Thread: 75gr Amax 223, Ladder test question

First up,I am wanting to try develop a load for 75gr Amax in my 223, if anyone had some data to help me with a starting point would be great, otherwise going to use info on Hodgons website.

Next thing is, I am going to attempt to do a ladder test, seems to be the best way to find a good load with the least shots used, just have a few questions.
Considering the Amax is so stink'n long and like other VLDs can be very sensitive to seating depth, how is the best way to go about a ladder test.

Do you take a guess at seating depth off lands (say 10thou)work out what powder charge shoots best, then do another round of testing for seating depth?
Or would you start with seating depth ladder test first at a recommended powder charge then do another for the powder?
I know you would usually start with powder charge, but my research online suggests that is seating depth was not in a good spot for your barrel then may be a waste of time working out powder until you get a decent idea of seating depth.

Many thanks

What is the barrel length and twist rate of your 223?

My son shoots a Savage 223, 26" barrel 1:7 twist in FTR competition.
We prefer to shoot 80 gr A-Max but these aren't available at the moment.

Last weekend we shoot the 75gr A-Max with 24.7 gr ADI 2208, seated 0.005" off the measured maximum - this is our 80 gr recipe (in Norma cases).
Looks like we could add a little more 2208 if we wished.

It's a 24" 1:8 twist, was going to use 2208 also.
Do you know what speed you are getting from either of those loads? Whats accuracy like?
Was going to try a seating depth of 0.010", seems to be commonly used, can always tweak later.

Accuracy with the 80gr is very good, competitive in FTR against other shooters using 308s.

Son shot a perfect score 60/60 last month at 500 yards with the 80 gr. Haven't used the 75 gr enough to compare.

The squares are about 1 MOA, so 11/12 are +/- 0.5 MOA. Is that accurate enough?

Originally Posted by Cyclops

Accuracy with the 80gr is very good, competitive in FTR against other shooters using 308s.

Son shot a perfect score 60/60 last month at 500 yards with the 80 gr. Haven't used the 75 gr enough to compare.

The squares are about 1 MOA, so 11/12 are +/- 0.5 MOA. Is that accurate enough?


Attachment 35319

What is your / your son's setup?

I am toying with the idea of going 223 myself for FTR to 600yds, mainly because that seems to be where the Americans have gone and a lot cheaper to do.

I found this interesting, http://www.longrangehunting.com/arti...223-mile-1.php

The electronic targets are way cool. I had to go back to manual for the 303 shoot and its not as fun.

@Beetroot we are using 2206h with the 75 amax's and they are mag fit length. Didn't bother measuring oal as it shot well enough.
The rifle is a tikka t3 hunter abs is a mates. I have just bought a t3 223 last week and will be trying the same thing. Although as I will have it all the time I will try adjusting seating depth and change of powder. From memory the case was full with a slight crush after using a drop tube.

Originally Posted by puku

@Beetroot we are using 2206h with the 75 amax's and they are mag fit length. Didn't bother measuring oal as it shot well enough.
The rifle is a tikka t3 hunter abs is a mates. I have just bought a t3 223 last week and will be trying the same thing. Although as I will have it all the time I will try adjusting seating depth and change of powder. From memory the case was full with a slight crush after using a drop tube.

My rifle is a Tikka also, wasn't going to try go for best accuracy and open up the magazine if I have too.
Any idea of what velocity you are getting?

The Tikka is only a Lite Stainless, but it seems to shoot very good, hopefully with a heavy projectile loaded it can be a light weight varmint/tactical/long range hunting/rabbit blasting/ goat destroyer, what ever you want to call it.
Have killed well with it out to 200yards, but would like to be able to take it out to 500/600yards and know it will perform.

I'll be back

We got an average of 2797 fps with an ES of 9 fps over 5 shots. This is slow compared to the adi book speeds. However we put done Australian outback 55gr blitz King loads through and they were only 3075 fps compared to the quoted 3275 fps on the pack. So the crony may have been reading slow that day.

Originally Posted by steven

What is your / your son's setup?.

