6.5 X 47 Lapua into 6XC accuracy results.

[reverend]

I had tried RE 15 with the fire formed XC brass from 6.5 X 47 Lapua brass, but found it to be too temperature sensitive.

I tried H4350 with bare 105 lapua's and got 3350 fps with 41.5 grains, but not great accuracy.

I used H4350 41.5 grains with Molyed 115 DTAC's, and got 3150 fps and for me great accuracy. I am not a benchrest shooter, I shoot off a bipod, and use my hand as a rear rest so I'm sure my standards are not up to many of yours, but I was very pleased with these groups. It seems this brass will withstand much higher pressures than previous Tubb XC brass, I could only achieve 2960 fps with 39 grains of H4350 with the previous batch of Tubb XC brass, and that was a max load.

30" Schneider 7.5 Twist
6.5 X 47 Lapua brass fire formed to 6XC
CCI 450 primers
41.5 grains H4350 Careful, this is fine in my rifle, may not be in yours, start 10% below. I wish I could shoot this well every day but I bet it will be a long time before I have this many good groups in one day again. The groups are all 3 shots at 100 yards.

UPS is at the door with new Norma/Tubb brass, I hope it works as well as the Lapua.

John

 

[roninboise]

Those were very impressive targets.

Did you open up the primer flash holes from the size they were or did you use them the way they came?

Ron in Boise

 

[reverend]

The only case prep I did was to size the neck with a 0.266 bushing, and chamfer the neck with a Giraud trimmer, the necks are shorter than a standard 6XC. This is the 3rd firing on these cases, I reloaded them when I got back home and the primer pockets are still tight.

I did uniform the meplat on the 115 DTAC's.

John

 

[reverend]

Here's a picture of 6XC cases. Tubb on left, 6.5 X 47 Lapua, prefire formed, fireformed and loaded, and the new Norma 6 XC on the right. Hope to get out tomorrow and try the new brass.

John

 

[mikecr]

Great shooting. Let us know about the Norma too..
Thanks for the info

 

[reverend]

OK preliminary information.

I weighed a very small sample of Lapua 6.5 X 47 brass and Norma XC brass, only 10 pieces of each, not sure if it's even statistically valid. I weighed them prior to any case prep. I also used a RCBS Chargemaster 1500 scale to weigh them, probably not the most accurate. I don't normally sort my brass or bullets.

The Lapua's ranged from 161.4 grains to 162.5 grains, 1.1 grain spread. Norma XC's ranged from 157.5 to 158 grains, 0.5 grain spread.

I didn't take my own advice and loaded one of the Norma's up with 41.5 grains of H4350, sure blew that primer right out.

Started loading again with a much lower charge. So far have worked up to 40 grains of H4350 that gives me a velocity of 3030 fps and groups from the low 0.2's to the mid 0.6's, closer to the groups I am familiar with than my previous lucky day. I think ultimately these cases will delivery more velocity than 3030 fps but will take less pressure than the Lapua 6.5 X 47 brass.

I like to shoot at pop cans at a distance because I can tell when I hit them. I know this doesn't qualify as a test of accuracy but after a sighter shot at 800 yards the next two shots hit pop can's as targets at 800 yards. We also alternate pop cans on the 500 meter rail, one standing up, one lying on end. One string of shots today resulted in 7 hits in a row. I will not tell you how many I missed.

I guess what I am saying is this combination of bullet, case, powder and gun has given me the most accurate rifle I have shot. I would think in the hands of a good benchrest shooter it would be phenomenal. Better than my Dashers and 6br in my hands.

I also had a couple of other observations, My previous 6XC barrel had about 2600 round through it before the groups opened up. Many more rounds than I anticipated with this cartridge. My current barrel has 2300 rounds through it and is still shooting very well. These numbers seem to be about the same as my experience with Dasher barrels. I shoot one of the final finish bullets through this gun about every 300 rounds, have no idea if this is good, bad, or indifferent, but the barrels seems to last longer than I had expected. I have only used these final finish bullets in this gun.

My last observation, which someone suggested to me, is that uniforming the meplat of the DTAC bullet seems to significantly increase it's accuracy. That is my experience. When I look at the tips of the 105 Lapuas they seem very uniform to me. I have not tried to uniform them. I could probable not improve them. Looking at the tips of the 115 DTAC, they are much less concentric, they appear much more symmetrical after uniforming them. The bonus on this effort is it transforms to DTAC to a spectacular varmint bullet. Prior to uniforming the meplat the bullet would just pass through the prairie dog, after uniforming them it vaporizes the dogs out to 550 yards, it might work further than that, I just haven't shot any further out than that.

Pretty long rant, no science, hope it is of some help.

John

 

[Forum Boss]

John,

This is really a great report. I think what you've observed is pretty significant. Seems to confirm that the small flash hole/small primer pocket may be a real plus in favor of the 6.5x47 brass.

If I understand correctly, you can get about 100 fps more with the necked-down Lapua brass compared to the 'old' Tubb brass. How is the velocity with the new Norma brass?

 

[reverend]

I think it may turn out that way, but there might be another outcome too.

