6x47L Help

[Clucknmoan]

Interesting turn of events on this deal. Tried the 105's jammed .010 with H4350 before I gave up on the combo. Dropped down to 39 grains to compensate for the extra FPS I would get jammed and shot 6, turns out I didn't compensate quite enough. 39 gave 3074 FPS wth an ES of 15 and I think the node is around 3040 to 3050.

Shot this better than anything by far. Had 1 flyer about .5" out, other than that a vertical of just over .5"

This might be the ray of light I was looking for. Plan on dropping a little more to get in that 3050 range and see what happens.

Thoughts?

 

[MDM]

How many rounds on the barrel now? Mine speed up somewhere between 110-150 rounds on them and I really don't even try to do much load development until 150 rounds. I just pick a load that I know "should" work and shoot steel until I get to that point. Maybe the barrel is ready to settle down for a bit.

 

[DHuffman]

This is now spitting random flyers and no better than 1" groups with 2 different bullets. I just don't see changing seating depth .10 or .15 tightening groups up an inch to acceptable levels.

The primer cratering is fairly irritating also. I've had factory bolts crater primers and fully accepted it as a risk with a factory action. Sent it in to have it bushed or change out the bolt head, no big deal. But to have this happen on a custom action is a little different, I expect more.

From my experience on both these issues in two different 6 x 47 Lapuas I have. I have seen groups shrink from an inch+ to sub .5" more than a few times by using seating depth increments of .003 that showed the seating node about .006 - .012 wide. Certainly narrow enough to hide in when jumping .020 increments. I'm not saying either one of us is right or wrong about it but relaying my experience.

As far as the primer cratering I would also expect more from a custom action as well, but that doesn't mean the bolt does or doesn't need bushed by itself. Again relaying my experience with one of my two 6x 47 Lapuas. It is what it is.

Both of mine were finicky compared to any other cartridge I load for. In the end 39.3g IMR 4451 got the results I was expecting in both. One seated at -.011 the other at -.017 CCI 450 primers & 105 AMAX's both about 3050 fps. The Remington would not get there until I bushed the bolt the savage on a model 10 action did not have cratering issues.

Glad to see you may have made some headway.

 

[JBT47]

I would also try Varget. I used Varget in my old 6x47 Lapua. Start at around 35gr and work up. My node with 105 Hybrids was 37gr Varget.

 

[Clucknmoan]

I've had better luck in getting one to shoot what it wants vs making miniscule changes to make it do what I want. So I moved on from H4350, I think it's clear it really doesn't want to shoot it. I am really not interested in something that's that finicky anyway. This will have to shoot all year round and I don't want to spend half my barrel life messin with it at every change of the season. I'm looking for something more stable than that.

Tried Varget today with the 105's at .015 off, starting at 35.0 up to pressure at 36.2. Showed a flat spot at about 3025 but didn't group very well and the ES went to crap. Tomorrow I will load some in the 3050 range with Varget and see what it does.

 

[DHuffman]

I've had better luck in getting one to shoot what it wants vs making miniscule changes to make it do what I want. So I moved on from H4350, I think it's clear it really doesn't want to shoot it. I am really not interested in something that's that finicky anyway. This will have to shoot all year round and I don't want to spend half my barrel life messin with it at every change of the season. I'm looking for something more stable than that.

Tried Varget today with the 105's at .015 off, starting at 35.0 up to pressure at 36.2. Showed a flat spot at about 3025 but didn't group very well and the ES went to crap. Tomorrow I will load some in the 3050 range with Varget and see what it does.

Best of luck to you and again I was telling you what worked for me. Was never my intention to insinuate "you're doing it wrong" or get into a debate.

I too tried h4350 first and moved on to a different powder because I couldn't achieve any repeatability with it.

36.7 grains of Varget is very accurate in my 6.5 x 47 Lapua with a 130 bullet. I have never tried it in either of the 6 X 47 Lapua's though.

 

[DHuffman]

Here's a picture of a target. Different caliber but perfect example of the seating depth adjustments affect on group size I'm talking about.

Group size reduced by more than half. Found the center of the seating depth node. I load these bullets -.025 shooting it year round and don't mess with it every change of the season.

 

[Clucknmoan]

Best of luck to you and again I was telling you what worked for me. Was never my intention to insinuate "you're doing it wrong" or get into a debate.

I too tried h4350 first and moved on to a different powder because I couldn't achieve any repeatability with it.

36.7 grains of Varget is very accurate in my 6.5 x 47 Lapua with a 130 bullet. I have never tried it in either of the 6 X 47 Lapua's though.

No offense taken at all an none intended. I appreciate all the info and suggestions from everyone.

Sometimes you get tunnel vision and lose track of the purpose and I had to step back and remind myself of that. This barrel seems to be really finicky which goes completely against the whole reason for this build.

I'll fool around a little more with it but if something doesn't show promise pretty quick, I'd rather spend $$ on a new tube than $$ on a bullets, powder and brass that at best will make a finicky barrel shoot for now. Maybe trhat doesn't make any sense, but that's how I look at it.

