SMK's in 69 and 77 grain

[SG4247]

Impressive, I would not have guessed AR Comp, ever.

 

[30378]

Out to 300yds only reason to consider 77s over 69s is wind conditions.

 

[Andy Legg]

I like to shoot the 77 SMK’s at 300 & 600 out of a 18” Wilson 1/8 Varmint barrel.

Mag length (2.260 COAL) w/23.4 grains 8208xbr & Federal 205m primers. Lake City brass. Bullets are sorted as well as the Brass.

Load shoots better than I can call wind…. That’s for sure.

Andy Legg

 

[7x57]

I have a 1 in 8 twist

since you are asking about benchrest shooting, then I presume that single loading is the routine and you are not limited to mag length ammo. With the 1:8 twist barrel, you may also consider the SMK80 or B 80.5 or B 80 VLD bullets. These bullets will be longer than mag length when properly loaded but that is not a problem with single load and you would get better BC than the 69/77's.

 

[XL105]

18" barrel ar15 with 77smk AA2520-25.0gr seated to 2.255 2725fps. Temp is in the 50s today.

Mk262 is ~2850 out of my 20" service rifle

What barrel twist?

 

[karrarararararar]

What barrel twist?

7.7

 

[Konocti's Wigwam]

I'm going to throw this out there, but on the basis of my one
Rock River EOP. It has a 20" Wilson 8 twist, full bull with Wylde
chamber. It will shoot under 1/2 MOA groups at 500 yards at
Spartansburg with the 77gr Sierras. The 69gr Sierras were over
0ne MOA. However and a fluke with this 8 twist barrel, the 69's
shot 1/3 MOA groups at 100 yards if I backed them down to
2650 fps when I noted it in my initial work ups. I used this load
in short range steel match's and took a few wins.

Fuj,

You make some good points. When I was reloading these I didn't have a chronograph, so not sure what the actual velocity was, I merely was building a ladder out of powder weights, picking my best groups. I'm pretty sure given the proper load and powder, either 69s or 77s could work great. There are a lot of factors.

 

[LiveFire]

What barrel twist?

1:8

 

[rebs]

lots of information on service rifles but I am shooting a bolt gun.

 

[Dgd6mm]

The 77, AR Comp, do a seating depth test.

 

[LiveFire]

With your barrel length velocity should not be a problem so I would choose the 77. The common powders regardless of action type include AA2520, IMR8208XBR, VARGET, TAC, H4895, N135, N540. I see most people with bolt guns using varget. The 69/77 also dont mind a bit of jump, so dont worry about having to run them out super long.

Do you have a target velocity?

This thread has loads for bolt and gas guns. You can search the thread for what you want. Lots of great data.

.223 - 5.56

Same Data

www.snipershide.com

 

[Zero333]

Depending on when the rifle was made... Tikka's 223 Varmint came in 12", 10" and 8" twists.
Sometimes the twist rate is stamped on the barrel.

If you have a 10" twist, go with the 69 smk
If you have the 8" twist I would try both the 77 and 69 smk. And don't overlook Horny-days 75 gr BTHP a try either.

I have a Rem700 sps tac 20" barrel with a 9" twist.
It shoots 75 gr Hornady BTHP very nicely same as the 69 smk, while the 77 smk sometimes shoot really good and other times not as good but still decent.
This rifle shoots sweet with 53 smk with H-335.

If you have an 8" twist, give the 77 smk a try. If you're not satisfied, then give the Hornady 75 gr BTHP and the 69 smk.

I've witnessed a Savage Axis shooting Hornady 52 grainers with Benchmark and Winchester brass at 300 meters. Fella wanted to know his velocity using my chrono. So I shot 10 shots at 300 and the group wasn't much bigger than 1"... The chrono showed the ES for those 10 shots was over 100 fps !!

 

[Dgd6mm]

I have a 1 in 8 twist

 

[coldboreshot]

which of these bullets do you recommend for 300 yds? what powder and seating depth?
this is for benchrest matches at 300 yds with a Tikka varmint rifle in 223 24 inch barrel

Sierra 69 mk, 4895 powder, cci 400 primer, Lapua brass or Norma alternative.