Gentlemen,

I just ordered a Rock River Arms AR-15 to use around the farm and for 3-gun matches. I plan to have the sights dialed in with full power 55gr FMJ ammo, but I thought it might be nice to have a reduced load for short range use as well. Maybe a 40-45gr bullet? Maybe I could get it to hit near the sights at 25-50yds. Any ideas? What powders would be suitable? I realize jacketed bullets will need to be kept above 1600fps or so to avoid lodging a bullet in the barrel, and I realize that a reduced load will not function the action. I'm thinking maybe something with the power of a .22 mag?

SSB

Check out Lee's Loading manual, they have a good discussion of reduced loads and how to work them up.

The problem with the small bullets, which I love, is that the AR twist is usually not going to like them. The smaller the bullet, the higher the twist #. 40's like a 1 in 12 or 14"...AR's usually are built at 1 in 8 or 10 for guys who like the 62 grainers....

AR-15's have a 1-12 twist. They should handle the lighter bullets just fine. The slowest safe load I see with a 45 grain bullet will be in the 3000fps range. Get yourself a new Sierra Manual. The have a section under .223 just for the AR-15.

AR-15's have a 1-12 twist. They should handle the lighter bullets just fine. The slowest safe load I see with a 45 grain bullet will be in the 3000fps range. Get yourself a new Sierra Manual. The have a section under .223 just for the AR-15.


Sorry, AR-15's can have 1in7...1in10. They are best w/ 55 grain..62grain bullets. Lighter bullets may work well, they may not.

Sorry, AR-15's can have 1in7...1in10. They are best w/ 55 grain..62grain bullets. Lighter bullets may work well, they may not.


I was just going on my Sierra manual. Has a list of all Manufacurers in specific caliber and gives the twist of that gun. Maybe a misprint.

I was just going on my Sierra manual. Has a list of all Manufacurers in specific caliber and gives the twist of that gun. Maybe a misprint.


It does get confusing at times. Most manufactured today have a 1in9 twist.

Singleshot, have you thought about a .22lr upper? or a .22lr conversion kit? both are available, and your rifle will function perfectly. JP

I don't have an AR, but I do have a .223rem bolt gun ... and it's pretty much a custom, and I had the bbl done w/ a 1:9" twist ... all I will say is that it shoots EVERYTHING from the 40grainers to the 75g Amax ... Here's the rifle ... it's the one on the left ... The one on the right is a Rem700 LVSF 7mm-08, set into a take-off Ti-SAUM stock:

http://216.77.188.54/coDataImages/p/Groups/251/251556/folders/188642/1901317FrickFrack.jpg

I've never seen a problem with too much RPM's ...

I am not quite sure why you say you need to keep them at 1600 fps. I have loaded quite a few jacketed rounds with small charges of powder (around 2.4 grain 700-X) with 55 grain FMJ, with a good velocity and without any fear of sticking a bullet.
If you are not worried about the load functioning the action, then use the cast bullet suggested loads and pick the velocity you want. Something down around 1100-1200 fps would be quiet, and accurate at 25 yards.