Sierra Heavy TMK 6MM Testing

[BBB]

To be totally honest, I’m still on the fence about it truly being a scope issue. It definitely could solely be the scope, but maybe I was also underestimating how bad the mirage really was, because tonight was crystal clear and it was apparent. Mirage can be terrible where I shoot and absolutely causes impact shifts. But these were pretty drastic given how good the data was. 6” high at 600 yards is a lot, even with bad mirage in the air.

The scope was a trijicon tenmile 5-25X50 FFP.

I have three of them, and they have been zero issues for me. It just seems a bit odd for the one on a little 6 creed to randomly take a shit between range trips, but still holding a rock solid zero and RTZ.

I hear you. It’ll be interesting to put that scope on a rifle/bullet that you have more history with bc-wise and see what the results are. Thanks for sharing.

 

[PathFinder]

To be totally honest, I’m still on the fence about it truly being a scope issue. It definitely could solely be the scope, but maybe I was also underestimating how bad the mirage really was, because tonight was crystal clear and it was apparent. Mirage can be terrible where I shoot and absolutely causes impact shifts. But these were pretty drastic given how good the data was. 6” high at 600 yards is a lot, even with bad mirage in the air.

The scope was a trijicon tenmile 5-25X50 FFP.

I have three of them, and they have been zero issues for me. It just seems a bit odd for the one on a little 6 creed to randomly take a shit between range trips, but still holding a rock solid zero and RTZ.

I've seen some absolutely wild effects from mirage on vertical correction, especially on a really flat range. Changing distance slightly changed height from the ground, and that changed the effect of the mirage. Drove me insane for a couple range sessions. Still haven't shot back and forth in that spot enough to quantify it, but it was on the order of .5 mil at 800 yards.

 

[glock233]

My money is still on zeroing. Glad to see it worked out.

 

[Castle Rock]

Stop with the nonsense.

1:7.5” twist is just fine for the 116’s. So is a 1:8” so far. You guys chicken little’ing are not helping anyone.

That’s the awesome thing about the internet, people who haven’t done something telling you that it is impossible.

I shoot 88 ELDMs in my 223 tikka just fine out to 1200 m, but that’s impossible

 

[huntnful]

I've seen some absolutely wild effects from mirage on vertical correction, especially on a really flat range. Changing distance slightly changed height from the ground, and that changed the effect of the mirage. Drove me insane for a couple range sessions. Still haven't shot back and forth in that spot enough to quantify it, but it was on the order of .5 mil at 800 yards.

Good to hear you confirm what I’ve seen on occasion also.

Yeah I was previously shooting down a dead flat road between two ag fields. The air is nasty, but didn’t seem terrible. It was also dead calm and just boiling.

Last night it was overcast and I drove up on the levee above the fields, there was a decent breeze in the air and the image was crisp.

I’m happy to know the bullet is performing well though, and I’ll check the scope again soon enough.

I hear you. It’ll be interesting to put that scope on a rifle/bullet that you have more history with bc-wise and see what the results are. Thanks for sharing.

Agreed!

 

[willfrye027]

Good to hear you confirm what I’ve seen on occasion also.

Yeah I was previously shooting down a dead flat road between two ag fields. The air is nasty, but didn’t seem terrible. It was also dead calm and just boiling.

Last night it was overcast and I drove up on the levee above the fields, there was a decent breeze in the air and the image was crisp.

I’m happy to know the bullet is performing well though, and I’ll check the scope again soon enough.


Agreed!

I’ve had some weird vertical stuff happen shooting in the same atmospheric/haze conditions that you shoot..also seemed to be sun position dependent as my range shooting directly east. I don’t remember how much exactly but enough to be missing 10” plates at 700, both high and then low depending on the sun position and mirage.

Maybe just a stacking of several factors and error but sure had mirage and sun position do weird things and cause me to question zero and chase my tail..

 

[Castle Rock]

“Light’s up, site up”
It is an old target shooter’s saying.

 

[huntnful]

I’ve had some weird vertical stuff happen shooting in the same atmospheric/haze conditions that you shoot..also seemed to be sun position dependent as my range shooting directly east. I don’t remember how much exactly but enough to be missing 10” plates at 700, both high and then low depending on the sun position and mirage.

Maybe just a stacking of several factors and error but sure had mirage and sun position do weird things and cause me to question zero and chase my tail..

For sure man. I’ve had plenty of weird shit happen with mirage also. So I don’t normally shoot in it at all to actually gather data. I think this was mostly a combination of that, and shooting a brand new bullet that I had no experience with or confidence in, paired with two weird range trips in a row, showing the same thing, at different times of day.

