Need help picking OCW load for .260

[david8989]

Okay here's the set-up:

<span style="font-weight: bold">GUN </span>
Savage 12 LRP .260
26" barrel
Bipod-front rest
squeeze bag-rear rest

<span style="font-weight: bold">Rounds</span>
140 AMAX
once fired R/P brass
CCI BR2
41.1-43.7gr H4350

<span style="font-weight: bold">Weather</span>
70 degrees
951' ASL
65% Humidty
2-8mph wind

This will be a 1K+ gun so i'd like to find the OCW on the top end and i'm new at reading these. There was one flyer with the 42.5gr charge that was called. I'm sorry these pics aren't a little more organized. I was thinking my OCW was 43.1gr but i'm not sure if im right. The deviation between 42.8 and 43.4 is only 0.088" in height and 0.139" in width. I need to get some imput and make sure i'm not just seeing what I want to see.

 

[Macmathews]

Re: Need help picking OCW load for .260

I like the node from 42.8 to 43.4

Try 43 grains

Kyle

 

[Macmathews]

Re: Need help picking OCW load for .260

Taking into account your 42.5 flyer , I would try 42.8 as well

Kyle

 

[david8989]

Re: Need help picking OCW load for .260

Also I seated these rounds at 2.825 with a max OAL for this rifle/round combo at 2.876...When I go to tune the load should I try .005 increments all the way to the lands or would .010 be sufficient?

 

[shoot4fun]

Re: Need help picking OCW load for .260

42.8
I found my sweet spot, using 142SMK, at .016 off the lands.

 

[david8989]

Re: Need help picking OCW load for .260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: david8989</div><div class="ubbcode-body">Also I seated these rounds at 2.825 with a max OAL for this rifle/round combo at 2.876...When I go to tune the load should I try .005 increments all the way to the lands or would .010 be sufficient? </div></div>

See, that's why I post here. I was looking for the highest charge so bad I missed the one right below it that grouped .397 for 32 shots, Thanks guys. Also anyone have any insight on the question above?

 

[shoot4fun]

Re: Need help picking OCW load for .260

My charge weight is a bit higher for my node. You may want to start another test at 43.7 and creep up by a tenth to just over 44, watching for pressure carefully. My load is over 2800 with a 26" barrel.

 

[8nbait]

Re: Need help picking OCW load for .260

My next move would be load some at 42.6, 42.8 and 43 and see if you get a duplicate. I would also shoot these at 200 yards if the wind isn't too bad. If you haven't hit pressure yet I would also try a few higher loads to see if you can find another node up higher.
If 42.8 looks good again I would fine tune at 42.7, 42.8 and 42.9 at 300 and see what you get. Then if it's not perfect mess with seating depth. But just my opinion.
gary

 

[david8989]

Re: Need help picking OCW load for .260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">My charge weight is a bit higher for my node. You may want to start another test at 43.7 and creep up by a tenth to just over 44, watching for pressure carefully. My load is over 2800 with a 26" barrel. </div></div>

I had just started seeing extracter swipes at 43.7 and didn't want to go any further. I had charges all the way up to 45.0 that I was seating at the range one at a time but never got past 43.7... Hell thats still 1.7gr over hodgdon max.

 

[shoot4fun]

Re: Need help picking OCW load for .260

Maybe 140 Amax develops pressure faster than 142 SMK. Looking at targets again, your node may actually be around 42.6. I would not go past 100 yds, as suggested, for OCW. Anything past 100 should be done as a ladder instead. Too many variables creep in for a valid OCW past 100. Run 42.5 to 43.1 in one tenth increments if you think you need further testing to confirm.

 

[bama1]

Re: Need help picking OCW load for .260

I gave up on 140 and 142. I use the 130 Berger. That is my hunting/target bullet all rolled up in one. (I still load the amax for burning powder and killing time). My gun doesn't group well enough for me with the 140's, Berger included.

 

[david8989]

Re: Need help picking OCW load for .260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dontknowdip</div><div class="ubbcode-body">

I gave up on 140 and 142. I use the 130 Berger. That is my hunting/target bullet all rolled up in one. (I still load the amax for burning powder and killing time). My gun doesn't group well enough for me with the 140's, Berger included. </div></div>

Well what do you consider a "good" group? The charge at 42.8gr is a 3-shot group at 0.376". I know it's not a 5 shot but I think I could make a 1/2 MOA group out of this load.

 

[bama1]

Re: Need help picking OCW load for .260

Like I stated, my gun will not shoot as tight as you got with yours and the 140 amax. It will, however, beat that with the 130's.
I had to back the 140 Bergers up 120 off to get it semi respectable. Just saying what I had to do with my gun.
I am glad that you can shoot the heavies, but I'm happy with the 130's bumping 3000fps. The deer are not.
I worked up a load with the 142 SMK that I thought was a keeper at 300 yards and it went to shotgun status at 600 yards? Mine is picky as hell!

