6XC built, now working on loads..

[6xcKY]

Original rifle was a Rem700 SPS Tactical .308. Local family friend is a FFL, got me a super deal on it and while I was new and knew nothing about bolt guns, I loved it. It was a great shooter for what purpose it was made, and though the 1/12tw 20" barrel only generated a muzzle velocity of 2550fps with 175gr SMK, it was still quite accurate even at 800-1000yd depending on the type of shooting we was doing.
Scope is a Bushnell Elite Tactical 3-12 which I bought after watching Lowlight's review of him beating the piss out of it and it still rocking on the range. While I wish I had more magnification especially at LR, it tracks perfectly and has always been more than reliable.




After shooting with the .308 for a little over 2 years, and going to a few matches and realizing that while it was a good shooter and accurate to its ability, I was still HIGHLY outmatched when it comes to shooting LR matches and Sniper competitions. Looking at the top of the list scores where I was going, you seen a constant in calibers. (6.5x47L, 6.5x284, 6.5CM, .260, .243, etc.) Not saying that calibers such as .308, 7mm, 338, 300, didnt place well, but they just apparently did not compete with these faster, higher BC, calibers and bullets.

I called around to several gunsmiths, got prices and quotes, and while there was not a huge difference in them, I have always been a "budget precision" type of shooter, and having to throw half down and send my rifle across the country, just was not a choice I was able to make. After talking to some of my local shooting friends, someone pointed me to a local smith, a guy who had been using lathes and shop machinery since the early 80's and been gunsmithing with friends since before that only lived about a 20min drive from my house. After a few trips to visit, and us talking about the type of shooting I enjoyed, and his (benchrest) he asked me if I had ever heard of David Tubb. I said no, and began to do my research. Needless to say, after seeing what he was able to do with the 6XC round, and do it repetitively, and how easy it was to load for, I made my decision. Not to mention, no one else I know of, in my area especially, has ever dabbled in the 6XC round.

All this was probably back in the beginning of Sept, I dropped off my rifle and told him to let me know as he worked on it and Id like to watch to see how it is all put together, and I learned more in just a few trips being hands on then I ever would have just reading online.

I did not plan on using the 115DTACS, but we still reamed for them anyway. I plan on only using 105 Hybrids as they show some potential already, just have to find the right node.

Other than the threading of course and a few other things, they do everything by hand. They only do a few guns a year so mass production isnt a problem they must worry about it. Here they are blue printing and straightening up the action and bolt face.


We have tested loads from 37.5gr H4350 (105 hybrid) up to 39.5 which gave me a MV of 2990fps. A pretty good group, but less than 60 shots are currently down the barrel, so we are still breaking it in and hopefully will find something that works soon. Here is the final product as it sits today, currently doesnt have my rail, rings, scope, or Harrid Bipod on it.

Barrel is a Krieger MTU 1/8tw with radial brake, HS precision stock.

 

[JGorski]

60 shots and it's not broke in yet? If you're not getting any blue on the patch when you clean it's broke in. My Bart was broke in after the 1st shot.

 

[JRWALLSIII]

39.0-39.7 H4350 with a 105
Works in every rifle I've ever seen
chambered in 6xc

The rifle should shoot great right out the gate but the barrel will not stabilize speed until you have around 250 rounds down the barrel.

 

[Barney88PDC]

Do you have any pictures of the chambering process?

 

[6xcKY]

Unfortunately I do not have pictures of the chambering process as I was oiling the reamer blades as he would cut then pull out to extract the shavings. He was super cool about letting me be hands on as much as possible and I loved it.

I know technically the barrel is broken in but I personally feel as if its not broken in yet until I find my perfect load and can get perfect dope with it consistantly without seeing deviations and changes in things like muzzle velocity and group sizing. I might be wasting time and material to some but it's what works for me.

37.5 through 39 was not impressive to me. .5moa at the best I would say. With 39.5 we was getting .25moa+ sometimes closer to. 5 moa but I was happy with it. Muzzle velocity was a constant 2990 and I was looking for around 3010-3020 with no pressure to be my max.

