7-08 & 243 brass resized to 260

[Icallem]

I bought some Winchester 7-08 and some Winchester 243 to use to make 260 brass. I resized all the brass. I loaded 35 grains of Varget with 140 amax bullets. This is the load I had been using with some Nosler 260 brass.
When I shot the 7-08 brass, the point of impact was about 1 inch high @ 100 yards. No heavy bolt and primers looked like always. Loaded them again, and when shot, same point of impact. When I loaded them the third time, some of the primers fell out.
I have been told that maybe the neck tension (thicker)is to high, as I had resized down. This causing high pressure.
I have not shot the 243 brass. Hopefully I will shoot it today and know more on Monday.
Does this sound right? Should you size up when making brass?
I’ll be away for the computer until Monday morning, but any comments would be welcome.
Thanks

 

[fw707]

Re: 7-08 & 243 brass resized to 260

I've made 40 rounds of brass for a new .260 rifle, 20 from once-fired .243 WW brass, and the other 20 from new .243 WW brass. They've been fired one time each with .260 loads, but I haven't loaded them back up so I can't be much help now.
I lubed the insides of the necks with Imperial and they ran through the die as smooth as silk.
I did notice that the bullets (A-Max and Scenars) took a little more than "normal" pressure to seat.

 

[sniperaviator]

Re: 7-08 & 243 brass resized to 260

Check the inside dimensions of the neck. There may be a bulge there from the neck down (or up).

 

[jrob300]

Re: 7-08 & 243 brass resized to 260

Have you checked H20 capacity of the Win. vs. Nosler brass? Win. brass often has the greatest case capacity (thinnest brass) but that may not be true in this case and is driving up pressures at the same load. Only way to know for sure is to measure.

John

 

[Oh really]

Re: 7-08 & 243 brass resized to 260

I use 7mm08 brass in .260 die! one step works great

 

[Icallem]

Re: 7-08 & 243 brass resized to 260

I got to try some of the loads over the weekend. After shooting, I could get a bullet to slide in the 243 brass, but not the 7-08.

 

[jrob300]

Re: 7-08 & 243 brass resized to 260

you mean that *after* you fired a round a new bullet would not slide freely in the 7-08 neck?

If so, you either have excessive neck wall thickness or a donut at the bottom of the neck where it meets the shoulder. Will the bullet slide in part way then get tight, or is it tight right away?

What is the outside dia. of the fired .243 brass neck? The 7-08? What is the neck wall thickness of each? (measure at 6, 9, 12, and 3 '0 clock)

John

 

[ChadTRG42]

Re: 7-08 & 243 brass resized to 260

You're mixing different types of brass which will effect the load and neck tension. When you neck down 7-08 brass, the necks become thicker. When you neck up 243, the necks become thinner. This will create different neck tensions and will effect the loads. If you want plinking ammo for 100 yards, this is ok. If you want precision ammo, pick one brass and sell the rest. Otherwise, you will not have any kind of consistancy in your ammo.

 

[Icallem]

Re: 7-08 & 243 brass resized to 260

After fired, I could not with finger pressure get the bullet in the 7-08 brass. The 243 brass would accept the bullet with finger pressure. I only have 50 pieces of the 7-08 resized, so will discard it and use the 243 brass. When Lapua is available, I'll get a couple hundred and just use that.

 

[bohem]

Re: 7-08 & 243 brass resized to 260

I have used Win 243 and Win 7-08 for several hundred rounds in my 260 gas gun. It works well. Part of the trouble you may be seeing is that Varget, it's awfully fast for a 260 and 140gr bullets. The thicker necks on the 7-08 wasn't a problem for me, but if you have a pretty tight chamber it may be causing some of your issues too.

 

[jrob300]

Re: 7-08 & 243 brass resized to 260

If you cannot finger seat a bullet in the brass after firing, then the stackup between bullet dia., neck thickness and chamber neck ID is too tight. An unsafe condition. You could use the 7-08 brass, but will have to neck turn it to give clearance to expand. Match chamber or SAAMI?

John

 

[Icallem]

Re: 7-08 & 243 brass resized to 260

It seems most of the trouble comes from a lack of supplies available.
I bought the rifle used and got some brass with it, Nosler and Rem., all of which had been fired in this rifle. I loaded several rounds with different amounts of varget and found one that worked well with the Amax. At that point I could not find the Amax bullet, so bought some Berger 140 VLD and thought I would try some 4831sc. They shot well, but nothing I found worked as well as the Varget and Amax. Needed brass, but only option was resize something. So I did. now here I am with part of it working and part of it not.
Hope Lapua is available soon.

 

[ChadTRG42]

Re: 7-08 & 243 brass resized to 260

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Icallem</div><div class="ubbcode-body">Hope Lapua is available soon. </div></div>
LOL! I don't think this will sove your problem. It might even make it worse. Just pick on brand and run with it. If you have a load for Varget and 140 A-max then run it. If you cannot find 140 A-max's, then you're not looking very hard.