6.5mm Rifle Build Questions

[SaulReichman]

My newest obsession is a hyper-velocity 6.5mm rifle. Two of my favorite rifles are my 6.5 creedmoor and my .257 Weatherby. I just wish I could get the accuracy of the creedmoor with the flat trajectory and ballistics of the Weatherby. That is why the 6.5-300 Weatherby has piqued my interest.

Unfortunately, the 6.5-300 Weatherby is a new cartridge and I do not know much about it. From what I have read, it is capable of shooting flat out to 600 yards or more. This type of point and shoot performance seems too good to be true.

I also cannot help but wonder how the new 6.5-300 Weatherby stacks up against similar magnum cartridges. The two that I have found that are similar in performance to the Weatherby are the 6.5 STW and the 6.5 Allen Magnum. I read that the 6.5 STW is ballistically the same as the 6.5 AM, just in a longer cartridge.

The 6.5 AM is approximately 200fps faster than the Weatherby using the Barnes 127gr LRX bullets. In addition the AM appears to be a shorter overall length because it is based on the .338 RUM case. This would make it seem to be far superior to the Weatherby for a custom rifle simply because of a shorter length, cheap brass, and much higher velocity. In fact, I have heard that the AM will shoot flat out to over 800 yards with no scope adjustment. Once again, seems too good to be true.

And these leads me to wonder if it really is too good and that the bullets can just not possibly handle all of the goodness that the 6.5 AM can give. I would think that for hunting deer-sized game or larger, at less than 1000 yards, the Barnes 127gr LRX bullet would be the best choice. However, I am honestly not sure if this bullet will hold up properly at the 3500fps of the 6.5-300 Weatherby, let alone the 3750fps of the 6.5 AM. It seems to me that the bullet would most likely turn into a bomb and obliterate most of the meat.

I apologize about my rambling here but I would much appreciate any possible insights y'all may have regarding these cartridges and if there is any practicality to any of them as hunting rounds or if I am woefully misinformed in any way.

 

[MudRunner2005]

Regardless off which hyper-6.5mm you go with...Get ready to replace a barrel in 500-600 shots. That's what a lot of guys have reported getting.

 

[Ragnarnar]

I suspect you'd have to shoot monolithics, conventional bullets would fail.
I'd also be hesitant to shoot anything up close, for the same reasons you point out.

I couldn't afford barrels every 500 shots like mudrunner points out but after you get a load developed, 450 rounds is more hunting than most people will do in their lives, assuming you practice with something else.

In either instance I'm intrigued, sorry I can't offer more to help you out.

 

[Beneviolence]

Hope I'm not stepping out of line, but for these 'hyper-velocity' rounds, can one just re cut the chamber a bit deeper every bit or does the whole barrel go?

 

[el matador]

Just a note about bullet drop: Every bullet ever made drops at the same rate, which is determined by gravity. Based on the time of flight you can determine how much a particular bullet will drop at a given range. To cut bullet drop in half you'll have to increase average velocity by around 40%. These 6.5mm bullets going 3750 fps are not going to shoot "flat" out to 800 yards unless you zero at 800 yards, but they will arrive at the target quickly and reduce bullet drop somewhat.

The accuracy of a rifle has very little to do with what cartridge you're shooting. A 6.5 caliber isn't inherently more accurate than a .257, although your individual rifle might be.

All of that being said, I think the 6.5-300 would be an awesome round. Brass and dies are easy to get, which is something you can't say for the Allen Mag. Also, if you research the 7mm RUM a little bit you'll find its pretty inefficient in standard length barrels. The 28 Nosler gives you about the same velocity while using 10 grains less powder. In a longer barrel you will notice the difference. You won't get advertised velocity out of the Allen Mag unless you use a barrel that's 30"+.

If I wanted a fast 6.5mm for hunting I'd build a 26-28" barreled 26 Nosler, 6.5-300 Win Mag, or 6.5-300 Weatherby. I'd shoot 140+ grain bullets well over 3000 fps and be one happy camper.

 

[Rich Coyle]

SaulReichman,

You don't have to be concerned using the Barnes 127 grainer up close. I made a wildcat based on the .300 and 7mm RUM. I necked it to 6.5 and pushed the shoulder back to match the .338 RUM. This gave me a longer neck so the barrel will last a little longer. I shot two deer about 50 yards distance. No problem. They also work at longer range. I shot an antelope at over 400 and it worked wonderfully.

On that same trip my son-in-law shot one at about 175 yards running Nolser Accubond 140 starting at 3,419 feet per second. Excellent results.

 

[parshal]

I chambered a 6.5-300 Weatherby for my buddy last month. It's a tack driver and it's incredibly fast although it's burning nearly 90 grains of Retumbo with 130's. The brass is expensive. With the Defiance muzzle brake there is zero recoil. It's amazing the lack of recoil. The concussion is impressive even for the shooter.

Personally, I shoot a 6.5 WSM. I get 140's right around 3300 fps. 270 WSM brass isn't cheap but it's cheaper than Weatherby and it burns only 64 'ish grains of powder. I've yet to burn out the barrel but figure it'll be toast by 800 rounds. A friend has chambered a lot of WSMs and gets nearly 1000 rounds out of his but he doesn't hot rod 'em like I do. I don't even let my barrels cool.

I wouldn't bother trying to set the barrel back when it's shot out. My 22 Creedmoor (another hot rod) has firecracking four inches down the throat although it's still as accurate as it ever was. From what I understand, setting the barrel back is only going to get you another hundred rounds or so and the labor to set it back will be the same as putting on a new barrel.

