6 X 47 Lapua group

[reverend]

I think the 6 X 47 Lapua cases with a 105 Scenars is going to be a great round. I've included pictures of a metal target at 700 yards. As near as I can measure this is a 0.735" group, only 3 shots. That's a dime taped below the group. Shot off a Harris bipod.

Lapua 6 X 47
105 Lapua Scenars
41 grains H4350
CCI 450 primers
3250 fps
30" Schneider 7 1/2 twist P5
RPA Quadlite action
273 no turn neck chamber
Only case prep resized with 0.267 neck sizer, trimmed and chamfered, bullets not sorted.

John

 

[swglenn]

Great looking group! It also looks like you have a great place to shoot. We are envious. I can get 3030-3050 fps out of a BRX but can't reach the 3250 fps that you are getting. Do you have any experience in the wind?

 

[reverend]

I am lucky to have 3 good ranges in the immediate area. Two are limited to 600 yards, this one has targets out to 1550 yards, you could put targets out much further than that if you wished. Has road access to 1100 yards, you have to hike after that. The range is backed by a 2000 vertical foot rise.

Unfortunately it is a public range and people don't realize what a treasure it is. Much trash, broken bottles, etc. Safety is an issue.

Volunteers clean the range frequently but it is still painful.

The range is quite often windy, mostly right to left and left to right shifts, 5 to 15 mph. Sometimes no wind, sometimes more.

I used 1 1/2 MOA of right windage for these shots.

I think a really good marksman with this cartridge is going to do very well.

I should have a 6.5 X 47 Lapua done next week, hard to believe it will shoot any better.

John

 

[Forum Boss]

Impressive group and impressive velocity.

Happy to see your rifle likes the Scenars. They are about .0005" skinnier than some other bullets so you need a tight bore.

Jason and I are planning a switch-barrel 6-6.5x47 + 6.5x47. We were going to go with a .272 neck on the 6mm and a .293 no-turn neck on the 6.5. Looks like it should work.

Who made up your reamer and who cut the chamber?

FYI, assuming a .530 BC for the 105 Scenars at 3250 fps, and a .595 BC for a Sierra 142 Match-King at 3000 fps, here is how a 6-6.5x47 stacks up against a 6.5x284.,Calculated with point blank software for 70deg F, 1000' altitude.)

10mph wind-drift at 700 yards
6-6.5x47 = 27.27"
6.5-284 = 26.57"

Drop from 100-yard zero
6-6.5x47 = 85.85"
6.5-284 = 99.17"

The 6-6.5x47 Lapua has over a foot less drop, and the wind drift is just 0.7" more with the smaller round.

With the kind of accuracy you've shown I think a LOT of people are going to be looking at the 6-6.5x47 as a possible replacment for their barrel-burning 6.5-284s.

 

[reverend]

My gunsmith is Dan Dowling, lives just a few miles from me. He uses PTG reamers.

He has made me quite a few guns, including several Dashers; Dans collaborative creation. Always does a great job, and is a heck of a nice guy. He is much more knowledgeable than me, I trust his judgment and I let him steer me through these projects.

In my experience the BC of 0.53 for the 105 Scenars is very conservative. I use Horus Visions Atag software on the range and use a BC of 0.585 for the actual elevation to match the calculated elevation. Seems to hold true for Nightforce's Exbal software also.

As for windage it is anyones guess. I use a Nightforce 8 X 32 NXS Scope with a MLR reticle and most of my guns have muzzle brakes. I try to guess on the first shot and can see where it hits with the help of the muzzle brake. The MLR reticle has 1/2 minute horizontal marks, you can easily eyeball smaller increments, measure that distance, and make your correction. With the high power scope you can easily read the mirage to make corrections to wind changes. I never dial in windage on the scope but try to dial in elevation. The spacing of the Nightforce at 32X is not exactly in 1/2 minute spacing, it's set for 22 power, but it doesn't matter as long as your measurements and correction are at the same power setting. I find the visual correction for windage is much quicker and more accurate, the scope is limited to 1/4 minute adjustments on the turret, you can eyeball much better than that.

This is probably common knowledge but took me a while to figure out.

John

 

[jb1000br]

Rev. Now THAT is what I'm talkin' about

Gotta post a pic of the rifle...

JB

 

[reverend]

Started life as a Palma rifle, I bought it used.

