Best overall SA 308 bolt face competition caliber?

#51
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">So far I think the 6.5CM...
I only ran the 7-08 in an old Douglas 22" barrel for a short time before it became my 65CM but am really leaning to a 26" 7-08 (or 7CM maybe).

The 6.5CM has been very consistent in matches for me and seems more intuitive to me (yeah, I know that's not too objective, but it's the only way I can explain it). I actually just stumbled into the 6XC on a trade, and while it's been good, I doubt I'll barrel it up again as a 6 after this season.

A seven at 2800 that feeds well out of SA AICS type mags is really what I'd like to end up with.

And bohem, I know no caliber shoots itself
wink.gif
</div></div>

It does seem like 6.5's are the best all around compromise.

I was surprised when I shot Christopher's 6.5 Creedmoor/140's and the recoil was as light as my 6x47L. I imagine his brake is more efficient than mine though. The 6.5C hits a little harder on steel, wind is the same, drops more but gets better barrel life.

If there wasn't a 3100 fps cap on velocity for the matches I'd try a 6-6.5x55AI of some kind. It would make a good cheater cartridge. 105's at close to 3400fps in a longer barrel. Lapua brass at a reasonable price. With the downsides of poor barrel life and fireforming.

I tried a 7mag pushing 176's at 3040fps as a cheater cartridge but I couldn't see where the heck I was missing because of the sight picture upset. I had no idea where to aim for the following shots. Lesson learned LOL.

I will say this...You sure shoot the Surgeon 6XC well.
 
#53
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DTubb</div><div class="ubbcode-body">Just to clear up any misunderstandings.

I used DTAC 115's every year at the 300 and 600 yard stages of Camp Perry (use a lighter weight Sierra for 200 yds).
I have also used them every year (excepting 2010) in all the 1000 yard matches at Camp Perry. I shoot at a 308 in the Palma Match so never use them there.

DTAC 115's hold by themselve both of the NRA Long Range Record scores (NRA changed course of fire 2005).
Old course of fire - Clean score of 1450 101x in 2004
New course of fire - One down score of 1249 68x in 2011.

DTubb </div></div>

FWIW - I really loved the 117 grain DTAC's back when you had them. Maybe it was just the "cool factor" of the polymer tips, but they were a heck of a lot of fun to shoot. Not to mention extremely accurate as well. Any chance those extra heavies will be made again?
 
#54
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">So far I think the 6.5CM...
I only ran the 7-08 in an old Douglas 22" barrel for a short time before it became my 65CM but am really leaning to a 26" 7-08 (or 7CM maybe).

The 6.5CM has been very consistent in matches for me and seems more intuitive to me (yeah, I know that's not too objective, but it's the only way I can explain it). I actually just stumbled into the 6XC on a trade, and while it's been good, I doubt I'll barrel it up again as a 6 after this season.

A seven at 2800 that feeds well out of SA AICS type mags is really what I'd like to end up with.

<span style="font-weight: bold">And bohem, I know no caliber shoots itself
wink.gif
</span></div></div>

I didn't mean that comment towards you in particular, I know you get it
smile.gif
It was a reminder for some other folks who may be reading it and wondering "should I dump my 308 and spend 6 months ammo budget getting a XXXXXX built?"

Usually, that answer is "no" IMO.

Enjoy, sir, it sounds like you and I are on the same quest. I've got a stack of 6.5CM brass and a couple spare tubes sitting on the shelf, as well as owning my reamer so I'll be with it for a while. I'm building a 7CM just as something to practice with since the ballistics are almost identical and I have a clone to my primary match rifle in everything except the bore size then but with better barrel life.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ranger1183</div><div class="ubbcode-body">I might have missed it, but nobody suggested the GAP 6mm Crusader? Seems like a heck of a flat shooter there. </div></div>

It is, though barrel life is mediocre. Steve123 mentioned a 6-6.5x55AI flavored round, which is essentially what you get from a GAP 6 Crusader.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Steve123</div><div class="ubbcode-body">6-6.5x55AI of some kind.</div></div>
 
#55
Re: Best overall SA 308 bolt face competition caliber?

This is all cool stuff and all but.

