Thread: Load development in the SI

I’ve been trying to develop a hunting load for my Kimber hunter in .308 but have not been able to nail it down so am looking for someone that will develop a hunting load that will be effective out to 500m.

Im well aware of the time and cost so will pay accordingly. I have some load data from loads that I’ve tried out.

Hobby time is at a premium for me at the moment so I’d like to spend it hunting rather than tweaking loads.

Based in chch
Cheers

what issue have you with currently tried loads????

My rem700 .308 was running 165gr Sierra hpbt on top of 40gr of 2206h at 2.80” getting 2650fps which was super accurate.

I stupidly sold that as soon as I got my kimber which is very light and rather short. So I opted for something in the 150gr weight.

Have tried 150gr sst and a few other projectiles in the weight range.

I’m playing with 150gr nosler BT on 44.0 gr of 2206h, fed primer and brass, loaded to 2.80” which is mag length.

Out of a 5 shot group I’ll get 3 touching, and 2 fliers all MV is within 10fps and I’m pretty particular when I’m prepping and loading.

I tried going up to 44.25 and 44.5 gr but groups opened up.

Warm barrel? Bedding issues? First 3 touch every time?

First is a flier 2-3-4 good 5 flier
Cool barrel down then another 5 and the spread is different. Opens up to over 1” in no particular pattern. With a couple touching and fliers

@257weatherby

light and short.....maybe superdiver is onto something....have you triple checked all screws....stock,action,scope ringsand scope bases....
have you eliminated the "nut behind the butt"
you shooting lightweight rifle to an inch group or just over.....I would assume you didnt buy short and light to shoot 500mtrs as the 80% of shots....even the 1" will get you there....

The rifle you have is probably not able to cut the mustard at long range (and from a hunting perspective 500 metres is long range. The characteristics of the rifle are a good indicator of its performance. Short and light gives lower velocity and less consistent accuracy, but is good to carry. Long and heavy gives higher velocity and more consistent accuracy, but is a bitch to carry. What you need to reach your goal is a 22-24" medium weight rifle.

Neck Sizing or full length sizing ??

As above, firstly check everything is tight. Might also be worth trying a bit hotter load if you haven't hit preasure signs yet.. My 16" 308 shot best at just above book max with 150BT. I think (without checking the ADI data) you can go up another grain yet before book max?

What twist rate have you got? what scope and mounts? what brass & neck size only or FL? Go on to GordensReloadingTools, and play with different projectiles & powders, it's a good place to start to work out a load, you already have some recorded speeds, etc.
I to my horror found my load of 44g 2208 with a 178 eldx was way up on pressure, yet the ADI info says I can go up another grain, but my recorded speeds 2575 were nothing like what they said 2670. There is an adjustment for speed which brought down the pressure; FYI - that load is for a Sako 85 22 inch barrel, 1/11 twist, I like a high BC projectile at distance .535 so lack of pace is what I'm trying to improve, but hasn't been a problem so far at the distances your after.

How thin and light is the rifle and barrel? Could be a contributing factor whether it be a hot barrel or rifle jumping about more then usual? I’m fussy as when doing load dev and never exceed three shots before letting it cool again. Also in saying that some rifles just shoot damn well and then others although will shoot well just won’t go that next level OCD well when you are trying to replicate that good experience from a past rifle.

Originally Posted by Strider B

My rem700 .308 was running 165gr Sierra hpbt on top of 40gr of 2206h at 2.80” getting 2650fps which was super accurate.

I stupidly sold that as soon as I got my kimber which is very light and rather short. So I opted for something in the 150gr weight.

Have tried 150gr sst and a few other projectiles in the weight range.

I’m playing with 150gr nosler BT on 44.0 gr of 2206h, fed primer and brass, loaded to 2.80” which is mag length.

Out of a 5 shot group I’ll get 3 touching, and 2 fliers all MV is within 10fps and I’m pretty particular when I’m prepping and loading.

I tried going up to 44.25 and 44.5 gr but groups opened up.

Short light rifles can shoot very well. Or Not. Depends entirely on the way the barrel responds to heat(ing). A barrel that is not carrying internal stresses etc can be very light and shoot well, I've had a very light (and reprofiled twice) Krieger that would consistently hold 75mm groups at 450M, but a current Rem model 7 with factory barrel won't even get close to that.

There is a well known rule of thumb (promoted by several people including John Barsness) that 46.0 gns of AR2206H behind a 150 to 165gn projectile in the 308 is very hard to beat. Its worked for me in several 308's and has proven out to be right on the money using OBT theory in the GTR tool for my 22" barrels - my Lithgow LA102 shoots 1/3 moa with this load and 165 Targex projectiles. I'd be working up if using it with anything other than 150 Gn projectiles.

Hey thanks for the replies

Everything is tight and snug where it should be. VX3i 4-14 scope is new

My previous .308 was a Rem700 s/s. It had a couple of inches on my Kimber which is 15" with a greystone can but was reliably hitting a 200 x 200 gong out to 600m, knocked over animals from 100 to 500m with a 165gr HPBT on 40.5gr of 2206h pushing 2650fps. The bulk of my hunting shots are 150-300m but I do get out target shooting gongs a bit to check wind drift and shooting at different angles affect my POI because its nice to know it can reach out a bit further if I need to.

Its been a bit different shooting my Kimber in comparison to my Rem 700 which is a fair bit heavier but i've put plenty of rounds through the Kimber and feel comfortable with my shooting but perhaps I need to put in some more time to get used to the rifle.

I may just be chasing the unreachable dream with this set up but would like to think it would shoot sub 1" reliably.

I had a brand new Leupold scope a couple of years ago that was faulty which made the load development extremely time consuming. If you’ve got another scope might be worth swapping it over. It would shoot a similar pattern to what you’ve described


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