I've never had the greatest luck with .223 reloadinhg

[LVLAaron]

For background, I'm no stranger to benchrest and 1 hole groups. I've mostly shot 6ppc, 6.5CM, 308 win all with excellent results. I shoot F-class and don't have any problems chasing mid single digit standard deviation or half MOA elevation at 500 yards.

But I've got this AR15 I put together for fun. Got an 18 inch WOA heavy varmint barrel on it. It's a dream to shoot. I've had the receiver for long enough that it's all broken in and smooth as silk. Barrel is pretty new. 10x SWFA SS scope on top. I shoot prone with a rear bag.

never had much luck developing accurate ammo with it. 1 MOA maybe. Nothing ever really stood out. Used all sorts of Hornady or Sierra bullets in this guy. Ended up sticking with the Hornady 75g HBPT Match.

Trued/lapped the upper to the barrel and bedded the barrel with loctite retaining compound. Saw considerable improvements. So I took a stab at reloading for it again.

First time I've used a chrono on this gun, FYI.


Using new Sig brass with the flash hole deburred. (Actually really nice brass. Very low weight SD, shoots great in other calibers, etc) Full length resize and use a .002 under mandrel to finalize the neck size. Rem 7.5 Benchrest primers. Mag length seating depth. Charges weighed with an RCBS Chargemaster. IMR 8208 XBR.


I shot some pretty good groups. The 5th, 6th, and 7th group were all about .7 MOA. Which I'm happy with given strong erratic wind and my eyes struggling with a 10x scope @ 100 yards.


Anyway, What the hell is going on with my velocities? I've never loaded anything that looks so poor on a chrony. Perhaps I've always been blessed with bigger cartridges and very nice bolt guns.

Sorry I don't have a super precise question. I'm just sort of scratching my chin a bit and pondering things. I've always had great luck with that powder/primer before and dont know a ton about gas guns other than I have one for fun and shooting while my bolt gun cools down.


Open to any and all questions, name calling, and banter.

 

[dstoenner]

I have found that 8208 is a great powder with 52 to 60 gn bullets. With 77 and 80s i use varget. My. Standard load for 77 smk is 23.5 Varget in any case with BR-4 primers. This has been true for every WOA barrel i have had and my rem 700. I also saw that Hornady 75s were about .75 inch groups with SMKs at .5

H4895 also isn’t as accurate as Varget.

My 2 cents

David

 

[LVLAaron]

Yeah, my spidey sense was that 8208 might be a little fast for the 75's. I've got gallons of Varget. Will give it a shot.

Do you have any feelings about BR4 vs 450s? I have both.

 

[retired]

while i have shot br primers in some of my ar's, if you are not single loading,
i think i would pass on the br4's
i have no idea what a woa bbl is, what twist ?
while the scope is nice, when looking for little groups, more powder, with quality is better.
have you inspected the crown ?
skip prone for precision get on a solid bench, with a real front rest, and rear bag.
else be happy with 1"

 

[DR_2297]

8208 shoots just fine with heavies. All I shoot in 223. 22.6 for the low node, 23.5 For the upper. 1/2 min or less from my NM AR’s and mid range bolt gun.

 

[LVLAaron]

8208 shoots just fine with heavies. All I shoot in 223. 22.6 for the low node, 23.5 For the upper. 1/2 min or less from my NM AR’s and mid range bolt gun.

What weight?

 

[LVLAaron]

while i have shot br primers in some of my ar's, if you are not single loading,
i think i would pass on the br4's
i have no idea what a woa bbl is, what twist ?
while the scope is nice, when looking for little groups, more powder, with quality is better.
have you inspected the crown ?
skip prone for precision get on a solid bench, with a real front rest, and rear bag.
else be happy with 1"

This is the barrel: https://www.whiteoakarmament.com/shop/barrels/varmint-predator-barrels/20-varmint-barrels.html
I have 1:8 twist

I shoot prone because that's who I compete in F-Class.

This thread was more about the ammunition itself than my shooting style. Is 100 ES normal in a gas gun?

 

[eric n]

I can only speak for a bolt gun.
The cheaper 450s have given me ES less then 20 with varget and 8208 and excellent accuracy on every barrel I’ve had.

 

[retired]

no
something wrong with your process.
tell us start to finish how these are loaded.

i agree probably not the best powder for that weight.

maybe 2520 for the 75's

This is the barrel: https://www.whiteoakarmament.com/shop/barrels/varmint-predator-barrels/20-varmint-barrels.html
I have 1:8 twist

I shoot prone because that's who I compete in F-Class.

This thread was more about the ammunition itself than my shooting style. Is 100 ES normal in a gas gun?

 

[JimSC]

I had some decent luck with CFE .223 and 77 gr SMK's. Anything between 23.1 to 23.7 would give me .5 or less five shot groups, velocity SD's were crap but they grouped really well out to 300. Twenty six inch barrel 8 twist gave me velocities around 2625 plus or minus 25.

