Forming brass for 6.5 Creedmoor

[TiGuy]

I want to try fireforming 6.5 x 47 lapua cases into 6.5 Creedmoor cases. The measurements look possible to me even though I have never tried anything like this before. All measurements are shorter/smaller on the lapua than on the creedmmor. According to my measurements on raw brass of the creedmoor of OAL, head and shoulder diameters, the Lapua case is shorter by 1.88 millimeters oal, head diameter is .5 millimeters smaller and the shoulder starts tapering at 35.7 on the lapua and 37.75 on the creedmoor. The shoulder/neck junction will need to stretch almost 2 millimetes as well,more like 4 millimeters for my chamber).

Please advise on what is a sensible amount of growth I can achieve in this process.

 

[js223]

Just wondering, are you trying to make a small-primer Creedmoor?

 

[TiGuy]

I'm trying to develop a round with stronger brass. If that means going with the Lapua brass and small primers, then yes.

The Hornady brass has failed me numerous times when shooting slightly hot rounds for 1000yds. The brass is just too soft IMO and must be loaded way below its potential or else the primer pockets blow and I have to throw away MORE cases...again.

 

[js223]

I don't have a 6.5 anything myself right now. But I'd have to wonder if blowing out the 6.5x47 would give you a short neck? Particularly since it's already shorter in length.

Maybe try Lapua .308 or .243 brass, which is often modified to .260 from what I understand. May have to trim it a bit after sizing? And turn the necks too?

Perhaps someone who's worked with these will chime in. Since I don't have a 6.5, it's just guessing on my part.

 

[TiGuy]

Yea, basically I need input on just how much "forming brass inside the chamber" is safe. 308, 260 and 243 cases would have to be shortened,shoulders bumped a lot) first in order to fit in the chamber. A 6.5 x 47 Lapua would fit in "as is". The neck to shoulder junction would have to fireform/stretch a total of .100 to .120 inch in order to pull this off.

Is that too much to ask for?

Is it dangerous?

 

[Cheechako]

Ti

There is no limit to how much you can move the shoulder. You can turn a bottle-neck case into a straight cylinder if you want. The main consideration is that you have to make sure the case headspaces on something.

But, in your situation, you not only have to control headspace but you have to understand that the case will be a lot shorter than a real Creedmoor. As much as 1 to 1.5 mm. There is nothing wrong with short cases so they would work fine. But, if it was me, I'd go to a bigger capacity case and be done with it. If you are getting loose primer pockets with the W brass you may also get them with Lapua brass. It could be that the rear of your chamber is too big in diameter and no matter what brass you use it will expand to fill the chamber and that could mean loose primer pockets.

Loose pockets because your load is too hot,that's what you said) means exactly what you said - your load is too hot and you're trying to squeeze too many fps from your case.

If you were switching from a W brand Creedmoor case to a lapua brand Creedmoor case I'd say it's worth trying. But making an entirely different case is a lot of effort for something that may not work.

JMHO

Ray

 

[CJ6]

TiGuy,You're better off forming your Creedmoore case from Lapua .243 cases.Taper expand,size,trim,fire-form.It sounds like you want too much from the case.Factory loads for a 140gr in a 28" barrel is only slightly more than 2800fps and the factory recipe is listed on their web site.

 

[TiGuy]

Thanks guys, I will try the 243 Lapua brass and run it through the creed die and go from there.

I'm probably chasing my own tail in this effort, but I found an extremely accurate node with Berger 130 VLD's and 40.9 grains H4350. Pushing 2933 fps at low ES/SD has been too promising to back down to 2840 fps at the next node with 40.1 grains just to keep the Hornady pockets intact. We shall see.

I'll probably try win brass first since i can pick that up today and try it out.

 

[CJ6]

TiGuy a fellow shooter at our club is having the same issues with the Hornaday brass as you.But he admits his loads are a bit warm,since changing to the Lapua brass he has had no primer pocket problems. He's shooting a T2k rifle.

 

[TiGuy]

Thanks CJ, I figured out how to make the 243 brass work for the creedmoor.

 

[Steve]

Ti,
are you able to get the proper case length using 243 brass?
If it is short, then by how much?
thanks,
steve