6BR pressure signs low loads

[Tokay444]

Good point I assumed the bushing dies left a portion of the neck at the base unsized.

They do. But that’s not where you said you were having problems.

 

[LRPV]

I thought I read in the past where they pick a # die. Is this so or am I thinking of a different company?

They have I believe 8 different sizes for every chambering they make dies for. They match up your brass to the one that fits it best. The larger the number, the smaller the die is. A D4 is smaller than a D1 for example. PPC, X47, BR, BRA and Dasher. Accept any of the normal size bushings, Redding, Hornady, RCBS, Wilson, whidden. And they include a Hornady lock ring and a brass comparator to measure with. Price is generally as cheap if not cheaper than other options as well.

 

[rickytan]

How much were you jumping the Hornady 105s when it was shooting .2s?

 

[Dolomite]

How much were you jumping the Hornady 105s when it was shooting .2s?

jumping between .020 to .030

 

[divingin]

Interesting I do dry the chamber after cleaning the barrel. I use Hoppes barrel blaster.

I also tumble the brass in walnut to remove the imperial wax case lube. Maybe I’ll try the brake cleaner on the brass next time.

On the blaster stuff: It's a degreaser that comes out under pressure. Is it possible you're cooling the chamber (the spray will be cold out of the can - release of pressure - plus evaporative cooling as the stuff evaporates) to the point where you're getting condensation?

I tumble for about 20 minutes to remove Imperial (if I don't simply wipe it off.) No need for brake cleaner.

 

[Dolomite]

On the blaster stuff: It's a degreaser that comes out under pressure. Is it possible you're cooling the chamber (the spray will be cold out of the can - release of pressure - plus evaporative cooling as the stuff evaporates) to the point where you're getting condensation?

I tumble for about 20 minutes to remove Imperial (if I don't simply wipe it off.) No need for brake cleaner.

Good point, I actually apply the blaster stuff to a patch and swab the chamber. I do the same as you tumble the imperial wax off, not sure how long I leave it in. I toss it in and walk away maybe an hour or so.

 

[LRPV]

Guys, do yourselves a favor. Buy a couple of pistol rods (short fixed handle cleaning rods) Put a 22 cal Iosso brush on one and a 40 cal on the other, buy some 3" shotgun patches and some Ronsonol lighter fluid. Soak a patch and run it in your chamber with the 22 brush, twist it around, pull it out and go back in with the 40 cal and you're done. The lighter fluid is a very good cleaner, leaves just enough protectant and the rest evaporates.

I hope you figure out your issues here and just so you know, it shouldn't be this difficult to get a rifle running. Something, somewhere is NOT right. Most any 6BR should run a 105 class bullet 28-2900 without showing overpressure symptoms on Lapua brass given that you have 28" ish barrel, enough neck clearance and your brass is not too long for your chamber. It's been said forever that if your BR won't shoot 30 grains of Varget and a 107 SMK then there's something wrong. (should probably replace that Sierra bullet with another brand by today's standards) but regardless there is something wrong that you might reach out to the builder of the rifle or the barrel manufacturer to figure out. Oh yea, even if you DO have a fast lot of Varget that is the reason behind the pressure symptoms, your velocity would be MUCH higher than what it is. I hope you get it figured out. Good luck.

 

[RickB]

what does it mean if my bullet won't drop into a fired case freely?

If a bullet will not freely drop into a fired case that suggests that you need to turn the necks. Not only could it contribute to early pressure, but could result in inconsistent bullet release affecting both grouping and consistency of pressure. I suggest turning the neck of one case to give you a total of 0.004" clearance (0.002" all around) and see if that changes things.

While you are at it, check the case length. If the case mouth is getting into the bevel at the end of the chamber neck that can affect pressure and other things. You may need to trim the case back to have adequate clearance.

 

[Dolomite]

I tested more loads and the bullet does fall freely into the case necks.

Case length has lots of clearance verified with bore scope.

Brass doesn’t seem to grow after firing and FL resizing.

Cleaned barrel to bare steel and dry chamber, loaded up hotter rounds 29-30.5 gr. 2750-2850. 30 gr seems to be the sweet spot running at 2800 in a 24” barrel.

