.223 OAL Question

[IDPA Mike]

I have a good cartridge made for my 55 gr. target and general shooting.
I am in the starting stages of working up to some distance shooting. I now have access to my clubs 200 yd range.
I am also looking to next season at Reading. I read on these threads that the bullet should just about touch the lands on the barrel. The longest that I can get my oal with the 69rg Sierra Match Kings is 2.270. Any longer and they won't fit in my mag.
Is this helpful for the accuracy of long distance shooting?
Any help is always appreciated.
Thanks, Mike

 

[bpm990d]

NRA HP uses single loading for the slow fire stages. The rounds do not need to fit in the magazine.

I would suggest a different bullet for the prone slow fire. Maybe a 75 or 80 gr. bullet depending on your rifling twist. Those should be seated to with .010 ~ .015 of the rifling.

B

 

[IDPA Mike]

NRA HP uses single loading for the slow fire stages. The rounds do not need to fit in the magazine.

I would suggest a different bullet for the prone slow fire. Maybe a 75 or 80 gr. bullet depending on your rifling twist. Those should be seated to with .010 ~ .015 of the rifling.

B

1 in 9 Twist 16" barrel.
If I like it I would like to get a new upper assembly for distance shooting.
Any help on this issue is welcomed also.
Thanks, Mike

 

[bpm990d]

Sight radius is going to be the biggest problem. 69s should shoot fine given the rig you are going to shoot. They are fairly tolerant of jump, although a 75 Hornady HPBT should work in a 9 twist without a problem.

Don't sweat the ammo, the rifle is going to be the challenge.

B

 

[jasons]

I load my 69 grain shortline ammo to mag length. (Specifically 2.255 +/- .005)

My 80 grain 600 yard ammo is loaded so the ogive is .020 off the lands for the specific rifle I'm shooting it out of. I have no idea what the OAL comes out to but it's well past mag length.

Uppers: Look no further than White Oak or Compass Lake. (Jasper is selling a really nice Compass Lake upper if you want to avoid the wait.)

Why wait till next season? There's still plenty of shooting going on, including 5 or 6 more NRA approved 80 round matches in Nashua.

 

[highscore]

Although it's a bit shorter than most people seat them, I load my Sierra 77's at 2.245. NO problems with accuracy and any slight difference in mags won't cause functioning problems. I've seen too many people have alibi's in rapid fired because they were trying to get that last few thousanths in length to fit in the mags. Anything that is to be loaded in mags is supossed to jump.

Sierra says to put 77 and 80's though a 7 to 8 twist barrel and 90's through a 6.5 twist. My 20" service rifle has a 6.5 twist and I've shot from 69 to 90's through it with good accuracy. The 80's and 90's were seated .010 off the lands which can be pretty close to 2.5" with some wear in the barrel. Try stuffing that into a mag! I also tried loading some 55's that a friend gave me to shoot through the 6.5 and they shot fine at 200 yards. That's supossed to rip the jackets off but they shot good groups, not that I would take a chance at a match shooting them.

I've seen 77 grain Sierra's shot at 1000 yards and they all made it to the target. I'm sure they cost the shooter a few points but it can be done.

It's hard to suggest a new upper without knowing if your talking service or match rifle and the distances your going to shoot. A 7 or 7.7 twist barrel will spin most bullets well as long as your not planning to shoot light weight bullets through it. I went with the 6.5 so I could shoot 90's (JLK's, not Sierra's which suck) and found that it shot everything I had well.

When my son was a junior he shot a lot of the 75 grain Hornadys in his Rock River and did very well with them. The CT State Association started getting Sierra's so we went with them, and they worked well.