Thread: "Karhu" A.K.A "Finnish Bear" 30-06 load developement

yeah 55 might be hundy slower....but shows definate promise.....wee tweak in depth might also change that ES you seem to like chasing....maybe LOL

Originally Posted by Micky Duck

yeah 55 might be hundy slower....but shows definate promise.....wee tweak in depth might also change that ES you seem to like chasing....maybe LOL

We shall see the charge weight ladder only tells me where the harmonics in the barrel like to be velocity wise the groups were irrelevant to a large extent. Will see where the 56.5gn load leads me and see if I can fine tune it. If I was only ever going to shoot this out to 200-300yards I guess the 55gn load would probably do. I really wanna see what I can ring out of this rifle accuracy wise and the lower the SD the better the potential for consistent accuracy. I know you think I'm mad Micky, but this is my happy place, I really enjoy tweaking loads and finding that sweet spot to make this rifle it's absolute best. I'll get there and I don't think it will be too hard.

your as nutty as a fruit cake...but I quite like fruit cake
you will get there...I KNOW you will.
you will end up with a good grouping load under inch and going like stink....I know it,you know it....
lets just hope you dont need to use 50-100 rounds to find it .

Originally Posted by Micky Duck

lets just hope you dont need to use 50-100 rounds to find it .

That is always the goal.....

well I guess this is as good of place to type this...and you can move it if its not..permission granted.

how to tune a load for accuracy
now I do this old school
load up say 5 different lots of ammunition as close to the same as each other as possible except for powder charge weights....5 grn difference between loads in big case
.25grn in smaller case
shoot these INTO TARGET to judge which are tightest groups.....
hopefully one will stand out as betterthan others
while doing this looking for pressure signs as per the manuals say to...hard /firm bolt lift..flattened primers, swipe marks etc
then if all is good i nthe world...you repeat the tightest group and it still is tight.
then maybe tweak seating depth by half turn on die either way and see if it gets better
right yo unow have found an accurate load thats not showing pressure... WRITE IT DOWN in vivid felt pen on paper or on your loading bench and dont change a thing..... if do change projectile,seat using die the same and hope it stays the same....

note carefully..NO chronigraph..... cause they werent a 'thing' back when this method was the way



now Dannyb does similar thing EXCEPT he works on chronigraph to find tightest VELOCITY between loads ,THEN works on accuracy via seating depth
for me velocity doesnt matter,I dont know and dont care,if book says its going to be quick enough to kill cleanly and its accurate. perfect. Dannyb on other hand shoots out further than my 0-350 at most,normally 0-100 so having really tight SD and high velocity IS IMPORTANT for small verticle spread at range.

to my mind neither of us is right or wrong..we both end up with a clean killing load that WE ARE HAPPY WITH and that is whats most important

Originally Posted by Micky Duck

well I guess this is as good of place to type this...and you can move it if its not..permission granted.

You're all good Micky what would a load developement thread be without your input about how I'm doing it
I expect you'll chime in with similar comments when I do my featherweight load developement thread too, in fact I'd be disappointed if you didn't.
Who knows I might get lucky and have it done and dusted with the initial charge ladder like I did with the 308 Lupo

Originally Posted by dannyb

Very different projectiles so it won't be anywhere near the same. Will do eldx ladder first as if I find a sweet load with them I won't bother with the 165btsp I'll just use them in my other 308win

Or hand them on to me, buy that is.

Originally Posted by SmokeyJason

Or hand them on to me, buy that is.

Sorry mate, will be using them in the featherweight

Does the Finnbear still have the fore-end pressure point or is it bedded ? over time the action will sink into the stock and possibly increase that pressure.

Originally Posted by Moa Hunter

Does the Finnbear still have the fore-end pressure point or is it bedded ? over time the action will sink into the stock and possibly increase that pressure.

Fully free floated, haven't had the action out of the stock yet. Don't intend to unless i run into problems. I will look at getting it pillar bedded and recoil lug and tang bedded to avoid issues around the timber compressing.

Made it back to the range this morning with 6 more rounds loaded to 56.5gn interesting results. If I exclude the last round shot I would have had an SD of 7fps, but even with the last round included the SD was still an acceptable 14fps over 6 shots.
What was strange was that between my last shots 2 days ago and today was that for the same charge weight I seem to have lost 21fps average. Not going to loose too much sleep over that. Still a ways to go yet.....
So my 6 rounds today shot at same target 3 rounds at a time 5 minutes apart gave interesting results, the cold bore shot was 1.5" right of the rest of my shots. I don't think I flinched or pulled it as all my shots felt good but I guess more testing will prove or disprove that.
Aside from the cold bore the rest of the 5 shots went into 1" at 100 yards which is not too shabby for 5 rounds. If I had only shot 1 x 3 shot group (I've numbered the shots on target) it would've been a very lousy group so shooting 6 rounds really helps to see where things are really at IMO.
My next step will be to do a seating depth ladder as described on Bergers website as copied below:

Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005.


Anyway here's a pic of todays group, probably be the weekend before I get back to the range to shoot the seating depth ladder.

Seating depth ladder loaded unfortunately due to work commitments i won't have time to shoot it till Sunday. I had 2 extra primed cases so loaded them as foulers

Finally got to the range today seating depth ladder results are in and I have settled on a load.
As per above 6 rounds at each depth, 10thou, 50thou, 90thou and 130thou from my jam/lands.
All of todays rounds were shot without a magnetospeed clamped to the barrel to ensure no external effects on grouping.
I shot 2 fouling rounds into the dirt, then started on my groups 3 shot group, cool barrel for 5 minutes then shoot second 3 shot group at the same target, allow 10 minutes for barrel to cool before moving on to the next seating depth, rinse and repeat.

My original charge weight rounds were 10thou and the 10thou rounds I shot today shot a similar group.



At 50 thou the groups tightened up, I'm also fairly confident I pulled the single to the left but even if I didn't that's pretty good and is where my final load is.


At 90thou the group opened up with a lot of vertical spread, nothing good here.



At 130thou the first shot was quite a bit lower and right of the rest of the 5 rounds so again nothing noteworthy here.



So I will settle on 50thou off the lands, will load up 50, use 3 to zero and then run a few with the magnetospeed to confirm velocity.
Looks like she's good to go velocity should be high 2700fps to low 2800fps with the increase in pressure created by seating the projectiles 40thou deeper than my charge ladder.

Well done. Very satisfactory result.

Good stuff. Nearly ready to sell then.