 

[david8989]

Re: Need help picking OCW load for .260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dontknowdip</div><div class="ubbcode-body">Like I stated, my gun will not shoot as tight as you got with yours and the 140 amax. It will, however, beat that with the 130's.
I had to back the 140 Bergers up 120 off to get it semi respectable. Just saying what I had to do with my gun.
I am glad that you can shoot the heavies, but I'm happy with the 130's bumping 3000fps. The deer are not.
I worked up a load with the 142 SMK that I thought was a keeper at 300 yards and it went to shotgun status at 600 yards? Mine is picky as hell! </div></div>

Well I wasn't trying to play one upper, I promise

I'm debating on how I want to move forward with this load development. I'm kinda thinking I just want to leave the OAL where it is and load up about 20 rounds and see what they do at 500+. Or, Go ahead and load up 5 at each 2.825, 2.835, 2.845, and 2.855 and see if I can truly get that group smaller by tuning the OAL at 100yds.

 

[bama1]

Re: Need help picking OCW load for .260

The 300 yard group I mentioned was a ladder test. It didn't work out down range. I wasted a bunch of time, money and components trying to make mine work at 100 with OCW and ladder test at 300. What really ticked me off was the best I got with the SMK's at 600 was one of the worst at 100. I would try your load down range and see what happens.
As another example, the 130's I'm so fond of did the same thing down range. The first load I tried was 42g H4350 and it shot one hole at 100. I took it to 600 and it sucked also. It all changed when I got the fps up. It is now good to 1000.
My amax load is close to yours but not as accurate. I don't know if its the caliber or my gun but this was the hardest gun for me to find a load for.
Anyway, I am a long way from being a sensitive person so even if you were trying to one up on me it wouldn't bother me!

 

[CapDog]

Re: Need help picking OCW load for .260

What kind of speed are you getting with that load? Just curious as all my loads are a little hotter in powder charge, but my barrel is only 24". I just did some fire forming and I was avg'ng 1/2 MOA or better at 200 with 44.5gr H4350 under 139gr Scenars. In fact the worst group of the 3 was 0.8" and the best were 0.6"

I think the max load you are quoting in the Hodgdon site is for the Nosler Partition. The 142gr MK has a list max as 44.5. However if you are getting pressure early then listen to your rifle.

I've also had great success with H4831. Just that in my shorter barrel I couldn't get the speeds I wanted so I switched to H4350.

 

[david8989]

Re: Need help picking OCW load for .260

To be honest I don't know the speed of the rounds. I dont have a reliable chrono to check the rounds unfortunately. I think i'm gonna make up (4) 5 round groups of this charge and shoot a 100yd chrono'd group and some longer range groups together and see how it does.

 

[Brandon05_88]

Re: Need help picking OCW load for .260

I like to run my targets through OnTarget then graph the horizontal and vertical in Excel. Like the 3rd post:

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1087602

I already have a sample spreadsheet made up. I just dropped in your charges and measurements. I used 42.5 w/o flyer. I got a cluster of groups within roughly 0.150" of each other in the 42.5 to 43.7 range. PM me your e-mail, and I'll send it to ya.

I'd re-run the test from 42.5 to 43.5 in 0.2 gr since oddly enough most people find their loads for 140ish bullets in that range.

I shoot the 140 Amax with 43.2 gr H4350, and the 142 SMK with 43.4 gr H4350 in a 26" barrel. Both are roughly 2,825 fps too.

 

[AMG04]

Re: Need help picking OCW load for .260

Like others have suggested, 42.8-43.4 looks like a nice node.

I run 42.8gr of H4350 under both 140gr VLDs and 142 SMKs. The chrono numbers average 2772 for the 142s and 2806 for the 140s.

After my initial OCW test consisting of 18 rounds, 3 rounds per charge in 0.3 gr increments(41.7-43.2), I loaded up a seating depth test consisting of a control (loaded length of initial OCW test), then 3 rounds loaded 0.020" longer, and 3 rounds loaded 0.020" shorter. Also in this second test I loaded an OCW validation... I loaded 42.4, 42.8, 43.2 with 42.8 being my choice for OCW to see how they would group together. Even though the powder charge varied 0.8 grains the result was a one hole group at 100.

I may have been lucky, but with 30 rounds fired I had a very good load that I have confirmed out to 880 yards.

In a long winded way I guess I am saying you are definitly in the ballpark somewhere between 42.5 and 43.5. Others seem to have similar results. To save components you could just pick 43.0 and move on to a seating depth test which may yeild more information than fine tuning the powder charge. The nice thing about the OCW is how much leniency it provides when subtle variences occur in a load such as not having the perfect charge...

 

[bama1]

Re: Need help picking OCW load for .260

Best I could do at 330 yards with SMK. Didn't work out down range. I know the horizontal stringing comments will probably follow, but unless it includes why the 130's don't do this, it won't hold water.