seating depth with 77 gr SMK's

[rebs]

How deep do you seat your 77 gr smk's in a bolt rifle ? I know all rifles are different but do these shoot better with a jump or close to the lands ?
My rile is a Tikka T3x 223 varmint heavy barrel 24"

 

[mac86951]

How deep do you seat your 77 gr smk's in a bolt rifle ? I know all rifles are different but do these shoot better with a jump or close to the lands ?

IME they will shoot well seated to mag length; there's always accuracy on the table for closer to lands, but that is very rifle dependent. More so, seating longer for more powder space makes a better loading; or switch to the 80+gr for BC and volume.

-Mac

 

[dolek]

I load them for one rifle that requires a jump of 60 when loaded at mag length . It shoots great at 200 yds, have not gone beyond that with it yet.

 

[Rdlningcltchdmpr]

How deep do you seat your 77 gr smk's in a bolt rifle ? I know all rifles are different but do these shoot better with a jump or close to the lands ?

I use the one's with chanelure. I seat them to the chanelure so they fit in my magazine. Tikka 22-250/8twist. I have a zero or close to zero freebore so they are close to the rifling but i don't know exactly. With H1000 and 8133 full/crushing they make 1/4" groups at about 3150 fps or thereabouts. It's always the powder type that really makes small groups.

 

[LVLAaron]

Mag length. If you're willing to go longer than that (single feed) I'd switch to the 80's

 

[dstoenner]

For my bolt gun i seat them out to be .020 off the lands and then chase the lands as It moves. I shoot with aics mags in my bolt gun which all seating out to 2.600 if needed

i take advantage if if i can

david

 

[Longtrain]

Those bullets were designed mainly for XTC competitions, the 200 & 300 yard stages, which does include rapid fire. Since they must be loaded to mag length, that’s their intended purpose, and they work well.

The 77 SMK were an upgrade over the great 69 SMK, giving the shooter a bit less wind to deal with. All that being said, sure, they can be loaded at different lengths depending on your chamber dimensions, and will work fine. Some competitors have shot them at the 600 yard stage too, using just one bullet type for a whole match. A good 80 grainer still beats them in BC and wind bucking ability.

 

[rebs]

Thanks for all the help. I'll give the 80's a try. Does anyone have a good starting point with RL 15 or Varget ?

 

[LVLAaron]

Thanks for all the help. I'll give the 80's a try. Does anyone have a good starting point with RL 15 or Varget ?

Your finish point is 24g of Varget or RL15 for mag length 77's or 80's seated long.

 

[dstoenner]

Thanks for all the help. I'll give the 80's a try. Does anyone have a good starting point with RL 15 or Varget ?

Try the berger 80.5. You’ll like them. At least both my 223 like them better than 80 smk and the copies

david

 

[Tempest]

Thanks for all the help. I'll give the 80's a try. Does anyone have a good starting point with RL 15 or Varget ?

My son uses 23.7 RL15 or Varget with 80SMK for service rifle. That was the node it liked. That barrel did not like it any faster. Not what/how long of barrel you have but starting 23.5 might be a good place to start.

 

[RegionRat]

Agree with the others, in Service Rifle shooting, 24 gr of RE15 with a REM 7 1/2 at mag length does a great job in the 77 SMK and 77 TMK. The same for Varget but maybe just a bump down to about 23.5 for very hot weather to keep the Varget in the happy spot. Of course, you should test to see what makes your rig happy regardless.

There are places where I am forced to use factory ammo across the course, and have had no problem shooting nearly clean at the long line with Black Hills 77 TMK. I sorted them for weight and runout and managed a 199-13X the last time. They aren’t the equal of hand loaded 80 SMK, but come close and prove the point about jump and seating depth sensitivity being less sensitive in some rigs.

Here is an old link that has not been updated in a long time, but still has decent Service Rifle pet loads.

http://radomski.us/njhp/cart_tech.htm

 

[Metal God]

I use both 77gr smk and have 2 different loads at 2 different seating depths . They are both for AR rifles but were worked up in two different rifles . Regardless I'm stuck with mag length so one is at 2.255 avg which put's some right at 2.260 and others at 2.252 . The other load is seated to the cannelure and crimped at 2.250 and is designed to replicate-ish the 5.56 MOD-1 load .

I think this is 23br IMR 4895 from my NM 20" AR @ 100yds . Sub moa 10 shot group with the two flyers from an AR is gtg for me .

SMK's are pretty jump stable so really what works in your rifle best is what you're looking for and you may just need to chase it for awhile . I agree with others who recommend the 80gr smk if you can seat long and are shooting more then 300yds .

Lately I've been playing around with starting jammed in the lands .020 with 308 TMK I have no conclusions on that load yet . I have another 308 load that likes touching the lands in my Savage rifle . Poor ES/SD from back when I held the rifle to tight to my shoulder but still almost 1/2 moa at 300yds