I am still looking for this round.
Use 308 bolt face
Use a Short Action
Load to a 2.810 OCL
Use brass you can find on the shelf at any Brass Pro or Sports Mans Warehouse
Will fit and feed from unmodified ACIS mags
Will for barrel life use a slow burning powderlike say H-1000
Will get a minimum of 3,000 rounds out of a barrel and still hold 1/2moa @100.
Push the 105 6mm A-Max/105Hybrids to 3,400fps (but can be loaded down to 2,900fps)
Get 7 to 10 reloads out of a piece of brass.

Now that would be a cartridge.
 
#56
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DaveD</div><div class="ubbcode-body">This is all cool stuff and all but.

I am still looking for this round.
Use 308 bolt face
Use a Short Action
Load to a 2.810 OCL
Use brass you can find on the shelf at any Brass Pro or Sports Mans Warehouse
Will fit and feed from unmodified ACIS mags
Will for barrel life use a slow burning powderlike say H-1000
Will get a minimum of 3,000 rounds out of a barrel and still hold 1/2moa @100.
Push the 105 6mm A-Max/105Hybrids to 3,400fps (but can be loaded down to 2,900fps)
Get 7 to 10 reloads out of a piece of brass.

Now that would be a cartridge.
</div></div>

6mm SLR?
 
#59
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mattsnuked</div><div class="ubbcode-body">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. </div></div>
Ding Ding Ding and we have a winner.
 
#60
Re: Best overall SA 308 bolt face competition caliber?

With most matches having a 3100fps limit these days, what do you need a 105 going that fast for? Your want list is like the old production saying. You can have it fast, cheap, and good. Pick two. You can pick a couple of your wants but will never get all of them. I have a feeling you already know that though.

My very first long range custom was a 22-243. I shot some matches with it and did fairly well. It was nice for targets that I couldn't get a rangefinder to range and had to mil with my reticle. I've never practiced milling much and wasn't super accurate, so the ultra flat trajectory was nice on compensating for some of my milling error. The downsides were I did have some called misses on days with lots of mirage that I'm certain were hits, and it got beat up by the wind past 600.

Most of the matches I have been shooting the last couple years have been team matches where I had a spotter so recoil wasn't as big of a deal. I've been running a 7 WSM built on a surgeon with 162 Amax's and a badger thruster brake. Have had fantastic results and most prone shots I could still spot my own hits and misses. The only time I had trouble was from awkward positions or off of some kind of barrier or shooting sticks.

With that all said I am having Beanland build me a 6.5 lapua right now. My partner and several other guys I know have been running them for a couple years now and they seem to be a good all around balance for accuracy, drop, wind, and recoil. Of course you can insert a 6.5cm, 260, 6.5slr or any other myriad of similar cartridges and them all be apples to apples. Each has it's own advantages whether it be case design, factory option, brass price/availability. Right now this will be my primary comp gun, but I can see myself putting together another .284 for matches where I know there is going to be lots of long shots and every bit of wind help and energy for hit/misses will be helpful. Prob a 284 win on a long action or 7 saum, either running 180 hybrids or 175 smk's.
 
#61
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DaveD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mattsnuked</div><div class="ubbcode-body">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. </div></div>
Ding Ding Ding and we have a winner. </div></div>

Really? Surprising, I thought that they shared within 1-2% of the same case capacity.
 
#62
Re: Best overall SA 308 bolt face competition caliber?

Change this angle a little, and you will get 1000 more rounds of barrel life, or 250 fps more, or, or, or a new magic powder that does the same, or maybe if you mix this and that powder at 40-60% ratio...or, or..

The older I get, and the more I shoot, I realize there is very little true magic in the world.....

Even though I still work very hard at finding it!
 
#65
Re: Best overall SA 308 bolt face competition caliber?

Not sure what happened with yours Charlie, but since the 6CM is very similar are you expecting the same turnout? I've got over 2k in my 6xc and it is still under an moa without a setback.
 
#66
Re: Best overall SA 308 bolt face competition caliber?

I really dig the 6XC, but am leaning towards a bigger pill for longer steel confidence. My 65CM isn't going anywhere and I'm only thinking 7something because I don't want two 65CM's.
If I were inclined to stay 6mm I may just keep it an XC or go SLR...

I've got a buttload of 308 brass, and have made 7-08 with success in the past.

Short of looking harder at the 7CM, I'm thinking a 26" 7-08 gain twist might get me 2800fps with 162 Amax's.

Now to change it up a bit-Does number of grooves affect speed on 7 pills?

