Need input and thoughts... UPDATE #3

[HuntClub]

Got a new Tikka in 7mm08. Took it to the range and got it on paper and ready to start load work up. So, 120 factory SST and 120 factory TTSX - total of 15 rounds to just get it on paper and start barrel break-in.

Loaded up (15) 140 TSX and (30) 150 game king. Tried the 140 TSX with Varget first- same seating depth and charges were 38.5, 39.0, 39.5, 40.0, 40.5. Was looking for a powder node and then would look at seating. Did not shoot the 40.5 load. I know (I think) what the powder node looks like but have never seen this before. Looking for opinions to correct my thoughts, or confirm them... looks to me like the gun just shoots to the same POI no matter what the load... which means I can miss the charge quite liberally without any real concern on placement. Is this correct?

No scope adjustment made during this run. 39.5 top was a definite pull up.

Your thoughts and experiences shared will be appreciated.

 

[William Vogel]

The 40.0 looks like it’s close to a node. I’d shoot around the 39.5 - 40.5 charges in .2 increments but with 5 shots each charge. POI shifts are not what I look for. I look for tight groups. I see POI shifts more with different bullets or different powder than with same components and different charge.

 

[357Mag]

Got a new Tikka in 7mm08. Took it to the range and got it on paper and ready to start load work up. So, 120 factory SST and 120 factory TTSX - total of 15 rounds to just get it on paper and start barrel break-in.

Loaded up (15) 140 TSX and (30) 150 game king. Tried the 140 TSX with Varget first- same seating depth and charges were 38.5, 39.0, 39.5, 40.0, 40.5. Was looking for a powder node and then would look at seating. Did not shoot the 40.5 load. I know (I think) what the powder node looks like but have never seen this before. Looking for opinions to correct my thoughts, or confirm them... looks to me like the gun just shoots to the same POI no matter what the load... which means I can miss the charge quite liberally without any real concern on placement. Is this correct?

No scope adjustment made during this run. 39.5 top was a definite pull up.

Your thoughts and experiences shared will be appreciated.

Hunt -

Howdy
Thinking out loud....

- You sighted in @ a certain range, and fired all shots at that same range.

- You maintained the same scope / mounts / mounted height above the bore for all shots.

IMHO:
You've arrived @ a certain point on the ballistic arch where the impact dispersion between all of the shots is negligible @ that distance; partially due to the above.

IF you were to....change the scope setting to adjust the impact point ( height of the groups ) relative to the center of the bullseye ( assumed aim point ) a significant enough amount; then re-fire the same loads.....you might very well see more " difference " in the resulting bullet impact points ?


With regards,
357Mag

 

[Dimner]

Personally, I run at least 5 or 6 charge weights to look at POI shifts. So with only 4 strings shot, you may have gotten lucky and found the a couple charge weights that are similar POI.

I would do another test focusing around 38.5 and 39.0. Doing the same thing again, with .2 or .3 grain steps. Something like 38.2, 38.5, 38.8, 39.1, 39.4. Hopefully my math is right. Doing this set would help identify if the steady node is on the side of your original, 39.0 test or 38.5 test.

I know you mentioned (I think) you pulled the 39.5, but my spidey sense is telling me the really stable load is lower.

It's hard, but really should ignore group size for now. Just look at POI on the horizontal as you mentioned.

Also, if this is a new rifle to you, did you fireform the brass and bump the shoulder back? Meaning, did you partial full length resize? Or is this the first time you have used the brass in this rifle? If it's the first time using the brass, and you intend to PFLR in the future, you should run the test with the brass prep you plan to use. I only mention this because the first thing I do with any rifle is fireform brass and bump the shoulder. I don't look for anything by rough FPS estimates while I am doing this. Today I should get my tikka back with a 30-06 rebarrel. First thing I'm doing is fireforming 100 cases.

