300 BLK Load Data

#51
Re: 300 BLK Load Data


SSK 300 WHISPER®
FOR SSK BARRELS ONLY!!
SUBSONIC DATA

(221 Remington Fireball parent case) Accurate Arms #2 powder, Remington 7 ½ primer, 16.5” barrel, 70F/21C.
Powder Bullet Average Extreme Standard
Grains Grains fps/fpe Spread Deviation
5.76 165 1022/383 12 5
6.20 190 987/411 33 13
6.54 220 999/488 32 13
6.74 220 1015/503 42 18
6.92 220 1027/515 34 12 Maximum
With Reloader #7 powder, other factors the same:
10.45 220 976/465 38 19
10.82 220 1055/544 49 17
11.00 220 1071/560 48 19
10.45 250 1012/569 73 28
With Accurate Arms #1680 powder, other factors the same:
10.30 220 1023/511 33 15
10.30 250 1013/570 44 20
11.40 250 1147/731 13 4
With Accurate Arms #2015 powder, other factors the same:
12.64 165 1046/401 63 35
12.00 200 1007/450 20 10
12.36 220 1073/563 27 10
12.00 220 1046/535 30 11
With Accurate Arms #9 powder, other factors the same:
8.08 165 1033/391 52 23
8.54 220 1013/501 71 27
8.78 220 1071/560 28 14
8.78 250 1040/601 36 12
8.54 250 1005/561 25 11
With Hodgdon H110 powder, other factors the same:
9.10 200 1061/500 39 15
8.65 220 1003/492 84 35
8.90 220 1012/500 27 -
9.10 220 1061/550 37 17
8.60 250 980/533 15 6
8.90 250 1052/615 41 15
With Hercules 2400 powder, other factors the same:
8.26 168 1103/454 30 11
7.90 168 1068/426 30 12
8.26 190 1062/476 21 8
8.58 250 1040/601 50 18
8.26 250 994/549 60 22
With Hodgdon H4227 powder, other factors the same:
9.20 220 1006/495 89 33
9.20 250 1011/568 89 24
9.30 250 1039/599 116 44
9.40 250 1027/586 135 35
With Accurate Arms #7 powder, other factors the same:
7.50 168 1050/411 31 13
7.70 168 1082/437 25 9
8.00 220 1016/504 20 11
8.00 250 1034/594 47 17
With Hodgdon H335 powder, other factors the same:
13.86 220 1031/519 54 20
With Accurate Arms #5 powder, other factors the same:
7.54 220 1045/534 24 9
7.96 250 1044/605 43 17

Author’s note: The two-decimal charge weights are obtained by dropping then charges into the scale pan, weighing and averaging them. – DAG




300 WHISPER®
Supersonic Data

Temperature 60-65F/15.5-18.3C
Powder Grains Powder Average fps/fpe Extreme Spread
125 grain Nosler Ballistic Tip
20.6 Hodgdon H110 2333/1511 20 Bolt Gun (BG)
20.6 “ “ 2283/1447 64 AR-15
22.0 Hodgdon H110 2438/1650 31 BG
22.0 “ “ 2396/1594 89 Too Hot, AR-15

150 grain bullet (Temperature 60-65F/15.5-18.3C)
18.8 AA# 2015BR 1615/869 29
18.9 Reloader 7 1834/1121 54
20.2 AA# 1680 1994/1325 40
18.0 Hodgdon H110 2073/1432 13 Bal. Tip
18.0 Hodgdon H110 2014/1351 29 AR-15

168 grain bullet (Temperature 60-65F/15.5-18.3C)
18.8 AA# 2015 BR 1672/1043 28
18.9 Reloader 7 1823/1240 19
20.2 AA# 1680 1906/1356 12
17.2 Hodgdon H110 1958/1431 27 Too Hot, Reduce 0.5 grains

190 grain bullet (Temperature 60-65F/15.5-18.3C)
17.7 AA# 2015BR 1564/1032 18
17.9 AA# 1680 1754/1298 34
15.4 Hodgdon H110 1725/1256 40 Reduce 0.3 grains

220 grain bullet (Temperature 60-65F/15.5-18.3C)
15.6 AA# 2015BR 1415/978 89 1 slow shot
15.4 Reloader 7 1485/1078 47
15.6 AA# 1680 1467/1052 64 BG
15.6 AA# 1680 1492/1088 11 AR-15
12.5 Hodgdon H110 1412/974 47
9.1 Hodgdon H110 1070/559 49
9.1 Hodgdon H110 1052/541 1 shot, AR-15

