need load data 223 rem. improved and imr xbr 8208

[bobcat93]

Hi guys,
I trying to work up some reloadsand if anyone has quick loads and could help me out I would appreciate it.
26" hvy barrel
223rem. Improved 40° shoulder

Lake city brass
Nosler custom competition 69 gr. Hpbt bullet
Imr xbr 8208 powder
Remington 7 1/2 be primers
Col 2.320"
Thank you for any input.

 

[Johnboy]

In a standard 223 Rem I was able to work up to 24.5gn in my 24 inch barreled 1:9 twist but went with 24.0gn because of pressure . My case over all length is at 2.290 putting the bullet just into the lands. In you case and having a longer case over all length, you should be able to work past my load, just work up and watch for pressure. I would start at 22.0gn, its low but you might find a lower node you might like, that's if you are not chasing a really fast load.

 

[40X Guy]

My son is running 24.5 grains of 8208 under 75 A-Max in his .223AI load gets 3,061 fps and is somewhat mild and it hammers. We had it to 25.2 but pressure started showing. With your 69 grainers you could safely start around 24.0 and go up in .2 increments watching for pressure signs. A very fun cartridge!

Frank

 

[bobcat93]

I fire formed all my cases with 23.8 grains. Then I tried 24.2 on my second reload, I had cratered primers and a case was ripped in half..must be to hot.? I would think I should be able to work up to at lease 25.3 grains. I never had this problem before in reloading. I have a 26 " barrel and a tight neck chamber. Also it is my first improved cartridge am I doing something wrong..maybe I need to try a different powder..reloder 15 , VV n150, or varget ..any advice

 

[lpreddick]

my 223 AI is a 14 twist and really likes 8208XBR 28 gr shooting 52 gr cheeks. heavier bullets seem to prefer slower powders.

 

[40X Guy]

Bobcat, we are using Lapua brass with a water capacity of 31.22 grains. COAL is 2.522 on our rounds. Rifle has a freebore of .100. I do know the 8208 powder will all of a sudden show pressure in the smaller cartridges. Looks like you are seating the 69's pretty deep in the case, and possibly rifle is chambered with light bullets in mind? Whats the twist rate and freebore of barrel and chamber?

Frank

 

[bobcat93]

The rifle is a rem m700 with a DBM stealth bottom metal and Accuracy International magazine barrel was set up for the 69grain nosler custom competition bullets ..I'm using lake city brass sent it all to the gun smith and he sent me the mock up reload to copy..this includes the case overall length
Maybe I over annealed my brass????

 

[Johnboy]

With QL and your numbers you'll be doing good to get around 24.5gn with this one powder of choice. Just saying what the numbers came up to be so don't hate. One other thing to remember is that an Ackley shoulder only offers a small margin ( more powder ) than a standard 223 case. The Ackley shoulder is more often used for it's shape rather than case capacity.

If in any way change brass the mill stuff might be stronger, but it holds less. I think Winchester would a better choice, even prep wouldn't be as hard for you

 

[varmintshooter]

Bobcat, I was just wondering if you have a load worked up with 8208 yet. I am shooting the 75 amax but with varget @ 3000. Was going to try 8208 when I run out of varget. I like what 40x had to say so I will try it as I am loading to an oal of 2.49". I really like 8208 in my reg 223 and 50 vmax.

 

[MLC]

I like it with LC brass @ 2.5" with hBN'd 75 AMAXs.
1/8 Broughton 5C cut by APA.
I've shot that combo out to 1200 yards.
I haven't shot the 69 out of my rifle but 26 grains in my rifle shoots pretty good.

Regarding the case separation, what is your forming process?
Also, I had to have my boltface bushed because of primer issues.

 

[bobcat93]

I was told lapua brass has less case capacity then lake city but I never did a test. The imr xbr is nice powder but doesn't fill the case enough ..I tried h varget and 24.5 gr. Was my max @25 gr. I got high pressure signs. So now I'm going to try imr 4046 and see .
I would think with the 69 gr. Bullets and a 26" barrel a slower powder should work well.. Net will be reloder 15 which I can pretty much bet to be a shooter, and h-335

 

[MLC]

I am certain that you will like those powders.
I used RE15 a lot but switched to 8208 because of the temperature variations where I shoot in the desert.

4064 is very accurate with 75's for me.
24 ish grains of 4064 Lapua case.

 

[bobcat93]

MLC.. Thanks for the input.. Most people on the web don't like imr 4064. But Im expecting good result's from it..it just feels right..but the targets have the last say so to speak

 

[MLC]

The length of the kernels is the only thing not to like.
4064 has produced average velocity and excellent accuracy in 223, 223AI, 6mm Rem, 6.5x55 and 308 for me.

How are you forming cases?

 

[bobcat93]

After sonic cleaning and prepping my brass I tumbled it to get it shiny. Then I annealed it, then I used Imr xbr powder with a mild charge. I lost about 6 cases out of 100. 4 of them ripped in half about a 1/2" above the head of the case, and two split down the side. All primers had cratering but it was very accurate I was getting 1" 10shot groups at 200yrd ..my rear rest sucks and I'm one of those guys who just can't seem to stop that swaying when I look through my scope

 

[MLC]

I meant from a straight 223 Rem case to Ackley improved.
Are the cases a tight fit when you chamber an unformed case or are you seating the bullet into the lands to fireform?
I suspect the case failures might have more to do with your forming than the pressures.

 

[bobcat93]

Ah-ha!. Yes I have them just kissing the lands..and I'm not sure if they were tight or not..I don't think they were because I full length sized in my redding 223 rem die so I could trim them all..maybe to much slop in the case to chamber fit?.. Fast expantion case the case to rupture.. Did you lose any cases when fire forming a 223 improve?

 

[MLC]

I have not had any failed cases but was having FTF with varmint bullets set to jump on unformed cases.
Then I read up on proper forming technique.