Ammo way slower (FPS) then advertised??

[Newtosavage]

You are spinning your wheels without a chronograph. Imo, anyone who wants to shoot past 300-400 yards needs one.

Yup, and they are so affordable now that you could spend more on two boxes of ammo than a chrono. Everyone should have one. It still surprises me how amazed guys at the range are when I set mine up. Like I'm some kind of ballistics expert or something just because I have a $100 chronograph. They always jump at the chance to use it if I offer too. Then I tell them what I paid for it and they always get a dumb look on their face and say they thought chronos were much more expensive. Go figure.

One day I was at the range working up a load and two guys were eyeballing my chrono so eventually I offered to let them use it. One of them had a custom 7 mag he was getting ready to take elk hunting. I warned him that if he liked his load now, he might not want to shoot his factory ammo over the chrono (getting back to the point the OP was making here...) He asked why not and I said he might be pretty disappointed.

I was getting 2900 fps. with my 139 grain LRX's out of my 20" barrel on my little 'ol 7mm-08. So he shoots a factory 140 grain Accubond over it from his 7 mag and gets 2980 or something like that. I can't remember exactly but I do remember how disappointed he was. I told him the chrono might be off because he was using a muzzle brake and it could be affecting the reading. So he took two more shots and they were all within 10 fps. of the first. Needless to say, he left scratching his head and wondering if he was ready for his guided elk hunt the next week. He said the outfitter told him to be ready to take shots out to 500. I wished him luck and said a little prayer for the guy that he would stumble on one inside of 250 and not clip the legs off one at 450.

$100 worth of chrono could potentially make or break your entire hunt, and considering how long chrono's last if you take care of them, you're talking an investment of less than $10-15/year.

 

[SDHNTR]

It was same kind of ammo but thinking back now yes it could have been for my last shoot at 200 and 400

Same kind is not the same as same lot. A change in lot could change a lot. Hahaha

 

[khuber84]

Do not run 200 or 250y zero, only run 100y zero. Get the applied ballistics app as they have the most extensive library of tested bullet BC. Plug the factory velocity into to the app, input current atmospherics and shoot at 600y to calibrate your velocity to match drops. I personally hate doing this backwards but it does work. I prefer to run with a known speed and tweak BC to get waterline at 1k yards. True at the max distance you plan to shoot. Also make friends with someone who has a dang chrono! I have guys ask me all the time at the range if they can run a few through my labradar, I've never told a guy no.

 

[fholdburg]

As others have stated. You need a chronograph and honestly shooting those medium distances consistently is a lot tougher than what people make it out to be.