I loaded up five 39.6, five 39.8 and five 40gr to test today.

I couldn't believe how much it changed on me when we began to shoot. 39.6 went to almost an inch. 39.8 was not much better either.

Then we shot the 40gr and all rounds bug holed. 2 hit a little right but it might have been the shooter. The other 3 to the left barely made a hole big enough to tell more than 1-2 shots hit it.

All of these groups were shot on a clean bore before each new group was fired. I will upload photos of each when I can but I'm currently on mobile

 

[6xcKY]

Top Left - 39gr
Bottom Left - 39.5gr
Top Right - 38gr
Bottom Right -38.5gr

These were shot by the gunsmith and his assistant, a little above 30° outside

 

[6xcKY]

Center - 39.6gr
Right corner - 39.8gr
Left corner - 40gr

 

[KYS]

60 shots and it's not broke in yet? If you're not getting any blue on the patch when you clean it's broke in. My Bart was broke in after the 1st shot.

Not every barrel is the same. Not all of us spend 600 rounds "finding our load" either.
I find that most Bartlein barrels need 150-200 rounds to settle in.

 

[KYS]

Unfortunately I do not have pictures of the chambering process as I was oiling the reamer blades as he would cut then pull out to extract the shavings. He was super cool about letting me be hands on as much as possible and I loved it.

I know technically the barrel is broken in but I personally feel as if its not broken in yet until I find my perfect load and can get perfect dope with it consistantly without seeing deviations and changes in things like muzzle velocity and group sizing. I might be wasting time and material to some but it's what works for me.

37.5 through 39 was not impressive to me. .5moa at the best I would say. With 39.5 we was getting .25moa+ sometimes closer to. 5 moa but I was happy with it. Muzzle velocity was a constant 2990 and I was looking for around 3010-3020 with no pressure to be my max.

I loaded up five 39.6, five 39.8 and five 40gr to test today.

I couldn't believe how much it changed on me when we began to shoot. 39.6 went to almost an inch. 39.8 was not much better either.

Then we shot the 40gr and all rounds bug holed. 2 hit a little right but it might have been the shooter. The other 3 to the left barely made a hole big enough to tell more than 1-2 shots hit it.

All of these groups were shot on a clean bore before each new group was fired. I will upload photos of each when I can but I'm currently on mobile

Are you using a rubber stock on this build?

 

[6xcKY]

Its a HS take off with a Remington buttpad. Been channeled and freefloated for the contour and action bedded.

 

[bjay]

60 shots and it's not broke in yet? If you're not getting any blue on the patch when you clean it's broke in. My Bart was broke in after the 1st shot.

I didnt know we need to brake in barrel
come with us man 6cm will try 1060 today..

Thats a nice xc above... maybe try 4831sc too

 

[6xcKY]

Thank you bjay. When the time comes and the funds are available I would love a Manners or the like. ..

 

[JGorski]

Not every barrel is the same. Not all of us spend 600 rounds "finding our load" either.
I find that most Bartlein barrels need 150-200 rounds to settle in.

Not quite, KY, I've got some loads ready to shoot that have 4 firings on them,(out of 98 shells) had my good loads figured out before I had 200 shots through the barrel, once I started using H4350 it was a done deal, after that I got my chronograph, then I was in test mode, got some DTACs, again, test mode, got just shy of 500rounds through it, Id guess.

Bjay, I'll bring the DTAC test loads, need to wring them out good.

 

[KYS]

DTACs are worthless in a 6 Creedmoor. I had over 1k loaded and pulled them all. The 105gr Berger's smoke them in performance right out of the box. And don't forget, the DTAC's come pointed. You point the Berger Hybrids and it's a whole other animal.

Almost every single 6mm barrel I have received from Bartlein needed 200 rounds to level out and maintain speed. First 6 Creed I had built started off at 3050 fps. By the time I had just over 200 rounds I was consistently hitting 3150, sometimes dropping near 3140. But it stayed right in there. Given the results I would say that's the "sweet spot".