250 grain bullet (Temperature 60-65/15.5-18.3 C)
12.0 AA# 2015BR 1101/673 42
12.1 Reloader 7 1211/814 44
13.9 AA# 1680 1304/ - 95 240 & 250 mixed
14.6 AA# 1680 1346/ - 82 “ “
14.6 “ “ 1377/1011 36 AR-15, 240
12.0 Hodgdon H110 1376/1009 46 240 grain

POWDER POWDER BULLET T/C 10” T/C 14” SSK 10”
GRAINS WEIGHT
8.1 AA #7 168 Hornady 965 962 1054
5.8 WW 231 168 Hornady 912 918 1032
(WW SP PRIMERS OAL 2.235)

AA1680 – 220 Sierra Matchking OAL 2.235 cases-unfired. Primer Rem. 7 ½”
NOTE: This primer seems to give the most uniform velocities with this primer.

12.2 1100 ---- 1196
13.3 1225 1261 1324
13.9 1287 1306 1366
14.9 * 1367 1427 1456
• Maximum case capacity – Maximum pressure. All above loads very uniform.

Velocities at 70 F

Do not seat bullets against rifling. Some T/C barrels will stabalize SOME 220 Sierra Matchkings at around 950 fps, others appear to need up to 1200fps to produce sub MOA groups.
 
#52
Re: 300 BLK Load Data

I believe Remington brass was shipped to MidwayUSA today.

brass.jpg
 
#53
Re: 300 BLK Load Data

I haven't had a chance to do any further load development with my stuff due to a miriad of family and work issues rearing their head lately.
I did come across some load information posted on other sites though.
Here are the links:
http://www.quarterbore.net/forums/showthread.php?t=5125
http://www.silencertalk.com/forum/viewtopic.php?f=128&t=68693
http://www.reloadersnest.com/frontpage.asp?CaliberID=135
http://listmequick.com/300/Sierra300whisper.pdf

And here is the data:

Barrel length: 10.5"
Port position: Pistol
Barrel Twist: 1 in 8
OAL: 2.15"
Dies: Redding 300/221
Brass: Hoser's Lake City Mixed Dates
Primer: CCI 400
Bullet type: Pulled Sierra Match kings from M118LR
Bullet weight: 175
Powder: Alliant 2400 7.9 Grains
Velocity: 1030 FPS (Average for only 3 shots)
Standard Deviation: 2 (for only 3 shots)
Extreme Spread: 5 (for only 3 shots)
Accuracy results at 50y, off ground with bipod, 4 shot group: .31"
Temperature: 62
Altitude within +-100' feet: 4,200'
Wind: 20mph gusts

Barrel length 10.5
Port position..... pistol
Bullet type.... SMK
Bullet weight... 220
Powder... N110..... 8.6gns 2.09oal
Velocity... 1000
Standard Deviation
Extreme Spread... 24
Accuracy.... .55"
temperature... 58
altitude... 300
wind.... calm

Barrel length 10.5
Port position..... pistol
Bullet type.... AMAX
Bullet weight... 208
Powder... N110..... 8.0gns 2.16oal
Velocity... 1028
Standard Deviation
Extreme Spread... 20
Accuracy.... 3/4"
temperature... 48
altitude... 300
wind.... calm

Barrel length: 16"
Port position: Carbine
Barrel Twist: 1 in 8
OAL: to fit magazine
Dies: Redding 300/221
Brass: Mixed head stamps
Primer: Tula small rifle
Bullet type: 210 grain Sierra
Bullet weight: 210
Powder: AA 1680 10.5 Grains
Velocity: 840 FPS (Average for 3 shots)
Standard Deviation: ?
Extreme Spread: ?
Accuracy results at 25y, off sandbag from bench, 5 shot group: less than 1/2"
Temperature: 65
Wind: 20mph gusts

*NOTE*
This data was not generated by me.
I only posted the data from entries that contain a sufficient amount of data to be useful / safe.
As with all hand loading, appropriate techniques must be adhered to.
 
#54
Re: 300 BLK Load Data

Posting for future reference.

Thanks for all this information guys, a friend of mine got the 10" upper and wants to reload ammo for it and this thread really helped me come up with all the information I needed.
 
