OCW 30-06, 180 Accu-Tips

[User4302021]

Given: Ruger M77 MkII, 30-06, sporter weight barrel

Equipment: Forster Co-Ax press, Forster benchrest dies

Components: 180 Rem Accu-tip, Rem once fired brass (weight sorted), AA4350, Fed 210

Preparation: Brass annealed prior to resizing


Length to lands 3.365"

Max mag length 3.365"

Full caliber seating depth 3.325"


Method:

A) 2 rnds fired of each charge (charge weights accurate to 2 kernals of powder) to find max charge via Magnetospeed,

B) 2 rnds of each charge fired in the manner of an OCW at 100 yards (experimental, regular OCW is 3 rounds per charge),

C) seating depth test in .005" increments.


Pressure Test:

57 grains - 2612, 2605 Avg. 2608 Base expansion .4680"

57.5 grains - 2635, 2653 Avg. 2644 Base expansion .4685"

58 grains - 2685, 2691 Avg. 2688 Base expansion .4685"

58.5 grains - 2695, 2693 Avg. 2694 Base expansion .4688"

59 grains - Not tested, no more room in case, grains started crunching.


Notes on pressure Test: Temperature 50*F, 58.5 grains was full pressure but not hot. 59 grains if able to test, most likely would have seen pressure. Velocity seemed more consistent beginning at 58 grains. Powder burn was clean with all loads, full base expansion happened at 57.5 grains.


Theory: Guessing that pressure would have been seen at 59 grains. I would expect a node to show up at around 2% backed off from pressure, I would expect the node to show up around 57.8 grains.




Modified OCW test, 2 rounds per charge. 1 round fired on wrong target and annotated. Lines drawn from center to center of each pair and from that center to POA.




Notes: Sporter weight barrel exhibits same up and down pattern as a heavy barrel, albeit much more dramatically. It seems that the group size has a large variation also. This would make sense given the thin barrel. There seems to be a relative flat spot between 58 grains and 58.2 grains. The height is similar and the direction from POA is the most consistent of the charges presented.


My prediction was 57.8 grains (59 grains x .98), the chosen charge was 58.1 grains.


Seating Depth Test 100 yards:

OAL 3.325"

OAL 3.330"

OAL 3.335"

OAL 3.340"



Notes: The seating depth test was as dramatic as the OCW. Group sizes were from over 3 moa to just over 1 moa with a .005" change in seating depth.

 

[ar10ar15man]

IMHO YOUR "data" are exactly why to do a simple ladder as a starting point and run from ocw. lots of rounds, very little useful DATA.

 

[User4302021]

IMHO YOUR "data" are exactly why to do a simple ladder as a starting point and run from ocw. lots of rounds, very little useful DATA.

What data am I missing?
In 20 rounds I found max pressure,
I found approximate speed
I found the best powder charge.
I found a spot where the barrel is on the upswing (positive compensation?).
I found two charges that not only have similar heights on the target, but similar orientation to the POA (so, both X and Y axis agreement).
Another 20 rounds found the OAL.
Another 5 rounds over the chrono will get me a usable average speed, ES and SD.

To go from a handful of completely new and unfamiliar components to a finished load in 45 rounds is fairly quick IMO.

 

[ar10ar15man]

ladder
10 to get max speed/pressure
node for best accuracy, or 2
maybe 6-9 for actual accuracy
6-12 for oal
log data all the time no need to shoot just for speed sd/es
31 shots not 45 maybe less
yes it is that simple and it works
but it is your money and time

What data am I missing?
In 20 rounds I found max pressure,
I found approximate speed
I found the best powder charge.
I found a spot where the barrel is on the upswing (positive compensation?).
I found two charges that not only have similar heights on the target, but similar orientation to the POA (so, both X and Y axis agreement).
Another 20 rounds found the OAL.
Another 5 rounds over the chrono will get me a usable average speed, ES and SD.

To go from a handful of completely new and unfamiliar components to a finished load in 45 rounds is fairly quick IMO.