 

[Sandstorm]

My 308 Tikka was about as easy to load for using Varget. Id just load 10 round's at 40.0
and shoot them at the same POA and see if it repeat's 10 X
If not...You know what to do.

 

[HuntClub]

Personally, I run at least 5 or 6 charge weights to look at POI shifts. So with only 4 strings shot, you may have gotten lucky and found the a couple charge weights that are similar POI.

I would do another test focusing around 38.5 and 39.0. Doing the same thing again, with .2 or .3 grain steps. Something like 38.2, 38.5, 38.8, 39.1, 39.4. Hopefully my math is right. Doing this set would help identify if the steady node is on the side of your original, 39.0 test or 38.5 test.

I know you mentioned (I think) you pulled the 39.5, but my spidey sense is telling me the really stable load is lower.

It's hard, but really should ignore group size for now. Just look at POI on the horizontal as you mentioned.

Also, if this is a new rifle to you, did you fireform the brass and bump the shoulder back? Meaning, did you partial full length resize? Or is this the first time you have used the brass in this rifle? If it's the first time using the brass, and you intend to PFLR in the future, you should run the test with the brass prep you plan to use. I only mention this because the first thing I do with any rifle is fireform brass and bump the shoulder. I don't look for anything by rough FPS estimates while I am doing this. Today I should get my tikka back with a 30-06 rebarrel. First thing I'm doing is fireforming 100 cases.

Already have loads made up but went the other way. Loads are 39.5, 39.7, 40.0, 40.3, 40.5. Trying to keep the speed in the 2650-2700 range. And, I may have gotten lucky and landed on the "x" from the beginning. Going to the range in the morning. Will adjust scope for expected placement based on what i got with first run - and will watch for the horizontal POI. ...Really hoping this is the right "x"

I did a Full Length sizing on the brass before loading. First time in this rifle. Will likely post results.

Thanks for your input.

 

[HuntClub]

UPDATED:
Made my test loads and used these four - 39.5, 39.7, 40.0, 40.5.

Adjusted scope up 2" & left 0.5".

A change to seating. 39.5 stayed at original depth. The others I moved 0.003 closer to the lands. These groups opened up! POI was pretty much as before - horizontal had little variation.

First shot on 39.5 was my fouling shot - i did not prepare for one - so I think it burnt me on the grouping. First was high and next two on top of each other. Then the others, again, opened up.

Thinking that I should try 38.0, 38.4, 38.8, 39.2 and maybe seat 0.002 deeper than original test.

Your input helps - Thanks!

 

[Dimner]

I think your next test is on the right track

 

[std7mag]

Several questions & observations.

This is a Tikka T3 (or T3X) hunting rifle?

Why so heavy on the mono bullet?

What is your COAL to the lands ( being a Tikka, I'm assuming there is enough length in the magazine to "load out")?

Why "searching for a 2,650-2,700fps" velocity range?

With those bullet weights in the 7mm-08, for a hunting rifle, I'd switch to a slower burning powder.
PP2000MR, RL16, RL17, H414, W760, H4350, IMR4350 range.

Stevens 200, with factory 22" Sporter barrel reamed to 7mm-08AI with 140gr bullets. (Ballistic Tips & Berger VLDs)
PPU (PVRI Partizan) brass
Fed210M

RL17 was speed king at 2,916fps
H414 & PP2000MR 2,832fps
(Note, these were accuracy nodes, not max charge)
PP2000MR gave lowest ES/SD numbers. ES-6, SD-2 over 10 rounds.

The Sierra's will probably like a jump of 0.020" off the lands.
While your mono's will want a jump of 0.050" off the lands.

Instead of testing 0.002-0.003", I'd do bigger jumps (0.010-0.015") then you can find tune if you'd like.

 

[HuntClub]

Test #2 results are in... not what I hoped for.

Test was 38.0, 38.3, 38.7, 39.0. Groups came in again at 39.0. Still looks like the 39.0 - 39.5 range is my best bet. There maybe a better seating depth but may test 38.7, 39.0, and 39.3 next.

