300 PRC OCW Test and Questions

[BStark78]

I’m looking for feedback on my first OCW test that I’ve run on my new 300 PRC. I followed the instructions and process on OCWreolading.com and think I have my scatter node pegged at 75.1gr putting my OCW at 76.2 or 74.0 any input is appreciated.

H1000
Berger 230 OTM Hybrids
ADG Brass
Federal GM215M

First 3 shot test was done with 0.3gr increments.



l wasn’t certain about the result so I re-shot the test w/0.1 gr increments. 75.1 came back much clearer in what I believe to be a scatter node.


Target 1 is 6 shots. I had a brain lapse and shot the 5th shot for target 2 at target 1.

Based on my retest I believe I should test -1.5% or 74.0 gr. (+1.5% or 76.2 gr is above Hodgdon max; I see pressure w/ADG brass at 75.7 gr). I’m planning to test 0.1 gr increments from 74.0-74.7 as the 5 shot 74.8 gr load was a half MOA group with little variation at 74.9 grs.

This is where I’m looking for input…what next steps would you take?

My plan is to retest as noted above, decide on a charge, tweak seating depth, and possibly test primers.

I’m loading for a factory Browning with an A&D FX-120i and an AutoTrickler V3. All shots are off a concrete bench, sandbags, and being measured with a LabRadar.

 

[JFrank]

It's starting to go away at 75.0 gr. I would shoot on each side of 74.8 to confirm the center of the window. ( im looking at them as overlaid... PC style)

 

[Bc'z]

Quit looking at size of groups and look at the horizontal plane of your POI.
Looking at your 1st target I would have chosen 75.2- 75.3.
Second target confirmed 75.2.

 

[BStark78]

It's starting to go away at 75.0 gr. I would shoot on each side of 74.8 to confirm the center of the window.

That’s how I read it as well - that the vertical shift starts at 75.0, peaks at 75.1 and drops back down at 75.2. As I understand it, I should shoot down to 74.0 gr. (- 1.5% from 75.1).

 

[BStark78]

Quit looking at size of groups and look at the horizontal plane of your POI.
Looking at your 1st target I would have chosen 75.2- 75.3.
Second target confirmed 75.2.

I’m not looking at group size, only POI shift. On the second target, 75.1 gr has the most off plane POI shift of all groups. 75.2 is nearly 5/8” lower than 75.1. 74.8/74.9 are nearly identical in horizontal plane POI.

I couldn’t explained the vertical shift of 74.8 on the first target, which is why I re-ran the test at 0.1 gr increments, 5 shots per group vs 3.

 

[Bc'z]

I’m not looking at group size, only POI shift. On the second target, 75.1 gr has the most off plane POI shift of all groups. 75.2 is nearly 5/8” lower than 75.1. 74.8/74.9 are nearly identical in horizontal plane POI.

I couldn’t explained the vertical shift of 74.8 on the first target, which is why I re-ran the test at 0.1 gr increments, 5 shots per group vs 3.

Looking at 1st target 2 outta 3 shots are on same horizontal plane in your 75.1 and 75.4 groups.
I'm looking at your 75.2 group of 2nd target next to your 75.4 in 1st target.
Notice how groups were rising out then coming back down, I believe this is compensation and your bullet is being released on bottom of barrels harmonic whip.
If your not seeing preasure, it would be interesting to see the targets shot from 75.1-75.5 in .1 increments.
I feel there is something there to be seen.

 

[BStark78]

Looking at 1st target 2 outta 3 shots are on same horizontal plane in your 75.1 and 75.4 groups.
I'm looking at your 75.2 group of 2nd target next to your 75.4 in 1st target.
Notice how groups were rising out then coming back down, I believe this is compensation and your bullet is being released on bottom of barrels harmonic whip.
If your not seeing preasure, it would be interesting to see the targets shot from 75.1-75.5 in .1 increments.
I feel there is something there to be seen.

I had not really looked at it that way across targets, but certainly see what your saying.

 

[jsthntn247]

I’d try another powder

 

[BStark78]

I’d try another powder

What would lead you to that conclusion?

 

[jsthntn247]

What would lead you to that conclusion?

