@ 10:09 pm (GMT)
Tony MenziesHi all,
I have read Nathan's knowledge base on the 7x57 and understand that the 162 a-max is a very good performer in this cal.
However I wonder what people think of this bullet for Sambar sub 300yards as mature stags are a very big and tough animal and the amax is highly frangible.
I have some 150g partitions and some 140g interlocks which might afford better penetration?
Any insights appreciated
@ 12:50 am (GMT)
Re: 7x57 bullet selection for SambarHi Tony, I would prefer to see you experiment with the 150gr and 160gr Partition bullets please (depending on twist rate). The A-Max is not up to the task though it can be done if launched at low velocities (2400fps). The 160gr Partition is ideal if your twist rate will allow it, offering far superior penetration.
Drive the Partition as fast and as accurately as you can manage. If your rifle is in good condition, you will find that you have to go well above book max to achieve full speeds.
@ 07:26 pm (GMT)
Re: 7x57 bullet selection for SambarNathan, really appreciate you input. Barrel is MAB 1:10. Although the action is M98 Famage made by FN pre-war, it is in excellent condition and as yet I have had no pressure issues, though to date I have stayed within manual recommendations.
@ 09:46 pm (GMT)
Re: 7x57 bullet selection for SambarOK, so we need a bit of a plan of attack. The 150gr bullet may be your go to bullet due to twist rate but it would be nice if you could test a pack of 160 grain bullets.
I will quote my own test loads below for 160 grain bullets (up to 168gr match style with soft jacket). Please bear in mind that I cannot condone my loads as my start loads are above book max. My max test loads are 6.5 grains above book max.
ADI 2208 (Varget), U.S made brass or Norma brass, Fed 210 Primer (or CCI or Win).
Bullet weight 160gr
Start load 41gr
Max test Load 44gr
ADI 2209 (H4350)
Max test load 49gr.
If using a 150gr bullet, my start and max test range is 1 grain higher.
The above loads will be dangerous in some rifles.
Please read the COAL article on this website before setting about load development.
Due to bore size, you must try to use velocity in order to increase fast killing potential Tony. This means that whichever way you go, you will need to perform serious load development, find near maximum for your rifle (primers starting to flatten or sticky extraction) and go from there. So you need to have all of your ducks in a row from a safety perspective. But at the same time, do not be so cautious as to flinch each time you step up a half grain as I have seen some folk do. The ADI powders and your cartridge will build pressure slowly- its not a finicky cartridge. So play it safe but do the business.
As you build velocity and recoil energy, accuracy may be negatively affected. You will need to make sure that the bedding is sound and that any loss of accuracy at high velocity is not caused by insufficient shooting technique (or flinching). This is another common trap- folk think that the rifle must be over loaded (producing fliers) when the shooter is at fault. That and poor bedding. So many rifles never reach their full potential.
If the cost of projectiles is too high, use the 154gr Interlock as a preliminary test bullet to get a basic handle on the rifle, then switch to the Partition for final load work.
I can't say which powder is better for you. ADI 2208 might be the way to go if you end up having to commit to the 150gr bullet weight. It would be ideal if you could experiment with ADI 2208 with the 150's and then 2209 with the 160gr bullets but sometimes we can't afford to experiment with both so we have to chose one. If I had to hedge my bets, in this instance I would go with 2208. This all depends on what you have on hand and as I said, what you can afford so have a think about what will suit.
OK, that will give you plenty to do over the coming weeks.
@ 10:06 pm (GMT)
Re: 7x57 bullet selection for SambarNathan,
That will give me plenty to do over the next month.
I am very grateful for your help