 

[JGorski]

DTACs are worthless in a 6 Creedmoor. I had over 1k loaded and pulled them all. The 105gr Berger's smoke them in performance right out of the box. And don't forget, the DTAC's come pointed. You point the Berger Hybrids and it's a whole other animal.
Almost every single 6mm barrel I have received from Bartlein needed 200 rounds to level out and maintain speed. First 6 Creed I had built started off at 3050 fps. By the time I had just over 200 rounds I was consistently hitting 3150, sometimes dropping near 3140. But it stayed right in there. Given the results I would say that's the "sweet spot".

Please explain what you mean by worthless? The first 2 and only groups I shot with them went 1.285" & 1.9" on a slightly windy day out to 300yds, not bad considering that was the only time I shot them. That was with 41.6 & 41.9grs. H4350, have some loaded up with 43grs H4831sc, maybe the slower powder will shoot them even better, but not sure if Ill get the velocity that I was getting with H4350(low-3037 high-3065, SD-12) (low-3065 high-3086, SD-9).

 

[bjay]

DTACs are worthless in a 6 Creedmoor. I had over 1k loaded and pulled them all. The 105gr Berger's smoke them in performance right out of the box. And don't forget, the DTAC's come pointed. You point the Berger Hybrids and it's a whole other animal.

Almost every single 6mm barrel I have received from Bartlein needed 200 rounds to level out and maintain speed. First 6 Creed I had built started off at 3050 fps. By the time I had just over 200 rounds I was consistently hitting 3150, sometimes dropping near 3140. But it stayed right in there. Given the results I would say that's the "sweet spot".

Hmm i guess this explain me brakin in 6creed on 26" well its krieger but its only pushin 3100 on 42gr h4350 hopefuly ill get to hit 3100 with 41.5 oneday ..
ive seen one diff blogs dtac vs. 105 hybrids i just dobt remember where.. what advantage pointed 105 hybrids and just a regular hybrids

 

[sandwarrior]

6xcKY,

I would recommend, if you can get some, is RE-17. It works great in those 'slightly under medium capacity' rounds. As long as you don't have a sharper than 30 deg. shoulder. Also, now that it's being seen around in a lot of places, CFE223 would be a good choice as well for that round/bullet combo. I've just started working with it in my 6mm Rem. AI.

 

[JRWALLSIII]

Please explain what you mean by worthless? The first 2 and only groups I shot with them went 1.285" & 1.9" on a slightly windy day out to 300yds, not bad considering that was the only time I shot them. That was with 41.6 & 41.9grs. H4350, have some loaded up with 43grs H4831sc, maybe the slower powder will shoot them even better, but not sure if Ill get the velocity that I was getting with H4350(low-3037 high-3065, SD-12) (low-3065 high-3086, SD-9).

If you like sound advice listen up.

Adam is 100% correct that a barrel needs a good 200 rounds to stabilize speed. If you just shoot targets with sighter shots then that does not matter. If you depend on constant speed, predictable speed then the barrel needs those rounds. Because the barrel will speed up from 0-250 rounds In my experience. And you will have to back down your charge to get in the same node as you began

As far as DTACs being the bullet of Choice that's up to you. DTACs shoot well at distance, that's a fact. But on paper at 100 they will get there but kicked 99.9% of the time by a 105 hybrid.

Accuracy is in the eye of the beholder.
Every XC that I have owned would shoot in the .1s or better at 100 with 105 hybrids. Have lots of paper cut out to prove it. And I have burned out 4 barrels in XC shooting 105 hybrids

 

[bjay]

Ive wanted to try rl17 even on my 260 but can find them..

