SD's in .223 /5.56
- Thread starter simonp
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you can get single SD digits, but it is sometimes frustrating and harder to get than in all other popular cartridges.
my goal is get less than 1 MOA water line at 1000m for 20 shots WITHOUTH flyers. I am maybe close, but not there jet. my Shotmarker keeps telling me, that 95% of higher and lower flyers are high and low velocity shots...
so I must do better behind reloading bench.
my goal is get less than 1 MOA water line at 1000m for 20 shots WITHOUTH flyers. I am maybe close, but not there jet. my Shotmarker keeps telling me, that 95% of higher and lower flyers are high and low velocity shots...
so I must do better behind reloading bench.
I figure it has something to do with it being a small cartridge. Given the same precision of powder measurement, a tenth of a grain is a bigger percentage of the total charge with a small cartridge.
My sd is usually in the teens but it hasn't caused me any problems.
My sd is usually in the teens but it hasn't caused me any problems.
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Some guys think it is the long skinny powder column. Others say 223AI gets better SD's, even with it's longer column.
222 Remington has a little shorter case and seems to be more inherently accurate, but I have not seen any chrono readings to show the SD data.
222 Remington has a little shorter case and seems to be more inherently accurate, but I have not seen any chrono readings to show the SD data.
Yes a 223 is challenging to get small ES/SD numbers but that would not affect short range accuracy
at all. Most will agree that it is the long thin powder column but there is no real proof.
If you are not getting good groups at 100 yards it is not the SD that is hurting your groups
it is something else.
For whatever reason I can get low SD/ES numbers in a 223 if I use a fast powder and heavy bullets
for example N133 with 75 gr Bergers vs say Varget or H4895. I have also recorded some of my
lowest SD/ES numbers using new brass, so go figure.
No need to go crazy chasing your tail trying to get super low SD numbers because they change day to
day. Find a load the shoots accurate in your rifle and work with it.
at all. Most will agree that it is the long thin powder column but there is no real proof.
If you are not getting good groups at 100 yards it is not the SD that is hurting your groups
it is something else.
For whatever reason I can get low SD/ES numbers in a 223 if I use a fast powder and heavy bullets
for example N133 with 75 gr Bergers vs say Varget or H4895. I have also recorded some of my
lowest SD/ES numbers using new brass, so go figure.
No need to go crazy chasing your tail trying to get super low SD numbers because they change day to
day. Find a load the shoots accurate in your rifle and work with it.
My speculation is the small case volume in and of itself plays a role. I use small-kernel powders (Vihtavuori N135, IMR 8208XBR) and measure each load on an A&D FX-120i scale, which can discern one to two kernels of powder as I drop a tenth or two light and trickle to desired weight. I don't think plus/minus .02-.04 grain is enough to induce a 40fps spread even in the little case.
I use Starline brass in my .223 because I never intended to compete with it... in terms of case weight and volume consistency, it's as good as the Alpha and Peterson brass I use in larger calibers. I anneal after each firing and trim as needed. Bullets are Hornady 75 ELDM and Sierra 77 SMK. I shoot to 1000 yards regularly with the ELDMs (chubby SMKs lose fizz too fast). Interestingly, my 75 ELDM load with N135 tracks my 6BR load with Berger 105 HT VERY closely to 1000.
I can get single-digit SDs for short strings, but longer strings (15-20 or more rounds) will usually run to 12-14 range. Good enough for me. In calm conditions with no mirage, a 75gr ELDM with 22.8gr N135 and CCI 400 gets me a satisfactory percentage of hits on a 12" plate at 1000. Out at 500-700... sub-MOA is attainable in those rare calm/no mirage conditions.
I use Starline brass in my .223 because I never intended to compete with it... in terms of case weight and volume consistency, it's as good as the Alpha and Peterson brass I use in larger calibers. I anneal after each firing and trim as needed. Bullets are Hornady 75 ELDM and Sierra 77 SMK. I shoot to 1000 yards regularly with the ELDMs (chubby SMKs lose fizz too fast). Interestingly, my 75 ELDM load with N135 tracks my 6BR load with Berger 105 HT VERY closely to 1000.
I can get single-digit SDs for short strings, but longer strings (15-20 or more rounds) will usually run to 12-14 range. Good enough for me. In calm conditions with no mirage, a 75gr ELDM with 22.8gr N135 and CCI 400 gets me a satisfactory percentage of hits on a 12" plate at 1000. Out at 500-700... sub-MOA is attainable in those rare calm/no mirage conditions.
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Is accuracy good enough with this combo for SD to even be a consideration?
No offense but this seems like a spray and pray load, not something designed to be shot at distances where SDs would come into play.
