wahoo shot my first reloads today

[Rbutler]

Got a little lee classic to make a few rounds and get a taste to see if i wanted to get something bigger. I made about 40 rounds of 70gr barnes triple shock. it was cool to watch the groups slowly tighten up as i had more powder. My questions now are:
1. All my BPS had in stock was cci 450 primers (SR magnum) can that be bad for an AR? i started low on the powder (suggested min was around 22 gr so i used 21 and worked up to 23)
2. will i notice the primer flattening on a semi auto? reason i ask is i stopped at 23 gr's of rl 15 but i noticed ppl saying 24.5 range is where they got the best groups so before taking a step farther i want to be sure im safe and not going to be meat grinder face.

current load:
PMC brass
CCI 450 primers
RL 15 Powder (stopped at 23 grains gettign about 2 MOA)
70gr Barnes TSX

[RaymondMillbrae]

Prrimer smear is a sign of overpressure.

SR Magnum primers are the primary staple for AR loads.

You didn't mention your COL.

In Christ: Raymond

[Rbutler]

Sorry about that my col was 2.25

[sonnyt650]

... 70gr barnes triple shock... 24.5 range is where they got the best groups

I found that my AR uppers like shorter, lighter weight bullets to the point where 55 grain white box rounds made better groups than hand loaded rounds with 68 or 75 grain Hornady Match bullets. The higher weight bullets didn't group at all covering a whole quarter of a large target, with 55 grain Hornady FMJs I get 4" groups of 30 rounds at 100 yards (didn't try with bench-rest targets), hopefully with 52's I get even smaller groups. Maybe I'll head out today.

[Fjold]

Do not start rifle loads below the minimum recommended loads in the manuals. The large/long cases of rifle rounds are subject to a condition called "detonation" with under powered loads that is thought to come from excess air space in the loaded cartridge and gunpowder position in the case. "Detonation" is when the powder charge explodes rather than burns and can ruin your whole day.

One grain lower than recommended in the 223 shouldn't be an issue but it's not a good habit to get into.

[diginit]

What Fjold said! The twist rate and length of your barrel determines the correct bullet weight. for example, A 1:9 twist likes 42 to 69gr bullets. too light and they spin too fast and can spin the jacket off the bullet. Too heavy they spin too slowly and they wobble in flight and vier off target. I find that my AR likes midrange bullet weights and charges.
Don't trust other peoples charge weights if they are over max in a semi auto, As they may be loaded for a bolt gun. Bolt guns have stronger recievers and can better handle high pressures.

[Rbutler]

sonny,
im seeing about 2 inches with the tsx's right now. hopefully about 24 gr of powder and i can tighten it up jsut a bit.

Fjold
Thanks for the info i did not know aobut the issue with too little powder but it makes sense.

diginit,
yea i have a 1 in 7 cmmg upper, if these dont pan out ive heard alot of good about the 60gr noslers so ill pick up some of those. the gn should be able to handle those.

[sonnyt650]

I decided to go shooting yesterday at benchrest targets: with 52 grain bullets at 100 yards able to get some 1" five-shot groups, while nearly all the rest came in under 2" even with fliers. The upper is a 16" 1-in-9 chrome-lined heavy upper with aftermarket piston kit, all parts from Bushmaster so not top-of-the-line. I really don't know if it's stability of the bullet or what, but yeah varying the bullet weight can change a crap barrel into a decent shooter.

Rbutler -- don't know if it applies to you since you have some data from elsewhere that led you down the right path.