Thanks for the compliment Steve!
 
#67
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mattsnuked</div><div class="ubbcode-body">Not sure what happened with yours Charlie, but since the 6CM is very similar are you expecting the same turnout? I've got over 2k in my 6xc and it is still under an moa without a setback. </div></div>
How hard do you push it(FPS)
Do you do anything special for throat maintenance
 
#68
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mattsnuked</div><div class="ubbcode-body">Not sure what happened with yours Charlie, but since the 6CM is very similar are you expecting the same turnout? I've got over 2k in my 6xc and it is still under an moa without a setback. </div></div>

SLR > CM > XC in terms of case capacity. So the XC is gonna squeeze just a few hundred more rounds of barrel life. My last XC held 3/4 MOA all the way to just shy of 2600 rds before setting the barrel back. I'm still waiting to hear reports on the Creedmoor, but it seems no one is saying anything. I believe that's because realistic barrel life for a 6CM run as a comp gun is gonna be about 2000 rds. I don't see how it really can be much more than that.
 
#69
Re: Best overall SA 308 bolt face competition caliber?

260, Rem brass, 139 scenars, either H4350 or H4831sc with cci br2's. Easy to load for, performs great, no feeding problems and your barrel life will be a minimum of 2500 rounds of well under sub moa performance. I would prolly shoot mine longer but with the cost of bullets and powder it's just when I change the tube.
 
#70
Re: Best overall SA 308 bolt face competition caliber?

6SLR and 6CM have the same H20 in my chambers. I expect to change the barrels on all my 6mm at 1500 rounds. It's not worth pushing them anymore to me.

I know some people get a lot more rounds than me. I shoot fast and run guns hards that is likely the main issue.

If my gun is not holding sub .4 MOA five round groups the barrel goes. I don't have the desire to shoot a 3/4 MOA custom rifle.
 
#71
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">6SLR and 6CM have the same H20 in my chambers. I expect to change the barrels on all my 6mm at 1500 rounds. It's not worth pushing them anymore to me.

I know some people get a lot more rounds than me. I shoot fast and run guns hards that is likely the main issue.

If my gun is not holding sub .4 MOA five round groups the barrel goes. I don't have the desire to shoot a 3/4 MOA custom rifle. </div></div>

You make some very valid points. However, my budget constraints have changed over the last year, otherwise I would have rebarreled my first XC at about 2k. I think a lot folks are in the same boat and that is the real reason a lot of people are shooting 6.5's and 7's for comps instead of 6's. A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round, for a variety of reasons already discussed. Only downside is, peak accuracy is gonna taper off after about 2k. Doesn't seem to matter what voodoo you use to try and increase that envelope. Barrel steel is what it is, nothing else we can really do to make it last longer for the application we have at hand.

-SBS
 
#72
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SagebrushShooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 264Charlie</div><div class="ubbcode-body">6SLR and 6CM have the same H20 in my chambers. I expect to change the barrels on all my 6mm at 1500 rounds. It's not worth pushing them anymore to me.

I know some people get a lot more rounds than me. I shoot fast and run guns hards that is likely the main issue.

If my gun is not holding sub .4 MOA five round groups the barrel goes. I don't have the desire to shoot a 3/4 MOA custom rifle. </div></div>

You make some very valid points. However, my budget constraints have changed over the last year, otherwise I would have rebarreled my first XC at about 2k. I think a lot folks are in the same boat and that is the real reason a lot of people are shooting 6.5's and 7's for comps instead of 6's. A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round, for a variety of reasons already discussed. Only downside is, peak accuracy is gonna taper off after about 2k. Doesn't seem to matter what voodoo you use to try and increase that envelope. Barrel steel is what it is, nothing else we can really do to make it last longer for the application we have at hand.

-SBS </div></div>

I'm shooting .260s now days
smile.gif
 
#73
Re: Best overall SA 308 bolt face competition caliber?

Pretty cool discussion!
Just my 2 cents.
I have shot a 6x47 Laupa, 6XC, 260, and a 6.5x284 in comps. My biggest concern has been energy on target. The comments here about a spotter not always being able to see impact on steel at the longer ranges is very valid issue. A spotter standing and looking thru 10x binos will not see as well as a shooter on the ground looking thru a 15x plus rifle scope. I think the 6's offer some real plus' as far as shootability are concerened and under some conditions both the 6mm and 6.5's will have impact issues. Main thing for me is to get out and shoot more because I am the weak link in the equation.
 
