Straight.260 vs .260 30 degree

[Deton8tor]

I currently shoot a straight .260 and it shoots very well. I have been reading on the .260 30 degree. Is there any advantage to the 30 degree over the straight .260? A rebarrel is coming in the near future and was wondering if there were advantages to the 30 degree.I will be shooting steel to 1000 and hunting. Weight is not an issue. Thanks for the replys and info.

 

[Steve Blair]

When you say .260 30°, do you mean like this? [br]
http://6mmar.com/65_SuperLR.php

 

[Deton8tor]

Mr. Blair, Same site just this info:

http://6mmar.com/260_Imp_30_.php

 

[Steve Blair]

The only problem I would have with the .260 Improved 30° is the short neck inherited from the parent cartridge. That is what the 6.5 SLR was intended to correct with little effect upon velocity. That said: either is a good choice and is likely to provide accuracy as good as the parent cartridge with potentially better case life. The .260 Improved 30° is easier to produce, only requiring firing in the new chamber. 6.5 SLR requires sizing before loading and is a wildcat cartridge. Don't expect much velocity difference but otherwise a good choice for something different in 6.5.

 

[mikecr]

Anything is probably better than stock 20deg shoulders and under-capacity condition..
30deg is considered an improvement over old designs -that still feeds well.
But why not just go to 40deg(260AI)?
If single shot, you can keep going to where you won't have to push loads into brass ruination for 140gr bullets.
There are dies available in 260AI as well. It's been around a good while.

 

[daj]

I currently shoot a straight .260 and it shoots very well. I have been reading on the .260 30 degree. Is there any advantage to the 30 degree over the straight .260? A rebarrel is coming in the near future and was wondering if there were advantages to the 30 degree.I will be shooting steel to 1000 and hunting. Weight is not an issue. Thanks for the replys and info.

I run my 260imp30 loads at 60Kpsi (QL). Lapua cases are on their 8th firing and have never needed trimming to length. There is one advantage compared to my straight 260.

 

[BradY]

I have the 30 degree wildcat. Accuracy is at 2850fps in a 30 inch barrel with a 140 berger. Can push it further, but really if I was doing it again I would go the straight 260AI. It WILL get better velocity than any of them and dies are so much easier to source. The 260AI is very close in performance to the 6.5x284 with less powder burnt. My gun does the same as a 6.5x47L essentially but Im burning more powder. Very accurate for f class, and doesnt have the recoil that a 7mm does, but at the same time it doesnt have the ballistic performance either...

 

[mikecr]

The 260AI is very close in performance to the 6.5x284 with less powder burnt.

The 260AI reaches the same TUNE as the 6.5x284 with less powder, because no more capacity is needed to reach that tune for ~140gr bullets.
Any less capacity than the 260AI will not reach the same tune without prices to pay for it.

 

[GSPV]

I would do a 6.5x47 Lapua.

 

[22BRGUY]

The only problem I would have with the .260 Improved 30° is the short neck inherited from the parent cartridge. That is what the 6.5 SLR was intended to correct with little effect upon velocity. That said: either is a good choice and is likely to provide accuracy as good as the parent cartridge with potentially better case life. The .260 Improved 30° is easier to produce, only requiring firing in the new chamber. 6.5 SLR requires sizing before loading and is a wildcat cartridge. Don't expect much velocity difference but otherwise a good choice for something different in 6.5.

I like this comment/post. In my mind the 6.5x47 is an excellent and accurate cartridge but lacks a little cartridge capacity for the heavies and can achieve some good velocities but has to have some very high pressures to do it. On the other hand, the 6.5x284 can achieve great accuracy and velocities with the heavies but because it burns so much powder to do it, it is very hard on barrel throats. The .260 powder capacity class seems to offer about the right happy medium. Of that group I like the 6.5 SLR design over the others because of the longer neck also. I wish someone would take the 6.5x284 case and push the shoulder back to about that +- 56 grain powder capacity. With the rebated rim which would produce a shorter fatter powder column and then the ability to have the longer neck in this design, I think it could really be a winner. This is all just my opinion tho and I know what opinions are worth.
Best Wishes.

 

[Raptor]

You need to also look at the best of both worlds when put on a modern action. The 6.5x55 If you down load it you get great barrel life and if you hot rod it it will run with a 6.5x284 and its deadly accurate...

 

[Deton8tor]

Thank you gentlemen for the information. I appreciate your time and experience.

 

[flatlander]

I've done a couple of 260 Imp 30* bbls - one on a M700SA, the other on a short Howa 1500. Both give excellent accuracy with my std FF load using Sierra or Lapua 123s running at 2880fps out of 26" bbls. The print for my reamer shows the same body taper as the 40* 260AI, which makes it a little more difficult to get the last round of ammo loaded in formed cases into AICS mags relative to 5 of the FF load. The formed Imp 30* cases feed just fine, and don't require trimming until the 3rd or 4th firing.

Haven't been shooting these two rifles often enough long enough to know how WW & Lapua cases will hold up; speaking of Lapua brass - I have to neck turn it before firing, as my reamer print shows a .295" neck dia, and loaded rounds in Lapua measure .295" on the neck. No prob with neck dia when using WW 243 or 7mm-08 necked up or down respectively.

 

[Rockfish Dave]

I've finished breaking in my 6.5 SLR Improved (reduced body taper) and plan on sending it off for salt bath nitride treatment along with my other barrels.