No marks on brass face.

Is 2800 fps too fast for a 24” barrel?

Now Heavy bolt lift now due to hotter loads is my guess?

What neck tension is ideal?

 

[Bill Norris]

U may need to test up and down from 30.0 gr. a bit to see what the barrel really likes.

2800 don't seem too fast for a 24 inch barrel.

Your rifle will tell you what neck tension it likes. Just experiment the range of .001 - .003 or so maybe a tad bit more to see what it wants to shoot.

 

[Dolomite]

I want to give a huge shout out and thank you to the boss man @Mark Buettgen at Bartlien. His knowledge and customer service is beyond exceptional. CUSTOMER FOR LIFE!!!!

 

[Dolomite]

U may need to test up and down from 30.0 gr. a bit to see what the barrel really likes.

2800 don't seem too fast for a 24 inch barrel.

Your rifle will tell you what neck tension it likes. Just experiment the range of .001 - .003 or so maybe a tad bit more to see what it wants to shoot.

Thanks I will definitely give it a try. I’ve been using .001 and the SD/ES were double digit.

 

[Dolomite]

THANK YOU everyone for all the tips, pointers and comments!!!

 

[Albany Mountain]

Well that was helpful.

 

[Lone Hunter]

THANK YOU everyone for all the tips, pointers and comments!!!

Any explanation on what the problem was in case someone runs into the same problem?? Or did I miss the explanation??

 

[Dolomite]

Any explanation on what the problem was in case someone runs into the same problem?? Or did I miss the explanation??

It’s in the original post. Go back to the beginging of the post it states the problem I was having.

 

[Dolomite]

There is no one answer I can give that fixed the problem.

if you read all the comments it lists down the problem and suggestions or comments on how to solve the problem.

I did everything at once or it was already part of my normal routine.

cleaned barrel to bare steel, degreased the chamber, loaded hotter rounds, seated closer to the lands. Unfortunately I did this all in one test, except neck turning. That would have been the final straw.

If I had to guess it had to do with cleaning the barrel or loading hotter and seating longer toward the lands.

I will continue to do all three experimenting with seating depth test. I found the powder node seating the bullet .02 off the lands which shot .2’s. Maybe that’s good enough.

If anyone has any detailed questions I’m more than happy to share what I did if not mentioned in my previous comments.

 

[Dolomite]

Harrells dies pretty much same as Redding and use either Redding or Wilson bushings. Is your chamber a Norma chamber or 6BR Remington chamber? 27 gr of Varget is max for 6BR Rem in the Berger book. Also the velocity for that max load with a 105gr bullet as stated in the Berger book is 2656 out of a 24 inch barrel.
Very similar to what you are getting. Do you have reamer print?

Forgot to answer your question. No I don’t have a reamer print but confirmed with the smith it was a standard 6br reamer with a .272 neck and .120 freebore. Yes I was following the info in the Berger manual which prompted the question on the heavy bolt lift and ejector marks on the brass. It seems like giving the barre a good cleaning loading hotter and seating closer to the lands solved the issues.

 

[Lone Hunter]

There is no one answer I can give that fixed the problem….

That’s what I was looking for. Didn’t know if you ever found out what the problem was. When I first started shooting 6BR I didn’t wipe out the excess cleaning oils good enough and had pressure signs starting low. Cleaned chamber correctly and that solved my problem. Glad you got it worked out. I hate it when some thing goes wrong but you learn by asking and doing.

 

[Dolomite]

There is no one answer I can give that fixed the problem….

That’s what I was looking for. Didn’t know if you ever found out what the problem was. When I first started shooting 6BR I didn’t wipe out the excess cleaning oils good enough and had pressure signs starting low. Cleaned chamber correctly and that solved my problem. Glad you got it worked out. I hate it when some thing goes wrong but you learn by asking and doing.

Sometimes it’s overlooking the small things that might make a difference. Dry clean chamber could have been part of the solution too. It’s all process of elimination. Trial and error.

good thing accurate shooter and all it’s good members are willing to help and share info.

i hope the information in this post will help someone else who is having the same problem.