#74
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SagebrushShooter</div><div class="ubbcode-body">...A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round... </div></div>

The acoustically validated number is really about 0.54 G1, which is enough to make a difference that the validated 0.59-0.61 6.5mm's going 250fps slower demonstrate lower wind drift.
 
#75
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SagebrushShooter</div><div class="ubbcode-body">...A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round... </div></div>

The acoustically validated number is really about 0.54 G1, which is enough to make a difference that the validated 0.59-0.61 6.5mm's going 250fps slower demonstrate lower wind drift. </div></div>

I thought the 0.54 G1 was the unpointed DTAC and the 0.59 G1 was the pointed DTAC... Don't shot a DTAC so I'm just recalling dusty stuff from my brain....
 
#76
Re: Best overall SA 308 bolt face competition caliber?

FWIW, I opted for a straight .243 at 22" suppressed. I'm hoping to send pointed 105's at 3000. There is something to be said for reduced recoil impulse of a 6mm, and the drift is slightly less than my 260 with 140's.

As a point of reference, my 223 bolt gun send pointed 82 bergers at 2900, and is doing duty as a practice and club match gun. 2013 season PRS matches will definitely be shot with the 243. That way, I'm only rebarreling approximately once a year on 243..
 
#77
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SagebrushShooter</div><div class="ubbcode-body">...A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round... </div></div>

The acoustically validated number is really about 0.54 G1, which is enough to make a difference that the validated 0.59-0.61 6.5mm's going 250fps slower demonstrate lower wind drift. </div></div>

I thought the 0.54 G1 was the unpointed DTAC and the 0.59 G1 was the pointed DTAC... Don't shot a DTAC so I'm just recalling dusty stuff from my brain....



</div></div>

FYI The new pointed 115 DTAC is the only bullet I use anymore in my 6x47L. I've fiddled with the Shooter ballistic program a lot this last year and the closest BC I can get to work right is .290 G7.
 
#78
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SagebrushShooter</div><div class="ubbcode-body">...A 115 DTAC with a .590 G1 BC at 3100 is damn near impossible to beat for a comp round... </div></div>

The acoustically validated number is really about 0.54 G1, which is enough to make a difference that the validated 0.59-0.61 6.5mm's going 250fps slower demonstrate lower wind drift. </div></div>

I thought the 0.54 G1 was the unpointed DTAC and the 0.59 G1 was the pointed DTAC... Don't shot a DTAC so I'm just recalling dusty stuff from my brain....

</div></div>

That may be true, I dont' shoot a DTAC and only know what they do with a couple friends that shoot them. I wasn't aware they were pointing the bullet now so that could be the case. 50pts (10%) of BC for pointing that bullet sounds like a lot though, unless it had a massive meplat originally or more than just the point was modified. Either way, if it does have a 0.59 G1 /.29 G7 that's a huge BC for a 6mm bullet.
 
#79
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body">
That may be true, I dont' shoot a DTAC and only know what they do with a couple friends that shoot them. I wasn't aware they were pointing the bullet now so that could be the case. 50pts (10%) of BC for pointing that bullet sounds like a lot though, unless it had a massive meplat originally or more than just the point was modified. Either way, if it does have a 0.59 G1 /.29 G7 that's a huge BC for a 6mm bullet. </div></div>

Well, the sectional density of a 115gr bullet in 6mm is 0.278, so a .290 G7 would roughly require only a form factor of 0.96. Now the DTAC shares very similar dimensions (in calibers) to the 142gr and 175gr SMKs, which have form factors of around 0.96 and the DTAC is pointed vs the other two which are not. So it is an impressive BC, but not that unrealistically so.
 
#80
Re: Best overall SA 308 bolt face competition caliber?

Good point, James.

The reduction in size vs. the 142 and 175 makes scaling the form factor more difficult when looking at the necessary calibers/turn for stability and structural integrity as well. So, I'll take that back... it's a Huge BC only in that I don't <span style="font-style: italic">think</span> anyone else is putting out a 6mm that pushes up on 0.6G1
 
#81
Re: Best overall SA 308 bolt face competition caliber?

