77 gr tmk

[fox 1]

just tested some of the new 77 gr tmk in my ar15 20 inch barrel 1 in 8 twist, will the larger pills take down my barrel life if I use them instead of the 60 gr . great groups with them , plus I can target shoot from 300 to 600 plus. thanks pete

[gbal]

Pete,in a word,no

 

The major barrel life determiner is not bullet weight directly,but much much more the temperature of the powder used in propelling it-few barrle 'wear out'rifling wise-they get cracked around the very high temperture stress area of the chamber throat,and 'fire crack' etc....of course heavvier bullets often involve heavier powder loads,but not much...

Pushing bullets to "Max" velocities especially aabove recommended max does reduce accurate barrrel life.Some powders burn 'hotter' to give more energy/velocity-they reduce barrel life.

But normal loads with the 77s are not likely to substantially reduce barrel life,anynore than the sam with 69s would degrade compared to 55g etc....nor do you need super hot for 600y with the 77s. Enjoy.

 

But have a read at the other current post "22-250 Rem pushing 69 Sierra TMKs at 3640' for some cautionary experiences especially with 'hot' loads....there is never an absolutely free lunch ...at 600yards!!

Bon apetit.

 

 

gbal

[fox 1]

thanks gbal,l I did three 5 shot test with vhrt 140 23-2 gr

23-6 gr

24-1 gr

 

the best group was 23-6 so will not be running hot so happy days then

[gbal]

Sounds good...if/when I get some,I'll run that load in my Aug for starters,and just wait another hundredth of a second before the fig 11's fall.....if/when they do !!

g