I bought a 2nd hand RCBS 505 scale a while back and weighed some bullets in it to check it and sure enough, 140 grain bullets weighed at 140 and 150 gr. bullets at 150.

I'm having some difficulty with a load though and maybe the scale is weighing low. How can I confirm if my scale is weighing correctly?

Generally, if a balance beam scale zero's out ok, then it is fine.

You can also get another one and check it against it as well.

Is it still weighing the bullets correctly? why do you think it's weighing low?

Make sure you carefully clean the pivot points of the beam and the base. Then if it zeros with no load and weighs known weights such as bullets it is probably OK. You could go to the expense of buying a set of calibration weights but I don't see why that would be necessary.

I have access to analytical scales at work and I made my own check weights, which I verified on the work scale.

quote:

why do you think it's weighing low?

See my entry regarding the 270 in the Medium Bore Rifles forum

quote:

why do you think it's weighing low?

I'm the guy that posted about the 270 bullet dropping 7 1/2 inches in 100 yards on the medium bore forum. You answered me there.

the most likely situation is that your 200 yard range is actually a three hundred yard range

quote:

the most likely situation is that your 200 yard range is actually a three hundred yard range

My error, sorry.

The range is measure in metres. It is a 200 metre range.

Buy yourself a set of check weights. Lyman used to sell them, along with others. Make sure whatever you get has traceability to NIST. I have a set I bought a million years ago and use them periodically just to make sure. Note, I have never found any of my scales off by more than +-.1 g in all the years I have used them.
C.G.B.

Hu, I almost hate to ask this, but did you use the wrong powder?

Maybe H4831 when the recipe called for H4350, or RL22 instead of RL15???

While your at it, I'd suggest pulling apart one of your left overs and reweighing the powder (If you haven't done so already). Some time we are off by 10 grains and don't notice it...

Thanks.

I pulled one and weighed it and it was indeed 57 grains.

I was loading my 7x57 first with H4350 and I'm certain I put the H4350 away along with the 7mm bullets when I switched to the 270 and brought the H4831 and 270 bullets from my locker.

quote:

Originally posted by Hublocker:
Thanks.

I pulled one and weighed it and it was indeed 57 grains.

I was loading my 7x57 first with H4350 and I'm certain I put the H4350 away along with the 7mm bullets when I switched to the 270 and brought the H4831 and 270 bullets from my locker.

If you'd loaded 57gr of H4350 behind that 150gr bullet I reckon you'd have known about it.

If you'd loaded 57gr of H4350 behind that 150gr bullet I reckon you'd have known about it[/quote]



I agree.

Hu, you are running me out of idea's.....

Any chance your barrel is slightly bent downwards, or you were shooting into a 30 mph head wind?

If you used the same scale to load up for the 7x57 and you also checked a couple of bullets and they measured close to expected weight, I think I'd drop the focus on the charge weight being the issue.

Someone in the other thread was thinking perhaps something to do with your barrel. Have you checked the crown of the barrel? Cleaned the barrel?

Did you by chance have to make significant adjustments to the scope to get it where you wanted at 100 meters when you took this load to the range?

Sorry if you've covered these already.

Okay, you are going to think I am crazy, but what are you shooting at at 200 meters? What size dot? It takes very little movement of crosshairs to make a 3 or 4" change at 200. You are only using a 4X. That in itself is somewhat limiting. Not talking down your setup, just speaking from experience... How big a dot are you shooting at? Can you accurately center it in the hairs with the 4X?

Something else to think about: cloudy or bright sunlight? We shoot lower when it is cloudy because the target is not lit as well. And again, 4" is not much crosshair change when you are shooting 200+.

quote:

What size dot?

The 200 metre target the range sells has a big white dot about the size of a teacup.

It's a big target, about 3-feet square.

Crown is good, barrel was clean and no, the scope was already set fine for 100 yards.

Well, so what all have we eliminated:
Crown.
Barrel was clean.
Scale was checked.
bullets were pulled and powder charge was checked.
Scope is a Leupold, no parallax.
Stock is glass bedded.

Did you check your rings and mounts to make sure everything was tight?

You were loading .277 bullets and not .284's??? You were loading for your 7x57 before you loaded for the .270??

I'll check the rings.

I put the 7mm bullets away in the cabinet when I got the .277 bullets.

quote:

Originally posted by Antelope Sniper:
Well, so what all have we eliminated:
Crown.
Barrel was clean.
Scale was checked.
bullets were pulled and powder charge was checked.
Scope is a Leupold, no parallax.
Stock is glass bedded.

Did you check your rings and mounts to make sure everything was tight?

You were loading .277 bullets and not .284's??? You were loading for your 7x57 before you loaded for the .270??

Nothing left but those damn bullet gremlins.

Have you mic'd those ".284" 150-grainers yet?
This has the earmarks of a .277 seated in place of 7 mm. Saeed once had Walther on with .270 loads in a Blazer of some 7 mm caliber and put the video out. Rounds were hitting at 50 yards on the ground!!!

I haven't seen this asked yet, so I'll ask it.

Have you mic'd the .277 bullets to confirm their diameter? It is always possible that the factory got the wrong label on the box and they are actually something like 139 grain 6.5m/m (.264") bullets....

(I doubt it, as they would have been awfully loose in the case necks, but it never hurts to check EVERYTHING.)

I'm starting to lean toward a loose scope set up. Try taking your scope, rings, and bases competely off. Then with a little brake fluid or other solvent, clean all of the screw holes and screws. Then put it back together with a little lokt tight as you go. Whilst you've got the scope off, it would be a good time to try another scope with a proven track record.
Before you take the scope off, at 100 yards, you can try shooting a square. See if the scope is tracking correctly. You can also shoot a group --at 100-- and then bounce the butt of the rifle sharply on the ground a couple or three times and then see if it's shooting to the same POA.

Buy a box of factory ammo. Shoot it at 100 yards and then at 200 yards. Let us know what happens.

quote:

I'm the guy that posted about the 270 bullet dropping 7 1/2 inches in 100 yards on the medium bore forum.

IF you're using book velocity projections to support your concern that your powder charge may be low you're leaning on a very weak idea.

Most of us find load book velocities to be happy guesses; it's not often are they very close to what we're actually getting. Affordable chronographs took the BS out of a lot of hopeful beliefs.

I suspect your scale is plenty accurate.