Sometime ago, as a starving university student, I wanted a hot 6mm cartridge for antelope and coyotes. Unfortunately, I could not afford the cost of a custom reamer and custom dies. After some noodling, I presented my idea for an affordable wildcat to a local gunsmith and he agreed to do work. After purchasing a medium weight barrel 27.5" in length, I instructed the gunsmith to push the .243 Winchester reamer in past what would be the correct depth for the .243 to what would be the correct depth for the 6mm Remington. I then set a secondary shoulder on some 7x57 brass and fireformed these to create what I called the 240 Gordy. The resulting case could be descibed as an extra long .243 or a fatter 6mm. Next, I loaded 70 gr. Ballistic Tips using 240 Weatherby light loads as a starting point.

The first loads produced acceptable velocities with no pressure signs. I kept loading hotter and hotter progressing in .5 grain increments. Each powder weight was recorded for velocity. I stopped increasing the powder charge after hitting 4200 fps. At this point, I was really excited by the velocities achieved and was anxious to concentrate on working up an accurate load. The final result was a 70 gr. BT at 3950, or thereabouts, grouping into 1.5" at 300 yds. This load was deadly on coyotes, antelope and deer. And, it would either toss gophers 15 ft. into the air or simply vaporize them at close range.

Thought some of you out there would be interested in something like this, as I was.

Bobby B.

Do you have pics?

Sounds like you are having some fun up there in canada

a 25 gibbs makes me go "HMMMM..."

I shoot a 240 Gibbs, it is a pretty amazing coyote gun. 26" Ron Smith gain twist fluted SS barrel on a 70 action in an HS stock, B&L 6-24 scope. Shoots very well, Gordey, what kind of ballistics are you getting from that? - dan

Boom Stick,

I have some photos around somewhere and will dig them up if you're really interested. Let me know.

Bobby B.

Dan,

Grampa Smith produes some excellent barrels. I've had 3 in 240 Gordy, 1 in 7RM, 1 in a wildcat 7mm with the same dimensions as the RM but with .25" longer neck and 1 Nifty 260. The Nifty 260 is the same concept as the 240 Gordy except it's an extra long 260 Rem rather than an extra long 243 Win.

I never chased the velocity with the Nifty 260 as I initially intended. While working up some loads, one produced pretty much a ragged hole with 100 grain Ballistic Tips @ 3300 fps. It's become my favorite deer rifle.

I intend to have Ron supply me with a 24" gaintwist .243 Win specifically for 70 grain bullets which I want to shoot in the local Rifle Rodeos. I also want a 26" gaintwist in 7RM for my March 09 Namibian hunt.

Bobby B.

quote:

Originally posted by Bobby B.:
Boom Stick,

I have some photos around somewhere and will dig them up if you're really interested. Let me know.

Bobby B.

I would post them for you on the thread if you email them to me.

I hear this quite often where someone takes a reamer and simply runs it in further. Looking at the couple of non belted reamers I have on hand they are tapered. As you run them in further how do you keep from having a chamber that is very big in the head area? Can someone that has done it explain what happens to the case in front of the web.

Paul

You're right. Running a reamer in long WILL result in an oversize butt if there is a lot of taper to the original cases.

On the "Ackley" cases it is not usually a problem since there is so little taper to begin with.

I've never seen a 240 Gordy but since the 243 reamer would have to be run in an additional .185" and there is only about .015" taper over the entire length of the case it would probably work OK for a hunting rifle. It's not someting I would tolerate but I'm a nit-picker.

Also, I have some reamers where the taper will stop just past the "full length" mark and they will continue straight from there for another .250" or so before the flutes end. Theoretically you could run those reamers in past the end of the flutes and still make a reasonable chamber.

Ray

Paul, your question is the same one I presented the gunsmith with. He and I concurred that the marginally greater than standard case head chamber dimension was relatively insignificant. It was one of the reasons why I initially selected the .243 as the basis for the 240 Gordy.

Ray, you're right on the money in regards to the reamer flutes.

Bobby B.

quote:

It's not someting I would tolerate but I'm a nit-picker.

Ray & Bobby Thanks. I agree not something I would go vfor but I like my chambers tight.

If I wasn't so lazy I would have drew it up and checked.