I am having a Mosin Nagant day ... 300 Win Mag
- Thread starter Clark
- Start date
I am running 150 gr NBT moly with 62 gr bulk 4895 that matches H322 in the QL library. QL predicts 3174 fps
I measure:
3189 fps
3093 fps
3159 fps
QL thinks that 100% if the powder will be burned with a 12" barrel... but the velocity drops to 2618 fps, and the NFA laws would get involved.
3110 fps for 21.5" barrel
3057 fps for 20"
2975 fos for 18"
2879 fps for 16", the legal minimum, and burning 62 gr Powder to get 308 performance with 16,474 psi muzzle pressure [louder than any gun I ever shot]
I measure:
3189 fps
3093 fps
3159 fps
QL thinks that 100% if the powder will be burned with a 12" barrel... but the velocity drops to 2618 fps, and the NFA laws would get involved.
3110 fps for 21.5" barrel
3057 fps for 20"
2975 fos for 18"
2879 fps for 16", the legal minimum, and burning 62 gr Powder to get 308 performance with 16,474 psi muzzle pressure [louder than any gun I ever shot]
I added 4 pounds to the butt
The Mosin 300 Win mag project has had 3 disappointing trips to the range, and things must change. Adding weight makes it kick less and thus more accurate.
The Mosin 300 Win Mag 150 gr 62 gr H322 [bulk 4895] is accelerating the bullet from 750 fps to 2200 fps during the interval between 0.4 ms and 0.7 ms
That acceleration is delta V / delta t =[ 2200-750]/[.7ms -.4ms] = 4,833,300 ft per second squared
The bullet reaches a speed of 3160 fps
The bullet weighs 150 gr = 0.021 pounds
The bullet advances 20 inches
The rifle weighs 9.2 pounds with scope and bipod
The rifle reaches a speed of 7.2 feet per second = 4.9 mph
The rifle has a peak acceleration rate of 11,000 feet / second squared
The rifle recoils 0.046" before bullet escapement.
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I have just added a 4 pound block of 4140 tool steel to the butt.
That sounds like the wrong kind of steel for ballast, but it was just the right size and I did not want to wait on Speedy Metals.
I drilled and tapped 5/16-18 holes to fasten the grind to fit limbsaver recoil pad to the steel block. I drilled a .25" hole with 0.8" deep .375" diameter countersink for the conventional wood screws to the stock butt. That is 4 holes in tool steel. I flooded it with Cool Mist /water mix to keep the steel from getting hot. When it gets hot, it can get harder than the drill. That wrecks the drill and leaver a hard spot that must be drilled out with a carbide drill. I don't have 115 sizes of carbide drills, so I have to be careful. I shortened some 5/16-18 cap screws with the grinder. To get the threads back in condition at the screw tip I ran the screws through a 5/16-18 tap. I did that with an electric drill. After enough power screwing, they are civilized again.
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Now the rifle weighs 13.2 pounds.
The rifle reaches a speed of 5 fps = 3.4 mph
The rifle has a peak acceleration of 7,666 fps squared
The rifle recoils 0.032" before bullet escapement
I predict that this change alone, at best could improve the 4moa performance to 2.8 moa
That is still not good enough to hunt. We need at most 2 moa precision.
But we are doing everything we can, and tomorrow I will cut off the muzzle that offends me.
And the next day, Wednesday, I will be back at the range to do testing.
The Mosin 300 Win mag project has had 3 disappointing trips to the range, and things must change. Adding weight makes it kick less and thus more accurate.
The Mosin 300 Win Mag 150 gr 62 gr H322 [bulk 4895] is accelerating the bullet from 750 fps to 2200 fps during the interval between 0.4 ms and 0.7 ms
That acceleration is delta V / delta t =[ 2200-750]/[.7ms -.4ms] = 4,833,300 ft per second squared
The bullet reaches a speed of 3160 fps
The bullet weighs 150 gr = 0.021 pounds
The bullet advances 20 inches
The rifle weighs 9.2 pounds with scope and bipod
The rifle reaches a speed of 7.2 feet per second = 4.9 mph
The rifle has a peak acceleration rate of 11,000 feet / second squared
The rifle recoils 0.046" before bullet escapement.