Both cases seem to be significant improvements over previous brass. I believe accuracy will turn out to be equal with both cases, several benchrest shooters using better rests will have to test that, I don't think shooting off a bipod with a hand as a rear rest is fair test, but it is what I am used to and my accuracy has increased with both of these new cases.

I think what still needs to be sorted out is, in my experience, equal amounts of powder produce greater velocity in the new Norma XC brass than the Lapua 6.5 X 47 or the previous generation Tubb brass. I don't know why this happens? Different volume in the cases?

The new Norma brass already produces roughly 100 fps more velocity with equal amounts of powder than the other two. The previous Tubb brass at a maximum load at roughly 2960 fps had small extractor marks on the case. I have only gone up to 40 grains of H4350 in the Norma brass, I am using 41.5 grains in the Lapua. I believe there is still greater velocity available from the Norma cases, the Lapua cases seem to be maxed out. I believe it is possible the Norma cases will achieve an equal to or faster velocity than the Lapua cases, but with a smaller powder charge.

Hope this is of some help. Probably just muddies the water.

John

 

[Asa_Yam]

For everyone touting the "superiority" of small primers and small flash holes in a case this size, here's an item for you to consider:

David Tubb originally considered both for the 6XC cartridge. Unreliable ignition was why these features were not incorporated.

According to reports from reputable sources, once case capacities exceed 35 grains, there are combinations of small primers, powders, and temperatures that result in hang fires, and failures to fire.

Friends that shot .308s loaded in URBR brass said the only primer that reliably ignited the powder was the Remington BR. Even then, you could still get a hang fire at times.

Time may prove me wrong. However, the 6.5x47 case is still too new for anyone outside of Lapua to have any operating experience with it.

 

[Forum Boss]

Asa,

Read the current Gun of the week. Darrell didn't have any ignition problems with 5 different powders, using CCI 450s: Varget, N550, H4350, RL15, and 4831sc.

His better recipes were running ES 12-13 with SD 6-7. He recently tried some CCI BR4s. Accuracy and ignition was just as good, but he said his velocities dropped about 35 fps with the same load.

As you say, we'll have to wait and see, but Darrell did a LOT of testing and he had zero FTF or hangfires.

 

[DTubb]

Glad to see the Reverend give some data.
When you use a small primer in a 6XC capacity,or larger) case it usually takes at least 1 or 2 grains more powder to equal the large rifle primer's velocity.
Years ago when everyone was using 308 URBR in Across the Course shooting we all thought it shot better than the like kind case in large rifle primer. Well Martin Hull took some 308 URBR cases back to the Sierra Test tunnel and yes it shot better groups - but guess what when he loaded his regular 308 large rifle primer cases down to the lower velocity,of the 308 URBR) they shot just as well.

I have experienced hangfires in the past with the 308 URBR and dont need to be reminded of the shortcomings therein. It is no fault except the primers when this occurs,IMO) and it will happen in time with the 6.5x47. As Plaxco once told me - the first time it happens it isnt your fault but if it does it again and you did nothing to correct the problem then it is your fault - that is why the 6XC has a large rifle primer.

I believe if you are looking for the ultimate in accuracy then it will be hard to beat the Norma's less than .002" body wall runout and 1/2 grain case weight variation.

Nice tip about the Praire dog exploding bullet - I guess I will have to try that sometime myself.
DTubb

 

[Wild_Bill]

Hi i just ran in the first 6X47 Lapua in Australia we are building 3 of them the other 2 will be finished this week. I tried the following powders H4350 H4831SC and H1000. at this stage with 107gr Sierra's the loads with H4831SC were the best at 200 metre's i also tried 3 primers the CCI 450, Rem 7 1/2 and PMC small rifle Mag. the primer powder combo was best with the Rem 7 1/2 the groups went from 1" to all touching at 200 M so the primer is very important. I will be finishing the testing with 115gr Bergers soon and will give some feed back when it is finished.

Cheers Bill
Australia

 

[rcw3]

Reverend

What's the OAL of the case once you fireform it to a 6XC chamber - it has to be short in the neck a good bit - no?

Robert Whitley

 

[reverend]

OAL for the Norma XC brass after trimming and one firing is 1.910", the same as I trimmed it to.

OAL for the Lapua 6 X 47 brass after trimming and 4 firings is 1.835". I don't know if this is what I trimmed it to, I just took enough off to chamfer the edges.

Yes the 6 X 47 Lapua case neck is short in the fireformed 6XC.

Hope this is of some help.

John

 

[reverend]

I have a few additional observations.

I have been shooting 105 Lapua's in the lapua cases getting 3250 fps. About 150 fps faster than I get out of the norma cases. Both are very accurate. Quite a few 100 yard groups in the 0.1's, most in the 0.2's and above.

I think if you want to push the upper limits of velocity the lapua cases handle it better. If you are willing to accept a little less velocity the norma cases are every bit as accurate. I have about 8 reloads on each type of case and they both are still fine with no failures. The Norma cases are certainly cheaper.

I have a gun being made in 6 X 47 Lapua, and one being made in 6.5 X 47 Lapua with tighter chambers, just waiting for the gauges. I bet they will be great shooters. My 6 XC with a chamber for high power shooting frequently shoots as well as my 6 Dashers with tight chambers.

Hope this is of some value, It's all fun.

John