The initial results are very promising.

http://forum.accurateshooter.com/index.php?topic=3821760.0

That is a link to my thread.

 

[XTR]

Just thoughts from someone who hasn't done it yet but is looking hard at the SLR designs (specifically a 6SLR).

It looks like there are a whole lot of variations on the idea of a 6.5 bullet in a 308 based case, all trying to get to the perfect spot, so I think it depends on your intended use. For my intended purpose I like that the SLR designs do not require fire forming. I'm looking a building something for precision rifle matches where you often don't get to police brass, so the idea of size and shoot with W-W or R-P brass works for me. The only drawback I see in this is that if I have to use Lapua brass I'll pretty certainly get a doughnut and would need to inside ream unless I'm seating well clear of it.

None of these chamberings are what I'd call easy on barrels (compared to a 308) so fire forming impacts useful barrel life. That's a downside I'd like to avoid. (thought once you wear out a barrel you can always keep it for a forming barrel.)

The SLR designs give you more neck, not a bad thing.

You can order dies from John Widden, that'll work for me. I'm sure if I ordered dies he can deliver dies before I could assemble the parts and get the rifle built, he'd probably run just about the same time as a reamer from JGS or PT&G.

In the 6.5 class, if you plan to run the 140s, on paper, it looks like the 6.5x47L has to reach just a bit far to give you the velocity that you can get from the 260 based cartridges with a tad more capacity. I'd guess the 6.5 Creedmoor would be pretty close to the right answer, (a little more capacity than a 6.547L, a better shoulder than a 260) if there were more brass options. These days I want more than one manufacturer making my components.


I'm pretty well set on doing an SLR when I take the next step in my build.

 

[Joe C]

I mentioned this on another thread so perhaps it is old to some but nonetheless...

I'm running the .260AI with great results. Shooting a 142g BC bullet, H4831SC, Wolf primers and Nosler brass I'm getting 2940fps and I'm on my 6th completed firing with no loose primer pockets or pressure signs. The gun has a 29" 8 twist Brux and is averaging 1.5" vertical for 10 shot groups at 600 yards. I couldn't be happier with my choice.

Don't have any idea how barrel life will be but I'm not really worried as I have a fire forming barrel and a new one waiting in the wings. Shot a 599-31x a couple of months ago in a match. That was pretty awesome for me. Looking forward to taking it back to Phoenix in October to give it another run at 1000 yards since I have my load worked up better from my first time there in February.

I like the round so much that I am building a long range hunting rig for this fall...

 

[Laurie]

I like this comment/post. In my mind the 6.5x47 is an excellent and accurate cartridge but lacks a little cartridge capacity for the heavies and can achieve some good velocities but has to have some very high pressures to do it. On the other hand, the 6.5x284 can achieve great accuracy and velocities with the heavies but because it burns so much powder to do it, it is very hard on barrel throats. The .260 powder capacity class seems to offer about the right happy medium. Of that group I like the 6.5 SLR design over the others because of the longer neck also. I wish someone would take the 6.5x284 case and push the shoulder back to about that +- 56 grain powder capacity. With the rebated rim which would produce a shorter fatter powder column and then the ability to have the longer neck in this design, I think it could really be a winner. This is all just my opinion tho and I know what opinions are worth.
Best Wishes.

What you describe here isn't a million miles away from the 6.5X55mm AI 40-deg. Charges are a little lower than your ideal level at ~52-53gn. With good quality Lapua brass available, it's a nice long-action cartridge for those looking for something between the '47L / 260R class and the 6.5-284.

Sadly, nobody seems to make off the shelf dies for it.

 

[TonyR]

I like this comment/post. In my mind the 6.5x47 is an excellent and accurate cartridge but lacks a little cartridge capacity for the heavies and can achieve some good velocities but has to have some very high pressures to do it. On the other hand, the 6.5x284 can achieve great accuracy and velocities with the heavies but because it burns so much powder to do it, it is very hard on barrel throats. The .260 powder capacity class seems to offer about the right happy medium. Of that group I like the 6.5 SLR design over the others because of the longer neck also. I wish someone would take the 6.5x284 case and push the shoulder back to about that +- 56 grain powder capacity. With the rebated rim which would produce a shorter fatter powder column and then the ability to have the longer neck in this design, I think it could really be a winner. This is all just my opinion tho and I know what opinions are worth.
Best Wishes.

What you describe here isn't a million miles away from the 6.5X55mm AI 40-deg. Charges are a little lower than your ideal level at ~52-53gn. With good quality Lapua brass available, it's a nice long-action cartridge for those looking for something between the '47L / 260R class and the 6.5-284.

Sadly, nobody seems to make off the shelf dies for it.

Maybe not the AI version, but Kelbly's is selling the 6.5X55GWI in some of their complete rifles. They might also supply dies. This is an excellent cartridge for LR F-Class for people who can't handle the recoil of a 7mm or 30 cal. It is very similar to the 6.5x55 AI except the shoulder angle is less, like 30 or 35 degrees. A friend has gotten 2000 rounds through his so far with no end in sight shooting the 140 class bullets in the mid-2900s

 

[Laurie]

Thanks Tony. Not one I've heard of before. We had a few AIs on the GB scene in the early F-Class days, but 6.5s have just disappeared at national level. In fact, if you want a good quality custom rifle here at modest cost, your best bet is to wait until a secondhand 6.5-284 appears. Even at club level F, we're more likely to see either the 6.5X47L (VERY popular) or .260 Rem and they're both widely used in tactical disciplines too.