6.5x47 Lapua Velocity? UPDATE!

[Spotcheck_Billy]

I've just started loading for the 6.5x47 Lapua and have encountered a problem with what seems to be high pressure signs at a low powder weight when doing some load development.

I very recently received a 28" Border barrel in 1/8.5" twist with 5R rifiling, chambered with a PT&G no neck turn reamer. I'm using new Lapua brass, 123gr. Scenar bullets seated .012" into the lands,COAL 2.692"), and BR-4 primers.

While breaking in the barrel I decided to start working up some loads using data gleaned from this board and the 6mmHot site. My research showed that Re15 would be a good powder to begin with, so I loaded up a few rounds with 35.0, 35.5, 36.0, and 36.5 grains of this propellant. When I reached the 36.0 load I encountered some stiff bolt lift on extraction and noticed pronounced ejector hole imprints on the brass. Looked like excessive pressure to me, so I dropped back to 35.5 grains and confirmed that the pressure signs were non-existant at this weight.

Running the 35.5 Re15 load over my Oehler 35P showed an average of only 2762 fps MV, which I figure to be in line for this powder charge and accuracy is very promising. I fully realize that every barrel has its own characteristics, some are fast and some are slow, but I'm disappointed at not being able to load to the powder charges and velocity levels that have been reported by reputable shooters loading for this cartridge. I would like to be able to drive the 123gr. Scenars to 2850-2900 fps.

Anybody out there tried H4350 or Varget in this cartridge? Other powders? All comments and suggestions are appreciated.

 

[Mark Walker in TX]

Billy,

That is odd as just yesterday I was shooting some Berger 130s using RE15, running 37.8g and a CCI 450, velocity was 2955 avg. No pressure signs at all. This is with a Krieger 8 twist 30" tube. Maybe you were further into the lands than you think?? For an odd reason, my barrel likes the 130s jumping about .002, which I have never had a VLD like to jump before. But, I trust what she tells me, and I do not argue.

The last Varget I tried was an older lot, but it was getting almost the same velocity as the RE15.

With the RE15, I did not get pressure signs until I got up to about 38.6g the 1st time out. It did not group as well, and that is why I am back down to the 37.8.

I am really liking this round!! Hope you get her going, too!!!!

 

[waterdog]

Billy,
You might want to measure a loaded round on the neck. My chamber has a .292 neck, and a loaded round measures a good solid .291. That is about as close as I am comfortable with. On my next 50 pieces of brass I turned the necks .001. The brass didn't clean up all the way around, but the loaded round neck measures .290.

I shoot 38gr. of R-15 in this gun with naked 130 Berger vld bullets. It is a Broughton 9 twist barrel. MV is 2900fps.
I have another 6.5X47 with a Kreiger 9 twist barrel. With molyed 130 Berger vld's I load 38.5gr of R-15. MV with this load is 2911fps with a 26" barrel.
Both these loads in both guns shoot good and I haven't tried any other powder yet. As Ranger said, this is a good round and I am impressed with just how easy it was to make it shoot good.
Good luck with yours.
Larry Isenhour

 

[Spotcheck_Billy]

Larry,
The necks on the loaded rounds measure .290". When I prepare the new cases for loading I first run them into a Sinclair expander mandrel to make sure that the necks are round, put a slight chamfer on the outside with a Forster tool, chamfer the insides with a Lyman VLD tool, then run the necks into a Redding .288" TiN bushing. I don't pretend to be a loading genius, but I don't think that I have a problem with case necks or bullet tension, but I've been wrong before

I'm bound and determined to get to the bottom of this one way or the other! Thanks for the comments so far, and please keep them coming.

 

[Mark Walker in TX]

Larry,
The necks on the loaded rounds measure .290". When I prepare the new cases for loading I first run them into a Sinclair expander mandrel to make sure that the necks are round, put a slight chamfer on the outside with a Forster tool, chamfer the insides with a Lyman VLD tool, then run the necks into a Redding .288" TiN bushing. I don't pretend to be a loading genius, but I don't think that I have a problem with case necks or bullet tension, but I've been wrong before

I'm bound and determined to get to the bottom of this one way or the other! Thanks for the comments so far, and please keep them coming.

Billy,

Sounds close to my process. I also expand with a Sinclair mandrel, then trim, chamfer and deburr with a Giraud, then size with a .289 TiN bushing. Mine is a .292 neck also, but I have not turned any off. Might try the .001 on the next batch of brass, though, just to square them up a bit.

 

[ChuckMiller]

I'm using 42grs of H4350 with the 123gr Scenar for 2950Fps. Barrel is a 28" Krieger 8.5", easy bolt lift and accuracy is very good, I'm seating just into the lands. Rifle has a 293nk and loaded rounds measure 291, this has been about the most hassle free build I've done. Tried RL15 after reading Darrels article, velocity was a little higher but accuracy was no where near the H4350. Different rifles, different loads!

