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simon6ppc

8 twist 223 75 amax

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orite chaps,ive bought a new 8 twist sako 223 with a 24 inch barrel..ime wanting to use the 75 Amax in it..the Amax touches the lands on 2.445.. so ive tried so far 23 grains of H4895 with 2.415, 2.420, 2.425, 2.430 ....with not to good results of just an inch at 100 yards,does this bullet need to speed up or jam into the lands even as this cal is new to me,any advice would be very help full,cheers Simon..

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Simon,maybe so far there is just too much jump-in 22 calibres,.010 to .020 from the rifling is often the best zone,and you seem a bit further out-there is no absolute,as rifles can be individual,and some are more fussy about very fine tuning (6PPC is prettty good with a wider envelope!).

Bullets-Hornady probably no exception-might be 10 thou different in length from the box,so COAL is relatively suspect-except for magazine length,so use a comparator and seat from the much more uniform ogive measurement.

There is usually an accuracy node within a grain-often half a grain-of the 'book max' load,and no reason to go beyond max-any imagined gains are vanity,as much as velocity ( within the 223's effective envelope). Good luck.

 

gbal

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I have a sako 75 with a 1-8 factory barrel and I have to single load the 75g amax for it , it won't load to length and mag feed. such a shame as the 75g amax shoots awesome with varget.

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orite chaps,ive bought a new 8 twist sako 223 with a 24 inch barrel..ime wanting to use the 75 Amax in it..the Amax touches the lands on 2.445.. so ive tried so far 23 grains of H4895 with 2.415, 2.420, 2.425, 2.430 ....with not to good results of just an inch at 100 yards,does this bullet need to speed up are jam into the lands even as this cal is new to me,any advice would be very help full,cheers Simon..

 

Maybe 23g isn't an accurate charge weight and 1" is as good as it will produce?

 

I would use a comparator as gbal suggests, seat the bullets 0.010" from the lands and then vary the charge weight using the OCW method.

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thanks for the replies chaps,i will measure from the ogive when i get the parts ive ordered.ime trying varget and vit 140 today

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hi i shoot a 1-8 tikka 20" and use 75 amax. found mine like a 20thou jump.

i use a sled and single feed

n135

running 2828 fps avg with a es 10

 

good luck with testing.

 

cheers

gibbo

 

 

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thanks for the replys chaps,at the moment i have a 5 thou jump which can shoot half inch at 100 yards with 22 grains of H4895,i don,t trust this load yet as i could have got lucky that day,but will be my load for the time being,ive owned quite a few calibers now over the years ive been shooting but i have to say to get these 75 Amax to shoot in a 8 twist 223 how i want has been very hard..

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thanks for the replys chaps,at the moment i have a 5 thou jump which can shoot half inch at 100 yards with 22 grains of H4895,i don,t trust this load yet as i could have got lucky that day,but will be my load for the time being,ive owned quite a few calibers now over the years ive been shooting but i have to say to get these 75 Amax to shoot in a 8 twist 223 how i want has been very hard..

Some barrels just won't shoot 75gr amax no matter how hard you try!!

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Some barrels just won't shoot 75gr amax no matter how hard you try!!

 

Is there any info out there as to why?

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Is there any info out there as to why?

It's as simple as some bullets don't suit some barrels.

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Give the Sierra tipped match kings a go in 77gr or 69gr I tried lots of different seating depths and power weight with the 75grain amax but still not great results.

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Give the Sierra tipped match kings a go in 77gr or 69gr I tried lots of different seating depths and power weight with the 75grain amax but still not great results.

in all fairness i have got them shooting well at the moment,but only with a starting load of H4895..there around 2.800 ftps ish,but my mate has the chrono at the moment so not sure..my fox bullet is a 50 grain blitz king with a max load of varget which shoots brilliant.i will try more powders very soon

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Is there any info out there as to why?

I think either Laurie or gbal mentioned it being something to do with them having a secant ogive instead of a tangent ogive or the other way round.

 

My .223 hates them too but loves the 75gn Hornady Match.

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thanks for the replys chaps,at the moment i have a 5 thou jump which can shoot half inch at 100 yards with 22 grains of H4895,i don,t trust this load yet as i could have got lucky that day,but will be my load for the time being,ive owned quite a few calibers now over the years ive been shooting but i have to say to get these 75 Amax to shoot in a 8 twist 223 how i want has been very hard..

This sounds like quite a light load for h4895. My go to load with h4895 was 24.8 grains. This achieved velocities of 2850 fps and achieved groups under quarter moa with hornady 75 gr bthps. You need to be achieving speeds around the 2800 fps . This is a hot load and I would suggest starting off at 23.5 grains and jump up in .2 grain increments. You will hit a sweet spot around 24.5 grains for the 75s. There's usually a couple of accuracy nodes. The one I was hitting was on the higher side of the charge weight but worked very well.

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They can be finiky , my 223 Ackley would show pressure signs at 23grains of H4895 . 2545 col , 75 Amax . With a 77 smk id reduce to 22.8 still got loads of H4895 . I don't know how people use more powder in a smaller case ! Std 223rem !

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My accuracy load with the 75gr A-Max in a standard .223 is an unpostable amount of VV N140.

 

Running 3070 fps in a 30" barrel.

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This sounds like quite a light load for h4895. My go to load with h4895 was 24.8 grains. This achieved velocities of 2850 fps and achieved groups under quarter moa with hornady 75 gr bthps. You need to be achieving speeds around the 2800 fps . This is a hot load and I would suggest starting off at 23.5 grains and jump up in .2 grain increments. You will hit a sweet spot around 24.5 grains for the 75s. There's usually a couple of accuracy nodes. The one I was hitting was on the higher side of the charge weight but worked very well.

ye cheers pal,i worked up to 24 grains from 22 increasing them 2 grains every load,ive now found 22.2 of H4895 to be the best,,but i have to say on 24 grains i had no pressure really,may be i should of gone up to 25 but i do believe that would have been hot,i have some berger 70 grain HPBT,S VLD which shoot awsum with a max load,but they are not really a hunting bullet

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ye cheers pal,i worked up to 24 grains from 22 increasing them 2 grains every load,ive now found 22.2 of H4895 to be the best,,but i have to say on 24 grains i had no pressure really,may be i should of gone up to 25 but i do believe that would have been hot,i have some berger 70 grain HPBT,S VLD which shoot awsum with a max load,but they are not really a hunting bullet

At 24.8 there was no pressure signs worth talking about. But at 25 grains there was pressure signs and also, at 600 yards they dropped by about 6 inches. So to my mind I had unburnt powder as the velocity went down and pressure went up. If you have found a good load at 22.2 grains, I would say this is the lower accuracy node. The new 69 gr tmk are a fantastic bullet which are devastating on quarry. I use 25.5 grains with these with velocities at 3100 or thereabouts.

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