That particular load is for my 16" M4 with a red dot so I can't speak to it's accuracy.
I do have a load using a 75 RMR with Tac for my WOA 26" upper that is very accurate with a SD around 5.5 for 10 shots. Effective out to 670 yards which is the limit of our range.
I do have a load using a 75 RMR with Tac for my WOA 26" upper that is very accurate with a SD around 5.5 for 10 shots. Effective out to 670 yards which is the limit of our range.
I've had good luck with tac and h4895 with light and heavy bullets. I've got a tac/50gr vmax load, tac/77gr smk load, and h4895/75eldm. The 77gr and 50gr are loaded on a dillon, 75 on single stage. The tac is thrown with Dillon measure. Heres a 10shot string with the 50gr vmax in a 17" bolt gun
Curious what your tax 77 SMK load is. Tac is fast becoming my favorite powder. I’ve yet to find a Berger that doesn’t shoot well with tac
I've had some solid groups from Tac but it is well known for being temperature sensitive. That sensitivity won't matter much for the typical distances people shoot 223, inside of 600 yards.
The 223 is a pain in the ass for what it is = frustrating to get low single digit sd's.
Lapua brass, annealed, debur flash hole, trim, wilson collet sizer, sinclair neck mandrel, sw precision trickled with beam scale to the kernel, shot hornady 75 eldm, 80 eldm, and 88 eldm.
I geat stellar accuracy at 100. Good days 1/4" to 1/2". Bad days 1/2" to 3/4" - all for 5 shots. SD's? currently 12 over a 10 shot string.
I like the accuracy, but the sd's suck compared to the effort induced for loading. To achieve both I believe I would have to change to a br based cartridge. Side note - I do get both out of my 6.5 grendel loaded with 123 eldm out of my howa mini. So, I am somewhat competent.
I have read and been told directly case prep is critical for the 223. I just listened to one of Hornady's podcast on load development and in that podcast they state hyper case prep similar to what I listed above produces no noticeable results compared to grab and go.
Lapua brass, annealed, debur flash hole, trim, wilson collet sizer, sinclair neck mandrel, sw precision trickled with beam scale to the kernel, shot hornady 75 eldm, 80 eldm, and 88 eldm.
I geat stellar accuracy at 100. Good days 1/4" to 1/2". Bad days 1/2" to 3/4" - all for 5 shots. SD's? currently 12 over a 10 shot string.
I like the accuracy, but the sd's suck compared to the effort induced for loading. To achieve both I believe I would have to change to a br based cartridge. Side note - I do get both out of my 6.5 grendel loaded with 123 eldm out of my howa mini. So, I am somewhat competent.
I have read and been told directly case prep is critical for the 223. I just listened to one of Hornady's podcast on load development and in that podcast they state hyper case prep similar to what I listed above produces no noticeable results compared to grab and go.
In the past 2 weeks I've run several 20-shot strings with the Garmin under the gun and I'm getting about 11fps SD with my SAC 223 barrel for DT SRS, shooting a 75 ELD-M at 2950 fps (loaded to just under 2.5") with 23.5gr AR-Comp in Lapua brass with 205M primer.
It's no where near as temp sensitive as imr non-enduron powders or re15. For awhile, tac was the powder uses in mk262 ammo. I will not say it's as temp stabil as h4350, h4895, or h1000, but its no where near as bad as re15 1+fps/°. I've found it easier to load, more temp stable, and smoother at pressure curve, than 8208.
You'll never convince me that it is more temp stable than 8208XBR, but RL-15 can be interesting.
I hate 8208, spikes hard suddenly at top end and I've never got as good accuracy with it as I can with varget or h4895, in 223 or 6br
That's interesting.
The first loads I ever tried in 6BR were with 8208, and the first group was under 1/4 MOA. The group was so small, I had to walk down range to make sure sure shots 2-5 had not missed the target. I only tried it because I had some in the powder measure from loading 223.
I've moved to Varget in 6BR because you can still find it as 8208 has disappeared. It still shoots in the .3s so I can't complain.
I've been a big believer in 6br, shot it in benchrest and even posted a tutorial on here 12+yrs ago about how to modify ai mags to run 6br(definitely should have patented it as primal rights is a fancy duplicate of mine) I initially tried varget and it shot good and showed promise, but I remembered what I found in 308 was h4895 was like varget but moar betterer. I've got a 20rd group with 2 different powder charge that I was chrono-ing for comparison. They both shot real well, and used same poa for them, group was .422" 20rd. That was with h4895 in a 26" barrel doing 2915fps, I could not match that accuracy at all or speed without pressure spikes with 8208. Alot of guys like 8208 and I won't doubt their allegiance, but it never did anything for me.
in 223 you should try all useless things in other cartridges like sizing with mandrell, lubricating bullets and inside neck.
i'm right now at lubricating bullets and inside necks, and I think it is better...
i'm right now at lubricating bullets and inside necks, and I think it is better...