 

[JGorski]

As far as DTACs being the bullet of Choice that's up to you. DTACs shoot well at distance, that's a fact. But on paper at 100 they will get there but kicked 99.9% of the time by a 105 hybrid.
Accuracy is in the eye of the beholder.
Every XC that I have owned would shoot in the .1s or better at 100 with 105 hybrids. Have lots of paper cut out to prove it. And I have burned out 4 barrels in XC shooting 105 hybrids

99.8% of the time I shoot 300yds. And with limited testing and I shot a few groups with Hybrids at 100yds, afraid to say the accuracy wasn't in the 1s or even in the 5s, they did much better at 300, course that's where Berger tells or suggest you shoot them at in the first place. I'll never waste these DTACs at 100yds, 300 or 600, that's it. As you can see, the Hornadys shot better at 100yds, but again, I didnt work up a load for the Hybrids, since I didn't have many left I went by someone's advice going with 42grs H4350, I think when I get my next 6 Creed Ill try 41.4, same load as Bjay is getting great groups with, only only 13 Hybrids left now.

 

[turbo54]

41gr H1000 and a 105 Hornady makes a nice little plinking load that's really easy on the rifle. Runs ~2725fps from my 24" bbl.

 

[KYS]

Please explain what you mean by worthless? The first 2 and only groups I shot with them went 1.285" & 1.9" on a slightly windy day out to 300yds, not bad considering that was the only time I shot them. That was with 41.6 & 41.9grs. H4350, have some loaded up with 43grs H4831sc, maybe the slower powder will shoot them even better, but not sure if Ill get the velocity that I was getting with H4350(low-3037 high-3065, SD-12) (low-3065 high-3086, SD-9).

I've shot plenty of 6 Creedmoor to know what works and what does not for me, I have also spread that same load development over several barrels/rifles. So far the only two bullets I would even consider using are the 105gr Berger Hybrid and the 105gr BTHP Hornady Match.

The DTAC does not perform at 100, its going to be run slower and it needs distance to perform. So what happens when your shots are 150 and in?

The DTAC was the bullet developed for the 6XC so it performs a little better but I would still shoot the Berger bullets. I recently switched my 6Crusader loads from the 115 DTAC to the 105 Hybrid. Made a huge difference in grouping @ 100 and performance out to 1k.

Take that for what you will.

 

[KYS]

Ive wanted to try rl17 even on my 260 but can find them..

I've always had the best performance out of H4350 in my 260 and RL17 in my 6.5 Creedmoor.

 

[bertshortmag]

If you like sound advice listen up.

Adam is 100% correct that a barrel needs a good 200 rounds to stabilize speed. If you just shoot targets with sighter shots then that does not matter. If you depend on constant speed, predictable speed then the barrel needs those rounds. Because the barrel will speed up from 0-250 rounds In my experience. And you will have to back down your charge to get in the same node as you began

As far as DTACs being the bullet of Choice that's up to you. DTACs shoot well at distance, that's a fact. But on paper at 100 they will get there but kicked 99.9% of the time by a 105 hybrid.

Accuracy is in the eye of the beholder.
Every XC that I have owned would shoot in the .1s or better at 100 with 105 hybrids. Have lots of paper cut out to prove it. And I have burned out 4 barrels in XC shooting 105 hybrids

So i have to ask what did you see for rnd count on the 4 barrels before they were shot out? And what powder did you use?

 

[JRWALLSIII]

I only used H4350

Accuracy is in the eye of the beholder. But I would not take a 6xc barrel to a match with more than 1800 rounds on it. I'm hard on barrel, I get them hot and enjoy shooting lots of rounds. At 2K the accuracy may be good enough for some. But in my mind if your gun shoots in the .2s or less day in and day out then it goes to .5 it's time for a new barrel.

 

[bertshortmag]

And not to hijack the thread but it seems like very good info. Thanks. Some fall in love with there barrels and dont ever want to give up on them. sounds like you have it dialed in.

 

[JGorski]

I've shot plenty of 6 Creedmoor to know what works and what does not for me, I have also spread that same load development over several barrels/rifles. So far the only two bullets I would even consider using are the 105gr Berger Hybrid and the 105gr BTHP Hornady Match.

