6.5 SLR & 260 30 deg imprvd

[Hengehold]

I am a NRA LR prone shooter that is interested in the two cartridges in the subject line. I would plan to use the 140 gr bullet. I have a few questions after reading the informative write ups on the

- is one case easier to make brass for than the other?

- 6.5 SLR HAS longer neck but what is the value added with the longer neck?

- Does one have higher velocities or better barrel life than the other?

- Has anyone shot out a barrel for either one?

-What is expected rnd count for barrel life?

Thanks,

Trevor

 

[22BRGUY]

Theoretically I think the longer neck should contribute to longer barrel life as the longer neck brass shields the neck/throat area somewhat better from the heat than shorter neck cases might. JMHO and other opinions on this are welcome.
I like the 6.5 SLR design because in several ways it reminds me of an overgrown .222 cartridge.

 

[Steve Blair]

Trevor, [br]
The .260 30° Improved will hold a little more powder than a 6.5 SLR. The .260 Imp. blows out the original shoulder to 30°, preserving the original neck length, and using a standard .260 Rem case. The 6.5 SLR is a true wildcat. The case must be formed before it can be fired. The die pushes the shoulder back to 30°, preserving body length and creating a longer neck. It should translate to a few more fps. Either approach will make a fine Mid to Long Range cartridge if conditions aren't too bad.

 

[flatlander]

Trevor,
I've been shooting a tactical rifle in 260 Imp 30* recently, and have experienced very fine accuracy with both S142MKs & 123MKs. However, limitations on OAL due to the need to run rounds through AICS magazines has more than negated the extra case capacity of the improved case. While I'm getting 2900+fps with the 123s in fireforming loads with RS Hunter/Data 85, best accuracy with 142s has come at only 2670fps with H4831SC out of the rifle's 26" Bartlein. Have yet to work up loads for the 142s with RL17 - that's about my only hope for getting close to 2800fps with them.

My reamer was ground with a short throat in anticipation of using mag-length ammo, so I'd expect that single loading the 260 Imp 30* in a target rifle with a 30" bbl, throated for 140s seated out would yield considerably higher velocities.

Whatever - those 4831SC/S142MK loads were consistently producing 600yd groups with very small vertical spreads, and the 123s are grouping pretty well even out to 1000yds - and that's with ball powder & some old W8-1/2 primers in FF loads. The only case prep I'm doing - whether forming cases out of WW7-08 or 243 brass - is chamfering the case mouths & de-burring the flash holes. No weight sorting or neck turning. Try it - you'll probably like it as much as I do mine.

 

[BradY]

Running 140 hybrids in the 30 degree improved with 43.2gr H4350 in a 30 inch barrel. 2835fps, awesome vertical spread at 1000yds. I have tested up to 44.5gr with no pressure signs and things were starting to tighten up suggesting getting close to 2950fps node too. Impressive ballistics for a 6.5mm. I will be done 1000 rounds after next weekend and it will need a rechamber as I have the long throat option and Im just about out of neck to hold bullets in. But I am running a barrel that is notorious for low round counts as its very soft steel. I expect to get about 2500 rounds out of it with two-three rechambers and will retire it from use (aside from fireforming) when it gets to 26 inches.

 

[Triggerf16]

Pile-on for the 6.5 SLR. I have one in a Rem 700/PTG bolt/Eliseo RTS tactical rifle.

It is a hammer! 43.0gr H4350 gives 2850+fps with 140 AMAXes. On steel I have seen 2" groups at 500 yards, and .3" groups on paper at 100. I intend on trying some H4831SC in a few months to see if it is any better.

I think is is an excellent balance. With the long neck you get good barrel life. With the 30-degree shoulder you get good headspacing and low case stretch. You will not go any faster than a 260. If you want faster go 6.5x284.

But you will fiddle with brass less than a 260 (better headspace and less trimming), and your barrel will last. 243 Win brass is easy to get, and not as expensive as 6.5x47. Case has just a smidge more capacity than 6.5 Creedmoor. I resized 243 Win brass in the 6.5SLR dies and shot it. You can use other brass (260, 7mm08, 308) in a pinch.

Those were my reasons. I like the cartridge. I will have more rifles chambered that way. I recommend it!

 

[jcampbellsmith]

I'm not sure I see the benefits of this complexity. I'm happy with my straight 260 Rem and I'm getting another one. Regards JCS

 

[MTETM]

Let's See...
We have 2 6.5 SLR/s barrels. Both started life at 27 inches.
We shoot 140's in the 2825 range with either 4831sc or H4350. We have had them over 2900 fps, but at the cost of primer pockets.
They will consistently shoot <.5 moa to 1000 yards.

