6.5/300 ultra mag

[huntinfool18]

has anyone had ony experiance with this round or now any thing about it? any info would be helpful.

 

[James Jones]

No experiance with that perticular round but have seen and delt with a couple other overbore 6.5mm guns and with all the accuracy notch seemd to come arounf 3000-3300fps , the bullets could be driven faster but accuracy went away fast. I think that the problem is that their arn't enough bullets out their to take advantage of this much powder behind this bore. A guy I know had a 6.5-300Wby for a while and his accuracy load was at a velocity around 3200fps and the accuracy started to fal fast after about 800 rounds.
If your wanting a hot 6.5 that I'd go with a 6.5-300Win mag I reload for a buddy that shoots a 25-300Win mag and its awsome the big advantage being that you can get Lapua brass,it would be a step up from the old 264 Win and with alot better brass.

I'm personaly having a 260 Rem built as we speak , I got a good deal on the barrel and I had a short and a long action so I could have chosen about any caliber but fi you look at the balistics of a 140gr 6.5mm A-max being launched at 2800-3000 fps its pretty impressive , and the barrel life will be good and the componets will also be easy to get. Maybe after a few thousand rounds I can have the barrel set back and rechamber to 6.5-300WSM.
My oppinion would be to either go up in caliber if you want to use that case or down in case size if you want to use that bullet.
From what I have seen with common bullet for the 6.5mm is that optimum velocity and accuracy can be had with a case holding around 65-75grs of powder.

 

[Wild_Bill]

I would also look at the short mags in 6.5 i prefer the Rem case over the Win case but both will work well. I would look at the 6.5 STW a 8mm Rem MAg necked to 6.5 the bigest case to build a 6.5 on it is extreemly over bore and should get the 155gr projectiles to 3300 without to much trouble. I have heard of a shooter using a 6.5WSM on a 30" barrel and he is supposidly getting 3200fps with the discontinued 155gr Sierra MAtchKing. The 155gr Sierra is awsome if you can get hold of them they will hold more energy but the BC is slightly lower than the 142 Sierra. Another good option would be the 6.5 300 Win Mag i would seriously look at it as it would not be far behind the STW or ultra mag. Their is deminishing returns with massive cases to bore diameters i would stick to a WIn MAg or smaller case and you will be plesantly supprised.

Cheers Bill
Australia

 

[Fiftydriver]

My 6.5mm Allen Mag is basically identical to the standard 6.5mm RUM but in a shorter improved design as it is based on the 338 RUM case.

Accuracy can be a problem at high velocity but I will say that the rifle I built for my wife is getting +3500 fps out of a 30" Lilja with the 142 gr SMK and getting one hole groups at 100 yards. This is still a pretty comfortable load.

I would agree that the bullet selection for this class of 6.5mm is very poor. Just not the bullet weight out there to make them work well. That said, I have some prototype bullets headed my way from Wildcat Bullets. They are 168 gr ULD RBBT and these should really make these big cased 6.5mm rounds run extremely well.

I suspect with a velocity in the 3300 fps range if you want to push them that hard they will be very impressive at extreme range. I will probably look to load them to 3200 fps personally.

Reports will be coming on these bullets soon. Another first for the 6.5mm family of bullets as far as Wildcat Bullets taking a caliber to new levels of performance. They should work well in any 6.5mm round from the 6.5 WSM on up but for big game hunting I would say the 264 Win Mag will probably be the smallest that I would recommend. In the 6.5 STW, 6.5mm Allen Xpress, 6.5mm RUM and 6.5mm Allen Mag these should perform very well.

With this bullet weight I may even test my 6.5mm Allen Mag punched out another 0.090" in length to use the 7mm RUM Case. May be pushing things a bit with the usible powders we have but I think with this bullet weight it would work. This would add about 8 grains to the capacity of the standard 6.5mm RUM, like that was needed /ubbthreads/images/graemlins/grin.gif!!

Still, I agree, bullet selection for a huge 6.5mm is still lacking but they will come with time.

Kirby Allen(50)

 

[6BR4ME2]

In theory a true wildcat that would seem to be very impressive..however the huge amount of overbore here would be very limited barrel life!! still fun to shoot however unless you plan on letting the barrel cool way down after each shot then using up barrel life during load development and an occasional poke on a hunt its not going to be able to be shot a whole lot...still would be fun until the barrel goes south on ya....

 

[eshell]

[ QUOTE ]
In theory a true wildcat that would seem to be very impressive..however the huge amount of overbore here would be very limited barrel life!! still fun to shoot however unless you plan on letting the barrel cool way down after each shot then using up barrel life during load development and an occasional poke on a hunt its not going to be able to be shot a whole lot...still would be fun until the barrel goes south on ya....

[/ QUOTE ]

This about sums it up.

