308 win build off a single shot 12 6br donor

[charlie b]

You might be surprised.

I had motorcycles for years and when I refinished them I used std spray bombs. When the surfaces are prepared well (sanded and degreased) the paint lasted as long as I had the bike. Even in some pretty harsh places. As long as rocks didn't hit it, the paint stuck well.

These days powder coating is the best way to go for durability. Small parts you don't need a gun, just a large enough plastic container to hold the part. Put some plastic beads and powder in there and shake. The static electricity makes the powder stick to the part. Bake, repeat, done.

[mikeinco]

powder coating is great for lots of things, but it is TOO THICK for some applications.
i had a spray gun and an air brush, but yes rattle can can work well. select the right paint and prep well.
i have baked finishes before...works well



You might be surprised.

I had motorcycles for years and when I refinished them I used std spray bombs. When the surfaces are prepared well (sanded and degreased) the paint lasted as long as I had the bike. Even in some pretty harsh places. As long as rocks didn't hit it, the paint stuck well.

These days powder coating is the best way to go for durability. Small parts you don't need a gun, just a large enough plastic container to hold the part. Put some plastic beads and powder in there and shake. The static electricity makes the powder stick to the part. Bake, repeat, done.

[charlie b]

Yes, it is too thick for some things, but outside of a receiver that would not really be an issue. Except maybe under the scope mounts.

I do like simple though, so rattle cans are what I use most of the time.

[mikeinco]

what temp is it cured at ??

Yes, it is too thick for some things, but outside of a receiver that would not really be an issue. Except maybe under the scope mounts.

I do like simple though, so rattle cans are what I use most of the time.

[charlie b]

Between 350 and 500F depending on mfg. Baked for about 30min. One coat finishes usually run about 0.001-0.002", You can apply them thicker with a gun. If you coat and then 'sap' the item to shed the excess it is a thinner coat. Have to practice a bit to get it right.

[mikeinco]

so
i left the trigger and safety in place at 170....no melted trigger parts.
i think the 350/500 might be a different story.
just saying
trigger guard is next up. it is brushed al finish.
2 coats of epoxy then on flat black enamel
all baked maybe 1 hr at 250

Between 350 and 500F depending on mfg. Baked for about 30min. One coat finishes usually run about 0.001-0.002", You can apply them thicker with a gun. If you coat and then 'sap' the item to shed the excess it is a thinner coat. Have to practice a bit to get it right.

[mikeinco]

got an email today..the bbl has been shipped from houston unlimited.
tracking says in the state and delivered tomorrow.
i need to finish up the brass.

[charlie b]

You're doing the threading and chambering next?

[mikeinco]

that is done...
this was sbn treatment(salt bath nitrite)
next is post treatment bbl clean, then re-assemble and shoot
zero scope/simple ladder test


You're doing the threading and chambering next?

[mikeinco]

so fully assembled, scope mounted, gonna load some ammo tomorrow.
black stock, black bbl, black recoil lug,black bolt handle ,collar and bolt, black scope , rings and base, black suppressor, even the red blade on the trigger was partially sprayed black.
get the picture ?

[charlie b]

You want a rifle no one can see at night? LOL

[mikeinco]

first shots today
bore sighted at 40yds and 2 shots
2 shots at 100 and good
then just one shot at 200 and good.
i was going to do a shoot and clean for 5 shots,
but the SBN is very HARD...LIKE A ROCK. so really no break in, just shoot it.
i did clean after 5 shots...no copper
i shot an 8 shot ladder at 200 yards( i have shot this bullet/primer powder before)

less than 1.5" spread for 7 of 8 shots. shot 7 was a flier....no known cause, velocity was on...probably the shooter
that was a 1.8 gr spread of powder. ran from just under 2500 to just over 2600 fps.
need to pick some spots and shoot some groups.
( i just cleaned the bore...8 shots...no copper..none)
no hiccups, brass looks good/primers look good, bolt ran ok
br match this weekend so next week before anymore work.

