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338wm load development

18 Jan 2015
@ 04:19 am (GMT)

Ben Law

i need to decide what my next step will be in my load development.

im loading 225gr sst's with adi ar2209

first batch of test loads were all reasonable with a few nice groups.

63 .762
63.5 1.23
64 1.13
64.5 1.46
65 .815
65.5 .574
66 1.28

today's groups were not quite as good, with some quite poor.
it was quite windy. but the bigger groups had vertical aswell as horizontal spread.

66.5 .862
67 1.8"
67.5 2.2"
68 3"
68.5 1.4
69 1.85
69.5 1"
70 2.2"
70.5 .763
71 1.2"

a couple of the 1-1.5" groups were 2 shots nice and close with 1 a bit off, so may have been the wind.

69.5 is adi's book max, 71gr is max in nick harveys manual.

i'm wondering if i should go above max to around 72 or so, or if i should just work around the 70.5gr load in .2 increments.

these are the primers after firing, 71gr on the far right. do you think they look safe to go higher?


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29 Apr 2015
@ 02:09 pm (GMT)

Ben Law

Re: 338wm load development
well thanks guys, looks like i have a few things still to try with the sst.

buck, no offence taken by me.
there has been a bit of a thing between "stalkers" and "long range hunters" so it doesn't surprise me your post got a reaction.
800 is a long way! i'm not ready to hunt out that far just yet, but hopefully in time i will be.
i want the rifle to be capable of that distance so its not holding me back when i get to that stage.
plenty of gongs and rocks to hunt in the meantime, yes lots of practice.
i will be hunting semi open faces. and yep, a mate is normally required to direct you in search of the deer.
30 Apr 2015
@ 06:35 am (GMT)

Thomas Kitchen

Re: 338wm load development
we have all been there in one way or another martin.
i was got told by a pro 1080 person that i can't be concerned with animal welfare cause im not vegan and as a hunter i must gut shoot everything and leave it to die in pain.

anyway that's enough of negativeness.

just a question to you more experienced guys when the groups change so surprisingly with only a little grain step is it worth going back and rechecking those couple of charge weights to see if you get such a difference again?
30 Apr 2015
@ 08:45 am (GMT)

Martin Taylor

Re: 338wm load development
If they are around a node then l will recheck Thomas, patterns should show up through your ladder tests, groups opening and closing.

Say for example my LR rig (only because l can remember the numbers!)
.4moa @ 73.5gn
slowly opening to .7 moa then back down to .3moa @ 77.5gn.
At 78.5gn the pressures are too high and groups move out to 1 moa.

Once the node @ 77.5gn is repeated and proven l will check either side to confirm it is a robust load i.e.; sound at slightly lower and higher pressures/temps.

And it may be a small window of .5gn or less depending on case capacity etc. l have sporting barrels with certain pill/powder combinations that are very finicky, others in the same rifle not fussed at all. I have discussed with Nathan rifles that have different charges for full v’s neck sized cases. So it’s easy to see how things progress when chasing extreme accuracy-repeatability hey!
30 Apr 2015
@ 07:51 pm (GMT)

Nathan Foster

Re: 338wm load development
Yes, as Marty said.

A half grain can make all the difference in a lot of rifles, shhrinking groups right down. This also means that over time and with wear, sweet spots have to be re-investigated.
01 May 2015
@ 01:30 am (GMT)

Warwick Marflitt

Re: 338wm load development
Guns n old girls both are finicky and have their special sweet spots? I can think of a few I'd like to re-investigate? My old LE 303, 22lr Miroku lever gun, Juliette . Cindy and Fleur. .
As I remember they all hit the target!
08 May 2015
@ 08:28 am (GMT)

Ben Law

Re: 338wm load development
took an rdo today and went back to the range, not a great day for it but you've got to go while you've got the opportunity.

i picked the tightest groups from my previous tests. (65.5gr - .574" 70.5gr - .763")

after 2 foulers my results today were:

65.3 - 2568, 2549, 2502 - .692"
65.5 - 2557, 2537, 2548 - 1.7"
65.7 - 2562, 2560, 2585 - first 2 touching 1 on its own. 1.5"
70.3 - 2783, 2767, 2759 - 1.1"
70.5 - 2778, 2773, 2799 - 1.8"
70.7 - 2786, 2817, 2768 - 2.3"
76.5 - 2933

i wanted to retest my 76.5gr load from last time and 77gr.
after firing the first 76.5gr load the bolt lift was a bit stiff, there was a slight extractor mark on the case aswell as some soot around the primer.
last time i noticed a the 2nd part of the bolt lift to be slightly stiff but i thought it might have been ok. being way over book max and not much experience reading pressure signs i decided to call it quits before i push it too far and cause damage to the gun or worse. i wasn't really completely happy with being that far above max, when seating bullets the powder was taking quite a bit to compress, i think 77gr would have been the absolute max i could fit in at that seating depth.

it was disappointing the loads that shot well previously did not shoot well this time round.
for some reason accuracy has been inconsistent in this rifle.

perhaps i need to recheck and possibly try re-bedding, perhaps my shooting needs to improve... i'm not sure.

i am heading into the alpine national park for a week in a weeks time, i think i will have to go with the 65.3gr (.692") load for now.
its less than ideal, so i will be limited in range.
i will try a few shots on some rocks at some stage to see how far i can stretch it.
08 May 2015
@ 12:40 pm (GMT)

Buck Slammer

Re: 338wm load development
Hi Ben, I don't think the lighter load that shoots best in your rifle will bounce off the Sambar. If you can hit him in the right spot, it will kill him. Interpreting from your posts you might be frustrated, which reminds me of a 8mm Remington Magnum I owned years ago. I was struggling to get a load to shoot under 1.75 MOA. If memory serves me correct I was using a 220gn Hornady with AR2213SC and a Federal 215M primer. fiddling with charge weight and messing with seating depth to no avail. Well, one day I ran out of Fed 215's and all I had was Rem 9 1/2 on hand. I loaded them and went hunting. Some time later I tested the load. Eureka!...the load consistently printed less than 1 MOA, which it did until it was stolen from a safe in a break and enter (I am sure those thieves never shot it as you would imagine 8mm Rem Mag ammo is scarce). I guess the point is if you try different components you might find an improvement which saves you hair loss and lots of time.
08 May 2015
@ 09:35 pm (GMT)

Nathan Foster

Re: 338wm load development
Just a question or three sorry Ben, with the clamp on brake, how do you ensure the brake locates to the exact same point each time to clamp it together. Is there a witness mark punched into the barrel or brake.

Or- do you leave the brake on. If so, how do you check for carbon caking near the muzzle.

Do you have a good carbon remover.

How does the rifle recoil with the brake.

How does the rifle recoil without the brake.

Just wanting to check carbon as a variable, the brake as a variable and shooting technique / felt or perceived recoil as a variable.
08 May 2015
@ 11:03 pm (GMT)

Ben Law

Re: 338wm load development
buck - you seem to have had some success with different primers, perhaps its worth trying the wlr pimers in place of the wlrm.

nathan - hoppes 9 for carbon. i have been taking the brake off after each trip to the range and cleaning the bore with hoppes & sweets and eliminator, i always thought sweets was 'THE' copper remover but eliminator seems to be doing a better job.

i don't have any witness mark, thought i might do this later if i get it shooting.
but i haven't decided if i will definately use it in future.
what i do is put the rifle in a bipod, set it level using the bubble level on the scope and then slide the brake on and set it using another level.

i suppose there could be some very minor difference in alignment, perhaps this is causing issues.
i'm thinking i might take it off next time i go to the range.

i have been cleaning the brake after each use, its a bit annoying to clean.
i have never been able to get every little bit of carbon out of the ports.

i feel there's quite a noticeable reduction in recoil with the brake on, its still quite a bit more than a 30/06 i believe.
i didn't mind shooting it without the brake but as it was shooting very poorly (around 3" with factory ammo) i thought the recoil may have been contributing to this.

i never did try factory ammo with the brake and i am yet to try handloads without.
when i first put the brake on and tested handloads groups averaged under 1" so i thought i was onto something.
09 May 2015
@ 10:14 pm (GMT)

Nathan Foster

Re: 338wm load development
Well, it looks like you can already see where I was going with these questions so thats good- just things to be mindful of.