My seating depth is 0.120" from the lands. I started here based on Barnes published data on COAL for the 140 TSX. Maybe I should try at 0.050 and work back? Maybe picked up a little more speed from the seating variance...

The 39.0 groups are 3/4" groups - that is with the one shot stretching the group. Again, your thoughts appreciated. Dug a couple of the TSX's out of the dirt to check expansion. included with picture.

On a side note - I picked up a box of Barnes Vortex 120 TTSX and did a three shot test. was aiming at the bottom line of target expecting the 120 to fly high (previous results in different rifle did that). And data on box said they would fly at 3000fps. They made 2818 over my chrono. Surprising results.

Thanks again for your input.

 

[FeMan]

Your load doesnt look happy. I shoot a lot of Barnes bullets and have always been able to get them to shoot extremely tight, usually around 1/4 moa. I would take whatever charge weight you think is shooting best and shoot it with jumps of 50k, 70k, 90k, and 120k. Take the best of those and go plus and minus 5k and 10k from there.

The other thing I would recommend is 4 or 5 shot groups. I have been mislead far too often from 3 shot groups to trust them in load development. If the first three are bad then you can always pass on the others and re-load them.

 

[Dimner]

Which stock do you have on your tikka? I may have missed that part.

i have a 308 in a wood stock (hunter version) that shoots lights out.

However, I have a 270 in the t3x syn stock that would shoot split groups like yours at 100 yards. Couldn't get it to do better than 1 inch groups. Tried for two seasons with all kinds of bullets and powders. So I decided to rebarrel it in a cartridge I really wanted.

Then I learned that all the guys on this site really know their stuff. I had stock interference. i had already done the freefloat test and that was fine, but i noticed that there was plastic burrs left over from the molding process that was touching the action and bottom metal. Also had one in the action screw hole.

I suggest taking the rifle apart and really examine all of the inletting to see if there are any issues. Also, I bought the lumey arms extra thick recoil lug. And don't forget to tighten your action screws to the appropriate torque. For the synthetic I use 35-40 ft lbs. I use 40 on the wood stock.

I'm going to be running a test soon to show before and after bedding a syn tikka stock. It will be my first time bedding.

 

[HuntClub]

Which stock do you have on your tikka? I may have missed that part.

i have a 308 in a wood stock (hunter version) that shoots lights out.

However, I have a 270 in the t3x syn stock that would shoot split groups like yours at 100 yards. Couldn't get it to do better than 1 inch groups. Tried for two seasons with all kinds of bullets and powders. So I decided to rebarrel it in a cartridge I really wanted.

Then I learned that all the guys on this site really know their stuff. I had stock interference. i had already done the freefloat test and that was fine, but i noticed that there was plastic burrs left over from the molding process that was touching the action and bottom metal. Also had one in the action screw hole.

I suggest taking the rifle apart and really examine all of the inletting to see if there are any issues. Also, I bought the lumey arms extra thick recoil lug. And don't forget to tighten your action screws to the appropriate torque. For the synthetic I use 35-40 ft lbs. I use 40 on the wood stock.

I'm going to be running a test soon to show before and after bedding a syn tikka stock. It will be my first time bedding.

I have the synthetic stock on. I took it off and cleaned it up. Gave is a "paint job" too. (pic attached) I did my 7mmMag and this stainless 7mm08. Got a few more ideas on testing. I may be a while before sharing more.

How do you like my camo jobs... thinking about doing this on the side for a few extra reloading buck!

 

[HuntClub]

CURVE BALL: Working on a 150 gr Sierra Game King load simultaneously. Think I have a load there, for sure.

First test was 18 shots at 38.5, 39.0, and 39.5. Powder 203-B.

First round of 9 showed promise. Second round seated a little deeper. 39.0 caught my attention. see photo attached.

