slick39, if you're using AMax bullets, I am asumeing that your either varmint hunting or maybe doing some casual target shooting.
IMHO, you would be better off with the Hornady #22601 95 grain VMax. Quite a bit quicker as well as devastating to coyotes and smaller varmints.
As far as a 120grain AMax, I can't find any reference to any 6.5 AMax until the 140 grain weight. Are you sure about your weight description?
I don't shoot a 260 Rem but I do shoot a 6.5x55 Swede out of a modern bolt action Tikka T3. I love that rifle/scope combination. It will shoot any bullet weight right up to the 160 grain VLDs, better than I can hold. If I miss, I can't blame it on the rifle.
The real difference between the two is miniscule. The 6.5 calibre is outstanding in good rifles. In cases with similar in capacity to ours, the lighter bullets do well with mid range to slower powders. I like powders like H414 and H4831 lots of people use Varget.
For bullets 130 grains or less, I use H414. For heavier bullets, I use H4831. They give me the best results in my rifle. I also use magnum primers in all cases.
Rather than ask for specific loads here, go onto the Hornady, Winchester or whichever powder maker's product you have and look at their reccomendations. Every rifle is an entity unto itself. Very seldom is there a magic load that works in every rifle. That is a pipe dream. Choose the weight you want to shoot and work up a load. If you are getting someone else to load for you, the reloader might be reluctant to spend that much time on your rifle. If you're lucky, you can both work together or he/she will allow you to use their set up to experiment with powder charges, primers and how close you seat the bullets to the lands.
Neck resizing, rather than full length resizing might help a lot as well.
There is so much more to reloading than most people realise. I have to wonder when someone says they keep their loads to less than a tenth of a grain in variance. I haven't seen a rifle yet that knows the difference between 1/10 grain between cartridges. I know, some people really do believe it makes a difference. Go to a bench rest match and see how reloads are made up on the fly. Neck resize only, powder charges thrown from all kinds of different measures, even the odd fellow with a dipper. No one that I've ever seen, check their thrown or dipped powder weights on a scale. For the most part, those people can really shoot and take accuracy very seriously. The price they pay for their firearms and accessories is staggering to most shooters. I will admit, there is the odd person that loads up enough rounds to complete a match. Most only have twenty or so cases that have the necks turned down to fit in the tight chambers and reload 6-10 rounds at a time. Most clean after every 15 - 20 shots as well. Some rifles require the copper fouling to be completely removed and some like it partially removed. Only trial and error, along with lots of practise will tell the truth.
We're very lucky with good bullets today. Especially with some of the European and North American makers. They all have Juenke guages and the bullet jackets are extremely consistent. When people rave about how accurate the new rifles are, they shouldn't forget how good the newer bullets are that help make those new rifles so accurate.