Visual inspection inside the muzzle of the rifle is very important. You know how hard it is to remove the carbon from the face of the muzzle and how it forms a very thick and tough layer. The same can occur within the bore so you need to get up close and inspect it. Make sure you use a bronze brush when cleaning. This issue and any changes to the mounting of the clamp style brake could be reasons why the rifle is shooting differently now than it was before.

Shooting technique is a potential issue. With this rifle, we are seeing a gradual opening up of groups as power and recoil increase which may not be reflective of barrel harmonics in any way. There are no signs of upper harmonic sweet spots; all we have seen with the last test, is that providing the rifle is going at .338-06 speeds, it shoots "OK".

By the same token, poor groups with increased recoil torque can be reflective of bedding.

4 areas to focus on:
Brake position (or leave brake off fif you want to test this also).
Technique, being sure to test using sand bags, not a bipod at this stage.
Bedding- pinch points- is the lug making good contact.

You could completely change things up by trying for example, the 225gr Speer BTSP. But I have a feeling that another factor is at play here. Even if the SST was not the ideal bullet for this rifle, I would expect to see a bit more in the way of at least one or two groups hovering around the inch mark. But- I could be completely wrong so don't take my words here too seriously. If you want to try another bullet, go for it.

Won't be too long and I will have the final book on technique / field work finished.
10 May 2015
@ 03:04 am (GMT)

Ben Law

Re: 338wm load development
next time i will test without the brake.
and see if i can get my hands on some other bullets.

the lug contact should be perfect, i thought i did that part of the bedding job really well.
it would be nice to have another stock to try a new bedding job with but its near impossible to find a stock to fit the left handed action.
i should have just gone right handed like all my other guns.

look forward to the new book.
10 May 2015
@ 10:43 am (GMT)

Warwick Marflitt

Re: 338wm load development
Hey Ben. I'm no expert on what you are doing. I have read this post with much interest as I'm setting up my 6.5 sweed so your posts here are a great deal of help . when I read your last entry about this being the only left hand rifle. I thought how well are you at shooting your right handed ones? What is the largest caliber in them and how tight a groups do you shoot with it? I say this as it's something that you have changed. I guess it's a mute point as you can't change it to a RH easily. Keep at it mate the 338-06 was a rifle I was keen to get and I talked about it with Nathan a bit and it was on my mind for a long time. I have a nice Sako and the right thing for me was to set it up and learn how to shoot it well. Maybe some light loads for practice of technique with the LH shooting will help. If you have to fire from some brass use trail boss and see how it goes without the recoil as a factor? Tell me to get lost Nathan or other members if you think that I'm wrong. And inventing problems. Keep at it Ben follow God's books and you will get it right and it will be a great feeling of satisfaction when you get it sorted.
11 May 2015
@ 04:45 am (GMT)

Martin Taylor

Re: 338wm load development
If this ends up a bedding issue Ben you can re-bed this stock, please do not think you need another!!

I feel that its leaning towards technique but you will be able to test that very quickly in the way you have discribed and reiterating what Nathan has said don't use a bipod over a test bench, it will drive you nuts, learnt that the hard way!!!

I don't think the lefthand thing should cause an issue. Once it's loaded, the side the action faces shouldn't change anything, as long a the stock shape allows for that grip.

Re-trying the factory stuff & brake will give you a good ldea and if possible a second known shooter may help your peace of mind. Keep at it mate.
11 May 2015
@ 06:49 am (GMT)

Thomas Kitchen

Re: 338wm load development
hi Ben
this has really has been interesting reading and i have been learning a lot thank you for keeping updates coming, hope you get it sorted.

just an idea have you got a mate that you can take to the range with you? maybe make 6 rounds of same powder charge. you shoot 3 your mate shoots 3 this might give you some idea if its rifle or shooter that needs more work.
11 May 2015
@ 10:23 am (GMT)

Ben Law

Re: 338wm load development
warwick, i dont think lh/rh is making any difference to my shooting.
for interests sake, my r/h rifles are 22lr, 223, 30-06. groups are around 1/2" with the 223, hardly fired the 30-06 remington core lokt's 1.5-2" but they don't seem to shoot well in any of my rifles, this gun has been in the safe a while but i'm going to pull it out soon and get it going. my blr in .270 was getting 3/4".