A third test at a little deeper seating and everything opened up significantly - groups at 1.25". No picture provided.

Final test today 39.0 using BR2 primer and Rem 9 1/2 primer. BR2 test shot 1 & 3 touching...pulled a Huntclub on shot #2. Rem 9 1/2 held its own too. Good group and location. Will probably stick with the BR2.

Oh, dang...it is hot here today!

Thoughts and suggestions appreciated.

 

[WVRJ]

Maybe I'm wrong,but I look at a rifle's accuracy in a different way between a hunting gun and a target rifle.I want a forgivable load in a hunting rifle.I usually want all the velocity I can get without losing accuracy by any major amount.Your original 40 grain load was where I would have maybe fine tuned a little,but I wouldn't have spent too much time and components improving on that load.I would say you hit a good node and it's wide enough to stay steady if you're in temperature extremes,or if your barrel is clean or fouled-maybe really fouled from a bunch of shots fired in a hurry and got the barrel really hot.I want a load that is consistent and predictable.If you go trying to find the magic powder charge that is something like 39.8 in the heat of summer,if it's a fringe weight on a tight node,the temperature can make it all fall apart.If you can turn accuracy that is as good as you got at 40 grains,stay there a little bit and see how it reacts to temperature,both ambient and a hot barrel.A wide band of consistency is a premium in a hunting rifle.

 

[Zero333]

My brother has a hunting 7mm08 and uses 42.5 gr Varget with 140 gr Gameking or Berger Hunting VLD.

 

[HuntClub]

FINAL UPDATE

So, working on the 140 TSX load, I decided to get past loading to the recommendation of the Barnes website and start fresh. Thought I would got 0.045 from lands and work from there. Test loads were Varget 40.0 grains, seating depth at 0.045, 0.055, 0.075, 0.095, 0.115, 0.125.

Friday was test day. Started at the 0.045 load work down the list. It was a rainy day so second shot was without chrono - but was able to set it up again shortly after that second shot. This group really surprised me. Second group was good too. Third group was only two shot because of spread.

Went home and reseated all other rounds loaded to test again at 0.040, 0.045, 0.050. Noticed the FPS dropped - guessing because of bullet tension being reduced from reseating.

Very please with the results and it appears the gun really likes this bullet closer, rather than further away from the lands. Going to do one more test at 0.043 with 40.0, 40.4m and 40.8 grains of varget.

Your thoughts appreciated.

 

[Zero333]

So, working on the 140 TSX load, I decided to get past loading to the recommendation of the Barnes website and start fresh. Thought I would got 0.045 from lands and work from there. Test loads were Varget 40.0 grains, seating depth at 0.045, 0.055, 0.075, 0.095, 0.115, 0.125.

Friday was test day. Started at the 0.045 load work down the list. It was a rainy day so second shot was without chrono - but was able to set it up again shortly after that second shot. This group really surprised me. Second group was good too. Third group was only two shot because of spread.

Went home and reseated all other rounds loaded to test again at 0.040, 0.045, 0.050. Noticed the FPS dropped - guessing because of bullet tension being reduced from reseating.

Very please with the results and it appears the gun really likes this bullet closer, rather than further away from the lands. Going to do one more test at 0.043 with 40.0, 40.4m and 40.8 grains of varget.

Your thoughts appreciated.

I wanted the flattest shooting load for deer. So I got my 300winmag and loaded 130 TTSX @ 3,550 fps.
( 24"bbl ). I'm also jumping the bullet 0.115".
Out to 330 yards it's "Point N Shoot" when I sight it in 2" high at 100 yards, it ends up roughly 3" low at 330 yards

So go as light TTSX as possible... Jump it a mile at very high rate of speed.


When bush/brush hunting deer, I use my 1954 Ruski SKS with a rear peep sight and worked over trigger (no creep and breaks at 3.5 lbs )
Sometimes I take one of my 243's if it's an area I've not ventured into before.