 

[Spotcheck_Billy]

Thanks Chuck. I'm going to try H4350 as soon as I can get back out to the range. I have a large quantity of it 'cause it's the powder of choice for mt 6.5-284. I'll report the results here.

 

[jb1000br]

My results with the 123/130gn and R15 combos are very similar to what others have posted. Similar charges give me vary similar velocities...

Billy - what is the diameter of your fired necks? IMO, switching powders won't help much here...you will still pressure out too soon...it might get you a few fps, but something is weird...

Also, all loaded rounds that I have mic'd have been between .2903-.2908...I much prefer my .293"nk to a .292"...

JB

 

[Spotcheck_Billy]

Jason -
Fired neck diameter measures .293", I certainly agree that something's weird!

I've exchanged e-mails with the barrel maker,JR at Border Barrels) and he's also looking into this.

 

[jb1000br]

Well, your neck is big enough...hmmm

Have JR tell you the land and groove dimensions.

JB

 

[Spotcheck_Billy]

Well, your neck is big enough...hmmm

Have JR tell you the land and groove dimensions.

JB

Will do! I'll send him an e-mail now and report as soon as I hear from him.

Thanks.

 

[Spotcheck_Billy]

Jason -
Just heard from JR. He informs me that the bore measures .2555" and the grooves measure .269"

I wonder if I didn't get ahold of a fast lot of Re15? It might be worth my while to go into town tomorrow and buy a container from a new lot. The lot that I'm using has been on my shelf for a couple of years. I've been using it to load 80gr. .223 without any problems, but that's apples to oranges.

I sure appreciate your help

 

[rcw3]

Spotcheck Billy

Typical 6.5 mm bore dimensions are .256/.264, yours are at somewhat of a variance,your groove dimension of .269 is big, about the biggest I've seen).

Robert Whitley

 

[2644ever]

Spotcheck Billy

Typical 6.5 mm bore dimensions are .256/.264, yours are at somewhat of a variance,your groove dimension of .269 is big, about the biggest I've seen).

Ditto. Is there a typing error? Like.269 instead of .266?

 

[Spotcheck_Billy]

Spotcheck Billy

Typical 6.5 mm bore dimensions are .256/.264, yours are at somewhat of a variance,your groove dimension of .269 is big, about the biggest I've seen).

Ditto. Is there a typing error? Like.269 instead of .266?

This is embarrasing

Yes, it's a typing error! I meant to type groove dimension is .2639". Sorry for the confusion.

 

[jb1000br]

so .2555 x .2639 So it is a liiiittle tight, but not tight enough to cause issues IMO...mine is a kreiger that was stamped .256x.264

JB

 

[Spotcheck_Billy]

It looks as if the problem was in the particular lot of Re15 that I was using!

I started working up some H4350 loads this AM, beginning at 38.0 grains and stopped when I reached 42.0 grains without any indications of excessive pressure. Hmm .....

So I drove into town and bought a new 1 lb. jug of Re15, and when I got home I loaded one round at 36.0 grains, which was the load that showed definite signs of high pressure when I used the old lot of Re15. No high pressure signs at all with this new lot

So far I've loaded up to 37.5 grains in half-grain increments and everything still looks just fine. I've seen differences in powders lot-to-lot before, but never this pronounced. I haven't chronographed any of these loads as I've been shoting them in my backyard, dodging the raindrops. If it clears up tomorrow or the next day you can bet I'll be at the range with my 35P and some 7/8" square targets,those free ones found on the 'net from Bob Latino Benchrest Stocks) and I'll post the results here!

I'd like to thank everyone who showed an interest in my dilemma and want to tell you that I really appreciate your help.

 

[SF340Driver]

Let Alliant know about the fast lot. They will send you some replacement powder. If the lot is too far off spec they will recall it.

 

[Spotcheck_Billy]

I finally got a chance to chrono test some loads using the new lot of Re15 that I bought last week. Results were as I expected when comparing with other published loads. No high pressure signs were noted.

36.7gr. Re15 123 Scenar avg. MV = 2861 fps.

37.5gr. Re15 123 Scenar avg. MV = 2960 fps.

100yd. 5-shot groups were very good, ranging from 3/8" to 1/2", but ES and SD were too high averaging in the mid twenties for ES and the high teens for SD with both loads.

I'm looking for single digit figures, so the tweaking begins

I've been in contact with Alliant about the situation with the powder. We'll see what they'll do about it!

 

[Mark Walker in TX]

Glad to hear you are back on track!!