I have a 6.5-300 Weatherby and it's a hoot, but I had to set it back and re-crown it at 750 rounds. Used to be 30", had to go to 27" to clean up the burnt throat. I was VERY careful not to let it get hot, and usually wait 2 minutes between shots, unless there's game afoot.

Mine is now shooting 139 Scenars at about 3,300, 123 Scenars at 3,450. With the 123s and a 100 yard zero, my 1k come-up is 19.5 moa.

 

[longgunshooter]

[ QUOTE ]
Another good option would be the 6.5 300 Win Mag .

Cheers Bill
Australia

[/ QUOTE ]

....? isnt that what the .264 Win is ??? a necked down .300, which is just a necked down .338 win??

please correct me if im wrong.

 

[Fiftydriver]

The 300 Win Mag is longer then the 264 and 338 Win Mags but about 0.120" so they would not all be the same.

Kirby Allen(50)

 

[malcarjeb]

I have a 6.5 RUM with a hart 29" barrel. It shoots the 120 barnes xlc bullets at 3850 with 106grs.of wc 872. It didn't take many rounds to get a good load as everything i have tried has worked great! It shoots the xlc's under a dime at 100yards if i do my part. I can't wait to start shooting some deer with it! /ubbthreads/images/graemlins/grin.gif

 

[remingtonman_25_06]

Jesus, please show the exit on whatever deer you shoot with that 120g xlc. At that speed, its gotta be pretty dramatic. I shot one buck with a 100g xlc out of my 25-06 at 3450fps. Ranges was about 150 yards. Bullet entered point of shoulder, and exited on the offside shoulder. It left about a pie plate size hole. I couldn't believe it. My dad also shot a litle buck with the 165g xlc out of 300 win mag at about 100 yards. Cant remember the details as I wasn't there, but I know it took 2 bullets and 1 was found on the offside and it lost 3 of the 4 petals.

 

[fiftybmg]

Pretty similar ballistics to the old .308 Norma.

Weatherby ammo quotes :

"140 Grain A-Frame, 0.401 BC, 3395 fps "

308 Norma starts with a 137gr GS-Custom 0.415 BC, 3280 fps [ my personal data ] . I'm pretty sure the legs can stretch more than that if I use a slower powder with better case fill. Barrel length is 25" .

 

[Frank in the Laurels]

I would think it would clean the first inch of rifling out in short order..

 

[WildRose]

No experiance with that perticular round but have seen and delt with a couple other overbore 6.5mm guns and with all the accuracy notch seemd to come arounf 3000-3300fps , the bullets could be driven faster but accuracy went away fast. I think that the problem is that their arn't enough bullets out their to take advantage of this much powder behind this bore. A guy I know had a 6.5-300Wby for a while and his accuracy load was at a velocity around 3200fps and the accuracy started to fal fast after about 800 rounds.
If your wanting a hot 6.5 that I'd go with a 6.5-300Win mag I reload for a buddy that shoots a 25-300Win mag and its awsome the big advantage being that you can get Lapua brass,it would be a step up from the old 264 Win and with alot better brass.

I'm personaly having a 260 Rem built as we speak , I got a good deal on the barrel and I had a short and a long action so I could have chosen about any caliber but fi you look at the balistics of a 140gr 6.5mm A-max being launched at 2800-3000 fps its pretty impressive , and the barrel life will be good and the componets will also be easy to get. Maybe after a few thousand rounds I can have the barrel set back and rechamber to 6.5-300WSM.
My oppinion would be to either go up in caliber if you want to use that case or down in case size if you want to use that bullet.
From what I have seen with common bullet for the 6.5mm is that optimum velocity and accuracy can be had with a case holding around 65-75grs of powder.

Pretty well said. There is a point of diminishing returns with the respect to case size and bullet caliber. After thirty plus years of shooting 7mm's I decided the 7mm STW was the break point between velocity and practicality.

The 7mm RUM is a proven barrel burner and even with the highest quality barrels and barrel treatments I can't imagine trying to put a 6.5mm bullet in front of 90gr's or more powder. Nobody I know is making 6.5 bullets designed for the kind of velocities that much powder will generate.

I love my .264wm and got excited about the 26 Nosler but the longer I thought about it the more I knew that in the long run the benefits just didn't justify the expense.

I have 3 .260 Rem's and they make a lot more sense.

 

[WildRose]

This about sums it up.

I have a 6.5-300 Weatherby and it's a hoot, but I had to set it back and re-crown it at 750 rounds. Used to be 30", had to go to 27" to clean up the burnt throat. I was VERY careful not to let it get hot, and usually wait 2 minutes between shots, unless there's game afoot.

Mine is now shooting 139 Scenars at about 3,300, 123 Scenars at 3,450. With the 123s and a 100 yard zero, my 1k come-up is 19.5 moa.

Just out of curiosity what powder and volume?

The .264wm can push 140's at right around 3000fps without too much trouble and only with 57gr of powder.