[charlie b]

Nice work Mike. Not that we expected anything less. Will be interesting to see how it dials in.

[mikeinco]

so i shot four 3 shot groups today at 200 yards. very mild conditions.

1) 2" 2551/7.5
2) 0.552" 2566/5
3) 2.5" 2579/10
4) 1.5" 2598/6
i think i'll use number 2.
need to go repeat with a couple of 5 shot groups.
n140 powder between 41 and 42 gr, lapua palma case, fed sr primer,lapua 185 fmjbt(actually a rebated boat tail) not your usgi fmj.
my biggest problem is it is a 24x scope and i shoot 42/48/55x mostly, a 1.5# trigger where i normally shoot triggers in the 1-4 ounces.
things to get use to.
then, need to confirm my 100/200/300 zeros and do some 600 yard shooting
need a better scope,,,,like a 5-25x nightforce or the older 5-22x

[charlie b]

Looks like you might have found a group!

Are those Lapua bullets the ones with the squared off back and a smaller boat tail? I had heard that is the 'best' shape, but, have not seen anything definitive either in shooting or analytically.

Scope magnification and trigger. I alternate between my 12BVSS with 5-25x scope and an Axis with a 4-16x scope. Kinda tough sometimes. Shooting with the lower power seems like a handicap. And the trigger pull is really noticeable, especially since the Axis is also about 3lb lighter rifle.

But, I have confidence in you. After a while I'll bet you are shooting in the twos or threes.

[mikeinco]

yes the rebated boat tail is not just a taper, but a dia reduction, then a boattail.
the national championship i won, was shot with a then brand new bullet, a 6mm 105 with a REBATED BOAT TAIL.
they are had to make.

Looks like you might have found a group!

Are those Lapua bullets the ones with the squared off back and a smaller boat tail? I had heard that is the 'best' shape, but, have not seen anything definitive either in shooting or analytically.

Scope magnification and trigger. I alternate between my 12BVSS with 5-25x scope and an Axis with a 4-16x scope. Kinda tough sometimes. Shooting with the lower power seems like a handicap. And the trigger pull is really noticeable, especially since the Axis is also about 3lb lighter rifle.

But, I have confidence in you. After a while I'll bet you are shooting in the twos or threes.

[charlie b]

Thanks. I need to go back and look at some supersonic flow information on rebated boat tails.

I know that the cast bullet folks like them due to less deformation of the boat tail by the combustion products.

[mikeinco]

i did clean the rifle. 13 shots, NO COPPER
this is the same as the sight in /ladder shoot.

sbn is hard and slick

[mikeinco]

did one more mod to the rifle today.
shortened MY ejector spring from about .5 to just over .4
it no longer launches the brass for a field goal, just a nice soft short eject.
this makes closing the bolt much softer/smoother.

[charlie b]

Did a bit of reading about rebated boat tail design. Quite an old concept and studied a lot. I had seen some of this in artillery ballistics papers done by Aberdeen, but, it seemed a result of how they made the artillery shells, not a deliberate intent in the design, ie, the large brass driving band serves the same role as the rebated BT.

From pure supersonic aerodynamics in flight it is almost a wash between rebated and std boat tails, as long as the boat tail angles are correct for the flight regime. The rebated boat tail helps in that regard as it seems to be better across a wider range of velocities.

The big difference is at the muzzle. Boat tails designed for the higher velocities are such that escaping muzzle gases flow forward over the bullet very well, resulting in a lot of turbulence in front of the bullet as it leaves the barrel. This turbulence is one of the causes of long range bullets needing time of flight to 'settle', and why flat base bullets are preferred at shorter ranges.

https://www.youtube.com/watch?v=ZDUL_1vrABI

The rebated boat tail is the best of both it seems. Just a little more difficult for bullet mfgs to make.

It also seems that if you use a muzzle brake this effect is much less of an issue since the majority of the muzzle blast is deflected by the brake leaving little to 'mess up' the bullet.