6xc vs 6-6.5x47 accuracy choice

[JohnMill]

I started to buy the stuff for a 6XC, but then read Joe SR's and Whitley's info on the modified 243. It seemed so simplethat I bought into the 6mmsuperLR (could not obtain reamers for the 6Competition) I do believe that given similar accuracy I want something that will last a long time. I went with the 7.5 twist and the 115 DTAC coated. Eye surgery stopped me from getting results to publish.
Newboy I hope you're right that it is as good as a 6.5-284

John
Sorry That is Joe Hendricks, sr's 6 CompetitionMatch (6CM)
John

 

[spclark]

My present hope is that the 6X47 has the correct case volume to push the 115 DTACs to 3000, with acceptable accuracy. Hope springs eternal. Another concern is that the larger case size cannot be reliably ignited with small rifle primers.

You compared case dimensions between 6x47 & 6XC? I think your quest for 3,000 fps a bit quixotic seeing as how the 6XC's case has more volume than the 6x47 & it's difficult to get that velocity on the DTAC 115 out of a 6XC if you expect to re-use your brass.

Earlier this year I tried using 6.5x47 brass for 6XC, found the results very good but the short neck that results puts my chamber at risk.

Latest experiment finds me necking down Lapua's Palma brass & pushing the shoulder back (takes time & effort but seems to be worthwhile). I just finished another 50 cases yesterday; the motivation is to learn whether a small rifle case head stands up better to the loads that cause Norma 6XC primer pockets to open up after sometimes a little as three firings. Ignition (using Wolf KVB-223REM primers with three different popular propellants for this cartridge) is excellent, though my outdoor shooting pretty much ends when the temps get to 40° or so. Accuracy at 600 yards is every bit as good as that with the Norma or Tubb (Gen II) 6XC cases shooting Berger's 105VLD.

 

[spclark]

Eye surgery stopped me from getting results to publish.

John, I was wondering why I hadn't heard from you in awhile... I hope everything went well, that you're healing up quickly & will be back on the line soon.

 

[MarkS]

onlyfineknives
3100 may be too fast. All my BRX guys like to shoot the 105 gr around 2975 to 3000, ths is where they shoot best. Most of the time VLD do not like to go very fast. The 6BR needs to be pushed hard to run over 2900, but the IMP's can 3000 and be at low pressures. Friends of mine are using 260 rem for Tac matches.

Mark Schronce

 

[flatlander]

My best results with DTAC 115s out of an 8tw .237" bore 30" Bartlein have come with N160 at 2975-3000fps. I use more Rem 7-1/2 primers than anything else in the 6x47; have tried CCI BR4s, but that didn't seem to make 'em shoot any better.

Also tried 115s with RL17, as fast as 3095fps, but used Wolf SRMs instead of CCI 450s. Since the 450s are the best I've tried with RL17 in the 6.5x47, maybe I should've tried them in the 6? There are no notes regarding the RL17 tests on my chrono data sheets, but IIRC, I decided to settle for more consistent accuracy at slightly lower velocity with N160.

I fell in love instantly with my first Dasher in 2004, and have built several more since then. I still think the Dasher's the 6mm cartridge to beat, even out to 1000yds. I tried DTACs in that 1st Dasher, but it didn't like 'em at all, while they're very easy to get to shoot quite well out of all three of my 6x47s. Too many rifles - not enough time to shoot. I'm primarily a LR HP shooter; have shot only one 1000yd. BR match.

 

[Laurie]

You should get 3,050 from the 6XC easily enough from 28" - mine with 30" likes the 105 VLD at over 3,100 with one powder and around the 3,050 mark with H4350.

One thing to consider is bolt face v primer type. I had my first 6.5X47L, a rebarrelled FN Special Police Rifle rechambered to .260 Rem because it pierced the small primers at not much more than starting load MVs and pressures, even using CC-450 and BR4 primers with amongst the toughest cups around. I can't run my Rem 700 based 6BR at the velocities often seen here for the same reason, although it's miles better than the FN / Winchester situation.

If you're planning on an out and out match or bespoke tactical action or budget to have a Remington or similar bushed, high-pressure small primer cartridges are OK. (We've no equivalent to Gre-Tan in the UK so bushing bolt faces and firing pin mods are effectively ruled out.) The 6XC uses large rifle primers and there is no problem here almost irrespective of action make and type.