I’m still going to look into the scope, but honestly think it was just…. Me lol

 

[B_Reynolds_AK]

For sure man. I’ve had plenty of weird shit happen with mirage also. So I don’t normally shoot in it at all to actually gather data. I think this was mostly a combination of that, and shooting a brand new bullet that I had no experience with or confidence in, paired with two weird range trips in a row, showing the same thing, at different times of day.

I’m still going to look into the scope, but honestly think it was just…. Me lol

Last week I thought the 88 TMK's were letting me down past 800 yards as far as BC as well. Went back out and found that my zero was .2 mil low at 100, as I forgot to account for that between the 80 ELD-M zero and the 88's. After I adjusted, the drops lined up perfectly.

 

[wind gypsy]

Iv got an osprey being chambered right now. Just looking for a premium cut rifles option. Hoping the osprey shoots good, but Iv had some really good ospreys and some ehh.


As for a smith turning down sure, lots of them don’t do it for free though, it essentially just adds money to the blanks.

I guess I could just buy whatever blank and see if LRI will recontour it for me. But even then it’s just more money and more time.

Ace makes tikka contour barrels already, reason I ask. I know bartlein won’t turn a shank down, atleast not last time I asked.

Agree. Hard to justify a custom contour if they wont give you the shank you want.

I'm pretty sure kampfeld didn't charge me to turn a shank down, if he did it wasn't much. Local guy who did my last barrel tacked on $30 or $40 to do it.

 

[mtnbound]

The 116’s today out of 16.5”-7.5”twist.

 

[huntsd]

The 116’s today out of 16.5”-7.5”twist.

6cm?

 

[huntnful]

6cm?

Took me a minute to see, but it’s written on the last line of his info. Yes 6CM

 

[huntnful]

Last week I thought the 88 TMK's were letting me down past 800 yards as far as BC as well. Went back out and found that my zero was .2 mil low at 100, as I forgot to account for that between the 80 ELD-M zero and the 88's. After I adjusted, the drops lined up perfectly.

I’ve done that a few times as well. Always good to double check things. Good to hear the 88’s are doing well also!

 

[walkingduckwaterfowl]

I shot the 107 TMK loaded from UM in my 20" 8 twist black/blued tikka .243 with omega 300 suppressor today. I didn't get the results I was hoping for. They were going faster than I expected at an average of 2985 FPS. Accuracy was 1.96" for 10 shots the way that I measured it...either way not what I was looking to do. Rooke mistake, I was not inspecting any of the brass for pressure signs and it is now mixed together with other brass that I shot today.


I then shot a 7 shot group with the 103 eld-x ammo from UM for 0.92". The average speed was screaming fast at 3055 FPS and I was happy with the accuracy I was getting. I noticed that recoil felt like it was more and started looking at some of the brass and there appeared to be ejector marks?






The ammo is expensive, so I switched to the 108 eld-m ammo from UM and shot 5 shots at 1.55". This group had two flyers that were likely me as well as two ejected primers and an average speed of 3040 FPS which to me seems like its absolutely cooking for a 20" 243 with 108gr bullets.





Based on the collective experience here, would it be worth asking UM to take it down a notch powder-wise on the TMK's, or is it more that the barrel just doesn't prefer the TMK? Also, I just brought home a brand new tikka specter 8 twist .243 today. Is it worth trying this ammo to see if it works in that individual rifle?

Also, on the pressure stuff in general, I have full confidence UM will work with me to find out the right answers. This was the "factory load" so I am surpised it was so spicy.

 

[Matt5266]

O ya that brass is showing some pressure
I definitely wouldn't shoot anymore of that. Id have your barrel inspected by a competent gun smith. Something might be off with your barrel. You know the load details they used? Is the bolt hard to close when clambering a round?

 

[walkingduckwaterfowl]

O ya that brass is showing some pressure
I definitely wouldn't shoot anymore of that. Id have your barrel inspected by a competent gun smith. Something might be off with your barrel. You know the load details they used? Is the bolt hard to close when clambering a round?

Rifle took it like a champ without heavy bolt lift. It hammers with almost every factory offering I have shot with it including cheap fiocchi 95gr sst that I used to get on paper today. Here is a photo of the load cards from UM. It doesn't show grains of powder or anything so probably not that helpful.

 

[blacktailcentral]

#notwalmartsafe

 

[mtnbound]

Took me a minute to see, but it’s written on the last line of his info. Yes 6CM

If you stare at my writing long enough it will make sense or at least that’s what I do when I’m trying to read it.

 

[huntsd]

#notwalmartsafe

How much powder did they put behind the tmks? Seems like those are cooking out of a 20”.