I've been shooting the DTAC's for about 18 months now. I can tell you the first 1000 I bought came with the 6XC as a package deal and they were the old style that were not pointed. Pretty large meplat if memory serves me correctly. I also remember there being a significant change in my DOPE when I switched over to the newer style that was pointed. I've looked at a lot of ballistic tables in terms of down range energy and you have to get a 6.5 140 grn close to 2900 ft/sec before you're gonna see any noticeable difference in impact energy on steel out past 800 yds. Even then it's not much. Only advantage I really see to 6.5 route is barrel life.

Really enjoying this discussion BTW. Good stuff all the way around.

-SBS
 
#82
Re: Best overall SA 308 bolt face competition caliber?

Well, if I could add my $0.02...

I'm not as good a comp shooter as many (most) of the above, but I do understand internal and exterior ballistic pretty well.

I would say, beyond the heavy sectional density of the 115gr DTAC, its biggest advantage is the fact it comes pointed. Its pointed meplat makes it the special bullet it is, and not the mediocre 0.54 G1 BC that Josh cited (G7 form factor of over 1.0).

So if you pointed 6.5mm bullets, you would see the ballistic advantage come back to them. In 6.5mm, most of the top bullets all have form factors closer to 0.90 and pointing those bullets would increase G1 BCs to 0.65+ for the 140grainers and over 0.60 for the 130grainers. I'm too lazy to manually point bullets, but its possible for someone more motivated.

On the internal ballistic front, I'm strongly in favor of 30* shoulder. We know that 30* shoulder is easier on the throat, less likely to result in neck growth, and, for whatever reason, more precise (just see 6 BR or 6 PPC in benchrest for evidence on its precision). And there are no downsides to a 30* shoulder so no compromises to get these benefits.

6XC, 6x47L, 6SLR, 6CM, 6.5x47L, 6.5CM, etc - all 30*. Pick one and go.
 
#83
Re: Best overall SA 308 bolt face competition caliber?

6.5 creed is very hard to beat all around. hornady is trying real hard to keep brass/ammo available and reasonably priced. 6.5 proj are good in the wind and i can see them impact on the long shots. as stated above 6mm barrel life is a concern for me "def not white collar bankrolled" so i like to keep em out of the shop as much as possible too. if i could afford a 6pack of barrels id run 6mm. 6.5creed factory match ammo is another great bonus all to itself. if you get in a jam its good to be able to order match ammo at a reasonable price if you have to.
 
#84
Re: Best overall SA 308 bolt face competition caliber?

SouthWest Ammo makes 260 ammo just as cheap as the hornady 6.5 creedmoor. They have is loaded in 7mm-08 brass (142gr SMK) for $24.99/20rds or 139 gr sceanars in rem brass for $29.99/20 rds.
 
#85
Re: Best overall SA 308 bolt face competition caliber?

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

So if you pointed 6.5mm bullets, you would see the ballistic advantage come back to them. In 6.5mm, most of the top bullets all have form factors closer to 0.90 and pointing those bullets would increase G1 BCs to 0.65+ for the 140grainers and over 0.60 for the 130grainers. I'm too lazy to manually point bullets, but its possible for someone more motivated.
</div></div>

This is one of the things that Hornady did right with their new 140 BTHP Match, it comes pointed. The BC of that OTM with a point has been shown right about 0.58 from several people, I thought it was going to be in the 0.56-57 range but I keep tweaking it more and more up to the 0.58 that Hornady publishes.

If you took the 140 JLK and pointed it up, I wouldn't be surprised to see it surpass the 7mm 180 Berger Hybrid (unpointed) as it starts with a BC already approaching the mid 0.6's

The 130's that I got from James a couple months back are dynamite, it's really tough to beat the speed and BC that comes from a 130 in 6.5mm, a medium load in my 22.5" 6.5CM is going almost 2900fps already.


<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">6XC, 6x47L, 6SLR, 6CM, 6.5x47L, 6.5CM, etc - all 30*. Pick one and go. </div></div>

Well said. I really like the 6.5CM's front end more than the 260 for 2 reasons, neck length and shoulder geometry. The functional case capacity is the same (water capacity after bullet seating) and they get the same kind of speed so I'll be keeping my 6.5CM for a while.
 
#86
Re: Best overall SA 308 bolt face competition caliber?

Let me preface this with: I don't have time to shoot, much less load, plus, I am just lazy...and it shows with my match placements this year!

