Wildcatting case forming question

[SteveOak]

Not sure if this is the right place to ask this but I didn't see a place that might be any better.

I am developing a cartridge for NRA High Power Rifle Silhouette. One of the challenges is to deliver a sufficient amount of energy to the 500 meter target to knock it over, even if the wind is blowing toward you and still have a cartridge that you can shoot for a 40 or 60 round match and the occasional multi day match.

I am heading toward a 284 case but shortened to reduce the case volume to the range of 40 to 43 grains of powder. This would permit leaving a long neck, 1.5 to 2 calibers which would permit seating the bullet out nicely so that it would not intrude excessively into the case. The bullet of choice is a 6.5 mm 142 gr Sierra MatchKing or other similar VLD bullet which is long for its caliber but does not have a correspondingly long bearing surface.

What technique would be useful to push the shoulder of the case back something like .25" without crushing a lot of cases? I know it can be done, at least the shoulder pushing part because I have 250 cases of similar configuration. They are nice, short, fat cases.

Inside neck reaming would be needed after the shoulder pushing operation.

Thanks in advance,

Steve

 

[jcampbellsmith]

I would be tempted to get in touch with John Whidden on a question like this in order to see if he has a hydroforming option? Regards
JCS

 

[dedogs]

Steve, You might want to look at Pbike257's thread here on this site concerning his "Wildcatter Shoulder Set Back Die". I have a set and they work wonderfully. He's a little slow to respond (busy guy) but I think this die is exactly what you are looking for. Do a search on this website and you should be able to come up with his contact info. I'd post a link but I don't know how to do that. dedogs

 

[Dusty Stevens]

Sounds to me like you want a 6.5x47 lapua and forget all the crazy case forming. I see you like a challenge but the main challenge youll have is holding your tongue when those center splats just smile at you in the headwind. Id suggest a 7mm- a 7-08 sounds perfect. A 7x6.5x47 sounds even better. No case forming and lots of dead rams not marginal rockers.

 

[Dusty Stevens]

Btw forgot to mention the 7mm-6.5x47 is the shortened version of the 284 case you are looking for

 

[SteveOak]

Steve, You might want to look at Pbike257's thread here on this site concerning his "Wildcatter Shoulder Set Back Die". I have a set and they work wonderfully. He's a little slow to respond (busy guy) but I think this die is exactly what you are looking for. Do a search on this website and you should be able to come up with his contact info. I'd post a link but I don't know how to do that. dedogs

That looks like the right method. In the vid he mentions 223 and 308 sized dies. I would like to talk to him and see if he has or will do a 284 sized case.

Do you have contact info for him?

 

[SteveOak]

Btw forgot to mention the 7mm-6.5x47 is the shortened version of the 284 case you are looking for

The 6x47 case has a .470" base. The 284 case has a .501 base.

 

[Dusty Stevens]

Yep sorry i was thinking of a custom i did a few yrs ago on the 284 case then figured out it was just easier to use the 6.5x47

 

[jcampbellsmith]

Btw forgot to mention the 7mm-6.5x47 is the shortened version of the 284 case you are looking for

The 6x47 case has a .470" base. The 284 case has a .501 base.

.284 Win has a .4728 base. Regards JCS

 

[SteveOak]

Btw forgot to mention the 7mm-6.5x47 is the shortened version of the 284 case you are looking for

The 6x47 case has a .470" base. The 284 case has a .501 base.

.284 Win has a .4728 base. Regards JCS

Actually .4728 would be the rim diameter, the same as a 308, 243 etc.

The 284 has a rebated rim which means that the rim is smaller than the base.

 

[357Mag]

Steve -

Howdy !

You could probably impress a 6.5mm Remington Mag die or a .264 Win Mag into service; as a near-term
case forming expedient.

Cut the die shorter w/ a cut -off wheel on a die grinder.

Both the above have similar shoulder diams, and around a 1 calibre neck lg.

Just a thought.


With regards,
357Mag

 

[357Mag]

STeve -

OOps.... forgot to mention. Both of those 6.5mm Magnum's run 25* shoulder angles.
This would aid the case forming process.

