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223 single digit S.D.

I have been working on this for a long time. I’m down to 13.8 SD at this point. The rifle is a stock Remington 700 5R and it shoot good but the 55fps ES still bugs me. I’m using Lapua brass, 24.9 gr of Varget with 69gr SMK at 2950 average MV.
 
My single digit SD is also with Reloader 15, but in my 1000 yd. Highpower M1A. I have no clue how big or small of a feat that is.

Danny
This is with the new Reloder 15.5. it's slower burning than 15, but has better temp stability. The 223 tends to be more difficult due to the much smaller case capacity compared to the 308. I still need to do load development on my m14, unfortunately below zero temps aren't conducive to load development.
 
I have been working on this for a long time. I’m down to 13.8 SD at this point. The rifle is a stock Remington 700 5R and it shoot good but the 55fps ES still bugs me. I’m using Lapua brass, 24.9 gr of Varget with 69gr SMK at 2950 average MV.
How far out are you shooting it? With those numbers it's likely you won't see much benefit at the distances 69's are usually shot.
 
This is with the new Reloder 15.5. it's slower burning than 15, but has better temp stability. The 223 tends to be more difficult due to the much smaller case capacity compared to the 308. I still need to do load development on my m14, unfortunately below zero temps aren't conducive to load development.
I missed the ".5". I wasn't really aware of that powder till a few days or more ago when reading this forum.

Danny
 
Berger 80.5, LC brass, CCI 41 out of a 20" service rifle
There is nothing available for RL15.5 and 90 grain bullets so I have been working with three-shot groups and chronograph. The throat in this barrel allows me to load them very long (they don't go below the neck/shoulder juncture) and my normal load has been 24 grains Varget, Lapua brass, CCI400 primer.
I have a 700 action bushed firing pin hole and Sako extractor. I don't "read" primers but check pocket growth and case head expansion looking for pressure. It's a process and I have one more step to go before deciding. I have met or slightly exceeded the velocity of Varget loads and still not showing excess pressure in my steps. I WOULD NOT be trying this with RL15 due to the nature of temperature swings here and will not print out any load numbers for what I have so far due to all the unknowns with this powder.
 
crowsnest2002
Thanks good article.
I already follow these steps as well as a few others.
They do work with my 308's and 243's but not my 223, if I could get a 25 fps extreme spread I wouldn't have started this thread.
Steve
 
I recently put together anAR15 pistol in 5.56 NATO. It has a 10.5 inch barrel was meant to shoot close up gongs, just a fun gun. Then my buddy who has a similar pistol pushed to shoot longer distances. So far I’ve hit our 12”x20” silhouette at about 450 yards.

Anyway, back to the topic at hand, we’ve been testing loads with 77 gr SMK and Varget and I had settled on the load/jump combination, and although it wasn’t really very tight, it held ok at distances. As a final step to the testing I decided to do a primer test, which I have never done before.

We test at 50 yards and that is where we zero also.

I had one other load along the way that had low ES and SD and it was with 62 gr Hornady FMJ and TAC. Neither of these two loads shoot really great but they are good enough for now, for what we are doing.

Primer Teat.jpg
 
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I recently put together anAR15 pistol in 5.56 NATO. It has a 10.5 inch barrel was meant to shoot close up gongs, just a fun gun. Then my buddy who has a similar pistol pushed to shoot longer distances. So far I’ve hit our 12”x20” silhouette at about 450 yards.

Anyway, back to the topic at hand, we’ve been testing loads with 77 gr SMK and Varget and I had settled on the load/jump combination, and although it wasn’t really very tight, it held ok at distances. As a final step to the testing I decided to do a primer test, which I have never done before.

We test at 50 yards and that is where we zero also.

I had one other load along the way that had low ES and SD and it was with 62 gr Hornady FMJ and TAC. Neither of these two loads shoot really great but they are good enough for now, for what we are doing.

View attachment 1304523
I'd like to see the pistol as well. Curiosity.
 
@crowsnest2002 Here is a picture of the pistol and the gong which was at 400 yards that day. Both of us were shooting this one. Since my turrets have caps, I'm trying to learn to use the reticle hash marks for elevations and windage. It is fun! BTW, we will be stretching this out, as the ballistic calculators say we will go subsonic after 700 yards (we are at 4400 feet where we shoot).

@RegionRat I knew someone might criticize that I only have three shots in these tests, but the purpose of the test was to see if/how much primers made a difference. I have shot XTC (wasn't very good) and F Class, where I attained Expert in LR and Master in MR, so I know the different requirements of SDs in different environments. I stated that this is a fun gun and this was a primer test.

AR15 Pistol (2).jpg
 
I recently have been struggling with 223 ES as well, more than any other gun I’ve had. Accuracy has been ok but the ES totally bugged me and probably does matter at 750 yards which is realistically as far as I practice with the 85.5 bergers.


Here is a write up on my experience and diagnosis for my particular situation.
 
@rckendall If all you have is three shot groups, don't bother with SD calculations yet.

Three values can be looked at in terms of their ES and Average, but the SD calculation on three samples isn't good for anything.
I completely agree but, in my case, I couldn't ignore the wildly fluctuating ES that got as high as 80FPS in one instance. There is much more for me to do before I can be satisfied with the RL15.5 option for my rifle but I will not blame what I see on the powder. Not yet anyway.
 

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