------------------------------
I have just added a 4 pound block of 4140 tool steel to the butt.
That sounds like the wrong kind of steel for ballast, but it was just the right size and I did not want to wait on Speedy Metals.
I drilled and tapped 5/16-18 holes to fasten the grind to fit limbsaver recoil pad to the steel block. I drilled a .25" hole with 0.8" deep .375" diameter countersink for the conventional wood screws to the stock butt. That is 4 holes in tool steel. I flooded it with Cool Mist /water mix to keep the steel from getting hot. When it gets hot, it can get harder than the drill. That wrecks the drill and leaver a hard spot that must be drilled out with a carbide drill. I don't have 115 sizes of carbide drills, so I have to be careful. I shortened some 5/16-18 cap screws with the grinder. To get the threads back in condition at the screw tip I ran the screws through a 5/16-18 tap. I did that with an electric drill. After enough power screwing, they are civilized again.
--------------------------------------
Now the rifle weighs 13.2 pounds.
The rifle reaches a speed of 5 fps = 3.4 mph
The rifle has a peak acceleration of 7,666 fps squared
The rifle recoils 0.032" before bullet escapement
I predict that this change alone, at best could improve the 4moa performance to 2.8 moa
That is still not good enough to hunt. We need at most 2 moa precision.
But we are doing everything we can, and tomorrow I will cut off the muzzle that offends me.
And the next day, Wednesday, I will be back at the range to do testing.
Attachments
*I went to the range both yesterday and today.
*The VZ24 has a long trigger. I ordered a Timney from Brownells
*The 1903 Turk bolt handle broke off. The late Randy Ketchum did not have enough penetration on the TIG weld. I am cannibalizing another rifle
*The Dumoulin 6.5-06 shot a 1" 5 shot group at 100 yards.
*The Mosin Nagant 300 Win mag shot a 0.7" 3 shot group at 100 yards today. It was finally shooting well enough to go to 100 yards.
*The VZ24 has a long trigger. I ordered a Timney from Brownells
*The 1903 Turk bolt handle broke off. The late Randy Ketchum did not have enough penetration on the TIG weld. I am cannibalizing another rifle
*The Dumoulin 6.5-06 shot a 1" 5 shot group at 100 yards.
*The Mosin Nagant 300 Win mag shot a 0.7" 3 shot group at 100 yards today. It was finally shooting well enough to go to 100 yards.
Attachments
I broke a bolt handle Thursday at the range. The TIG weld had no penetration.
Today I drilled and tapped both halves with 1/4-28 thread.
I screwed them together. Clocking did not work out. There was a half a thread gap when oriented.
I filled that gap with Silver solder.
Today I drilled and tapped both halves with 1/4-28 thread.
I screwed them together. Clocking did not work out. There was a half a thread gap when oriented.
I filled that gap with Silver solder.
Attachments
I tried to put a Stoney Point Aftermarket turret on a 1973 Leupold Vari X ii 3x9x40 riflescope [The 350 Chevy of all riflescopes]
Stoney point has been sold. These have been dropped from the product line. They were always made in China. They have not been on the Stoney point web site for years, but new supplies keep coming in.
My guess is that it is all bootleg.
The scope elevation adjustment slot was designed for a coin [Yeah,,, LEOPOLD!]
They get adjusted by screwdrivers and the Aluminum slot gets beat up.
The Stoney point turret driver would not fit.
I thought it was because the slot was beat up. So I started de burring the Stoney point driver and the Leupold slot.
But measuring with pin gauges, the slot was 0.069" and the driver is 0.071".
It is not going to fit.
So I milled the screwdriver like tip of the Stoney point turret down to 0.066".
Still no fit.
Wrong radius on the tip.
So I changed the radius and it went in.
Then on to the standard Stoney Point turret nightmare, the shims.
I could not select from Stoney point or my collection of washers to get it to stop rattling.
So i tried bending a washer like a Belleville washer [spring].
That was to much force for the wimpy turret and it would not turn.
