Best overall SA 308 bolt face competition caliber?

[KevinU]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 264Charlie</div><div class="ubbcode-body">You are not going to get close to 3000 rounds in a 6SLR. my last 6SLR barrel went south at 1400 rounds. </div></div>

I gave up on my 6slr barrel at 920rds.

Have 970rds on a 6mm Competitive Match, throat has only moved .005. It's shooting very well. Others have been reporting 3000+ rounds of barrel life. The key might be the slightly larger case capacity compared to the 6slr/243...., and the use of slow burning H1000?

DaveD, how many rounds do you have on your 6CM?

 

[milo 2.0]

Re: Best overall SA 308 bolt face competition caliber?

I almost have to side with Kevin U on this.
He and I shot last Monday on my local range. He pretty much handed my ass to me on a platter. My 6.5x47 Lapua was no match for him and his gun. I stalled out at 600 yards, can't remember how far he got. The wind was howling.

I would have never dreamed a 6mm would out do a 6.5mm. I'm thinking of building a bench gun, the 6CM might just be it.
Miles

 

[Lowe Left]

Re: Best overall SA 308 bolt face competition caliber?

No first hand knowledge of this caliber, but found it interesting and if you're a 7mm fan...

284 Shehane used in a short action.

During the NORCAL TBRC, one of the shooters was using one in my squad. We started talking and he told me that he did the 284 Shehane with an extremely short throat, like .01-something. He did this because he wanted to be able to run the 162-amax or bthp (I don't recall which) right at 3000fps out of a short action. The Shehane allowed him the powder capacity, over straight 284, while still seating the bullet way back. That particular barrel was running mid 2900s according to him. I don't recall what barrel life was, but it wasn't shockingly low or I would've remembered.

He won the long range stage with that set up @ the NORCAL TBRC.

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowe Left</div><div class="ubbcode-body">No first hand knowledge of this caliber, but found it interesting and if you're a 7mm fan...

284 Shehane used in a short action.

During the NORCAL TBRC, one of the shooters was using one in my squad. We started talking and he told me that he did the 284 Shehane with an extremely short throat, like .01-something. He did this because he wanted to be able to run the 162-amax or bthp (I don't recall which) right at 3000fps out of a short action. The Shehane allowed him the powder capacity, over straight 284, while still seating the bullet way back. That particular barrel was running mid 2900s according to him. I don't recall what barrel life was, but it wasn't shockingly low or I would've remembered.

He won the long range stage with that set up @ the NORCAL TBRC. </div></div>

Sounds about right. I am running my straight 284 on a short action, feeding from Alpha mags @ 2.950". My barrel doesn't like the 162s very much, but can get them to ~2925-2950. I use the 175smk, and run them over a moderate charge of 54gr H4831sc, for ~2825fps.

 

[Jedi]

Re: Best overall SA 308 bolt face competition caliber?

284 shehane would be my choice
Will i $hit can my 6.5x47 to build one
NO
gains DO NOT warrant $$

 

[7mmRM]

Re: Best overall SA 308 bolt face competition caliber?

Steve,

25-26" 708 or 7CM. 162s @ 2800 + would fit your critera nicely in all aspects- trajectory, wind, energy AND bbl life.

My 22" 708 (runs 162s mid 2700s) is nearing the end of its bbl life. Not sure on exact round count as I bought the bbled action 2nd hand. But its close to 4k down the pipe, and actually it still shoots fine. At any rate, Ill be spinning up a 25- 26" tube for the next go.

Still a little up in the air as to 708 or 7CM. Leaning 708 as Im already geared up for it.

Im also spinning up a new tube for my 243 in the next few weeks. If the new 7 turns out like I think it will, this 243 may actually last some time... As Ill be shooting the 7 waaaay more!

 

[Gray]

Re: Best overall SA 308 bolt face competition caliber?

260 rem/ 139 Lapua Scenar/ Lapua brass

 

[uracowman]

Re: Best overall SA 308 bolt face competition caliber?

If money is no object, then run whatever you want that will destroy your barrel after 1000 rounds.

If you want to talk about being economical, very few rounds will stack up to a .260/6.5CM/6.5x47.

 

[jeffersonv]

Re: Best overall SA 308 bolt face competition caliber?

7 SLR

Oops! There I said it.

It doesn't exist yet?
It's only a reamer and some dies away...

No fire forming, easy inexpensive brass, high B.C. bullets with the AMAX option (saves $$$), manageable recoil, possibly decent barrel life, and a bit of energy down range?

You said best right?

Should be a performer. Seems ideal to me. About the max you could pack into a SA but really no more than a 7-08 except for better case design/bullet seating.

I run a 6.5 CM now and it is great. If I were to try to improve on it I would try a 7 SLR. Even so, the improvements would be mostly in the brass availability/price, not so much the performance of the round.