The DTAC does not perform at 100, its going to be run slower and it needs distance to perform. So what happens when your shots are 150 and in?

The DTAC was the bullet developed for the 6XC so it performs a little better but I would still shoot the Berger bullets. I recently switched my 6Crusader loads from the 115 DTAC to the 105 Hybrid. Made a huge difference in grouping @ 100 and performance out to 1k.

Take that for what you will.

It don't matter what these DTACs will do at 100 or inside of 300 for that matter, I only practice at 300, I'll never shoot them at any other range but 300 or 600 and possibly out to 1K if I ever try my hand at F-Class, I bought them to compete at 600yd BR next year. And since the ballistics are so close(out to 600) to my 105 Hornadys HPBT loads I wont have to touch the scope If I switch midway through the match, they're that close. My next 6 Creed is going to be throated for the VLDs, Hybrids and alike, hopefully it's a hammer like my first Creed, or even better

 

[KYS]

It don't matter what these DTACs will do at 100 or inside of 300 for that matter, I only practice at 300, I'll never shoot them at any other range but 300 or 600 and possibly out to 1K if I ever try my hand at F-Class, I bought them to compete at 600yd BR next year. And since the ballistics are so close(out to 600) to my 105 Hornadys HPBT loads I wont have to touch the scope If I switch midway through the match, they're that close. My next 6 Creed is going to be throated for the VLDs, Hybrids and alike, hopefully it's a hammer like my first Creed, or even better

To each their own. The ballistics are not "close". Loaded properly the pointed Hybrids are half a mil (.5) higher then the DTACS at 500 yards, roughly the same at 600. That's a fact. It's the efficiency in the powder charge, size of the case, and bullet weight that are out performing the DTAC.
That is simple science.

 

[JGorski]

To each their own. The ballistics are not "close". Loaded properly the pointed Hybrids are half a mil (.5) higher then the DTACS at 500 yards, roughly the same at 600. That's a fact. It's the efficiency in the powder charge, size of the case, and bullet weight that are out performing the DTAC.
That is simple science.

I was talking about trajectories with DTACs vs the HPBTs, DTACs coming out at 3052 is 10.9" high @100 and zerod @600, 105 Hornadys are coming out @3158 and are 10.5" high at 100 and zerod @600, I'd say that's pretty close. Do you have any before and after pics of the Hybrid being pointed, just looked at mine and can't really see how pointing them anymore than what they are would do anything for the BC.

 

[KYS]

I'll post some pics if I have any that aren't pointed. They add about 6-7% in BC when pointed. That info came from Josh @ Copper Creek.

 

[JGorski]

I did it for you, Whidden says 5% and the most you can close up the point is 30-40%, this is pretty small already.

 

[6xcKY]

So do you guys think I have even come close to hitting my high node area yet? The chrono was not available for the last 3 groups, but my primers are not showing much pressure at all, and at 39.5 we was in the 2990fps range.

Would you guys call it safe to bump up to 40.5-41gr and check the group sizing, muzzle velocity, and pressure points on those?

 

[bjay]

So do you guys think I have even come close to hitting my high node area yet? The chrono was not available for the last 3 groups, but my primers are not showing much pressure at all, and at 39.5 we was in the 2990fps range.

Would you guys call it safe to bump up to 40.5-41gr and check the group sizing, muzzle velocity, and pressure points on those?

Im one of them few guys accuracy comes first before fps..on my 6creed that i just broke in few days ago..i tried shoot while brakin in barrel and zeroing scope at the same time.i shot 40.2-42.4 in .2gr incriments on round per load all the way till i finaly start seeing presure sign..ive noticed when i got to 42 i kinda feel stiff bolt lift,so i did not shot last one (42.2) then wen back and do groupings and crono at the same tym heres my findings look at my groups again this is first tried out.look at 41.4-41.8 (has a flyer that i called)vertical abd one wholer but i choosed one the lower node 41.4. Went back tried it again 41.4 to 400yd still .2 -3 moa but his FPS went up to 3060..my point like everyone saying above on 6mm bulet dont expect to much on the begining specialy on fps it will still increase ..all these are 5shot

 

[JGorski]

So do you guys think I have even come close to hitting my high node area yet? The chrono was not available for the last 3 groups, but my primers are not showing much pressure at all, and at 39.5 we was in the 2990fps range.

