Gunsmithing I want to invent a new cartridge!!

[Wild_Bill]

Re: I want to invent a new cartridge!!

OK just call Dave Kiff the 6.5 Creedmore case has already been necked to 6mm call dave ask for the 6mm Creedmore reamer then buy a Forster 6mmBR Benchrest seating die and have the chamber reamer run into the sleve as it is soft to make the case fit perfectly. Now for the sizing die buy a Redding Type S bushing full length sizing die and use 2 smaler bushings in the 6.5 die and you can neck it down then load the cartridge properly you could also neck the cases down the first time iin a 6mmBr die before you start to reload.

As for the 30-284 being the same as the 7.7 swiss it is not you can use the cases to form the swis cases but they are not the same so be carefull in saying that things are the same like the 6mmX47 Swiss match is not the same case as the 6mmX47 Lapua the swis case has a longer neck and diferent capacity load data is not interchangable.

We have build around 15 6X47 Lapuas and they are a great calibre the 6mm Creedmore would be just as good. Have it chambered in an 8 twist and shoot 105's to 107'a and you are good to go.

 

[Don Black]

Re: I want to invent a new cartridge!!

7.7 Swiss ??

 

[bohem]

Re: I want to invent a new cartridge!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wild_Bill</div><div class="ubbcode-body">
...As for the 30-284 being the same as the 7.7 swiss it is not you can use the cases to form the swis cases but they are not the same so be carefull in saying that things are the same...
</div></div>

I necked, loaded, and fire-formed 284 to 7.<span style="font-weight: bold">5</span> Swiss with no issue from all 3 k31's that I have owned.

I don't know about a 7.<span style="font-weight: bold">7</span> Swiss, I'm assuming that's a typo, but as to the 7.5 I have found no functional difference when forming brass.

 

[Wild_Bill]

Re: I want to invent a new cartridge!!

Sorry 7.5 Swiss yes you can use the cases to fireform to the swiss chamber but the chambers are diferent. you just cant say they are the same chamberwe they are diferent if you went to fire the 7.5 swis fireformed case in a 30-284 it would not fit the same with the 6X47 Swis match and the 5X47 Lapua they are totaly diferent even though you can form either case into each other.

You should say you can form a case into another not they are the same.

it is like people saying the 260 is the same as the 6.5 creedmore the creedmore case is shorter and it has a longer neck but the balistics are close.

 

[Swamper]

Re: I want to invent a new cartridge!!

There are lots of different approaches to the same solution...

I bought a 22" Shilen match barrel in .308win from a guy on Ebay a few years back. Had a tightneck chamber. Being somewhat compulsive, and owning a .30-06 AI reamer, I reamed the barrel just enough to get the AI shoulder on the .308 case. Living in the country, I just test-fired the barrel with Fed American Eagle and used the hand reamer until I got the fired cases looking right. The barrel is on a Long Action 700 in a H-S Precision Tactical stock which fits the heavy barrel contour unlike the PSS or Sendero stocks.

So what do I have, besides an expensive die proposition? The rifle shoots beautifully, BUT... The long action makes all the difference in bullet seating. It is a 1:11 twist barrel, so kinda marginal for over 200gr bullets, but with the right twist you have a super case for launching the heavy .30s.

I bought an AR-10 highpower upper in 6mm/.22-250. Hardly fired, like the .308 match barrel. The taper on the .22-250 case means can't stack more than 6 or 7 in a magazine, so... I reamed the Hart barrel with a .22-250 AI reamer I had... Fired the barrel until I got the 40deg shoulder right where it should be. Basically this is about .001 longer than Tubbs 6XC case in the body. Maybe a bit shorter in the neck. So, now I have a 20 shot repeating Match AR upper with lots of brass and 107smks plus 100gr hornady and 87gr sierra spitzers. 27" barrel on an A-2 upper receiver with a Tompkins bubble front sight on the barrel band mount.

Different ways... Long action, short cases for bullet seating flexibility. Ackley Improved case for optimum capacity and brass life. Bullets and barrel twist also part of the equation.

How about a .338/.22-250 AI for a big brother to the Whisper?

I had a couple of big magnums, but sold all of them; .30-378, .300 & .338 RUMs. Figured to standardize on the .338/300win. Owned a reamer. Did one of my rem 700 bdl barrels in .338win. Basically a necked up .300win mag. Very flexible. 65gr to 79gr of XMR 4350 with a 250gr bullet. Low end kicks like a .308, top end is about like the RUM! Lots of flexibility though. No flexibility in the big maggies. Had Pac-Nor do a Palma barrel for my TRG 42 in .338win which I reamed to .338/300. Headspaces on the shoulder, minimum oal chamber... Has a 1:10 twist for 300gr bullets, not that I've fired any yet...

I am standardizing on the .223rem, the .308, and .338/300 with the 6mm/22-250 and .450 Marlin as specialty rifles. With the right barrel twist, action, and bullet selection the three mainstays will do anything; and I don't have to get tons of loading gear, cases and other stuff.

Aside from Sixguns by Keith, and Zediker's Competitive AR; Frank Barnes' Cartridges Of The World is the other book I can pick up and get lost in every time I take it down from the shelf. Yet, aside from a general fascination with firearms and pursuit of accuracy, I don't want anymore new chamberings in the stable. Sure I don't, but I keep trying to convince myself....

Great conversation here.
Thanks!