.260 Rem (left) 6.5mm Super LR (left Center) 6.5 Creedmoor (right center) 6.5 x 47 Lapua (right)

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

I've been giving 7SLR, 7Creedmoor, 7-08 and 7-08AI some consideration, as I love 7mm.

You'd think these would all be about "six of one, a half dozen of the other", as case capacity is very close amongst them.

However, there's been enough "hubbub" about 7 Creedmoor being so much more efficient than 7-08, that it can achieve 100fps+ better velocity from a 162 than the 708.

Obviously, the downside to the 7CM is you are beholden to Hornady for brass.

If the "case efficiency" of the CM is really that improved, I would expect the 7SLR to also have that advantage over the 708. But of course, the brass would be more available.

There's also the argument the SLR's long neck would improve throat life, but I don't know if I buy that.

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

Another thought:

With all the wildcats and chamberings out there, I'm surprised this doesn't exist:

A shortened 284 or shehane... Push the shoulder back ~.250" or so, lengthen the neck a bit, and shorten the case overall. Essentially, you'd have the shoulder/neck geometry of the 7SLR, but also the extra case capacity of the fatter body of the 284.

Seems like this would allow the 162/175 bullets to be seated to the neck/shoulder junction, the use of a standard .473" bolt, and a ~5gr case capacity increase over 708.

Of course, this amount of case prep and work would SUCK for use in a tactical competition cartridge. Still, would be nice to have the ability to have a TRUE, .473" BF, short action, 7mm cartridge that could get the 175s to ~2800fps

 

[tigerfan_9]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">I've been giving 7SLR, 7Creedmoor, 7-08 and 7-08AI some consideration, as I love 7mm.

You'd think these would all be about "six of one, a half dozen of the other", as case capacity is very close amongst them.

However, there's been enough "hubbub" about 7 Creedmoor being so much more efficient than 7-08, that it can achieve 100fps+ better velocity from a 162 than the 708.

Obviously, the downside to the 7CM is you are beholden to Hornady for brass.

If the "case efficiency" of the CM is really that improved, I would expect the 7SLR to also have that advantage over the 708. But of course, the brass would be more available.

There's also the argument the SLR's long neck would improve throat life, but I don't know if I buy that.



</div></div>

My question with the whole Creedmoor case being THAT much more efficient as per the 7mm Creed vs 7-08 argument is why aren't people seeing the same velocity increase in the 6.5Creed over the 260? the velocities for the loads people put here are nearly identical for both rounds so why would it be different for a 7mm?

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tigerfan9</div><div class="ubbcode-body">My question with the whole Creedmoor case being THAT much more efficient as per the 7mm Creed vs 7-08 argument is why aren't people seeing the same velocity increase in the 6.5Creed over the 260? the velocities for the loads people put here are nearly identical for both rounds so why would it be different for a 7mm? </div></div>

That is a good point. I hadn't thought of it that way.

One point of contention, however, is I don't think the alleged velocity boost of 7CM vs 708 can simply be translated to an equal boost if both are necked down to 6.5, as the whole dynamic will change.

That said, however... If the CM case is just "so efficient", I would certainly still expect to see <span style="font-weight: bold">SOME</span> velocity boost of 6.5CM over 260. Perhaps the CM case is in the sweetspot at 7mm, but some of that goodness would surely translate to 6.5mm.

You're right though, while 6.5CM velocities are "on par" with 260 (albeit with a little less powder, indicating a more efficient case design), it certainly doesn't outperm 260!

 

[jeffersonv]

Re: Best overall SA 308 bolt face competition caliber?

So where did you end up on this Turbo?

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jeffersonv</div><div class="ubbcode-body">So where did you end up on this Turbo? </div></div>

I called and left a message with Robert Whitley, the creator of the 6 and 6.5SLR to chat about it, and pick his brain over some of the details, so that I can spec a reamer.

I'm about 99% on giving 7SLR a go. It'll at least match 708 (a fine chambering in and of itself), and it sure <span style="font-style: italic">looks</span> sexier.

As it is, I'm pretty happy with my short action 284, but I have a nice Badger M2008 that takes AW magazines. After using AW mags a little, AICS and Alphas just don't cut it.

 

[turbo54]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Another thought:

With all the wildcats and chamberings out there, I'm surprised this doesn't exist:

A shortened 284 or shehane... Push the shoulder back ~.250" or so, lengthen the neck a bit, and shorten the case overall. Essentially, you'd have the shoulder/neck geometry of the 7SLR, but also the extra case capacity of the fatter body of the 284.

Seems like this would allow the 162/175 bullets to be seated to the neck/shoulder junction, the use of a standard .473" bolt, and a ~5gr case capacity increase over 708.

Of course, this amount of case prep and work would SUCK for use in a tactical competition cartridge. Still, would be nice to have the ability to have a TRUE, .473" BF, short action, 7mm cartridge that could get the 175s to ~2800fps </div></div>

After re-reading a thread from a few months ago, I see that I'm not the first to think of this. "Jedi" mentioned it a while back.

