AR 15 load starting point?

[TrxR]

I am building a AR 15 with a 19" barreled chambered in .223 Wylde.

Im looking for a load starting point.

Going to try using the following.

Bullets: Sierra 77smk (9377)
Brass: IVI military brass
Powder: 8208XBR
Primers: CCI BR4

Anyone have a good charge weight starting point?
I have seen mentioned that you have to start lower with military brass?

Thanks

 

[Dusty Stevens]

You may want to check sierras load data. Youre going to have a severely reduced case capacity at mag length and not enough barrel length for load data from most that would shoot that bullet. Sierra will happily answer an email from you- theyre great at the customer service

 

[Uncle Ed]

Nothing against this forum but chances are you will get "more" answers in AR15 type reloading forums. Most of the people here do not have 30 round mags on their bolt action benchrest rifles.

At the m4carbine.net reloading forum they had a very good postings on Sierra 77smk loads and duplicating Black Hills ammo MK262 mod 1 load data.

https://www.m4carbine.net/forumdisplay.php?72-Reloading-amp-Ammunition

https://www.ar15.com/forums/armory/Reloading/42/

I compromised to be in this forum and have a Ruger Ranch .223 that uses magpul pmags for Zombie attacks.

 

[TrxR]

Nothing against this forum but chances are you will get "more" answers in AR15 type reloading forums. Most of the people here do not have 30 round mags on their bolt action benchrest rifles.

At the m4carbine.net reloading forum they had a very good postings on Sierra 77smk loads and duplicating Black Hills ammo MK262 mod 1 load data.

https://www.m4carbine.net/forumdisplay.php?72-Reloading-amp-Ammunition

https://www.ar15.com/forums/armory/Reloading/42/

I compromised to be in this forum and have a Ruger Ranch .223 that uses magpul pmags for Zombie attacks.

Thanks I cant join AR15 as they wont allow Gmail addresses. I will try m4 carbine.

I will also email Sierra as this is a popular bullet for AR precision shooting.

 

[XTR]

Service rifle shooters load 77s to mag length all the time. Most shoot 77s from the short lines in rapids where you have to shoot from a mag and 80s from 600 where you slow fire single load. The 77s are very jump tolerant.

Your load should be somewhere in the neighborhood of 23gr to 23.5gr Work up to it.

 

[Uncle Ed]

Thanks I cant join AR15 as they wont allow Gmail addresses. I will try m4 carbine.

I will also email Sierra as this is a popular bullet for AR precision shooting.

At the Accurate Shooter link below you will find Sierra load data from their manual for the .223 and 5.56 plus much more info.

223 Rem + 223 AI Cartridge Guide
http://www.accurateshooter.com/cartridge-guides/223rem/

 

[jepp2]

I think you will find this extremely helpful.

 

[jepp2]

Brass: IVI military brass

I have seen IMI, but not IVI. If IMI case capacity is just like the rest.

 

[TrxR]

I have seen IMI, but not IVI. If IMI case capacity is just like the rest.

Nope IVI its the Brass the Canadian Military uses.

 

[nicholst55]

Sierra has .223 data for the AR available online. Run a web search for 'Sierra 223 AR data.'

 

[Lone Hunter]

Sierra has .223 data for the AR available online. Run a web search for 'Sierra 223 AR data.'

Look above at jepp2's post and he posted the link to the data.

 

[Liven The Dream]

Rem. Brass CCI Primers. R-15 start at 23gr. 69gr. Sierra or 75 gr. Hornady

 

[Steve Ladino]

I am building a AR 15 with a 19" barreled chambered in .223 Wylde.

Im looking for a load starting point.

Going to try using the following.

Bullets: Sierra 77smk (9377)
Brass: IVI military brass
Powder: 8208XBR
Primers: CCI BR4

Anyone have a good charge weight starting point?
I have seen mentioned that you have to start lower with military brass?

Thanks

Got my buddies AR-15 5.56 20" 1/8 twist to shoot 77 grain TMK's @.625/100 yds. with 23.8 grains of Varget and CCI 450 primers at 2.255 COAL Federal brass (looked like NATO Brass) full length resized.

 

[Uncle Ed]

Sierra has .223 data for the AR available online. Run a web search for 'Sierra 223 AR data.'

On the main page of Accurate Shooter "here" there is Sierra load data for the .223 and 5.56. Plus tons of accuracy articles on reloading. And this is some of the best info anywhere on the web.

223 Rem + 223 AI Cartridge Guide
http://www.accurateshooter.com/cartridge-guides/223rem/

 

[Uncle Ed]

Nope IVI its the Brass the Canadian Military uses.

One of the solutions to the early M16 jamming problem was to use harder brass in the 5.56 cases. I assume Canada and the other NATO countries followed in making their 5.56 cases since Canada uses the same basic rifles.

Below the 1968 Congressional hearings on the M16 jamming problem, they found the 5.56 cases were too soft. And now Lake City cases have the hardest brass and harder than Lapua.

Below the mil-spec requirements for 5.56 cases and the hardness requirements in the lower left.

 

[TrxR]

I see sierra list n 140 as their accuracy load and they don't list 8208 at all. Anyone have any experience with n140?

 

[natdscott]

You may want to check sierras load data. Youre going to have a severely reduced case capacity at mag length and not enough barrel length for load data from most that would shoot that bullet. Sierra will happily answer an email from you- theyre great at the customer service

Yeah, but no.

I would hazard that 75% or BETTER of all Highpower records ever set with the AR-15 were set with the 77 Sierra, possibly in combination with another bullet.

It's that good, and was DESIGNED for mag-length AR-15 loads.

23.8 RE-15
2.235-2.255" COAL
Rem 7.5 or CCI BR4
Lake City Brass
0.002-3" tension for mag loads, 0.001" tension for slow fire loads
No Crimp

 

[dcali]

24 grains of Varget under a 77 SMK at mag length seems to be a pretty common load in high power circles. It’s a little stout, so work up to it.

 

[55fairlane]

I shoot a RRA NM (service) rifle 20 inch 1 in 8 twist wylde chamber

My across the course load is

77 SMK
23.2 grain IMR 8208XBR (max load )
2.250 C.O.A.L
CCI small rifle primer

This load will just plain hammer at 600 yards

This load data is for reference only

For 200/300 yard matches

68 grain Hornaday (not match)
23.5 grains IMR 8208XBR
2.235 C.O.A.L

68 grain Hornaday match
23 grains IMR 8208XBR
2.250 C.O.A.L

69 grain SMK
23.5 grains IMR 8208XBR
2.235 C.O.A.L

These loads will hammer

This data is for reference only

 

[Dusty Stevens]

I shoot n135 under a 75bthp hornady in mine with a cle chamber and its the best bullet in mine by far