Barrel Accuracy

[Bc'z]

I have been wondering if I need to find a different node or move within the node, of course I have been thinking about a a lot of things, have not really thought that I may need a new powder in the mix.

Try H4831SC with 135-140gr bullets look between 44-45gr of powder, primer of choice to begin with magnums aren't necessary.
If you cant find love with these components you never will.

 

[Texas10]

With regards to epoxy bedding, and this comes from decades in aerospace manufacturing, slow cure epoxies are much harder and stronger than fast cures. IMOP 5 minute epoxy is way too soft to use a bedding. Epoxy must be mixed accurately, and mixed thoroughly. It's not like polyesters where a catalyst is introduced and migrates through the material. You can screw up the ratio and the mix, and many times polyester will still harden. I once sprayed a coat of Simtec polyester enamel and realized I forgot to add the catalyst. I quickly mixed a hot batch (extra catalyst) and sprayed over the top of the first coat and it still cured throughout.

Not true with epoxy. Eyeball it and give it quick stir and it's time for some celebration because you've now gone where no man has gone before. It may seem to work adequately, but it'll never come up to full strength. Epoxies generally tolerate up to a 6% mixing error. More than that and again, you're experimenting with the unknown. Resist the temptation to add extra part B hardener. If you want faster cure, add some heat. 170F is about as hot as you want to go with a room temp curing epoxy.

 

[Dusty Stevens]

Every stock needs to be bedded no matter what the stock maker says.

 

[Evan]

How does it shoot at 100? If it isn't less than 0.5" at 100 then it won't shoot small at longer distance either. Bullets don't "go to sleep" and they won't magically shoot with less dispersion the further out you go. A 0.5" group at 100 doesn't shoot less than 3" at 600 unless the wind blows them in, but a couple groups in a row will tell you if you got lucky or not.

You don't need a BR setup to shoot sub 1/2MOA. People all over the world have shot smaller than that laying on the ground with only a bipod and their hands. Practice and a rifle system capable of that accuracy are all it takes - which you should have with your rifle, barring any malfunctions or flaws.

That leads nicely into my next question: has this action/stock/scope combo shot smaller in the past with other barrels on it? If you had a premium barrel on it before and it shot better than your current barrel - that narrows things down some. If you only had the factory barrel and then this Proof, and both barrels shoot 4" at 600, then you likely have bigger problems in the rifle system to sort out before the barrel's quality begins to limit you.

 

[AllenOne1]

Interesting! An idea that I have stuck in the back of my head. Are you bedding with epoxy/Devcon or something like Acraglass?

It's all epoxy in one form or name or another....I have had good success with Devcon and Acra-Glass. I have also used JB Weld too. I have used clear Devcon epoxy as well and added dye to make it the color I wanted. I haven't tried any of the "5 minute" epoxy, but I am sure it would probably work too.
What do you have for a trigger in this thing??? What is the pull weight???[/QUOTE]

Trigger is the standard AccuTrigger adjusted to 1.2 lbs

 

[AllenOne1]

How does it shoot at 100? If it isn't less than 0.5" at 100 then it won't shoot small at longer distance either. Bullets don't "go to sleep" and they won't magically shoot with less dispersion the further out you go. A 0.5" group at 100 doesn't shoot less than 3" at 600 unless the wind blows them in, but a couple groups in a row will tell you if you got lucky or not.

You don't need a BR setup to shoot sub 1/2MOA. People all over the world have shot smaller than that laying on the ground with only a bipod and their hands. Practice and a rifle system capable of that accuracy are all it takes - which you should have with your rifle, barring any malfunctions or flaws.

That leads nicely into my next question: has this action/stock/scope combo shot smaller in the past with other barrels on it? If you had a premium barrel on it before and it shot better than your current barrel - that narrows things down some. If you only had the factory barrel and then this Proof, and both barrels shoot 4" at 600, then you likely have bigger problems in the rifle system to sort out before the barrel's quality begins to limit you.

I have only had the factory barrel and the current aftermarket barrel on this rifle so that is what is leading to the questions I guess, I'm not sure if I can even shoot that small. It is shooting one hole at 100 yards so I probably need to move to 2-300 yards as suggested above and see what it is doing at an slightly longer distance.

As you start to shoot smaller it gets harder to figure out what the next thing is that needs to be worked out.

 

[jelenko]

It is shooting one hole at 100 yards

Whoa! With very [very] high probability if it's shooting 1 hole groups at 100, it's the wind at 600 that's opening it up to about .6 MOA.
What is the actual size of the groups at 100 - are they 3 or 5 shot groups?