So I scrounged up a coil spring that would pass a .25" shaft on the inside, shortened it down to 3 coils, and stretched it out.
That works.
But the scope is so old, it does not have the standard elevation rate of 15 moa [minutes of angle] per revolution.
It is more like 6 moa or 6.5 moa, that i can see in my Leupold zero point boresighter system.
Stoney point has been sold. These have been dropped from the product line. They were always made in China. They have not been on the Stoney point web site for years, but new supplies keep coming in.
My guess is that it is all bootleg.
The scope elevation adjustment slot was designed for a coin [Yeah,,, LEOPOLD!]
They get adjusted by screwdrivers and the Aluminum slot gets beat up.
The Stoney point turret driver would not fit.
I thought it was because the slot was beat up. So I started de burring the Stoney point driver and the Leupold slot.
But measuring with pin gauges, the slot was 0.069" and the driver is 0.071".
It is not going to fit.
So I milled the screwdriver like tip of the Stoney point turret down to 0.066".
Still no fit.
Wrong radius on the tip.
So I changed the radius and it went in.
Then on to the standard Stoney Point turret nightmare, the shims.
I could not select from Stoney point or my collection of washers to get it to stop rattling.
So i tried bending a washer like a Belleville washer [spring].
That was to much force for the wimpy turret and it would not turn.
So I scrounged up a coil spring that would pass a .25" shaft on the inside, shortened it down to 3 coils, and stretched it out.
That works.
But the scope is so old, it does not have the standard elevation rate of 15 moa [minutes of angle] per revolution.
It is more like 6 moa or 6.5 moa, that i can see in my Leupold zero point boresighter system.
Attachments
-
Stoney point aftermarket elevation turret driver reduced from 0.071 in to 0.066 in and old Leupo.jpg -
Stoney point aftermarket elevation turret driver reduced raidus of driver to fit old Leupold sco.jpg -
Stoney point aftermarket elevation turret tried shimming, tried bending washer, spring worked th.jpg
10 times to the range and I think I've got it.
I took the 300 Win Mag Mosin to the range; 8-22, 8-26, 8-28, 9-3, 9-9, 9-10, 9-16, 9-17, 9-23, and today [9-25].
1) I loaded some 300WinMag ammo after finding only 90% of the primed brass would fit into the Mosin Nagant 300WinMag.
The difference seems to be a bulge in front of the belt.
300WinMag 125 gr Nos Bal Tip Moly, 66 gr IMR 4166, 3.34" over all length [OAL]
Quickload predicts 3174 fps 47 kpsi
a) Mosin Nagant Krieger barrel 14 pounds as tested with 4 pound butt plate and bipod
I fired 7 rounds.
Fired one sighter at 50 yards
Fired one over the chono and into the dirt
1.2" 5 shot group at 100 yards [ or 0.6" 4 shot group if I could throw out one]
What does it all mean?
good enough to proceed to long range target practice for big game.
Why did things improve?
Copper fouling powder, IMR-4166, lighter bullets, lighter triggers, less wind, and me shooting better.
I took the 300 Win Mag Mosin to the range; 8-22, 8-26, 8-28, 9-3, 9-9, 9-10, 9-16, 9-17, 9-23, and today [9-25].
1) I loaded some 300WinMag ammo after finding only 90% of the primed brass would fit into the Mosin Nagant 300WinMag.
The difference seems to be a bulge in front of the belt.
300WinMag 125 gr Nos Bal Tip Moly, 66 gr IMR 4166, 3.34" over all length [OAL]
Quickload predicts 3174 fps 47 kpsi
a) Mosin Nagant Krieger barrel 14 pounds as tested with 4 pound butt plate and bipod
I fired 7 rounds.
Fired one sighter at 50 yards
Fired one over the chono and into the dirt
1.2" 5 shot group at 100 yards [ or 0.6" 4 shot group if I could throw out one]
What does it all mean?
good enough to proceed to long range target practice for big game.
Why did things improve?
Copper fouling powder, IMR-4166, lighter bullets, lighter triggers, less wind, and me shooting better.