1 barrel is at 2400 rounds. Loads must be longer and use about 1 gr more powder for the same velocity as the other barrel which only has 1100 rounds through it.
The 2400 round barrel was set back .030 at 1200 rounds. The other barrel has not been touched.
Both of these barrels are on "tactical" match rifles and are shot hard...The barrels have been plenty hot on many occasions and they still perform very well.

The 2400 round barrel will be setback this fall and used as a practice barrel next year. The next barrel will be chambered the same way.

To date, we have 500 brass formed. We have never trimmed any of it and the only cases we have "lost" were in load development running 140's over 2900 with 4831sc.
All of the brass is formed from WW 243 cases. We have not experienced any donuts. Case forming is easy and the FF loads have been very accurate. Some used in practice, some in matches, some on a dog town....wife likes to shoot pdogs with her match rifle...

Hope this helps...

 

[22BRGUY]

Let's See...
We have 2 6.5 SLR/s barrels. Both started life at 27 inches.
We shoot 140's in the 2825 range with either 4831sc or H4350. We have had them over 2900 fps, but at the cost of primer pockets.
They will consistently shoot <.5 moa to 1000 yards.

1 barrel is at 2400 rounds. Loads must be longer and use about 1 gr more powder for the same velocity as the other barrel which only has 1100 rounds through it.
The 2400 round barrel was set back .030 at 1200 rounds. The other barrel has not been touched.
Both of these barrels are on "tactical" match rifles and are shot hard...The barrels have been plenty hot on many occasions and they still perform very well.

The 2400 round barrel will be setback this fall and used as a practice barrel next year. The next barrel will be chambered the same way.

To date, we have 500 brass formed. We have never trimmed any of it and the only cases we have "lost" were in load development running 140's over 2900 with 4831sc.
All of the brass is formed from WW 243 cases. We have not experienced any donuts. Case forming is easy and the FF loads have been very accurate. Some used in practice, some in matches, some on a dog town....wife likes to shoot pdogs with her match rifle...

Hope this helps...

Thanks for this info; Are you saying that with this cartridge it will be necessary to set the barrel back at about 1200 rounds? Why did you set the barrel back at that stage....loss of accuracy?
thanks much

 

[mgdietrich]

Trevor:

You are a heck of a shooter, but I feel that unless you are very recoil sensitive there are better bullets available today then the 140gr class 6.5's.

I am shooting a straight 284 with 180gr sierra's and that combo will take significantly less wind than a 6.5 bullet running 2900. I have 1000 rounds down my 284, am setting it back because I didn't have the right neck so I can now avoid the donut since I am switching to Lapua brass from WW.

Another option that many are doing would be a fast 6mm, the Berger 105 Hybrid is darn slippery- Litz and Whidden make straight 243's shoot great! They can read the wind better than myself, that is why I need the ballistics.

If you want to shoot a 6.5, which is still darn good- I would keep life simple and go 6.5Creedmore or a straight 260. I have played with Wildcats, the benefit did not outweigh the hassle to me, but there are many options.

Morgen

 

[MTETM]

I was starting to chase the throat a little. I did not notice a significant change in accuracy prior to the set back. It was also the beginning of the new match season, and I thought I might as well start "fresh".

Let's See...
We have 2 6.5 SLR/s barrels. Both started life at 27 inches.
We shoot 140's in the 2825 range with either 4831sc or H4350. We have had them over 2900 fps, but at the cost of primer pockets.
They will consistently shoot <.5 moa to 1000 yards.

1 barrel is at 2400 rounds. Loads must be longer and use about 1 gr more powder for the same velocity as the other barrel which only has 1100 rounds through it.
The 2400 round barrel was set back .030 at 1200 rounds. The other barrel has not been touched.
Both of these barrels are on "tactical" match rifles and are shot hard...The barrels have been plenty hot on many occasions and they still perform very well.

The 2400 round barrel will be setback this fall and used as a practice barrel next year. The next barrel will be chambered the same way.

To date, we have 500 brass formed. We have never trimmed any of it and the only cases we have "lost" were in load development running 140's over 2900 with 4831sc.
All of the brass is formed from WW 243 cases. We have not experienced any donuts. Case forming is easy and the FF loads have been very accurate. Some used in practice, some in matches, some on a dog town....wife likes to shoot pdogs with her match rifle...

Hope this helps...