While a neat idea - and it surely provides more case capacity than any other non-magnum short action 7s, it really just doesn't apply for "competition" cartridges, as the case prep is rigorous and involved.

As far as I'm concerned, a competition cartridge needs to have READILY available brass, and caseprep can't require any kind of special treatment that can't occur in my Dillon 650. Nothing worse than thinking about where your spent brass is ending up while shooting a fast-paced stage at a match.

 

[buffybuster]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Another thought:

With all the wildcats and chamberings out there, I'm surprised this doesn't exist:

A shortened 284 or shehane... Push the shoulder back ~.250" or so, lengthen the neck a bit, and shorten the case overall. Essentially, you'd have the shoulder/neck geometry of the 7SLR, but also the extra case capacity of the fatter body of the 284.

Seems like this would allow the 162/175 bullets to be seated to the neck/shoulder junction, the use of a standard .473" bolt, and a ~5gr case capacity increase over 708.

Of course, this amount of case prep and work would SUCK for use in a tactical competition cartridge. Still, would be nice to have the ability to have a TRUE, .473" BF, short action, 7mm cartridge that could get the 175s to ~2800fps </div></div>

I like this idea.... wheels are turning.....

 

[The_FNG]

Re: Best overall SA 308 bolt face competition caliber?

I thought we worked out in you Holy Grail of SA 7mm, IMR 8208 XBR was the secret to the 7CM velocity.

Oh and i've definitely decided on the Shehane...now i just gotta find some 8208 and RL17 and compare, but with the Aussie heat in the summer here, i'm uncertain RL17 will be stable enough.

 

[jeffersonv]

Re: Best overall SA 308 bolt face competition caliber?

Which reamer are you looking at?

The /s reamer is supposed to be for mag fed rifles.
I think I read somewhere (probably here) that someone who is running this already got the /s reamer and now has regrets and is thinking the longer reamer was the way to go. Not sure how long his action was?

But then again, there probably isn't a 7 SLR reamer yet anyways. I'll be interested to see what you get worked out.

Looks like the /s has a shorter throat. I'm not sure that solves the NSJ issue as well as the 7 CM but I could easily be missing something.

Maybe I'll be hitting you up for your reamer one of these days.

 

[jeffersonv]

Re: Best overall SA 308 bolt face competition caliber?

I still find this interesting...

Any updates Turbo?

 

[jeffersonv]

Re: Best overall SA 308 bolt face competition caliber?

The no fire forming is what has me interested in the 7 SLR as much as anything else. Ya. I keep bringing this up. Is that a problem?

I have a .223 AI that I am thinking along the same lines by re-cambering to a 22-204 for much the same reasons. No fire forming and possibly improved performance over a .223 AI. I love the AI but don't love fire forming. I know it is very close to a 222 Rem mag except for the improved shoulder and better brass life. Not sure that is worth the cost of new dies?

Sooo. BTT for any 7 SLR updates!
See what happens when you get me started!

 

[bribri]

Re: Best overall SA 308 bolt face competition caliber?

Tag, great info guys......

 

[bribri]

Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jedi</div><div class="ubbcode-body">284 shehane would be my choice
Will i $hit can my 6.5x47 to build one
NO
gains DO NOT warrant $$ </div></div>

Just curious as to why you would prefer the 284 over your 6.5x47? I too am considering re-barreling my 6.5x47 to a 284 and running the 162 amax to 2900-2950, and still fitting in a short action.

I compared ballistics and from what I found, there wasn't much differnce until you get passed 1000 yards.

Just curious to hear your thoughts on the subject.

 

[Red_SC]

I have found H1000 to be cumbersome in my 6 SLR. You might want to look at the 6mm Competition Match to fill those needs.

What velocity did you get with H1000?

 

[mattsnuked]

It's been a long time since I tried but if I'm remembering correctly I could over 3 grand. It was a compressed load. 4831sc and H4350 have been the best powders for me in this cartridge.

 

[HodgdonExtreme]

It's been a long time since I tried but if I'm remembering correctly I could over 3 grand. It was a compressed load. 4831sc and H4350 have been the best powders for me in this cartridge.

I've had the same experience. A FULL case of H1000, drop-tubed and compressed, with 105 berger@ 2.865" was yielding between 2975 and 3015. 26" barrel, too. Recoil and report was "dull". Extreme spread (tried Tula LR and CCI LRM) was high. Accuracy was 3/4-1moa.

Switched to H4350 and the whole thing came alive. Recoil is stacotto, SD and ES are tight, accuracy is limited only by how well you can shoot. Velocity is as much as you want, or are allowed to have. It can buzz the 105s past 3200 if you want.

I'm sure H4831sc would do dandy as well, but I didn't bother trying as 4350 did so nicely.

Back on topic: A 6mm capable of flinging 105 hybrids at 3100+ is the correct choice for a tactical match rifle.

 

[Red_SC]

Thanks for that information.