 

[topwater225]

I'm going to throw another possible cause at you, as I have experienced this with an MPA and XLR Element Chassis. You may cringe at the idea, but I would bed the chassis and action. I personally witnessed non-explainable flyers on a buddy's MPA chassis in a similar configuration as yours, and he chased his tail for a very long time trying to diagnose the issue. Finally, I brought up the idea of bedding. Being out of other options, he bedded it, and the problem was solved. The rifle is an incredibly consistent "small group" shooter. That experience left me thinking about Chassis and bedding in general. I'm a Chassis fan and never really thought about bedding one. But then it happened to me with a .223 in a XLR Element Chassis. This time my first step was to bed. Again, problem solved. All this being said, I am currently building a 6X47 on a Curtis Custom and MPA Chassis. I should know how it shoots by next week. BTW....I switched exclusively to 110's and I absolutely love them, and have shot over 1k of them to date.

 

[boltfluter]

Clucknmoan,

I would personally seat the 105 VLD at .020 into the lands with
Varget. At least to start with. You may be amazed at the results. Then you only have one direction to go with seating depth. Good luck.

Paul

 

[DHuffman]

I'd rather spend $$ on a new tube than $$ on a bullets, powder and brass that at best will make a finicky barrel shoot for now. Maybe trhat doesn't make any sense, but that's how I look at it.

What doesn't make any sense to me is giving up on a barrel before doing a thorough seating depth test.

You're going to think I'm trying to pick a fight with you but I'm not. I'm only trying to help you from my experience with two of these 6 x 47s. I struggled with my first one for a year trying to make it do what everyone on the internet said it should do. I would mess with it for a while then get frustrated and walk away from it. I shot up over 600 rounds trying different power/bullet combinations. Finally I resolved myself to finding the load and with a rough idea where I thought the node was loaded 4 rounds each in .1 increments to find the center of the powder node then loaded 4 rounds each from +.010 through -.020 to find the optimum seating depth. It was a lot of work but short of just dumb lucking onto a good repeatable load I wouldn't have found it with .3g powder and .020 seating depth increments.

You mentioned something along the lines of "finding what it wants not making miniscule adjustments to make it do what you want". In my mind they are the same in this application.
You mentioned tunnel vision. I had it on my first 6 x 47 and it never repeated until I changed my approach to the cartridge.

I'm not an expert and maybe I did it wrong but that's how I got there, with that I'll get out of your thread but I hate to see you give up on a barrel without trying a thorough seating depth test.

 

[wapiti25]

The Berger hybrid 105 likes more twist than a 8. Try the VLD jammed first then try seating more in .005" increments. I have also found IMR 7828sc to be a good powder in my rifle. My rifle is an 8tw Bartlien 5r in a Bat action. I have shot 10 shot groups @ 600 which is just under 1 MOA, not great but that is what it is (105 VLD and 105 A-max). My barrel has about 250 rounds on it now. CCI 450's are good. I have had better luck with a 6mmDasher. Good luck

 

[basshusker]

Bolt bushed by gretan on one and ptg bolthead on savage fixed multiple issues (similar) for me.
J

 

[Clucknmoan]

Update on this. Thanks MDM, 450's seemed to solve the cratering issue, not too concerned about that.

Bored a few days ago so I shot 5 from .010 jam to .025 off in .05 increments. As I suspected it still shot nothing better than about 1.2 inches. ES did seem to show favor as single digit at .005 jam and again at about .015 off but it certainly didn't reflect it on paper.

From here I will probably bed the chassis and give it a few more to see what happens, but I'm going to go ahead and order a barrel.

 

[Erik Cortina]

Update on this. Thanks MDM, 450's seemed to solve the cratering issue, not too concerned about that.

Bored a few days ago so I shot 5 from .010 jam to .025 off in .05 increments. As I suspected it still shot nothing better than about 1.2 inches. ES did seem to show favor as single digit at .005 jam and again at about .015 off but it certainly didn't reflect it on paper.

From here I will probably bed the chassis and give it a few more to see what happens, but I'm going to go ahead and order a barrel.

Quit wasting your time and components.
Check firing pin fall, if good (~.250”), then order new barrel. Get a Brux, Krieger, or Bartlein.

 

[jdh47]

If your necks are coming out of round from firing you could have a bad chamber. Erik most probably is correct. I would trust his judgement.

 

[Clucknmoan]

Appreciated. Took the glass off, put it in the back of the safe and ordered a 7.5 twist Brux yesterday.

 

[dennisinaz]

Is it possible that you have a scope base screw hanging down. The hard bolt lift happens when the bolt hits the screw. Can't feel it without a round chambered but the case head will hold the bolt head still so the screw can rub. This happens a lot so you might check it. Will cause all the symptoms you are having to some degree.

 

[accuracyman]

I had three different 6x47L rifles that were all picky with this round. Had hard extraction problems with mild loads. Never did get any of them to shoot reliably. It turned out the reamer I used was too small at the web so extraction was hard. A new reamer eliminated that problem but the 6x47L was still finicky with either a 8 twist or 7.5. Took a friends advice and chambered a new barrel for 6XC and never looked back. The 6XC is easier to tune and not at all finicky. Stick a Berger 105 or Sierra 107MK touching with 38.8g of H4350 and enjoy the experience. They all shoot now. Hard to figure sometimes....but definitely frustrating. This combo also shoots the 115's well, slight drop in powder charge, and a 7.5 twist barrel.

Good luck and hope the new barrel cures your problem. If not give the XC a try.

 

[RDavies]

Have you tried getting someone else to shoot it in their front rest and rear bags? Reason I ask is that my 6MMs prefer a different rear bag and front rest set (hard, slippery bags with no fore end side pressure)up to my 7MMs as well as a much different hold (prefers free recoil). If I shoot my 6MMs exactly the same way as my 7MMs, they shoot OK, but not great, and Vice Versa if I try to shoot my 7MM how my 6MMs prefer.