#55
Re: 300 BLK Load Data

Trimming 5.56 brass.

I have had good luck trimming 5.56 brass with a RCBS Bench trimming tool.

I remove the hand crank and install my handy 18 Volt Dewalt drill. I use the .22 inside neck bushing.

Im setting the finnished length to around 1.850 and after resizing this results in aproxamatly 1.860 after pasing them through the Foster resizing die.

Havent started loading yet, Just preping brass. wainting on my AAC 9" barrel to show up. Should be next week.

Plan on loading 125's supersonic and the 175 SMK's and 220 SMK's sub sonic.

We'll see how it goes.
 
#57
Re: 300 BLK Load Data

Dr. Phill. I've been looking forward to your report on the results of using V-V powder. I really like using it in other calibers (particularly N-350 and N-105 in pistols). According to my Edition 8 of the V-V reloading guide, N-110 has a similar burning rate to H-110 and N-120 to AA 1680. How do your trials go?
 
#58
Re: 300 BLK Load Data

Just got one lb of the new Alliant AR-Comp powder which has been specificlly designed for .223 and .308 heavy bullet loads on the AR platform. I wonder how this is going to work for the 300 Blk? Supposed to be an "improved" RL-15 for heavy bullet loads, manufactured in Sweden, extruded, but with a shorter "rod" than Varget.
 
#59
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ted99</div><div class="ubbcode-body">Just got one lb of the new Alliant AR-Comp powder which has been specificlly designed for .223 and .308 heavy bullet loads on the AR platform. I wonder how this is going to work for the 300 Blk? Supposed to be an "improved" RL-15 for heavy bullet loads, manufactured in Sweden, extruded, but with a shorter "rod" than Varget. </div></div>

Way too slow. Suitable powders from Alliant are, IMO, RL7 and 2400.
 
#66
Re: 300 BLK Load Data

Copied here from the general reloading area.

I had my first range day with my newly assembled 300 BLK rifle and I saw primer craters on both of the loads I tested.

Rifle Info:
New CMMG 16" bbl on an Aeroprecision Upper/Lower
Standard Spring
Spikes Heavy Buffer (ST-T2?)
SI Defense BCG
Timney Trigger
UBR stock

Loads derived from QL:
Winchester .223 Brass, run through Forster die w internals removed to form shoulder, chopped, chamfered, full-length sized, trimmed to 1.365"

Hornady 150gr FMJ-BT
2.065" OAL (based on advice for ogive to clear PMag rib)
W296 Charge Range 14.8gr-16.6gr (based on a 10% redux of max calculated by QL)

I don't have the load info in front of my for the Hornady 110gr round nose but I saw the same cratering on even the lowest charge. The velocity was a tad higher than QL predicted but only by about 50fps.

What could be causing this high pressure? Would a new, rough chamber be gripping the brass too much or maybe for too long?

Is my QL load data somehow way off? For the 150gr load, predicted velocity is 1984fps. My measured velocity was something like 2030fps.

I didnt see any case head marks. Just cratering. The case sides did show marks that I am assuming were imprinted from the chamber walls.

Thoughts? I'd hate to have to back off from the low end charge just get the pressure down. Thanks Hiders!!
 
#67
Re: 300 BLK Load Data

I would not be overly concerned with the cratering.
The SAMMI Spec 300 BLK chamber is very high pressure.
Pressure signs that you should be concerned about are such things as swipe marks on the case head from the ejector, primers popping out, or flattened primers.

Err on the side of caution of course...
 
#73
Re: 300 BLK Load Data

19.7gr 1680
Federal SR Match
LC Brass, converted from .223
155gr Lapua Scenar, HbN coated
16" bolt action, 1-8" Twist
Wind at zero mph, 102f, 27% RH

Group was a bit tough to shoot using an H25 reticle, reticle was thick enough to completely obscure the shoot and see dot.

300AAC_155ScenarGroup.jpg
 
#75
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jdberry</div><div class="ubbcode-body">Anyone tried Berry's plated bullets? The 110's are $108 per 1000. </div></div>

I'm curious about this as well. Anyone have any info on this?
 
#77
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: silenshot</div><div class="ubbcode-body">Anyone has good high power load for Speer 125gr bullet with VV N110 powder for 300Blk? </div></div>
I have used H4198 with 125gr TNT. It is very similar to N110's burn rate. I have gone up to 17gr with no signs of over pressure. BLK load development is on hold until deer season ends but I would start from 15.5gr of N110 and work up from there.