martin, i think at some stage i will re-bed this stock.
its a bit annoying though not to be able to easily get hold of a fibreglass stock or even a laminate stock as the l/h ones are $102 which is $2 too much for boyd's to send to oz.

thomas, i'm sure i could find someone to put a few rounds through it but the guys i hunt with are bush stalkers and don't shoot groups and aren't 'precision shooters' really so i doubt they would do much better, i think they would be lucky if they shoot their own rifles at better than 1.5-2 moa.
17 Aug 2018
@ 11:09 pm (GMT)

Ben Law

Re: 338wm load development
bit of an update.

for the last couple of years i have basically left this on the back burner while i have been busy with other stuff.

i finished up with a bit of work with the 285 amax, coal 89mm, from 57gr 2209 (2150fps) - 62gr (2350fps), with most groups coming in at or just under 1 inch , with a couple around 2", the best was .7"

but i decided to have a bit of a play earlier this week, in pretty poor conditions (30-40kph winds).
one load printed a nice group, 64.5gr, av 2446fps, es 22fps.

tested a few 225gr speer btsp as well. the groups don't look the best, but doesn't show a .7" group I shot with the 68gr load a while back, I do think the speer may show some sort of higher node, velocities are low and should have a long way to go before reaching max.

17 Aug 2018
@ 11:11 pm (GMT)

Ben Law

Re: 338wm load development
285 amax

225 speer btsp

18 Aug 2018
@ 08:07 am (GMT)

Martin Taylor

Re: 338wm load development
G'day Ben,
All those groups have split or possibly doubled, two together then one away.
Is that a normal pattern for this rifle?
18 Aug 2018
@ 09:35 am (GMT)

Ben Law

Re: 338wm load development
I seem to remember a lot of groups where the first 2 shots were very close togeather and the 3rd a flyer.

I don't have many photos of previous groups unfortunately.
I also often used just 1 target then patched it up and shot the next group, sometimes adjusting the scope between groups. Which hasn't made for great record keeping or allowed me to see how the groups change.
18 Aug 2018
@ 11:43 am (GMT)

Nathan Foster

Re: 338wm load development
Hi Ben, normally I would run 2213sc in the 06 and 338 if running the heaviest of bullets. Or better still, SF powder. But if its working for you, then all is well. Just keep an eye on pressures as per usual, primers, case life etc.

Yes, as you get into the bigger stuff, you'll find that minor stock annoyances become major issues. Muzzle brakes are generally only a band aid for these problems, they allow us to keep going for a bit but in the end we may reach a point where the kit is just not working for us. But sometimes we are simply not in a financial position to do much about it. It can certainly be a bit hit and miss, on the one side of the coin, yes we have a left hand action, on the other side of the coin we are forced to single feed it because the gun maker tried to make a one size fits none action. Again we just do what we can to get by. All of this experimentation will pay off for you one way or another, its all good learning.

I will go over your Tikka sling tension issue in the upcoming videos on LR shooting. But it will be some time before we are done.
18 Aug 2018
@ 02:58 pm (GMT)

Ben Law

Re: 338wm load development
If I were doing it all again I might go a different way about it.
Being LH makes things difficult. A LH sendero 300wm would be nice, but since they don't make them I would have to build one. Or go a T3 in 300wsm and mod the mag box... Or just put up with a RH sendero.

Single feeding isn't that big of an issue with the 285, and can be worked around by cutting the tips off allowing them to fit in the mag as you have advised before.

I'm not sure on SF powder availability around here, but I do have a preference toward ADI powders being locally made and normally available.

I will try 2213sc in the 06 at some stage, and I'll keep it in mind for the 338 too.

I have put the muzzle brake aside, not used it at all with the 285s, I don't think its necessary and would prefer to run without it.

I don't mind the tikka stock apart from being plastic. That said I do wonder about modifying a bell and Carlson stock for the LH action, they have the m40 stock but the drop at the heel i'm not so sure about, they also now make their medallist varmint stock which is a McMillan a3 shape, budget isn't a concern (within reason).
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