Will using mixed up brass empties affect my handloads?

I've been using Winchester brass for my 270, but some have been reloaded two or three times now.

I have nearly two boxes of Federal empties on hand. If I use the Federal empties for my next go-round of reloading and shooting will that make a significant change in my loads if everything else (primer, powder charge and bullet) remain the same?

What if I use some mixed Winchester and Federal?

If the Federal is close to the winchester in weight they may have about the same volume.
I would do 5 or so loads and compare, check for pressure first.
It is always advisable to rduce the load say 5% work back up.
Dave

I wouldn't use different brass if I were shooting competition, but for game shooting you should be within the perameters of your rifle--say 1 1/2 inches at 100 yards from the bench.

Yes, this can have a huge effect on your load. Winchester is a realitively thin brass, switching to Federal will likely increase you pressure. If you are going to switch brass, you need to back off and work up again.

I recommend dropping your load at least 5% and working back up when you change ANY component of a load, including brass.

Almost all of the time you'll find the original load would have been perfectly safe, perhaps just as accurate or even more so than with the old component, and you may feel as if you have wasted some time doing the new work-up.

BUT, once in a while you'll find enough added pressure with the new component that it is a darned good thing you did the new work-up.

It is not a waste of time either way. In the first instance you have proved the old load is safe with the new component. In the second instance you have proved it definitely ISN'T!

I believe that actual tried and true knowledge of the situation is never a waste of time, components, or effort.

I dont sort hunting brass. I dont think youll be shooting benchrest with a .270. I had some old 30 cal. I necked down to .270 one time. With the thick case walls on military brass youll run the pressure up faster. Thats the only time Ive paid attention to headstamps on hunting or plinking rounds but do what you want. Its your call.

While I like my hunting ammo to be all it can be and so I segregate my components, I have to admit that unless you're running right at the ragged edge of top performance, you will only find PERHAPS a slight differnce in POI. But not enough to keep you from killing stuff.
I have read post claiming vast differnces in performance and pressures caused by a few grains difference in case weight but I've never found that to be the case.

My experience with the 270 is that Federal and Remington brass are nearly identical in case capacity, but Winchester is thinner and needs more powder for the same velocity. Any time I change case brands I find it a good idea to back off some and work my way back up.

I use mixed brass all the time, with mixed results.. The only way to really tell just how much variation there will be is to load some up and shoot them for comparison. Some chamberings/rifles are more affected by it than others.

In making up original cases for my X 41 series of wildcats I mixed what was available without consideration of manufacturer or original cartridge. To clarify, there were many manufacturers of .257, .270,.308 and 30-06 and these were all mixed. Three of the four rifles shot 2" groups or larger. The forth ,7mm X 41mm., was about 1 1/2".
When the cases were all segregated Things worked out rather well.
It does make a difference.Individually per rifle it is a matter of degree. roger