BTW I am also a prone shooter. My 30+ pound front rest is gathering dust since I discovered how much easier it is to shoot with a good bipod and a rear bag

 

[dstoenner]

Yeah, my spidey sense was that 8208 might be a little fast for the 75's. I've got gallons of Varget. Will give it a shot.

Do you have any feelings about BR4 vs 450s? I have both.

I cannot speak to using 450s with the 223. I use 400s for practice ammo and BR-4s for match loads. To me the powder column is neither large or fat warranting a magnum primer. I have heard people claim great success and great failure with them.

I guess the only way to know is try some loads and see how they work.

David

 

[Bc'z]

I'm liking benchmark for the lighter 55-60 gr bullets , running 25 Grains. These shoot 1/2" out of both mine and wife's ar's
Using varget with my 69 gr bullets. 25.3 gr shoots .7 out of both rifles

 

[swadiver]

in my 7.7 twist Savage/Bartlein bolt gun, 73gr Bergers with a moderate load of 8208 XBR, shoots 5 shots from the .1's" to the .4's" at 100 yds

 

[retired]

you obviously never learned how to PROPERLY shoot off the rest.
you think there is a reason br shooters do not use bipods ?
my 26" shoots right at .2 off a rest and rear bag...and it is an ar.

I had some decent luck with CFE .223 and 77 gr SMK's. Anything between 23.1 to 23.7 would give me .5 or less five shot groups, velocity SD's were crap but they grouped really well out to 300. Twenty six inch barrel 8 twist gave me velocities around 2625 plus or minus 25.

BTW I am also a prone shooter. My 30+ pound front rest is gathering dust since I discovered how much easier it is to shoot with a good bipod and a rear bag

 

[DR_2297]

What weight?

22.6 or 23.5. If you are playing under 200 then go low. Only issue is locking back an AR bolt in standing and it may not seal the chamber consistently if you have hard brass or brass sized well undersize. 23.5 is beginning to get hard on brass but it is my “go to” 600 yard charge in all of my 223s. 77’s or 80.5 / 82 Berger. Have fired multiple 10 and even a couple of 20 shot 1 MOA strings, prone from sling @ 600.

 

[retired]

i have said it many times
DEFINE YOUR ACCURACY REQUIREMENTS.

1 MOA is less than average in my world, but sling shooters think it is good

 

[retired]

how many of the 1 moa 600 yard 10/20 shot strings were done with 75's?
how many were done with MAG LENGTH ammo ?

22.6 or 23.5. If you are playing under 200 then go low. Only issue is locking back an AR bolt in standing and it may not seal the chamber consistently if you have hard brass or brass sized well undersize. 23.5 is beginning to get hard on brass but it is my “go to” 600 yard charge in all of my 223s. 77’s or 80.5 / 82 Berger. Have fired multiple 10 and even a couple of 20 shot 1 MOA strings, prone from sling @ 600.

 

[Liven The Dream]

R-15 or N-140
24 24.5 is a standard go to for AR’s .

 

[Ned Ludd]

FWIW - I don't think your ES issue is the 8208, that's a fine powder for heavy bullets in the .223.

I've seen similar erratic ES patterns when using a mandrel for the final neck sizing step. One guess might be that your neck tension isn't consistent. Do you feel a difference in resistance for some rounds when seating bullets? Try using an appropriate sized bushing/die, or some other neck sizing method and see if you can get more consistent neck tension and/or whether the ES improves. When using a mandrel to size the necks, it's critical that you first size them down at or below the intended diameter, then use the mandrel to open them back up. It seems like a great idea, but in my hands the neck tension was never as consistent as with a bushing die and the result was erratic ES values. Usually one shot would be way out, the others not too bad, which is what your numbers seem to indicate. I also surmise that when using a mandrel to open the necks up as the last step, springback will make them tighten up about half a thousandth, as opposed to sizing them down with a bushing, where the springback will open them up just a tick. I personally just found it more difficult to get consistent neck tension when using the mandrel as the final step.

In my hands with heavies (80-90 gr) in the .223, typical ES values for 5-shots will range from 12 to 15 fps, up to the low 20s. I don't normally get ES values quite as low as with .308 loads, likely because the case is approximately half the size and therefore variance has almost twice the effect. ES values in the 30-40 fps range (or higher) may not be noticeable at 100 yd, but they won't help you much at longer ranges.

For shooting groups during load development with your AR, I would also suggest a higher power scope if you have one, 10X is a little on the low side. Also, turning off the gas system (if it's possible) and single feeding will help with potential precision issues due to bolt carrier group cycling/movement during load development. I understand you won't be shooting it that way during a match, but the less potential for movement you have while shooting groups during load development, the better your confidence in the results will be.

 

[DR_2297]

how many of the 1 moa 600 yard 10/20 shot strings were done with 75's?
how many were done with MAG LENGTH ammo ?

None. All 82 Bergers single loaded.