 

[AllenOne1]

Whoa! With very [very] high probability if it's shooting 1 hole groups at 100, it's the wind at 600 that's opening it up to about .6 MOA.
What is the actual size of the groups at 100 - are they 3 or 5 shot groups?

They are 5 shoot groups but i don't have any actual measurements that I have saved. That seems like an oversight in my data records now that you bring it up.

If they are just enlarging the original hole I don't typically measure them but have been using them to confirm and refine zero point of impact on the bullseye. Even the cold bore shot is in the group.

Moving out the distance may give me more information as it would spread the shots.

 

[Rdlningcltchdmpr]

I have been wondering if I need to find a different node or move within the node, of course I have been thinking about a a lot of things, have not really thought that I may need a new powder in the mix.

New powder for sure.

 

[jelenko]

Moving out the distance may give me more information as it would spread the shots.

I wouldn't worry about it. Sounds like the 'one hole' is in the 1' or 2's.
As long as there's no wind, going to longer distances doesn't add any information on group size - because the measure of group size in MOA, not inches. I.e., essentially a 1" group at 100 yards will be 2" at 200 yards. They are both the same MOA.

 

[MikeMcCasland]

How does it shoot at 100? If it isn't less than 0.5" at 100 then it won't shoot small at longer distance either. Bullets don't "go to sleep" and they won't magically shoot with less dispersion the further out you go. A 0.5" group at 100 doesn't shoot less than 3" at 600 unless the wind blows them in, but a couple groups in a row will tell you if you got lucky or not.

You don't need a BR setup to shoot sub 1/2MOA. People all over the world have shot smaller than that laying on the ground with only a bipod and their hands. Practice and a rifle system capable of that accuracy are all it takes - which you should have with your rifle, barring any malfunctions or flaws.

That leads nicely into my next question: has this action/stock/scope combo shot smaller in the past with other barrels on it? If you had a premium barrel on it before and it shot better than your current barrel - that narrows things down some. If you only had the factory barrel and then this Proof, and both barrels shoot 4" at 600, then you likely have bigger problems in the rifle system to sort out before the barrel's quality begins to limit you.

I agree very much with what Evan is saying, and I'll add on to it a bit.

I'm not sure how many load combos you've tried, but not every 6.5CM is going to shoot the 140/H4350 combo well.

As much as some of the 'tactical' FB groups and forums would disagree with this, sometimes the 6.5CMs prefer a different powder (RL16, or H4831sc) and a different bullet (140 Hybrid, 142 SMK, etc.). Secondly, you have to approach your load dev from a methodical standpoint; start simple by finding the powder charge node, then work the bullet from .005" off to ~.075" off the lands in .010" increments (I'm normally much closer than .075" off, but extending the range due to the recent PRS blog published tests). Fine tune the depth in .003" increments once you find the area it likes, then go back and confirm your powder window in .1gr increments.

A bipod and good gun handling can turn in some small groups. It's usually a matter of testing a few powders first to identify the one the barrel likes, and then doing the above mentioned testing.

For reference, I've had 3 6.5CM barrels (2 bart, 1 krieger) cut off the same reamer, and for whatever reason none of them liked the same bullet, nor could they agree on which powder they liked. If it doesn't shoot with H4350, it's probably going to shoot with RL16. If it doesn't like the 140 ELDM, it'll probably like the 140 Hybrid or 142 SMK. I'd start either .020" off for your powder charge testing.

 

[AllenOne1]

I agree very much with what Evan is saying, and I'll add on to it a bit.

I'm not sure how many load combos you've tried, but not every 6.5CM is going to shoot the 140/H4350 combo well.

As much as some of the 'tactical' FB groups and forums would disagree with this, sometimes the 6.5CMs prefer a different powder (RL16, or H4831sc) and a different bullet (140 Hybrid, 142 SMK, etc.). Secondly, you have to approach your load dev from a methodical standpoint; start simple by finding the powder charge node, then work the bullet from .005" off to ~.075" off the lands in .010" increments (I'm normally much closer than .075" off, but extending the range due to the recent PRS blog published tests). Fine tune the depth in .003" increments once you find the area it likes, then go back and confirm your powder window in .1gr increments.

A bipod and good gun handling can turn in some small groups. It's usually a matter of testing a few powders first to identify the one the barrel likes, and then doing the above mentioned testing.