Would you guys call it safe to bump up to 40.5-41gr and check the group sizing, muzzle velocity, and pressure points on those?

Sure, why not, though 41 might be too much, unless you're using moly coated bullets. Tubb used to shoot 39.6grs H4350 with 115DTACs(Moly), uncoated 105s would be right about the same. Id load up in .2 increments. 39.7, 39.9 etc.

 

[JGorski]

Im one of them few guys accuracy comes first before fps..on my 6creed that i just broke in few days ago..i tried shoot while brakin in barrel and zeroing scope at the same time.i shot 40.2-42.4 in .2gr incriments on round per load all the way till i finaly start seeing presure sign..ive noticed when i got to 42 i kinda feel stiff bolt lift,so i did not shot last one (42.2) then wen back and do groupings and crono at the same tym heres my findings look at my groups again this is first tried out.look at 41.4-41.8 (has a flyer that i called)vertical abd one wholer but i choosed one the lower node 41.4. Went back tried it again 41.4 to 400yd still .2 -3 moa but his FPS went up to 3060..my point like everyone saying above on 6mm bulet dont expect to much on the begining specialy on fps it will still increase ..all these are 5shot

Bjay, This is a super nice group, but you have to measure group outside to outside then subtract .243, looks like a 257" group from here. Very nice indeed.

 

[bjay]

Bjay, This is a super nice group, but you have to measure group outside to outside then subtract .243, looks like a 257" group from here. Very nice indeed.

Lol do we measure hole orinclude powder burn i realy not sure haha
Jay which is the rightway first or secont photo.

 

[JGorski]

First is more correct, what I do when the group is tight like that I find a bullet hole and measure it to where I get .243, then you know how far out to measure the whole group, it's usually right where the edge of the carbon is on the hole.

 

[JGorski]

pretty much like this.

 

[sandwarrior]

Ive wanted to try rl17 even on my 260 but can find them..

I have not seen it since the election. I finally saw RE15 in a local store (that usually has more good stuff than most around). It may be just around the corner this coming year. I was lucky in that I use RE-19 and RE-22 in two of my primary rifles and secondary reserves got sent out and I grabbed a couple extra pounds of it before the 'shortage'. I am now down to my last pound of each. I do still have about 4# of an 8# jug still left. And a ton of AA4350.

 

[6xcKY]

40gr seemed to group tighter than the 39.6 and 39.8 so I went home on lunch and loaded 40.2, 40.4., 40.6, 40.8, and 41.0.

I will see what I am capable to achieve with these loads and hopefully I will reach a higher node without seeing my primers pancake any.

 

[JGorski]

40gr seemed to group tighter than the 39.6 and 39.8 so I went home on lunch and loaded 40.2, 40.4., 40.6, 40.8, and 41.0.

I will see what I am capable to achieve with these loads and hopefully I will reach a higher node without seeing my primers pancake any.

Have any pics of your targets? You are testing those Hybrids at 300yds, right? Berger even suggests shooting them at least 300yds.

 

[KYS]

Sure, why not, though 41 might be too much, unless you're using moly coated bullets. Tubb used to shoot 39.6grs H4350 with 115DTACs(Moly), uncoated 105s would be right about the same. Id load up in .2 increments. 39.7, 39.9 etc.

DTACS are BN coated. Stay away from any molly coating as it can trap moisture if you don't clean it out of your barrel each time. Boron Nitride lets you run a touch hotter load while keeping the pressure down.

"DTAC 6XC Precision Loaded Ammunition is built from the following components: Sierra 115gr DTAC Boron Nitride Coated bullets, a proprietary powder mix, Russian primers and Norma brass."