Sierra states 13.7 - 17.7gr of N110 for their 125gr bullets (SPT & HP/FN), with 17.7 being the maximum load and their recommended hunting load. 2000fps and 1100ft.lbs. Accuracy load was 16.4gr on N110 (1900fps, 1002ft.lbs).

Hope that helps.
 
#78
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: phreakmode</div><div class="ubbcode-body">19.7gr 1680
Federal SR Match
LC Brass, converted from .223
155gr Lapua Scenar, HbN coated
16" bolt action, 1-8" Twist
Wind at zero mph, 102f, 27% RH

Group was a bit tough to shoot using an H25 reticle, reticle was thick enough to completely obscure the shoot and see dot.

300AAC_155ScenarGroup.jpg
</div></div>


Damn phreak that is a .5 inch load at nearly 200 yds? That is sweet.
 
#79
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sami</div><div class="ubbcode-body">I have used H4198 with 125gr TNT. It is very similar to N110's burn rate. I have gone up to 17gr with no signs of over pressure. BLK load development is on hold until deer season ends but I would start from 15.5gr of N110 and work up from there.

Sierra states 13.7 - 17.7gr of N110 for their 125gr bullets (SPT & HP/FN), with 17.7 being the maximum load and their recommended hunting load. 2000fps and 1100ft.lbs. Accuracy load was 16.4gr on N110 (1900fps, 1002ft.lbs).

Hope that helps. </div></div>

It helps a lot. I would also like to ask for proper OAL for this bullet and how much it affects the pressure? Could too deep or too long insert cause overpressures?
 
#80
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: silenshot</div><div class="ubbcode-body">It helps a lot. I would also like to ask for proper OAL for this bullet and how much it affects the pressure? Could too deep or too long insert cause overpressures? </div></div>
I don't have my reload data at hand but since it was for a AR15, I seated them maximum length for AR15 magazine to feed. If you're shooting bolt action, I would recommend seating as far out as possible, close to touching the lands.
 
#82
Re: 300 BLK Load Data

Ok,

I've tested some loads from 8.8 to 9.4 grains of N110 with silencer using 8" barrel with noveske, but the rifle won't cycle. What do you say, could an adjustable gas port with possible enlargement of the gas hole solve the problem?
 
#83
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: silenshot</div><div class="ubbcode-body">Ok,

I've tested some loads from 8.8 to 9.4 grains of N110 with silencer using 8" barrel with noveske, but the rifle won't cycle. What do you say, could an adjustable gas port with possible enlargement of the gas hole solve the problem? </div></div>
If you plan to run only subsonic then just drill the gas hole a bit bigger. If you plan to run supersonic as well, then add adjustable block. I drilled my Fireball barrel with 7/64 drill bit and that took care of the cycling problem.
 
#85
Re: 300 BLK Load Data

Factory Noveske AR 10" 300BLK Rogue Hunter. 1:8 twist Pistol length gas system. All groups were shot over a CED M2 Chrono with IR screens. Temp was 40F, at sealevel.

Optic was a Trijicon RMR 01 red dot optic with 4 MOA dot. My setup is more for quick target acquisition not surgical precision so my expectations for accuracy were not that of a bolt gun with 25x optics.

Supersonic Rounds UNsuppressed.

All brass is converted LC 5.56 brass from bradswarehouse.com
Primer: CCI 400
Bullet: 110gr Hornady VMax
OAL: 2.000"
Powder: 18.5gr H110
10 shot average 2042, Hi 2086, Low 1990, ES 96, SD 28

Brass, Primer, OAL, same as above 19.0gr H110
5 shot average 2127, Hi 2138, Low 2112, ES 26, SD 10.1

Brass, Primer, OAL, same as above 19.5gr H110
5 shot average 2195, Hi 2217, Low 2171, ES 46, SD 15.5

All supersonic loads showed good accuracy potential (as much as I expected with a 4 MOA dot). I would not go past 19.5 grains as it looked like the primers were wanting to just start to flatten some. Within 100 yards in the woods pigs are in trouble.

Subsonic loads shot through same weapon with AAC SDN-6 can.