 

[spclark]

The 6XC uses large rifle primers and there is no problem here almost irrespective of action make and type.

Ah, but it doesn't HAVE to if the shooter is willing to spend a little time at the bench!

I've been making 6XC brass out of Lapua's new Palma brass for about a month now.

Yes, you need to go slow bumping the shoulder back or risk a few creases, but the few I've had don't seem to be affecting accuracy any & get ironed out in time.

Yes, you may want to ream the necks before the last stage of forming, the necks grow pretty thick below what once was that for the 308. I neck turn to 0.013" also at the last stage of forming up, then do a final trim to length.

(First experiment was using Lapua 6.5x47 but the necks are too short - by about what you need to cut off the Palma brass to get 'em to work in a Redding bushing die - about .07" which leaves a bit for a final trim later after reaming & neck turning.)

First batch of 25 were used for load tests first, then shot at 600 yards twice with good results.

I shot 44 rounds this past weekend of newly made up brass at 1,000 yards using the same load as in fired brass, either Norma's 6XC or Tubb Gen II & POI, velocity, SD's are identical.

My standard load Berger 105VLD Target (hBN-coated at home) set -0.020" off the lands with 8208XBR at 36.7 grains & Wolf KVB-223REM sr primers. I'd been using 37.0 grains (3,100 fps @ 75° SD <5) but I was seeing 1 in 5 LR cases getting a tad loose after three or four firings (prompting the initial SR case experiment) & have backed off to 36.7 which seems to work just as well at 1,000 yards. I need to chrono some of those later this week, get an idea of what -0.3 grains is doing to velocity.

 

[DennisH]

My issue is that I would like to not do a lot of fireforming if possible

DON'T get a BRX! Fine gun, fireforming is a pain!

6.0x47L, easy to resize.

I have a 6br, 6brx, two 6.0x47L, and a 243 (Savage VLP)!

The accuracy is unbelievable with all the above, so far, the 6.0x47L has my vote. But the BRX is getting close.

The 6br is a fun gun to shoot and I use it to get people "hooked" in our sport!

I have a 6.5x47L and shooting 120 smk's with RL15 will get you between 3,000 & 3,100 fps. Also another very accurate gun!

 

[spclark]

DON'T get a BRX! Fine gun, fireforming is a pain!

For the BRX specifically or in general?

I've been fire-forming 6RAT cases in my spacegun out of 6.5 Grendel brass this season, doesn't seem to be a big deal. For offhand or 600 yard slow fire the fireforming rounds are just as accurate as those made in fired cases.

(I have 100 new Lapua 6.5x47 cases I'd like to unload too if anybody's interested; $60 shipped USPS/CONUS. All have been half-necked down to 6mm but only 20 have been fired once in my 6XC just to see what would happen. Be no big deal to push those shoulders back to where they started out. Some with the false shoulder have Wolf KVB-223REM primers in 'em - I have the blue box too.)

 

[DennisH]

My issue is that I would like to not do a lot of fireforming if possible.

DON'T get a BRX! Fine gun, fireforming is a pain!

My response was referring to his above, states "would like to not do a lot of fireforming", this being the case, I stated stay away for BRX or anything else that needs to be fireformed!

D

 

[Baron]

The 6.5 X 47 came along, and many of the guys jumped in the 6 x 47 wagon. I know of 5 top shooter that tried to get the 6x47 to shoot, but could not. I know many do get them to shoot, but you don't see many in long range benchrest. The 6BR, 6BRX, and 6Dasher own the 600 yd line. Mark Schronce

Sheron Rabun shot a 2.686” group at the 1K Nats in WV with her 6x47L shooting 115VLDs. Which was the smallest group shot for the 3 target LG event.
When you get the 47L case to shoot it is hard to beat. I did not see any XCs at the Nationals.
Baron Graham

 

[LESLEY]

For some reason I'd seem to think that the ability of the shooter, the quality of the ammo, the quality of the barrel fitting, and the quality of the blank would have more to do with accuracy than which cartridge. I wonder why David Tubb isn't shooting the 6x47 if its so much better? Just my 'pea' sized brain goin' again!

Because he makes a living off of the XC