Anyone got any comment on SRP vs magnum SRP for velocity spreads?
I've been using CCI 450s (because I have them). Got an SD in the 15-20 fps range (measured across 20 shots) for a couple of different loads.
Lapua brass, Varget and H4895.
Am considering trying some CCI 400s to see if the small magnum primers are causing the greater ES.
No accuracy issues at close ranges but noticing a bit of vertical inconsistency at 600m from time to time
I've been using CCI 450s (because I have them). Got an SD in the 15-20 fps range (measured across 20 shots) for a couple of different loads.
Lapua brass, Varget and H4895.
Am considering trying some CCI 400s to see if the small magnum primers are causing the greater ES.
No accuracy issues at close ranges but noticing a bit of vertical inconsistency at 600m from time to time
An SD of 15 - 20 will mean an ES of much greater (3× +) and you'll certainly see that rear its ugly head at 600m. At 1 - 200 it is a non-issue.
Sorry, can't help to the magnum vs standard primer on effects on SD, other than by regurgitating the usual 'case by case' line. I do know that sometimes you'll just have to switch powders (even great ones like those you have listed), and that case fill is usually your friend (more the better). Those seem to be standard ways to tackle the .223 SD battle.
Currently I'm playing with my latest .223, and while Varget gives me more consistent velocities, RL-15 is giving more consistent accuracy...I want both dammit. N135 showed promise with the 69gr SMKs, so I'll be messing with that next. This barrel does not like to be run hard, which is the exact opposite of the barrel it replaced.
I inadvertently loaded a small batch of .223s with CCI 450s instead of the usual CCI400 (75ELDM and IMR 8208XBR). No real significant change... slightly higher SD.
I speculated in my earlier post that small case capacity might contribute to difficulty achieving low ES/SD. Slightly rethinking that: maybe it's more accurate to say the small bullet/neck contact area as compared to larger-caliber rounds is in play.
Pfft. I quit caring. AS has been written here so many times - the bullet speaks, and the 75ELDM bullets are finding 12-14" plates at 1000 often enough to satisfy me regardless of SD around 11-12.
My current new pet load is 77 SMK with 22.5 N135, CCI 400 --> 2800fps and superb accuracy out to 500m, which is the furthest I've taken it. The relatively low velocity and fat bullets give a nearly-12-mil elevation requirement at 1000, but for positional practice inside 600 yards... these SMKs have been hiding in back of the cabinet for years. Good to have a use for them. I also found two 500-count boxes of 69 SMKs... even older. Might have to dig into the back of the safe, pull out my heavy-barreled AR.
AR-Comp behind a 75 ELD in Lapua brass with 205m primer is giving me the best adds I’ve ever had in a 223 bolt gun, about 9.5 fps SD
Cci 400 are not made for high pressure cartridges. If you want to try something else try the bench primers or 41s. I got a 75fps increase just trying 41s. Sd was similar
I used to love AR-Comp but I refuse to develop any loads with it now because I will never pay the current pricing for it, it has just gotten ridiculous
Would you consider .223 with book loads to be "high pressure" that CCI 400s wouldn't be suitable for?
Any 223. Cci made the 400s for light loads. They have examples of older calibers(.218 bee maybe?). It's in their manual. Lots of guys use them but they pierce easy.
I stopped using it, but in the past I've used the Lee Factory Crimp die in .223/ 5.56 heavy loads. It did seem to help with ES/SD's. All tested on Oehler Ballistics lab.
I actually use 450 in my 223 bolt gun loads
Lol, I'd like to see proof of this statement because it sounds made up as shit. Fgmm and rem small rifle primers have a thinner cup than cci400, 450, and br4. There's a reason why fed made fgmm ar primers, because the chance of slam fire with standard fgmm in an ar is real. Doing some primer tests to see what effects of primer change were, I had a known fine load with br4(6br, 29.5gr h4895, and br4) had pierced primers with small rifle rem and blanked a couple fgmm. No issues with 450 or 400. This was my experience, not heresay.
I had a Tikka Varmint in .223 that would flatten and crater CCI 400s with the mildest loads - mild enough to get carbon soot down the case body. But they never pierced. CCI 450s would flatten with moderate loads. I can speculate why that rifle was such a pita wrt handloads but I don't know for sure.
