helping reading/picking 300wm ocw results

[RckyMtnRutt]

So i just ran out today and did a 10 shot OCW at 300 yards. I know it isn't a ton of data to go off of but trying to find a load for my FIL's x-bolt 300wm. Conditions were pretty good 55 degrees maybe 4mph wind to the S/E. laying down in the bed with a really good rest so i feel like the gun put them where they were supposed to go.

180gr AB
Hornady brass (not my choice but what he had)
h-1000
fed 215m

77.5-78.5gr were both where i was aiming the whole time which makes me think that would be where the gun likes it (also almost same fps). I was aiming bullseye the whole time for all shots.

Velocities
76.5...2970.6
77......3008.9
77.5...3036
78.0...3038
78.5...3036.5
79.0...3108.6
79.5...3069.9
80.0...3126.7
80.5...3148.3
81.0...3140.1

 

[K.E.C. Darkside]

What you said ^^^^^^^^^^^^^^^.

 

[Tiny Tim]

From your velocities, that would suggest a point worth investigating, but your POI is all over the place.

Looks to be more of a "ladder" than OCW. Your POI suggests 76.5-77.

I generally do two of these side by side and compare velocities and POI.

 

[PddPdd]

Any chance you could post just the portion of the target containing all your hits? The text on the powder loads is too small for me to make out.

 

[Koda_]

Thats called a pressure ladder not an OCW test. Though since you shot at 300yds you might be able to pick up an accuracy node between similar charge weights that line up horizontally (elevation) wise but I cant read the small numbers on your target pic to tell. If you want to fast track this try an OCW test with the 3 charge weights in a row that had nearly the same velocity to see which charge weight has the best group. OCW is at least 3 rounds of each charge weight.

 

[MagnumManiac]

May I say this suggests to me a ladder test, which is meaningless @ 300.
The test you should have done is OCW group testing with 3 shot groups with each powder charge.
I don't understand why your shots are all over the target, as those velocity differences should NOT have caused such a variation in height at 300.
What is the rifle sighted in for?

@Koda_ beat me by 3 seconds

Cheers.

 

[RckyMtnRutt]

Thanks for all the feedback and yes i know i should have done 3 shot groups. I guess i usually do ocw. This is my first time doing a ladder. Just figured this might be able help me save components since i am just using all of mine for him. Also, the gun is sighted in at 100 yards for him. I didn't want to re-zero it for him or adjust anything since he dialed it. I saw his windage was sitting at 1 right. But figured this was how he set it. I didn't know where or if i was going to hit pressure and didnt want to pull bullets and dump powder. I was just making sure i could run these. I have never run hornady brass and thought it might not reach max.

I will be going back and running 3 shot groups with 5-6 different charge weights. Was just trying to dial in what the gun liked for velocities and dispersion. The wind picked up for the second half of the shots (7-9mph) but i dont think enough to push the bullets that far right. Top to bottom shots high to low 78.5, 77.5, 76.5, 77.0(touching), 81.0. Shots right 78.0,79.0,80.0,79.5,80.5.

I could have pulled the right shots. Im not used to such a heavy trigger but i had a sinclair front rest and rear saddle bag. Laying down in the bed of my truck. Hopefully this picture comes through more clear.

 

[Koda_]

Im not certain I would trust any group size shot from the bed of a pickup... seems like that would add to barrel harmonics?

There's a not much discussed load development method called the Saterlee test, where you run a pressure ladder just like you did (one shot each charge weight) at 300yds and the idea is you look for 3 (or more) charge weights that are on the same elevation and thats your optimal charge weight node, windage spread does not matter let em drift. I tried this a few years ago and was left staring at my target scratching my head, so many questions about pulling shots at that distance, flyers etc.
You have 2 groups with that, but only two shots respectively... again who knows about flyers etc. 76.5 and 77 are touching. You have 80 and 80.5 same elevation.

Your pressure ladder didnt mention finding any pressure signs so maybe do a true OCW test around the higher velocities... might as well keep an extra 100fps on the table. But I also wouldnt ignore the low ES node around 78gn charge weight either.

 

[RckyMtnRutt]

Im not certain I would trust any group size shot from the bed of a pickup... seems like that would add to barrel harmonics?

There's a not much discussed load development method called the Saterlee test, where you run a pressure ladder just like you did (one shot each charge weight) at 300yds and the idea is you look for 3 (or more) charge weights that are on the same elevation and thats your optimal charge weight node, windage spread does not matter let em drift. I tried this a few years ago and was left staring at my target scratching my head, so many questions about pulling shots at that distance, flyers etc.
You have 2 groups with that, but only two shots respectively... again who knows about flyers etc. 76.5 and 77 are touching. You have 80 and 80.5 same elevation.

Your pressure ladder didnt mention finding any pressure signs so maybe do a true OCW test around the higher velocities... might as well keep an extra 100fps on the table. But I also wouldnt ignore the low ES node around 78gn charge weight either.

Yes, i think you are exactly right. These are my thoughts as well. First time trying this out and i was left with what did i just do. I usually do 3 shot groups through all my powder charges on a bench at 100 yards. I just couldn't load my heavy *** bench by myself and didn't want to deal with it.

I did not hit any pressure. Primers were all great and i usually try to push it a grain over until i get one of: bolt lift, flattened primers, ejector swipe then i back off and leave it. Pull whatever is after that. I usually run my 300wm longer but FIL said they wouldn't feed out of the magazine. When i got the gun(x-bolt) my tikka 300wm loads that are loaded longer fit and cycled. But figured why not run them sammi for him if that's what he wants. I run rl-22 and haven't run h-1000 so i wasn't sure what to expect especially with hornady brass. I've always heard super soft and not a long life span. I usually run lapua and norma for my 300wm.

Anyways back to my regular real ocw which i always called ladders. It was once fired brass and I still have 35 once fired sized of his brass. So i'll run it back with 3 shot groups and see how it goes. Seems like it is running pretty fast up high which is nice to see.

Thanks for the feedback I really appreciate it.