As I wrote above My son shoots a Savage 223, 26" barrel 1:7 twist, Model 12, straight from the shop with addition of scope & rail + bipod.
When we can get them we will use 80 gr A-Max, trying 75 gr as no 80gr left to purchase.

This rifle has been shot out to 1000 yards. In heavier winds (aka Trentham) it can struggle at 1000 - though its first ever shot at 1000 at Trentham was an 'X'.

Originally Posted by steven

I am toying with the idea of going 223 myself for FTR to 600yds, mainly because that seems to be where the Americans have gone and a lot cheaper to do.

223 is less expensive and can be equally competitive.

Originally Posted by Cyclops

As I wrote above My son shoots a Savage 223, 26" barrel 1:7 twist, Model 12, straight from the shop with addition of scope & rail + bipod.
When we can get them we will use 80 gr A-Max, trying 75 gr as no 80gr left to purchase.

This rifle has been shot out to 1000 yards. In heavier winds (aka Trentham) it can struggle at 1000 - though its first ever shot at 1000 at Trentham was an 'X'.




223 is less expensive and can be equally competitive.

Cyclops, what speed are you getting with the 75s and how about the 80s?

Originally Posted by puku

Cyclops, what speed are you getting with the 75s and how about the 80s?

I've never measured the muzzle velocity so can't say.
Electronic targets give an estimate of terminal velocity which can be used to judge consistency of load.

I've used e-target terminal velocity to work back to a muzzle velocity for ballistic calculators - but it is a rough and ready guess to get ballistic calculations to match what we see on the range. My son would say the ballistic calculation or range chart will get you onto the target for your sighting shots, consideration of environmental conditions on the day will get you to the centre.

Maximum safe load for the 80gr A-Max was determined by examining the primers after trying a sequence 24.0 - 24.8 gr 2208 in 0.1 gr steps. 24.8gr was reckoned to be a little hot so we settled on 24.7 gr. This was used for the 75 gr, being a lighter projectile a little more 2208 could be tried if we wanted.

Originally Posted by Cyclops

I've never measured the muzzle velocity so can't say.
Electronic targets give an estimate of terminal velocity which can be used to judge consistency of load.

I've used e-target terminal velocity to work back to a muzzle velocity for ballistic calculators - but it is a rough and ready guess to get ballistic calculations to match what we see on the range. My son would say the ballistic calculation or range chart will get you onto the target for your sighting shots, consideration of environmental conditions on the day will get you to the centre.

Maximum safe load for the 80gr A-Max was determined by examining the primers after trying a sequence 24.0 - 24.8 gr 2208 in 0.1 gr steps. 24.8gr was reckoned to be a little hot so we settled on 24.7 gr. This was used for the 75 gr, being a lighter projectile a little more 2208 could be tried if we wanted.

Do you know what the OAL is with the 75gr?
When determining a .005" seating depth was that just something you tried and ended up working, or did you test to find what shot best?
I think I'll probably try a seating depth of .010" off the lands and give that a crack, .010-.015 off seems to be pretty common according to Google.

Originally Posted by Beetroot

Do you know what the OAL is with the 75gr?

Actually no I don't. I seat both the 80gr A-Max and 75 gr A-Max to the same length determined on the length measured with a Hornady OAL gauge, but haven't actually measured the OAL of the finished product.

Originally Posted by Beetroot

When determining a .005" seating depth was that just something you tried and ended up working, or did you test to find what shot best?
I think I'll probably try a seating depth of .010" off the lands and give that a crack, .010-.015 off seems to be pretty common according to Google.

The 0.005" was something we tried. We were seating them a bit shorter but went longer because we could (and I re-measured the maximum length with the OAL gauge).

We haven't done enough shooting with the longer length to tell if there is a significant difference.
I think we can say they don't shoot/group any worse that our shorter loads.

They worked well enough at the Nelson Champs in Westport.
The 223 Savage with the 80gr A-Max shot the highest score (of any shooter) at 700 yards in the rain on the Sunday.
So I think we can say that this combination of handload, rifle and shooter is working well enough.

I use the 75gr Amax in my truflight barreled savage.....1 in 7 twist 18 inch barrel.
25.5 gr 2208 and oal 6mm
I'm getting 2800 my.