diameter 55 Grain Spire Point Boat Tail With Cannelure 250 Count by Hornady (midsouthshooterssupply.com)

 

My two fave pills in my four ARs are Hornady 62gr FMJBT for general shooting and for accuracy 75 gr Hornady FMJHP Match. 3 are 1:7 the other 1:8. Lastly Hornady 55gr FMJBT is as light as I go. I have got moa with those in my 16” Mini 14.

 

I keep 55gr Hornady polymer tip varmint pills for home defense.
There may be too many great choices for the AR/223/5.56

 

The groups on my 1-7 twist got much better with 77 grain bullets.