Neither my Defiance nor Terminus-based .223s flatten, let alone pierce, CCI 400s with loads exceeding max as shown by Hodgdon or Vihtavuori.
Point being that a blanket statement that CCI 400s are unsuitable for .223 bolt guns is bullshit.
Neither my Defiance nor Terminus-based .223s flatten, let alone pierce, CCI 400s with loads exceeding max as shown by Hodgdon or Vihtavuori.
Point being that a blanket statement that CCI 400s are unsuitable for .223 bolt guns is bullshit.
It's in speer( the manufacturers)manual. Try reading a reloading book like you probably tell every new guy to.
Now, I just use berger, Sierra, and Hornady manuals. Never used any Speer bullets so I never saw the point in getting their manual. Sounds like Fudd lore authored their shit......add 1 more reason not to get Speer manual.
It may be fudd lore that doesn’t make it wrong. Every time someone asks about piercing primers in 223/5.56 they are using 400s. I know I have had that experience. 400s aren’t a high pressure primer.
As usual, @spife7980 speaks truth. It's the blanket statement "[a]ny 223. Cci made the 400s for light loads" to which I object. I did "try reading a reloading book." Multiples. Plus powder vendor web sites.
My old Speer manual specifically delineates between CCI400 and 450 based on powder and bullet. Vihtavuori just says "small rifle primer." Hodgdon shows Winchester SRP. Alliant shows Federal magnum. Old Sierra guide shows Remington 7 1/2 (magnum). Just as different guides show different min/max loads for the same bullet and powder, they show different primers.
Given my experience with my Tikka Varmint versus my custom .223 builds, the barreled bolt action itself can affect how a primer performs; the Tikka cratered 400s even at minimum powder weights and my customs only flatten them at exceeds-listed-max charges - never a crater, let alone a pierce. I don't hotrod my .223s - 75/77gr bullets at 2800-2850fps or so out of 28" barrels is as fast as I want to go. I have zero need to spend more $$ for magnum primers for my specific rifle/cartridge use case.
So bottom line is - not ALL guides ALWAYS specify magnum primers... and I violated my "don't get sucked into internet [discussion]" credo....
I'll check but I've got 2 loads for my 223 wylde bolt gun. One is br4, h4895 and 75gr eldm@3005fps. The other is loaded on a Dillon with tac, 77smk, and I think cci 400(need to check notes, as it might be 450s). That load is running 2995fps, never had any issues with pierced or blanked primers. Generally I run 450 or old br4 as the thicker cup let's me push pressure in my srp creedmoor brass. I do stand by what I said about rem 61 /2 primers blanking well before 400s.... I seent it.gif
cratered primers and flattened are two different things.
cratered primer is from large hole around firing pin - those are non-custom bolt heads. you ~wont see cratered primer from good custom bolt head.
flattened primers are from higher pressure or thin primer cup.
and after that there are pierced primers.
they can be because you have too large hole around firing pin, or you have too much pressure, or your primer has too thin cup. or all those things combined.
Looked last night, both my 50gr vmax night load and my 77smk Dillon loaded 223 wylde use cci 400 and tac. The 77smk is running 2995ave in 24" nucleus. The night load is 50gr vmax@3135 ave in a 16.5" cz600trail. Not sure if you want to call those high pressure, med pressure, or whatever. Never had a pierced or blanked primer in those loads and rifles. I think I've got 2 or 3 bricks of 400, everything else is 450 or br4.
Bullet weight isn't going to be a factor, it is a pressure issue. However since these bullets are mostly used in LR match situations shooters are pushing the pressures beyond SAAMI in most cases so it's likely that is the case.
i should add that my SD is in the teens, but that number was for a 20 round string. 77gr nosler bthp, Lake city brass, cci 450, and 8208 xbr. I think varget was about the same consistency.
My process is the same for 5.56, .308, and 300 norma. Rcbs chargemaster to weigh powder.
My process is the same for 5.56, .308, and 300 norma. Rcbs chargemaster to weigh powder.
Speaking on the Ackley side, I typically see between 8-11 SDs. Using 90s and N140 has been a solid combo out of my 26" bolt gun. My last load I chronoed:
AB 5.56 brass
Annealed and trimmed
25gr N140
90gr SMK
AVG: 2784
SD: 9
ES: 24
AB 5.56 brass
Annealed and trimmed
25gr N140
90gr SMK
AVG: 2784
SD: 9
ES: 24
My standard .223/5.56 loads usually have an SD in the 12-15fps range. Full match prepped stuff gets down to the 8-9 range, generally. Plenty good for my uses of LR target shooting and varmints.