If you want fast get the Weatherby. If you want fast and a bit cheaper to reload get the WSM. I've shot two elk at 400 with it and Bergers Hybrids. One heart shot and one not. Had to follow up on the second one. I can't comment on the other cartridges you mentioned. The only other 6.5 I've had was a 264 WM. I shot a muley at 400 with that one. DRT with 130 Sciroccos.

 

[SaulReichman]

SaulReichman,

You don't have to be concerned using the Barnes 127 grainer up close. I made a wildcat based on the .300 and 7mm RUM. I necked it to 6.5 and pushed the shoulder back to match the .338 RUM. This gave me a longer neck so the barrel will last a little longer. I shot two deer about 50 yards distance. No problem. They also work at longer range. I shot an antelope at over 400 and it worked wonderfully.

On that same trip my son-in-law shot one at about 175 yards running Nolser Accubond 140 starting at 3,419 feet per second. Excellent results.

That is some mighty performance you are getting there with your wildcat! That is about the same numbers I am seeing reported with the 6.5mm Allen Magnum. However, the AM uses a .338 RUM case and then gives it an Ackley Improved shoulder angle instead of pushing the shoulder back like you did. Honestly, your wildcat design sounds mighty appealing.

I am happy to hear that the 127gr Barnes performs so well. I am a little weary of pushing the Accubond that fast at such close range but it sounds like it works. Do you find that the 127gr lose stability when pushed that fast? I know that my .300 Weatherby favors the heavier pills.

I chambered a 6.5-300 Weatherby for my buddy last month. It's a tack driver and it's incredibly fast although it's burning nearly 90 grains of Retumbo with 130's. The brass is expensive. With the Defiance muzzle brake there is zero recoil. It's amazing the lack of recoil. The concussion is impressive even for the shooter.

Personally, I shoot a 6.5 WSM. I get 140's right around 3300 fps. 270 WSM brass isn't cheap but it's cheaper than Weatherby and it burns only 64 'ish grains of powder. I've yet to burn out the barrel but figure it'll be toast by 800 rounds. A friend has chambered a lot of WSMs and gets nearly 1000 rounds out of his but he doesn't hot rod 'em like I do. I don't even let my barrels cool.

I wouldn't bother trying to set the barrel back when it's shot out. My 22 Creedmoor (another hot rod) has firecracking four inches down the throat although it's still as accurate as it ever was. From what I understand, setting the barrel back is only going to get you another hundred rounds or so and the labor to set it back will be the same as putting on a new barrel.

If you want fast get the Weatherby. If you want fast and a bit cheaper to reload get the WSM. I've shot two elk at 400 with it and Bergers Hybrids. One heart shot and one not. Had to follow up on the second one. I can't comment on the other cartridges you mentioned. The only other 6.5 I've had was a 264 WM. I shot a muley at 400 with that one. DRT with 130 Sciroccos.

I have not heard of the 6.5wsm wildcat before and it is certainly interesting. I am sure that it gives you plenty of room for some long bullets (if they ever make some good ones for the 6.5!) and brass is definitely easy to get.

With your experience working with the 6.5-300 Weatherby, do you think it is worth picking up a factory rifle in the cartridge? I am still tending toward something like the Allen Magnum so that I can take advantage of the available brass and shorter case length.

 

[parshal]

You'll see the 6.5 WSM called a 6.5-270, 6.5-300 or 6.5 Leopard. You should also look at the 6.5 Sherman. If I were making a wildcat where I didn't mind fireforming I'd make a Sherman.

The Weatherby that I made was a Vanguard 300 Weatherby. I changed the trigger and used a Bartlein Varmint barrel. I didn't even bother bedding the factory Tupperware. I'd imagine a factory 6.5-300 would be similar.

 

[SaulReichman]

Thanks for the help y'all. Leaning toward the 6.5-300 Weatherby now.

If I wanted to shoot the 140gr Hornady bullets, I am not sure that they would hold up in the 6.5mm Allen Magnum. I am also not sure that the Barnes 129gr will shoot accurately at the AM speeds. This sort of leaves the Weatherby then.

Still would prefer to use the .338 RUM brass of the AM instead of the Weatherby brass and also not have to use the Weatherby size action...

 

[Jester896]

my shooting partner has just made 3 of the 6.5-300s. We are necking down .270WSM. 2 of them are on a S/A and mine is on a L/A.

We were shooting steel @ 500 during deer season when 3 stepped out about 100 yards to the left of the steel in a food plot. We were shooting 142 SMK M at the steel. Long story short,, 100 yard zero..8MOA up for a 606 yard kill DRT. The deer turned it's neck almost parallel to it's body prior to the shot...went through all 4 sides.

The bullet did frag a small piece off but still managed to hold together for the most part for a strong wound channel. I can only imagine better results with a hunting bullet @ 800. I wouldn't want to shoot anything up close.

 

[parshal]

Has your buddy had any issue reaching the lands on the short action?

 

[Jester896]

Has your buddy had any issue reaching the lands on the short action?

wherever it is right now would be fine for me...out of the first 8-9 rounds 5 went in the same hole. I think they were 142SMK M. I understood him to say OAL was 2.850. It will be a little longer before I get my L/A up and running. Running 62.0 of IMR7828SSC. I don't remember if he is using Norma or Nosler brass. The bullets have been 142SMK M or 140 SST.

 

[parshal]

Try around 64 grains of Reloder 26.