For reference, I've had 3 6.5CM barrels (2 bart, 1 krieger) cut off the same reamer, and for whatever reason none of them liked the same bullet, nor could they agree on which powder they liked. If it doesn't shoot with H4350, it's probably going to shoot with RL16. If it doesn't like the 140 ELDM, it'll probably like the 140 Hybrid or 142 SMK. I'd start either .020" off for your powder charge testing.

It appears I still have a lot of work to do. Need to collect some components to mix up the powder/bullet combinations but at the very least I need to go back and reconfirm the powder window in .1 gr increments I'm in .3 gr increments now, and need to recheck bullet seating depth, currently at .010 off. Need to recheck distance to lands now that I have some rounds through the barrel as well.

What distance do you test your powder charge and seating depth at 100 yds or do you move out to 2-300?

 

[Evan]

It appears I still have a lot of work to do. Need to collect some components to mix up the powder/bullet combinations but at the very least I need to go back and reconfirm the powder window in .1 gr increments I'm in .3 gr increments now, and need to recheck bullet seating depth, currently at .010 off. Need to recheck distance to lands now that I have some rounds through the barrel as well.

What distance do you test your powder charge and seating depth at 100 yds or do you move out to 2-300?

My method is this for ~40gn load cartridges:
- load up 3 shot sets in 0.5gn increments of your chosen components at a nominal seating depth: I like to jam bullets 0.010 as a starting point to make sure I'm getting the maximum pressure and won't run into problems. If I have factory load data for a cartridge, I'll take the top charge and increment down from there.
- shoot at 300yds (furthest I can reliably spot bullet holes) and watch for POI to stabilize on target. It should climb and then level off and then maybe start climbing again if there's another "high node".
- load up 3 shot groups at midpoint of the "level" stable POI charges and vary seating depth in 0.020 increments from 0.020 in all the way to 0.060 or more out of the lands.
- shoot at 100yds, looking for the best group - round, not spread out vertical or horizontal.
- if needed/desired, load more around the best seating depth (i.e. in 0.005 increments around 0.020" out, if that depth shot the best)
- load up at least 20 of your best load and shoot groups to verify the load is repeating and consistent.

With how forgiving I found the 6.5 Creedmoor to be, I wouldn't worry too much about 0.1gn increments. You won't magically squeeze smaller groups between 0.3gn bad ones. It will probably take a rather large change - like different powder or bullet or seating depth. For me a powder has always either worked or it didn't right away and tuning it just made it better. I've never had a powder shoot 1 MOA at one charge and then tune in to 0.25MOA at a different one.

If the 140ELD isn't working (would be a bit odd, it's a very forgiving design) then I would try out some 123gn match bullets. A lot of people have got the 123 class to shoot REALLY well, and if you just want to see what the best your rifle can do, don't worry about giving up some BC.

My 6.5 really liked RL-17, but it's hit or miss. No other rifle I've ever owned has shot RL-17 like this rifle did. It also shot IMR-4350 very well. To be fair every rifle that IMR-4350 is suitable for has shot the smallest with it in my experience. My 6.5 Creedmoor liked 41 all the way to 41.5gns of IMR-4350 with the 147 ELD. 41.7gns of RL-17 with the 147ELD loaded at magazine length (jumping some 0.100" to the lands) was the magic combo in that rifle though.

 

[AllenOne1]

Not sure if you guys want to keep hearing about this but someone had questioned what kind of groups I was shooting and I didn't have an answer so I wanted to post this update.

Today I went out and shot a seating depth test, it was a hot 86 degrees and 60% humidity about 12- 2 time frame so not the best time to be running the tests and I was having a little trouble getting comfortable on the gun.

Test was done at 100 yards with 5 shot groups the results as follows

-.010 = .412 grp
-.015 = .522 grp
-.020 = .412 grp (this group looked the best on paper)
-.030 = .544 grp
-.040 = .487 grp

No other changes were made to the load other than the seating depth.
The load I have been shooting is right at -.015

Is it right to assume that changing seating depth from -.015 to -.020 would show up on the target at 600 yards as a potentially .66 better group, if so that change alone is a significant improvement.

Still a lot of work to do.

 

[jelenko]

What would happen if a few more 5 shot groups were shot at, say, -.015 and -.020? I'm thinking that there might be a 'dispersion' of group sizes. The average of a few groups might indicate different results?

 

[AllenOne1]

What would happen if a few more 5 shot groups were shot at, say, -.015 and -.020? I'm thinking that there might be a 'dispersion' of group sizes. The average of a few groups might indicate different results?

Yes I think you could shoot it 5 times and get 5 different answers on this one. When the barrel was new it didn't like -.020 load, now it seems to prefer it in this round of tests.