.3 increments is a very small change for a 75 grain powder charge and your poi is moving all over the place with those small changes. Your gun does not like that powder/bullet combo.

 

[Sandstorm]

Or your gun is not stable in the bag's..also what speed are you getting.

Your gun does not like that powder/bullet combo

Id try H4831sc if your not happy with the results when your done.
Im thinking also that .3 incriment shouldnt produce the amount of movement were seeing.

 

[BStark78]

Or your gun is not stable in the bag's..also what speed are you getting.

Id try H4831sc if your not happy with the results when your done.
Im thinking also that .3 incriment shouldnt produce the amount of movement were seeing

Best ES/SD I’ve seen was at 74.5 (13/9 - not in this chart).

 

[Sandstorm]

Yea...Id switch powders../ and or..You my friend need to get those SD's down.
I wouldnt persue this one....Try something new, Im sure youl find the right combo for that gun.
If you plan on shooting it further out, I wouldnt bet on this load.
Those 30s shoot better than that with the right combination. Keep at it Sir.

 

[Sandstorm]

If you run it slower it will group well around 74.4 to 74.7range with the right seating depth.
Not sure what your end purpose for this gun is.....but you should be able to do well in the 2680s
even with H1000

 

[BStark78]

If you run it slower it will group well around 74.4 to 74.7range with the right seating depth.
Not sure what your end purpose for this gun is.....but you should be able to do well in the 2680s
even with H1000

This is a hunting rifle. I’m really looking for consistency across a wide temperature range.

 

[Sandstorm]

Run them in a lower node then and
you will see better results (2c )
Shoot well my friend
John

 

[BasicMagic]

Tell me about your barrel. Factory or after market, twist rate, length, profile, what action and stock, who installed barrel?

How far from the lands are you parking these?

 

[BStark78]

Tell me about your barrel. Factory or after market, twist rate, length, profile, what action and stock, who installed barrel?

How far from the lands are you parking these?

This is a factory Browning Hells Canyon Long Range. It has a 26” 8T fluted barrel, .700 at the muzzle, bedded action and recoil lug (looks good). I’ve checked the action screws, the rings and bases as well as the optic - all good. The stock (factory) on the forend has some flex, but is free-floating.

I’m using sorted ADG brass, Redding competition dies, GM215M primers, H1000, A&D auto trickler, 2 thou neck tension, and am annealing every other firing.

230 OTM Tactical @ 0.30 OL. I seating depth tested these bullets and they shot best at this jump. Once I’m locked in on a load I’m going to tweak this a bit.

I’m am hoping for consist 1/2 MOA groups.

 

[BasicMagic]

This is a factory Browning Hells Canyon Long Range. It has a 26” 8T fluted barrel, .700 at the muzzle, bedded action and recoil lug (looks good). I’ve checked the action screws, the rings and bases as well as the optic - all good. The stock (factory) on the forend has some flex, but is free-floating.

I’m using sorted ADG brass, Redding competition dies, GM215M primers, H1000, A&D auto trickler, 2 thou neck tension, and am annealing every other firing.

230 OTM Tactical @ 0.30 OL. I seating depth tested these bullets and they shot best at this jump. Once I’m locked in on a load I’m going to tweak this a bit.

I’m not expecting 1/4 MOA groups from this rifle. I am looking for consist 1/2 MOA.

Alright heres what I am thinking. Increase neck tension a little to increase initiation pressure and tighten up your velocity spreads (possible incomplete burn at 26")

If you have a limb saver or other after market recoil pad remove it.

.7" at muzzle for a 30 cal is not a heavy profile. Make sure the barrel cools down as much as possible in-between groups. 5 shot groups for a varmint or less profile barrel might be more shots than that barrel can pump out consecutively.

Are you shooting these round robin or complete groups?

How are you measuring this powder?

How good of a group shooter are you? Can you shoot small groups? Do you shoot magnums often? Flinch can happen with big boys.

If it has a break make sure it is securely attached.

 

[CharlieNC]

I don't see a node. With that high capacity I would look at a wider charge range at 0.5 increments, which I think a ladder test may show more clearly than ocw.