 

[JGorski]

DTACS are BN coated. Stay away from any molly coating as it can trap moisture if you don't clean it out of your barrel each time. Boron Nitride lets you run a touch hotter load while keeping the pressure down.

"DTAC 6XC Precision Loaded Ammunition is built from the following components: Sierra 115gr DTAC Boron Nitride Coated bullets, a proprietary powder mix, Russian primers and Norma brass."

Yup, got the moly thing from 6br.com, old, old article. My DTACs of BN coated, too.

"I use moly-coated bullets exclusively, so the loads listed need to be reduced 1-1/2 grains if an uncoated bullet is substituted. All of my long range loads are seated long and are pushed back into the case upon the closing of the T2K bolt. Likewise, all of my long range loads are full-length resized each and every time (approximately .003 inches shoulder set back). I use the Superior Shooting Systems Custom 6XC die set (see below). I used the .268 bushing in the sizing die with the expander plug (for long range only; I use a smaller bushing for across the course rounds)." David Tubb.

 

[6xcKY]

Have any pics of your targets? You are testing those Hybrids at 300yds, right? Berger even suggests shooting them at least 300yds.

No, I figured if I couldn't hit the broad side of a barn at 100yd then it wouldn't be too impressive further out.

 

[6xcKY]

Was able to pull the trigger a little this afternoon. Was between 30-35º out and in the shade but no wind. Went up in .2gr increments starting at 40.2 in the center, then 40.4 in the top left corner going clockwise to 41.0gr in the bottom left.

You will notice on the 41gr (bottom left) 1st shot and 3rd shot went through same hole, but either I pulled the 2nd middle shot, or it was a bad load, or possibly a group opening back up but dont think its that considering the 1-3shots entered same hole instead of triangulating.

 

[bjay]

Was able to pull the trigger a little this afternoon. Was between 30-35º out and in the shade but no wind. Went up in .2gr increments starting at 40.2 in the center, then 40.4 in the top left corner going clockwise to 41.0gr in the bottom left.

You will notice on the 41gr (bottom left) 1st shot and 3rd shot went through same hole, but either I pulled the 2nd middle shot, or it was a bad load, or possibly a group opening back up but dont think its that considering the 1-3shots entered same hole instead of triangulating.

I can see 40.4-40.8 impact almost the sane with no shift.. look like your 41 starting to jump on fps.try play 40.8 more adjust seating depth

 

[JGorski]

When it warms up to over 75F you'll probably see a shift in POI, and speed.

 

[6xcKY]

Making progress with the XC, here is a photo of it completed, with my equipment attached.



Here are the 3 latest groups, 40.7 is looking like a keeper, its a little hot as it was right on the lands, but we are backing it off on the next trial run to see if the pressure remains, though it still isn't close to being dangerous..

 

[6xcKY]

Been a while since I have updated this, as due to the bad weather we have been experiencing in the SE, not much range time available after work in the evenings.

My Bushnell is currently at the repair lab getting evaluated, so it will be a couple weeks getting back to me. Currently we still have my 'smiths scope on it.

Due to the fact we couldnt get the groups to tighten up like we wanted, we went back to the drawing board. Turns out we had 2 different issues. A slightly bad crown, it was sanded, but still had enough
of a burred edge to cause problems. We got a Dave Manson crowning tool, and boy is that thing amazing. Shined it right up.

Once this was done, we reinstalled the muzzle brake, even though the groups was still right around a 1/4moa, we felt like we could still push it a little further, just for giggles...And this was the results...

The muzzle brake design ended up creating two crowns for the rifle, just the design of the creator, which the name will not be mentioned, because I do not like to infringe on someones business because of one problem, one person has had. We removed the muzzle brake, put on the thread protector, and consistently shot this group. 40gr H4350, 105 Berger Hybrid, 2.705 (.10 from lands).

 

[6xcKY]

Forgot to add, muzzle velocity is still to be determined, chrono is currently down, but I am sure it is will buzzing at a good pace...