40-x rebuild

R

rsmithsr

Well-known member
so the rifle came in and i inspected and fully dis-assembled.
1982 rifle with OEM bbl...pretty tired.
ordered a replacement from krieger....just over one week from order to delivery(this tues).
( an in stock bbl !) a number 9 is close to the original tho i will use 24-26" as a finished length.
rebedded the action with pillars added. made new hex drive action screws.
installed the timney HIT-ST, breaks nice at 12 oz.
i need to look at bbl length/velocity with reloader 26. i can get 3000 fps with a 220 smk from 26.5"
sit back and wait time.
 
so.....long wait on a couple of items. i had the bbl nitrited. took a while, and decide on a folding stock.
none fit the bbl dia, so went with a mcmillian front half and an ar back with a quality hinge in the middle.
8.5-25x luepold scope in burris insert rings. 9" thunderbeast suppressor.

the plan is to mimic the mk13 sniper rifle a bit. lilja mk13 bbl, reamer is navy mk13 reamer, bullets are 220 smk. quality available brass (NOS ABM..applied ballistics ammo line) win lr mag primer and 3.5 oal, and 2800-2850 in velocity with the 24" bbl of the later rifles. reloader 26 powder is a variation from h1000 but more vel/less pressure.

initially nothing worked well. lots of 3 shot groups that were 2 and 1. started over and got some improvement.
72.7 and 10 off shot .47 at 200 today. well under the 1moa spec of the mil rifle. ammo is in the 2825 ball park so perfect.
so next up is to collect300/ 600/1000 yard zeros/accuracy. testing has been in front and rear rests, final proofing will be bipod and rear bag/support.
 
yes AND NO
this is a mk248mod1.
ammo designed for the mk13 sniper rifle.
they started on 700 actions but went to stiller actions around mod 7.
it has a higher operation pressure...68k plus vs std of 65
it has a LONGER coal 3.5" vs 3.34 of oem
you can look up the mil spec as mk 248 mod1
reloader powder 26 makes it much easier to obtain the performance.
mk13 is 26", ,mine is only 24 and i am still getting their performance.
this is a single shot action.
as with all reloading work up a safe load in your rifle.

Worker said:
220 SMK at 2825 fps ,is this a 300 Win mag ?
Click to expand...
 
i have a nightforce 5.5-22x-50 coming that will replace the 8.5-25 luepold.
both are 30mm tubes but the nightforce has 100 moa internal elevation....
i can crank to the moon!
 
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pics

black on black rifle...
 

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so today was 600 yard zero.
the prone guys were practicing and they let me set up a bench
after pit duty. 2 fouling shots tracked well, then 5 target loads with
started low but centered, finished in the x ring of a 300 yd f class target.
ballistic software was off by 1.5 moa in elevation, windage stayed true.
next up is to find a 1000 yard practice day
 
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so six month later and i finally get a day at 1000 yards.
bad news is its all e targets no one is shooting paper.
so three guys on an e say i can shoot with them.
set up my bench and wait my turn.
the guy that owns the e, wants me to shoot at the berm to ensure i am centered up well and do not destroy his target. so i aim high centered but over the top. goes well but they say i went way high. so second shot i am at the center of the bottom of the frame.....bingo,,,,hit wood. third i am at the bottom of the bullseye....hit the bottom a little right, crank a little for the right, and shoot the fourth shot. wind is mild left, shot is 2.5 left and 2.5 down. that is a click each but will pass on the left right due to the breeze.
all is well. load works gun tracks..happy camper
 
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