From here on out, I will always own a 6.5 CM and a .308 barrel.

I have tried a bunch of stuff, chasing the perfect caliber. I have come to realize that the 6.5 CM is pretty close to the perfect balance between performance, cost, precision, barrel life, availability, etc.

I am getting over 2800 from a factory loaded 140 AMAX... that's tough to beat for a buck a round, that I don't have to load...at 3am, the night before I have to leave for a match in 3 hours (yes, I have been there, more than once).

I have never had an issue with being able to spot my own splash or trace with the 6.5 that I wouldn't have had with the .30 cal. And, for the record, I feel this is the most important skill a shooter can have, if I felt that the 6.5s compromised this in any way, I wouldn't run them.

At the last 4R match, Pirtle and I both ran .308s and we hit a lot of shit, out to 1100 yards, in a 25 MPH, full value wind. In a known distance, known wind situation, a .308 is hard to beat. Its the situations where the range may be a little off or the wind may be a little switchy that you need a better BC and more velocity...i.e. the vast majority of matches.

That being said, when Hornady starts making loaded 6CM available (or when George starts making Super Ken load it for sale), I will probably try one.

I am also going to play with a .284 loaded a little long in an AIAE. The 7s intrigue me with ballistic performance and potential barrel life. This is the next project when I get around to it. I will be watching the development of the 7CM very closely as well.


Oh and, by the way, I am dead serious about 10 or 15 guys getting together and buying a Promethius and hiring someone to load for us...did I mention the lazy part?
 
#87
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">

So if you pointed 6.5mm bullets, you would see the ballistic advantage come back to them. In 6.5mm, most of the top bullets all have form factors closer to 0.90 and pointing those bullets would increase G1 BCs to 0.65+ for the 140grainers and over 0.60 for the 130grainers. I'm too lazy to manually point bullets, but its possible for someone more motivated.
</div></div>

This is one of the things that Hornady did right with their new 140 BTHP Match, it comes pointed. The BC of that OTM with a point has been shown right about 0.58 from several people, I thought it was going to be in the 0.56-57 range but I keep tweaking it more and more up to the 0.58 that Hornady publishes.

If you took the 140 JLK and pointed it up, I wouldn't be surprised to see it surpass the 7mm 180 Berger Hybrid (unpointed) as it starts with a BC already approaching the mid 0.6's

The 130's that I got from James a couple months back are dynamite, it's really tough to beat the speed and BC that comes from a 130 in 6.5mm, a medium load in my 22.5" 6.5CM is going almost 2900fps already.


<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">6XC, 6x47L, 6SLR, 6CM, 6.5x47L, 6.5CM, etc - all 30*. Pick one and go. </div></div>

Well said. I really like the 6.5CM's front end more than the 260 for 2 reasons, neck length and shoulder geometry. The functional case capacity is the same (water capacity after bullet seating) and they get the same kind of speed so I'll be keeping my 6.5CM for a while.</div></div>

I point the 140 JLK's. They seem to match up to a .655 BC. They are very impressive bullets.
 
#88
Re: Best overall SA 308 bolt face competition caliber?

Not to divert the topic here, but holy fuck y'all are making some huge claims on BC increases via pointing.

I had been under the impression pointing was good for .01 or so.

Have I really been out to lunch on this pointing business? Think I can point a 7mm 175smk from .64 to .70???? How about a 338 300smk from .77 to .85?
 
#89
Re: Best overall SA 308 bolt face competition caliber?

The smaller the diameter the bullet the greater the gain is from pointing. In the case of the 140 JLK it increased the BC from about .627 to .655 or about 4%. Thats not exactly an enormous gain.
 
#90
Re: Best overall SA 308 bolt face competition caliber?

I re-point the new pointed DTAC's and the re-pointed ones hit about 10" higher at 900 yards. That was shooting both at the same time, one group was 10" higher. The point's are pretty crappy on the last 4000 DTAC's I've bought, looks like a corkscrew.

In my 223 shooting 75 Berger VLD's @ 2920 fps I gain about 3-3.5% over a non-pointed. Can't really see the difference until 600 yards, but there and out it's obvious.
 
#91
Re: Best overall SA 308 bolt face competition caliber?

