Tonights load test

[ricky5042]

168gn A-max with TR140 COL 2.200"
41.5gns 2521 fps 1.239"
41.7gns 2488 fps .328"
41.9gns 2514 fps .300"
43.8gns 2666 fps .840"
44.0gns 2692 fps .471"
44.2gns 2717 fps .649"
45.7gns 2798 fps .505"
45.9gns 2802 fps .934"
46.1gns 2850 fps .468"
46.3gns 2827 fps .744"
46.5gns 2843 fps .775"
46.7gns 2841 fps .635"
46.9gns 2855 fps .529"
47.1gns 2861 fps .1.077"
I had another case with a fracture in the base but didn't separate this time.

Rick

[gbal]

Ricky,

 

A good safe loading with N140 for 175 g bulletsis often found around 42.5-43 g.

That is where you have the best groups (41.7/41.9 in the .3s) for your 168s (with,here,similar TR140)

Pity you missed out all the 42g and almost all the 43 g options.

Much above that seems to me way too much powder,and another case separation is consistent with this,and your groups are at least doubling in size with these high powder loads.

As I understand it,you are not shooting competitively at 1000y with a custom action.I'd suggest you load down,as above.You may not get any better than .5 from a factory rifle,and maybe not that-as you are seeing at 50y-and you need some 5 shot groups with the more accurate loadings.

42/3 grains will be easier to shoot well too-and that might help groups.

 

 

COL 2.200" :What is this-SAAMI specs for the 308win case alone is 2.015",and of course the bullet adds quite a bit more -variably-to cartridge overall length. ???

Gbal

[ricky5042]

Hi Gal the other week I tried the TR140 from 40gns to 45.5gns and the best was 41.5gns .160" then 40.5gns .321" then 44gns .390" I am trying to find a load which will do all the distances iv been shooting, 2-3 & 400 at east holme 3-5 & 600 and 9-1000 at bisley but im starting to think I may have to forget about the 9-1000 and stick to 600 as the max range.

soz my oal is done with bullet comparator.

 

Rick

[gbal]

Hi Gal the other week I tried the TR140 from 40gns to 45.5gns and the best was 41.5gns .160" then 40.5gns .321" then 44gns .390" I am trying to find a load which will do all the distances iv been shooting, 2-3 & 400 at east holme 3-5 & 600 and 9-1000 at bisley but im starting to think I may have to forget about the 9-1000 and stick to 600 as the max range.

soz my oal is done with bullet comparator.

 

Rick

[oaken]

Rick

You seem to be chasing your tail here.

Before you discount 900/1000 work out the muzzle velocity you need to achieve to stay supersonic (ie, stable) with your chosen bullet. 168Max will be about 2825fps. I don't know your setup so can't advise on whether this is realistic.

Don't bother testing low charges if you want to shoot extended distances, its a waste of ammo and your time as you have already tested your loads to 2861 presumably without pressure. ?!?!

By all means shoot test groups at closer ranges. If a bullet and charge is consistent at 300 it will remain so until it hits transonic speeds, whatever range that may be at.

Shooting groups can be very misleading especially with only 3 shots. The slightest wind plays havoc with your results. Focus more on the vertical spread.

I notice that your groups get larger with increased loads, this could well be more to do with your shooting position and how you handle recoil.

I would highly recommend that you read up on ladder testing (Google it, there's loads of info out there), it will enable you to find your sweet spots with minimal fuss. Then fine tune your load by altering your bullet jump.

You may well run into high pressure if trying to achieve the velocities required for extended ranges so watch your brass carefully for stiff bolt lift and extractor marks on the web and of course flattened, cratered and loose primers.

I think your case separation stems not directly from pressure but your reloading and possibly insufficient brass grip in the chamber. Traces of oil, sizing wax or even water/rain in the chamber will very quickly cause brass to fatigue as in your pic.

Hope this helps

Rup

[gbal]

Hi Gal the other week I tried the TR140 from 40gns to 45.5gns and the best was 41.5gns .160" then 40.5gns .321" then 44gns .390" I am trying to find a load which will do all the distances iv been shooting, 2-3 & 400 at east holme 3-5 & 600 and 9-1000 at bisley but im starting to think I may have to forget about the 9-1000 and stick to 600 as the max range.

soz my oal is done with bullet comparator.

 

Rick

OK:look at your two groups from 41.5g....1.239 and .16 _what does that suggest about consistency?

 

Your best groups are in the 41.7 to 43 g loadings going way above is counterproductive,and way above what have been found to work well....ruptured cases should be raising eyebrows....

 

The 168g H is not a good 1000y bullet,ok to 600.

You may well have to just accept that-maybe develop a separate 1000y bullet/load,especially in a factory rifle,which just wont offer top accuracy or precision or pressure tolerance.

 

As a comparison, in my Rem 700,at its best a 1/2 to one moa rifle at 1000,load was 43.6 V N140,@2600 with Sierra 190g

Read Laurie's extensive experience on 308 loads/bullets/and stop wearing out your rifle to no purpose.

 

I still don't get this col-I wasn't asking what instrument was used,but what was measured that came out as 2.2 "-my loaded ammo was (primer to bullet tip) is about 2.8-2.9,allowing for +/- 5 though fiddling with seating depth.The brass needs to be trimmed when it exceeds 2.015 or so-I do hope you don't mean your brass is now 2.2 inches...but with heavy powder loads it will stretch.....and rupture.

Ease off the 168/600 loading-quite a bit (remember my load was 190g Sierra,and V140,not tr140.

Get a better 1000 y bullet if you want a 1000y capability (the 190 should shoot at 600 just fine).

Shoot 5 shots groups when you are close-for some reliability-you would benefit from a chrono too-for consistency-absolute velocity is just not the holy grail some think they are pursuing,unless you really need it and have the right bullet for the distance.And its not really just a weight issue-the berger 168 Hybrid(not VLD)eg is a good one:167/8 scenars /sierras are not...it's all in Laurie's posts!!

 

Gbal

[gbal]

From Accurate Shooter site 308 win

 

 

168g @ 2600 fps

cartridge overall length (COL) 2.80 (or very close for several bullets)

 

Look too at effects of barrel length and twist rate,especially for 1000y

 

And remember much of the data is for custom(=better) rifles....

 

No need to reinvent the blind alley.

Fine tune for your rifle what has worked generally....

 

Gbal

[ricky5042]

Hi my measurements are from the base to the ojive which is why they seem short, my brass has been sized and debured.

My new ones to try Wednesday are starting 10 thou off the lands with the 168gn A-max and 44gns of TR140 oal is 2.288" or from the tip to base 2.922" then im coming back further in 1 thou increments to 2.238" or 2.872"

I have a crono and im going to see how much difference there is from shot to shot then take an average to load into the shooter app.

 

Rick