AR Barrel Questions

[Sugarbug]

I would try the 82 and the 80.5 you are going to be at a disadvantage by running at mag length. The more bullet you have in the case means that there is less powder in the case so velocity will be down.

I hope you can read the wind!

I would use Winchester commertial brass and a Remington 7.5 or Wolf primer. Powder would be 8208XBR, Reloader15, Varget or if you have any AA-2520 id give it a try, my fastest 80 grain loads out of a 20" service rifle were with it.
When you test loads and switch powders load 10 of each powder use the last 5 shots to determine grouping, some powders don't play we'll with others and will take a few shots to settle down.

Buck

We will get a baseline to see where I'm at at next month's FPR match. I'll be using Mickey's or Rick's rig most likely. Wanting to mag load for the classes that it is required.

Would you prefer 77gr for the little extra room (shorter bullet) or still go with 80.5 or 82?

 

[BKliebert]

You're not going to have a significant difference in speed with the 77 over the 80.5 or 82.

Being that you are handicapping yourself by keeping the COAL at mag length you need to select a bullet that has the highest ballistic coefficient. What you're loosing to speed you're going to gain a little with a bullet that bucks the wind better. I have seen some incredible scores shot by people who accidentally left their long line ammo back at the hotel and were forced to shoot their 77 load at six but those were very experienced guys.

The most important thing is to find a load that is the most accurate in your rifle, it's ok if it's a little slow as long as it shoots like a laser if you stick with it long enough you will learn to read the wind.

Buck

 

[Sugarbug]

You're not going to have a significant difference in speed with the 77 over the 80.5 or 82.

Being that you are handicapping yourself by keeping the COAL at mag length you need to select a bullet that has the highest ballistic coefficient. What you're loosing to speed you're going to gain a little with a bullet that bucks the wind better. I have seen some incredible scores shot by people who accidentally left their long line ammo back at the hotel and were forced to shoot their 77 load at six but those were very experienced guys.

The most important thing is to find a load that is the most accurate in your rifle, it's ok if it's a little slow as long as it shoots like a laser if you stick with it long enough you will learn to read the wind.

Buck

Thank you for the advice, Buck.

 

[RStewart]

You're not going to have a significant difference in speed with the 77 over the 80.5 or 82.

Being that you are handicapping yourself by keeping the COAL at mag length you need to select a bullet that has the highest ballistic coefficient. What you're loosing to speed you're going to gain a little with a bullet that bucks the wind better. I have seen some incredible scores shot by people who accidentally left their long line ammo back at the hotel and were forced to shoot their 77 load at six but those were very experienced guys.

The most important thing is to find a load that is the most accurate in your rifle, it's ok if it's a little slow as long as it shoots like a laser if you stick with it long enough you will learn to read the wind.

Buck

Buck,
If he shoots my rifle it'll be my bolt rifle. I recently converted it it to a mag feed. I can load and shoot my long loaded 80 SMK's through it, so I can keep my speeds up around 2950 fps. If he shoots an AR, as you say, he's gonna lose something loading those to mag length.
Rick

 

[owen502]

Just load whatever you have above 75 gr. until you have shot a while it won't make any difference.

 

[Ritten]

Just load whatever you have above 75 gr. until you have shot a while it won't make any difference.

This x 100.