I dont shoot matches that often, but im currently building a 7-08. I picked it due to the barrel life, the fact that I also have a butt ton of 308 brass, and from the research I did for load data. I have seen many postings of 2700ish with the 162AMAX out of 20-22" barrels. Also, the loads were not completely maxed. For my build I should be able to get 2750-2800 with the 162AMAX out of a 24" tube.
 
#92
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">Not to divert the topic here, but holy fuck y'all are making some huge claims on BC increases via pointing.

I had been under the impression pointing was good for .01 or so.

Have I really been out to lunch on this pointing business? Think I can point a 7mm 175smk from .64 to .70???? How about a 338 300smk from .77 to .85? </div></div>

The impact of pointing is basically governed by two things: the size of the meplat in calibers BEFORE the pointing and the size of the meplat in calibers AFTER the pointing. So if you have a bullet with a small meplat in calibers like the JLKs you are unlikely to pick up much BC (like the 4% cited above). However if you have a bullet with a large meplat (Hornady HPBTs tend to have large ones) you can pick up a good bit. A good meplat prior to pointing is in the 0.05" range and a crappy one would be over 0.07". Most pointing can bring the meplat down to under 0.04".

I would say you are highly unlikely to increase the BC as much as you cite for either the 7mm 175gr SMK or the 338 300gr SMK.
 
#94
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">and good barrel life.
</div></div>

yup, stay away from .243 if your on a barrel budget, if you dont want to spend a barrel a year. but love how flat it shoots.
 
#95
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">If the offered info is directed my way, please leave DTacs out of the picture. I can't stand them and the way their originator pushes them but shoots SMK's....</div></div>

I have been having great luck with 105 A-max's but please dont buy them all oout of stock everywhere...
grin.gif
 
#96
Re: Best overall SA 308 bolt face competition caliber?



Barrel life. Barrel life. Barrel life.

Looks like this is what the singular topic of concern finally becomes.

The answer to that riddle is here: Shoot reduced loads (the next lower node) at short range targets for many practice drills.

Now. Which round wins? For me its XC first, and 243Win second. In a windy condition long range match run it wide-assed open with heavies.

Otherwise, all the horsepower that is available does not have to be used all the time. Engine life will also be greatly reduced if you run your F-150 full throttle every where you go.

Anyway, re-barrelers have to make a living too.
 
#97
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: grandslam</div><div class="ubbcode-body">260, Rem brass, 139 scenars, either H4350 or H4831sc with cci br2's. Easy to load for, performs great, no feeding problems and your barrel life will be a minimum of 2500 rounds of well under sub moa performance. I would prolly shoot mine longer but with the cost of bullets and powder it's just when I change the tube. </div></div>

This. Overall, though many are comparable, .260's are just hard to beat for barrel life, ease of loading, recoil and long range performance.
 
#98
Re: Best overall SA 308 bolt face competition caliber?

As little as I'd like to admit this:

I think the 260, 6.5 Creedmoor or 6.5 SLR are really tough platforms to beat for short action competition cartridges.

The brass is prolific, it's exterior ballistics are excellent to the point no reasonable cartridge is "far" superior, the recoil is low, and the barrel lasts.

A 6.5mm chambering that gets the 123s to 3000fps or the 140s to 2800fps is just a well rounded do-all cartridge for our sport.

An important thing to consider is the ranges to most of our targets! The 1000 yard shot is rare. The 1000+ yard shot is extremely rare. A lot of chamberings really start to walk away form the 260 out past 1000, but with so few shots like that at matches, it's silly to design a match rifle specifically for them.
 
#99
Re: Best overall SA 308 bolt face competition caliber?





<span style="font-size: 11pt">Incidentally, another way to stave off barrel wear-out is this:

<span style="font-weight: bold">Gain twist rifling</span> = less pressure caused = less torching caused = mamma happy.

Less pressure since the bullet isn't required to begin twisting at as high an rpm as desired, but desired twist (stabilization) is eventually attained before bullet / muzzle exit.</span>
 
#100
Re: Best overall SA 308 bolt face competition caliber?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: beanns2</div><div class="ubbcode-body">I dont shoot matches that often, but im currently building a 7-08. I picked it due to the barrel life, the fact that I also have a butt ton of 308 brass, and from the research I did for load data. I have seen many postings of 2700ish with the 162AMAX out of 20-22" barrels. Also, the loads were not completely maxed. For my build I should be able to get 2750-2800 with the 162AMAX out of a 24" tube. </div></div>

This gets my vote.
 
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