 

[User4302021]

ladder
10 to get max speed/pressure
node for best accuracy, or 2
maybe 6-9 for actual accuracy
6-12 for oal
log data all the time no need to shoot just for speed sd/es
31 shots not 45 maybe less
yes it is that simple and it works
but it is your money and time

You are using 3 rnd groups instead of 5 rnd for OAL, and chronoing as you go. So not a fair comparison. If you apply those same standards to the test I did, you can cut out 13 rounds. So, my 32 rounds to your 31.

If you have to go back and run another ladder (as often happens), you are going to add another 10 rounds to your number.

The ladder still doesn't tell you what is happening on the X axis because you have too many variables out at distance to pick the fly s*** from the pepper.

 

[ar10ar15man]

yes
but you did not and i do..all the time
i cannot remember ever having to redo my basic ladder.
keep telling yourself you did it your way .
life is not FAIR
(YOUR WAY..no groups under 1" at 100yards...yep you got a handle on this reloading stuff)

You are using 3 rnd groups instead of 5 rnd for OAL, and chronoing as you go. So not a fair comparison. If you apply those same standards to the test I did, you can cut out 13 rounds. So, my 32 rounds to your 31.

If you have to go back and run another ladder (as often happens), you are going to add another 10 rounds to your number.

The ladder still doesn't tell you what is happening on the X axis because you have too many variables out at distance to pick the fly s*** from the pepper.

 

[User4302021]

yes
but you did not and i do..all the time

Hence the unfair comparison.

(YOUR WAY..no groups under 1" at 100yards...yep you got a handle on this reloading stuff)

Factory Ruger rifle, sporter weight barrel, 6x Leupold M8 scope, Remington brass, AA4350, and Remington hunting projectiles. 1.3 MOA group (5 shots, not 3) with the final load.

I dare you to do better with the same components and equipment.

 

[User4302021]

i cannot remember ever having to redo my basic ladder.

log data all the time no need to shoot just for speed sd/es

So, your signature says you are a precision target shooter, out to 2,000 yards even, and you don't shoot at least a ten round string to gather average velocity? And you never have to redo a ladder test?

Sounds like questionable testimony to me.

 

[ar10ar15man]

I JUST DID A USED 308 win savage with 185's to .34 at 100 and under 1/2 moa at 600 (inside the f class 3" x ring)
6x and 1.3 is your limit, not the gun.
i have shot better with a vintage 4x and a milsurplus wwII rifle.
you seem to insist your method works , but the results does not support your OPINION.
DONE, NO MAS GO AWAY.
( ps it it take you 5 shots to hunt with, try another sport..)

Hence the unfair comparison.

Factory Ruger rifle, sporter weight barrel, 6x Leupold M8 scope, Remington brass, AA4350, and Remington hunting projectiles. 1.3 MOA group (5 shots, not 3) with the final load.

I dare you to do better with the same components and equipment.

 

[User4302021]

I JUST DID A USED 308 win savage with 185's to .34 at 100 and under 1/2 moa at 600 (inside the f class 3" x ring)
6x and 1.3 is your limit, not the gun.
i have shot better with a vintage 4x and a milsurplus wwII rifle.
you seem to insist your method works , but the results does not support your OPINION.
DONE, NO MAS GO AWAY.
( ps it it take you 5 shots to hunt with, try another sport..)

Let me guess, heavy barrel Savage, Berger 185's, match grade brass and premium powder. Yeah... that's the same. o_O

If you say you have an off the rack milsurp rifle that will shoot under 1 moa, and it wasn't made in Switzerland, I would call BS on that too.

It doesn't take 5 shots to hunt with, it doesn't even take 3. But being a super duper longrange shooter and all, I at least figured the concept of statistical significance would be familiar to you.(Weren't you the one that mentioned lack of data?)

Also, in case you forgot... this is my thread. If you don't like the conversation, then you are the one that is required to leave.