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.4gr Accurate 1680
3 shots 954, 964, 994

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.6gr Accurate 1680
5 shots 1013, 992, 1024, 995, 997

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.8gr Accurate 1680
5 shots 1048, 1017, 1025, 1029, 1049

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 12.0gr Accurate 1680
5 shots 1002, 1024, 1021, 1023, 1015

I have no idea why 12.0 grains averaged lower than 11.8 but that is what the numbers said. There was defenatly some indication that the charges lower than 11.8gr were not stable. You could tell that the holes were not round. Both 11.8 and 12.0 grains the bullets appeared to be stable at 25 yards and showed the best accuracy.
 
#89
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gumby223</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jdberry</div><div class="ubbcode-body">Anyone tried Berry's plated bullets? The 110's are $108 per 1000. </div></div>

I'm curious about this as well. Anyone have any info on this? </div></div>

They did not work for me. Groups were 4 ft. at 100 yards. The AR puts a nice crease in them when they feed, and I think the jacket may be tearing off at some point. I tried a few loads in the 1600 fps range with the same results. I've got a few hundred of them, so I may try them again some day. They may work with ~5 grains of Trailboss for a super quiet subsonic load, but definitely will not cycle an AR. That will be the first load I try with them if I give them a shot again.
-Dan
 
#91
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Barney88PDC</div><div class="ubbcode-body">Factory Noveske AR 10" 300BLK Rogue Hunter. 1:8 twist Pistol length gas system. All groups were shot over a CED M2 Chrono with IR screens. Temp was 40F, at sealevel.

Optic was a Trijicon RMR 01 red dot optic with 4 MOA dot. My setup is more for quick target acquisition not surgical precision so my expectations for accuracy were not that of a bolt gun with 25x optics.

Supersonic Rounds UNsuppressed.

All brass is converted LC 5.56 brass from bradswarehouse.com
Primer: CCI 400
Bullet: 110gr Hornady VMax
OAL: 2.000"
Powder: 18.5gr H110
10 shot average 2042, Hi 2086, Low 1990, ES 96, SD 28

Brass, Primer, OAL, same as above 19.0gr H110
5 shot average 2127, Hi 2138, Low 2112, ES 26, SD 10.1

Brass, Primer, OAL, same as above 19.5gr H110
5 shot average 2195, Hi 2217, Low 2171, ES 46, SD 15.5

All supersonic loads showed good accuracy potential (as much as I expected with a 4 MOA dot). I would not go past 19.5 grains as it looked like the primers were wanting to just start to flatten some. Within 100 yards in the woods pigs are in trouble.

Subsonic loads shot through same weapon with AAC SDN-6 can.

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.4gr Accurate 1680
3 shots 954, 964, 994

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.6gr Accurate 1680
5 shots 1013, 992, 1024, 995, 997

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.8gr Accurate 1680
5 shots 1048, 1017, 1025, 1029, 1049

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 12.0gr Accurate 1680
5 shots 1002, 1024, 1021, 1023, 1015

I have no idea why 12.0 grains averaged lower than 11.8 but that is what the numbers said. There was defenatly some indication that the charges lower than 11.8gr were not stable. You could tell that the holes were not round. Both 11.8 and 12.0 grains the bullets appeared to be stable at 25 yards and showed the best accuracy. </div></div>

I have the same upper as you do and I am trying to find my subsonic load as well. I am surprised though that this upper needs close to 12 grains of AA1680 to get close to sonic.
 
#92
Re: 300 BLK Load Data

I have a Model 1 Sales 10.5" SBR in .300/221, and using 220gr SMKs, I found that 8gr & up to 8.8gr of AA#9 would cycle my AR, AND be subsonic. I researched extensively on Quarterbore's Forums, but that site is down now. A major factor in cycling these 10" AR's is gas port diameter, which strangely, has not been discussed in this thread,. . .unless I missed it. I had to bore my gas port out to .086"
I have used 18gr of W296 w/147gr FMJs & got 1950fps, but will back off to 17-17.5gr, until I install an adjustable gas block. At, or slightly above max, this load seems to cycle really agressively, and is hard on the gun & brass.
 
#93
Re: 300 BLK Load Data

Hey Matt, I have a couple questions about your 10.5" Mod 1 upper.

Did it come with that length because I'm only showing 16" lengths on their site...

Did you have to rebore the diameter yourself on the gas block? From what I understand a pistol gas system is the best for functioning with and without a can, and with full velocity and subs.

How is accuracy on your upper?

Thanks bro!