If a final 30* shoulder angle is desired for the wildcat, you would likely fire-form to obtain it.

I worked on a fore-shortened .284Win-based wildcat ( 46gr D85 ball powder capacity ).
To sharpen case shoulders closer to 30* before fire-forming, I used a spark plug replacement adapter sometimes used w/ compression tests; that I got @ an auto parts store. I used the adapter and a small arbor press, to sort-of " hemi- phy " the shoulders. In this instance, the wildcat did not prgress to the point of chambering a rifle for it, none-the-less; the cases could have readily been loaded & fire-formed.


With regards,
357Mag

 

[mysticplayer]

Been wildcatting for many years so I am not going to say good or bad but here is a thought.

Take your parent 6.5-284 or 284, cut it at 1.5" and measure how thick that brass is.

You are trying to form some very thick brass.... and eventually form a neck at 11 thou properly annealed.

The 6.5X47L is a very accurate set up and do very well in F Open at mid range. 140/142's are the goto bullet all the way out to 1000yds.

Jerry

 

[XTR]

Is this just an exercise in making a wildcat, if not why not run a 7-08? I seem to recall that Mr Tubb had good results with it in sillywet shooting

Edit: or if the goal is to shoot 6.5s then use the 6.5x47L.

I think one of these would be a better choice over a modified 284 case, esp a shortened one, for reliable feeding. I've heard that 284s can be difficult at times to get to feed well, a shortened one is probably more so.

 

[jcampbellsmith]

Btw forgot to mention the 7mm-6.5x47 is the shortened version of the 284 case you are looking for

The 6x47 case has a .470" base. The 284 case has a .501 base.

.284 Win has a .4728 base. Regards JCS

Actually .4728 would be the rim diameter, the same as a 308, 243 etc.

The 284 has a rebated rim which means that the rim is smaller than the base.

Steve. Apologies, I stand corrected. Regards JCS

 

[357Mag]

Steve -

Oops 2.0 .....

I stated wrong powder capacity for the short .284-based 6mm wildcat, previously mentioned.
It was more like 44.0 gr. I can locate the case, an re-measure; if it would help you at all.


With regards,
357Mag

 

[SteveOak]

Is this just an exercise in making a wildcat, if not why not run a 7-08? I seem to recall that Mr Tubb had good results with it in sillywet shooting

Edit: or if the goal is to shoot 6.5s then use the 6.5x47L.

I think one of these would be a better choice over a modified 284 case, esp a shortened one, for reliable feeding. I've heard that 284s can be difficult at times to get to feed well, a shortened one is probably more so.

David Tubb may or may not have used a 7-08 for HPRS although he did use it at Camp Perry. For Silhouette he did use a 243 customized to permit the use of VLD bullets for a while as he found the benefit of reduced recoil to outweigh the occasional 'rung' Ram.

He also convinced Remington to legitimize the 6.5-08 as the 260 Remington so that he could use it to shoot Hunter Rifle class of HPRS. 6.5 mm cartridges have proven to be superior to both 7 mm and 6 mm cartridges for Rifle Silhouette.

 

[CJ6]

Give Bill Shehane ( www.scopeusout.com)a call, he did a 6mm Shehane short based on the 284 case. He may be able to give you a few tips based on what he's already done with it.

 

[SteveOak]

Steve -

Oops 2.0 .....

I stated wrong powder capacity for the short .284-based 6mm wildcat, previously mentioned.
It was more like 44.0 gr. I can locate the case, an re-measure; if it would help you at all.


With regards,
357Mag

It would be helpful, thanks. 44 gr is getting pretty close to my target.

Also, not quite sure how you would have used the sparkplug adaptor. Can you elaborate?

To sharpen case shoulders closer to 30* before fire-forming, I used a spark plug replacement adapter sometimes used w/ compression tests; that I got @ an auto parts store.

Thanks,

Steve

 

[muleystalker]

6.5 creedmoor seems like it would fit the bill.