John

 

[Forum Boss]

In my experience the BC of 0.53 for the 105 Scenars is very conservative. I use Horus Visions Atag software on the range and use a BC of 0.585 for the actual elevation to match the calculated elevation. Seems to hold true for Nightforce's Exbal software also.--John

John,

My experience with both the 105,6mm) and 123,6.5mm) Scenars is that they impact a little below predictions at 200-450m or so, and then impact a little higher past 600m. This is using the JBM Calculator or the Pejsa Ballistic spreadsheet, and the factory stated BCs.

I know some people,Henry Childs for one) have stated that the stated BC of Scenars,especially the 123gr 6.5mm) is too high, but that has not been my real-world experience.

Interestingly, I just did a QuickLoad projection for the 6-6.5x47 using H4350, 30" barrel, .250 shank in neck, 5000psi start pressure,a typical correction I use for in-lands seating). Based on a 47.0 H20 capacity, it predicts 3249 fps. Using a 3625,default) start pressure, it predicts 3235 fps. Both appear to be VERY close to Reverand's observed results with a 41.0 grain load.

This is exciting because it suggests the case can hit the "upper node" of 3200+ when shooting the 105s. That being the case, there may be little reason to experiment with the 115s.

 

[mikecr]

Looks like a pretty high pressure though. Higher than I would go

 

[Forum Boss]

Looks like a pretty high pressure though. Higher than I would go

Reverend is using a Schneider bbl. If it is the polygon form type it may be able to run a little faster than others. The Quickload projection I did was at 63,000 psi, which is the cartridge's factory rating,as a 6.5 mm). Seating depth is critical in pressure calculations, however. I ran a model with 0.25 of bullet shank in the neck. If you seat the bullet lower I think you would, indeed, be over-pressure with the 41.0 gr load he's using. Powder lot variances will make a difference too.

 

[Buzzbee]

Hey John,

I'm on the front range of the eastern slope. You are lucky to have Dan down the road from you, my 6x47Lapua is being build right now, I would like to get some information on the dies, who's are you using, where did you find them and how are they ?

 

[reverend]

Here's info on die's
I got the die info off a previous post.

6mmx47 Lapua

FR005945- Benchrest seater
FRU00036- Ultra seater
FRU04180- Full length die and Ultra seater
FR005265- Full length sizer
FR004176- Full length sizer and Benchrest seater
FR006449- Neck sizer
FR004749- Neck die and Benchrest seater

,Diameter used for neck sizing in all 6x47 dies is 0.267")

6.5mmx47 Lapua

FR006015- Benchrest seater
FRU00057- Ultra seater
FRU04256- Full length sizer and Ultra seater
FR005346- Full length sizer
FR004255- Full length sizer and Benchrest seater

Chris B.
Graf and Sons
800-531-2666

I also use a Dasher Redding competition neck sizing die held short. I imagine even a 6BR bushing neck sizer held short would work. I use a 0.266 bushing on my BR's and Dashers, since you're compressing the neck, thicker, you probably would want a larger bushing, 0.267 or 0.268 for the 6 X 47. Probably any 6 br, 6 Dasher, or 6X47 seating die would work. I have found I have more crushed case necks if I don't use the expander ball, so I use it on all initial sizing. I don't use the expander ball on subsequent resizing. Haven't used the full length sizer yet.

I have 6 reloads on the cases and they still are fine, easy extraction, tight primer pockets.

My 6.5 X 47 was finished yesterday, hope to shoot it today.

I believe Dan may have an extra set of dies, you might check with him.

Hope this is of some help.
John

 

[Buzzbee]

Thanks john, I spoke to Dan briefly last night, he said he will be out of the pocket in the next few,I'll be sure to ask him about the dies when he gets back.

 

[ArtinNC]

.735 at 700 yds That isn't to bad !! .

 

[JEFFPPC]

Nice shooting. For what hrs worth the conventional wisdom I have always heard for 6mm is best accuracy is under 3000. I know after many years of 6brxs for me with 106 and 107 bullets 2975 to 2990 has been the spot in all but one barrel it wanted about 2920 and was my only button rifle barrel.

 

[Fuj]

I wonder how it groups now after 17 years ??

 

[Ranger188]

I have a 6x47L and it's the most accurate tactical rifle I own.
I think the round needs just the right reamer. (PVA)
Heard it's a hit or miss on this cartridge.
I swear I could close my eyes and it will still shoot in the .2's
Would like to put it in a BR action, but don't want to mess it up.
Running my in the 3100 fps range also.

That group is pretty small. Just saying.
Did you see how much the bullets dimpled the target @700 yds.
17 years ago.
Just saying.

 

[Capt. Oblivious]

I wonder how it groups now after 17 years ??

Shooting 105s at 3250fps out of that small case im sure his changed that barrel a couple times