• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

.223 77SMK Where to Start?

i scrapped the 77 sierra and Tac loads out of my long range ar-15. An now shooting 77 bergers with aa2520 with wolf srm primer. nice velocity and excellant accuracy.
 
Old topc, but lets try anyway..,

With my custon 223 rifle krieger barrel and 1/9 tw, I loads some 77 MK with 24 grains of Reloader 15 and CCI SP at magazine lenght. Compressed load, but accuracy is good.

But my cronograph show me average velocity at 3010 fps. Is this correct or my chrony is bad?
 
I believe this chart can shed some light on the subject of "primer thickness. ( note: I believe there is a misprint. Federal "200" should be "205") Also CCI 41's are designed for AR's and 5.56 the have a very thick cup and as long as your trigger is at least 1 pound you should have a problem setting them off. Be aware load development should be treated the same as CCI small magnum primers. I personally use Rem 7 1/2 BR's in all my accuracy loads and have never had a problem. Federal also has an AR specific primer now ,but I have no personal experience with them yet. Dan.


http://accurateshooter.net/Blog/calhoonprimers02.png
 
navyrad8r said:
i was warned by my mentor to avoid the remy primers at all costs for all gas service rifles. Federal regulars needed a litle extra caution as well, but if you uniform primer pocket and pay attention to look out for the occasional "proud" primer, you should be fine. i went with CCI, WW, wolf, and Federal regs.
cheers,
doc
Rem 7.5, Tula srm, cci 450/br2 are a must. In a small rifle primer the term magnum does not mean a hotter spark but a harder/thicker cup to prevent slam fires. If you use Tac powder either use more neck tension or a slight crimp so that the powder will burn more efficiently.
 
Wolf SRM is a great choice. It’s a magnum primer but it is not hot, actually generates a milder ignition flame than Rem 71/2 which is one of the hotter ones. Wolf SRM’s advantage is thicker cup and more consistent MV which is critical for long distance (read 600 yards) shooting. CCI 400 would be the worst choice since it is one of the thinnest cups and not for hot loads.
 
liseo said:
Old topc, but lets try anyway..,

With my custon 223 rifle krieger barrel and 1/9 tw, I loads some 77 MK with 24 grains of Reloader 15 and CCI SP at magazine lenght. Compressed load, but accuracy is good.

But my cronograph show me average velocity at 3010 fps. Is this correct or my chrony is bad?
Your Chrony is optimistic. Later! Frank
 
liseo said:
Old topc, but lets try anyway..,

With my custon 223 rifle krieger barrel and 1/9 tw, I loads some 77 MK with 24 grains of Reloader 15 and CCI SP at magazine lenght. Compressed load, but accuracy is good.

But my cronograph show me average velocity at 3010 fps. Is this correct or my chrony is bad?

Perhaps you did not unfold your Chrony completely, which is why your velocity readings are beyond optimistic.
 
Why would you worry about slamfires with Remington 7 1/2 primers?

Remington ran Lake City from 1941 till 1985, do you think Remington loaded CCI or Tula primers at Lake City?

And Remington 7 1/2 primers were used to light off the ball powder used at lake city in their 5.56 ammo.

Now look at the flash photos of the primers going off and see why they said the 7 1/2 primers were mini-flamethrowers. ;)

Primers - Small Rifle Primer Study
A Match Primer Study in the 6BR Cartridge
By Germán A. Salazar

http://riflemansjournal.blogspot.com/2009/06/primers-small-rifle-primer-study.html
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
166,248
Messages
2,215,279
Members
79,506
Latest member
Hunt99elk
Back
Top