Thanks for this info; Are you saying that with this cartridge it will be necessary to set the barrel back at about 1200 rounds? Why did you set the barrel back at that stage....loss of accuracy?
thanks much

 

[22BRGUY]

Thanks MT

 

[Hengehold]

Thanks Morgen,

I am trying to stay away from a case with too much recoil. Shot execution is half of the game and I don't really know where my recoil threshold is. I can shoot a 155gr all day/every day and not develop a flinch but I am sure that there is a limit. I wanted to keep the recoil similar to a palma rifle since I know I can handle that for a long shooting event. The 7mm 284 is very appealing though. I have all the components and dies. Just haven't put one together yet.

I think that I will end up going with the 6.5-284. I hate the idea of buying a new barrel every year but it is a proven performer and will not need to reinvent the wheel.

-Trevor

 

[mgdietrich]

Trevor:

You would do very well with a 6.5X284 I am sure, I have never shot one but everyone I hear says the recoil is less that a 155 palma gun, so you should be good.

You sure you son't want to shoot a .22 rimfire at 1K and give the rest of us a chance?

 

[Triggerf16]

If you really want to beat the ballistics of the 6.5SLR at 2850, without the recoil of the 284 Win, then I would look at the 6.5SAUM that George Gardner at GAP developed.

He uses an oversize case with an "over slow" powder (H1000) to get 3150fps with 140s at 53000-55000 psi. He recently won the Snipershide Cup with a barrel with 4000 rounds through it.

It seems too good to be true, but the results speak for themselves. By keeping the pressure low, George kept temps down, and kept throat erosion down. Only one barrel setback of .112 at 2000 rounds.

Worth looking into if 140s at 3150 are your goal. The big downside is brass availability and prep.

 

[Hengehold]

thanks Morgen but I think I will hold off on the 22 LR for now

 

[Hengehold]

triggerf16,

I would like to keep velocities less than 3000 fps to mitigate chance of bullet failure. Could I use the H1000 concept with the 6.5-284 since there is excess case capacity when using the 4831SC? I am not sure how much difference this would make in barrel life but I would think that it could improve the useful life of the barrel and still reach the 2950 neighborhood with a 30" barrel.

- Trevor

 

[Triggerf16]

Trevor,

I doubt you will experience bullet failure, but I also understand that faster is not always better. I have a 6.5 SLR for just that reason (otherwise 6 SLR or 6.5 SAUM would be faster).

As far as slower powders, it cannot hurt to try H1000 in the 6.5-284. I doubt you can jam enough in there to get past 2900fps, but I would like to be wrong. The case capacity is 68.3 gr of water vs 73.6gr in the 7mm SAUM.

The advantage of the H1000 is that you might find with 55gr of H1000 that the case is full, velocity is 2880, but pressure is low (53000psi?). If you could achieve that, your barrel will last a lot longer than if you used a hotter powder like H4831 or H4350.

http://www.6mmbr.com/SixFive284.html

Lists this as a load:

Hodgdon H1000 - 55.0, RWS primer, Sierra 142 bullet, 2880 fps. Notes: Hodgdon Max load (compressed). Moly SMKs. Win brand brass, necked-down.

Give it a try and see what you think. Lots of good info on that page.

 

[STOMP442]

H1000 works very well in the 6.5-284 with 140s as well as Retumbo. 55-57gr seems to be the sweet spot with velocities right in the 2950 mark. Those are my go to powders with that cartridge and it never fails to impress.

 

[bruce moulds]

the super lr has less capacity than the 260, about 2 gns of water less.
forming cases is easy, and while doing so you set the headspace perfectly for your chamber, allowing them to be used in a matches while fireforming.
the super lr will have a little more barrel life than the 260, and way more than the 6.5/284, probably double, whatever powder you use in the big case.
the difference in wind deflection is very small between the two, in fact unnoticeable in the real world.
the 6.5 is way more shootable than the 284 in anyone's language, allowing better shooting simply due to reduced violence.
the long neck of the super lr might help barrel life, but certainly won't hurt it.
it simplifies bullet seating and using different bullets.
the super lr is possibly the smallest capacity that can fit enough h4350 to meaningfully propel 140 gn bullets.
while the 7mm might have a little advantage in the wind, the super lr is so accurate that its vert gives a wide target.
the sling target has a 2 moa bull and a 1 moa x ring, which a good wind reader can deal with.
the super lr seems to have quite a wide accuracy node at the top end with 140s and h4350.
it is not the best in the wind, (big kickers) or the best barrel life, (30br) least recoil (6br).
what it is, is the ultimate compromise.
here in aust fclass circles it is becoming known as "the game changer"