6mm x 6.5 Rem mag

[hemiford]

Looks like an intriguing wildcat, anyone here have any
experience to share ?
It appears to be ballistically similar to the 240 Weatherby,
but should fit in a short action Rem 700.

 

[Trickymissfit]

Looks like an intriguing wildcat, anyone here have any
experience to share ?
It appears to be ballistically similar to the 240 Weatherby,
but should fit in a short action Rem 700.

you really don't want to know what Ackley said about it! The round is similar the 6mm/.284, and that round is well known for being seriously overbore. The 6.5 mag is slightly larger than the .284 case, so your increasing the over bore to even more of the same. Add to this the fact that a 6.5/.350mag case is about as common as a smile from an ex wife.

I used to shoot with some guys that were big into the 6/284, and they went thru a couple barrels a year! One got the grand idea of shortening the shoulder length by .100", and adding .050" to the neck length. He lost about 75fps, but the barrel lasted over a year. Another guy tried the same thing and went .150". Lost about 100fps (maybe 120fps). Both guys saw tighter groups, and over double the shots thru the barrel!
gary

 

[adam32]

What did Ackley say about it?

 

[hemiford]

I thought "short and fat" was an improvement, for the burn.

Improvement over the long and skinny 240 Weatherby, that is.

Personally, I'm not overly concerned with barrel life.

Brass availability, now that could be annoying.

 

[Trickymissfit]

What did Ackley say about it?

pretty much nothing good about it what so ever. Way over bore just like the .284 case, but worse. It's pretty much been proven that the 6mm Remington improved is about all the 24 bore can handle. Yet it's also known that the improved case has gone into over bore, but not by a great amount. In otherwords your simply blowing powder down the barrel
gary

 

[Trickymissfit]

I thought "short and fat" was an improvement, for the burn.

Improvement over the long and skinny 240 Weatherby, that is.

Personally, I'm not overly concerned with barrel life.

Brass availability, now that could be annoying.

The .243 Winchester is known to be fairly efficient even though it's a well known bad case design. Still it will push the 105 grain Amax to 3000fps, and maybe even 3100Fps. The 6mm Remington is often down loaded in manuals, but it will do 3200fps with some stiff loads in a 26" barrel. The two cases are based off the Mauser case family (.471" case head). The Weatherby is based off an oddball .450" case diameter, but also loaded at a pretty high chamber pressure. Then you look at the 6BR using the 105 grain bullet. Using a fraction of the powder, we find that 2800fps is quite doable (some are getting 2900fps with the 107 grain Sierra, and these loads must very hot!) The 6BG will push the 107 grain bullet to 3000fps, and this case is nothing but a stretched 6BR for a shoulder length of about 1.45", or .110" shorter than the .243. Now that case is not quite as efficient as the 6BR, but also way more than the .243 or 6mm Remington. I shoot the 6mm/.250 AI, and it will push the 105 or 107 to 3100fps with a 1.51" shoulder length. Guess what? That's right there with the Weatherby case! Also right there with the big overbore cases.
gary

 

[adam32]

3100 with a 105 in a Wby? Ummm you're shorting it by at least 150 fps. My .243 Ack will send em at 3250 with 6+ loadings and 3400 with only 2-3 firings per case.

Overbore is in the eye of the beholder...half the company's in business today wouldn't be in business if being Overbore was such an issue.

 

[adam32]

pretty much nothing good about it what so ever. Way over bore just like the .284 case, but worse. It's pretty much been proven that the 6mm Remington improved is about all the 24 bore can handle. Yet it's also known that the improved case has gone into over bore, but not by a great amount. In otherwords your simply blowing powder down the barrel
gary

Ya gotta break some eggs to make an omelet...

I don't wanna know what Ackley would say about the 22-284 then...gun)