Am I the only one?

[Hardegg]

I have a 300/221 ar15 with 16" barrel and a "Jet" Supressor .
The upper was built by AR15 Barrels and I have no complaints with the gun. It shoots great functions well and accurate.
My question is, out of All the subsonic load data I have found online, none seems to be close to my experiance.
I am loading 220 gr SMK's with Hogdon H110 powder in Keith Davis' brass

Once again everything functions fine. But I am loading 10 gr's of powder and am averaging around 1045 FPS. That seems to be more powder than any load data I have found online. The barrel is barely broke in right now about 150 rds through it. and I am loading to max oal that will function properly.
Also this is new brass not "fireformed" when I reload this brass will my velocities change?

This just makes me curious more than anything of why my results seem so differant.

Allen

[pmc]

Your not the only one. Every gun is different and we are all shooting in vastly different conditions. For instance I was shooting today at 700 ft of elevation on an 82 degree day with 85 % humidity. With the whisper we tread a fine line with keeping the rounds subsonic and with no SAAMI standard those internet loads are only a rough starting point.

FYI my standard load is 9.2 gr of Alliant 2400 with a 240 SMK.

Pmc

[ranger dave]

well this may help you what kind of scale are you using get a dig and weight every load with souch a small powder charge a 1/10 of a grain makes a big difference all so if you have a pistol gas tube watch out fireing supper sonic loads they are too hot and will do real damage to your gun ssk has a gas reg for supper and sub sonic loads my best load is 147g win with 8g of 2400 i did a form one and built my own can allso i have seen alot of 300/221 made with a 1 in 10 twist barrels a little slow for 240g i made my gun around the load i wanted to shoot i will never pay $ 30 for a box of bullets try my load see what you think:uzi2:

[Hardegg]

I am using a RCBS Electronic powder dispensor and scale and I am measuring every load
my last ten shots I chronograph with 10.0 grs had an
extreme spead of 43.58 and an average of 14.28.

Average speed was 1034 fps
With high being 1055 fps
Low being 1011 fps

I do have a pistol gas tube with a JP adjustable port 1:8 twist thanks for the info on shooting supersonic as I did not know about possible damage with supersonic loads though. I will be sure to tune it down before trying that

[Hardegg]

I lied The chrony specs above where with Sierra SMK's
The last ten I chrony'd were with Hornady 220gr interlock round nose.
Same 10 grs of H110 functioned fine in my AR except for 1 jamb.

the average speed for those was a bit higher at 1106 fps with 1 round going supersonic.
Accuracy semmed good but I was only shooting 25 yds for chrony results. I can't wait to try them out at 100 yards.
I did however shoot 1 round of SMK and 1 round or the hornady into an old iron that didn't iron any more:)
The SMK outer shell sheared off but the core left a hole about the size of a 22 round (it did hit a little thicker area of the iron)
The Round nose on the other hand left a nice size entry hole and expanded real nice and blew that crap outa the back side. Not to scientific I know but was interesting to see how little the 200 SMK did to it.

[ranger dave]

i get around 2 moa out of my ar im very happy with it for what it is semi auto 100 to 150 max range ( with sub sonic loads) i used a ssk 300 whisper in iraq never could get supper sonic loads for it i look at it as a long range sub gun i have put over 5000 rounds through my 30/221 fired in sub gun matches with great resaultes guys with mp5s and 9mm guns hate me but i put a 147g bullet down range at 1100 fps just like the 9mm guys:smile: so doom on you and your 9mm feel free to e mail me if i can help shoot_ranger@yahoo.com