John
 
#94
Re: 300 BLK Load Data

Hey John, I got the upper about 5 years ago, I believe they were selling them to people with their form 1 paperwork. I think I do remember them being advertised on the site. I never at any time modified the gas block, I only modified the barrel by opening the gas port to .086". It is a pistol length gas system. Best accuracy was with 8.8gr AA#9 under 220gr Sierra Match Kings, consistently MOA & under.
 
#95
Re: 300 BLK Load Data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbohardtop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Barney88PDC</div><div class="ubbcode-body">Factory Noveske AR 10" 300BLK Rogue Hunter. 1:8 twist Pistol length gas system. All groups were shot over a CED M2 Chrono with IR screens. Temp was 40F, at sealevel.

Optic was a Trijicon RMR 01 red dot optic with 4 MOA dot. My setup is more for quick target acquisition not surgical precision so my expectations for accuracy were not that of a bolt gun with 25x optics.

Supersonic Rounds UNsuppressed.

All brass is converted LC 5.56 brass from bradswarehouse.com
Primer: CCI 400
Bullet: 110gr Hornady VMax
OAL: 2.000"
Powder: 18.5gr H110
10 shot average 2042, Hi 2086, Low 1990, ES 96, SD 28

Brass, Primer, OAL, same as above 19.0gr H110
5 shot average 2127, Hi 2138, Low 2112, ES 26, SD 10.1

Brass, Primer, OAL, same as above 19.5gr H110
5 shot average 2195, Hi 2217, Low 2171, ES 46, SD 15.5

All supersonic loads showed good accuracy potential (as much as I expected with a 4 MOA dot). I would not go past 19.5 grains as it looked like the primers were wanting to just start to flatten some. Within 100 yards in the woods pigs are in trouble.

Subsonic loads shot through same weapon with AAC SDN-6 can.

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.4gr Accurate 1680
3 shots 954, 964, 994

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.6gr Accurate 1680
5 shots 1013, 992, 1024, 995, 997

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 11.8gr Accurate 1680
5 shots 1048, 1017, 1025, 1029, 1049

Converted LC 5.56
Primer: CCI 400
Bullet: 220gr SMK
OAL: 2.120"
Powder: 12.0gr Accurate 1680
5 shots 1002, 1024, 1021, 1023, 1015

I have no idea why 12.0 grains averaged lower than 11.8 but that is what the numbers said. There was defenatly some indication that the charges lower than 11.8gr were not stable. You could tell that the holes were not round. Both 11.8 and 12.0 grains the bullets appeared to be stable at 25 yards and showed the best accuracy. </div></div>

I have the same upper as you do and I am trying to find my subsonic load as well. I am surprised though that this upper needs close to 12 grains of AA1680 to get close to sonic. </div></div>


8in Noveske 1:8 twist
208 Hornady Amax
11.8g A1680 ave.
COAL (need to check, but fits in PMAG)
Lake city once fired brass
Win Small Rifle Primer (it's what I had on hand).
Velocity at 1043fps. for an n=20 shots
Accuracy, about 1.5in at 100 yards for 5 shots


Action will cycle/lock on empty magazine with a Gemtech Sandstorm and one weight removed from standard buffer

BTW the Hornady Whisper Ammunition (208 AMax)was around 950fps and would not consitently cycle the action with a suppressor

 
#96
Re: 300 BLK Load Data

Recently put together an AR and love the subsonics.

Noveske 16" 1:7 barrel
Pistol length gas
Standard buffer and spring
OPSINC 12th suppressor
Lil Gun powder
CCI BR4 primer
Winchester modified 223 brass
Hornady 208 AMAX
COL 2.140

8.0gr >>>1092fps (1 MOA @ 100yds w/Bushnell zoom dot)
7.8gr >>>1060fps

I posted this on the Blackout forum as well.

Working on figuring out the AR loads for the light bullets now.
 
#97
Re: 300 BLK Load Data

Same as above w/208's & Lil Gun but using LC brass fm Wildcat
The magnetospeed wouldn't read all the rounds but everything cycled and locked back
3 ea.:

6.5gr 925fps (only one read)
7.0gr 1014,1016,1015

tried some 4064 w/ 110 VMAX all cycled but no lock back and only one read
LC brass and rest same as previous post

6.0 gr 1016fps
7.0 gr no read but actually sounded quieter than the 6gr load

forgot to include in spec: Carbine buffer w/ regular spring. The carbine spring is on the way.
 
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