77gr TMK vs SMK question

[SilencedShooter11B]

I fully intend to verify this hopefully in the next few days on the range but while I was mulling it over I thought I’d see if anyone had a similar experience or input.

I was breaking in my 20” stainless 1:7 proof barrel (AR15) and found a Varget load that shot very well with both 77gr SMKs and TMKs at 100yds doing confirmation testing, and both had the same POI with said powder charge: 24.3gr Varget, CCI BR4, new LC cases, no crimping, temps were in the 80s. No pressure signs except maybe the slightest bit of primer flattening but nothing else of note. Velocities after 50rds averaged 2698fps and I was in the low teens with my SDs. I’ve since refined my reloading process to help with consistency.

Now my question: given the near identical performance at 100yds, would the two bullets using the same load and primer etc be fairly close when it comes to the dope say out to 600yds or so? I am going to test this out in a few days and see, and it may come down to the TMKs bucking the wind better than then SMKs. Or do you think past a certain distance there will start to be a noticeable difference in the two? I know actually hitting the range and finding out is the only real solution but until then I thought I’d ask the experts.
Thanks guys

 

[Skg_Mre_Lght]

In Wyoming wind, I notice around 1/10 mil or two difference between the two past 400.

 

[Chickentoast]

^Agree, a couple 10ths at 460 and half a mil at 940. 75 eld-m equivalent to TMK, and 80 eld-m noticeably better.

 

[SilencedShooter11B]

^Agree, a couple 10ths at 460 and half a mil at 940. 75 eld-m equivalent to TMK, and 80 eld-m noticeably better.

might be able to get away with the 75 ELDs in my gasser but the 80ELDs are gonna be way too long for mag/case length. I’ve got a fair bit of them for my Valkyrie and they’re running really well in it

I’ve got a good bit of 73 &75 ELDs but that’ll be testing for another day

Only have time to see what these 77TMKs do out to 400-600 compared to my current SMK load

 

[Chickentoast]

I also couldn't use the same load for SMK and TMK - TMK was much more finicky. Nice that you can.

 

[AManWearingAHat]

I think the TMK's have a slight bump in BC over the SMKs so I would expect a little difference in dope as the ranges stretch out.

 

[Doom]

You can answer your question by running both bullets in a ballistics calculator.

 

[SilencedShooter11B]

You can answer your question by running both bullets in a ballistics calculator.

the BC calc data for the TMK on-paper info more closely resemble real life dope ive gathered with the 77gr SMKs. This is using Hornady and Federal calculators. I don’t have a purchased app calculator that’s possibly more accurate

the only question that is answered by running the data is potential and it seems pretty far off

 

[Skg_Mre_Lght]

I also couldn't use the same load for SMK and TMK - TMK was much more finicky. Nice that you can.

My precision ARs shoot both equally as well with 23.2gr XBR 8208, Remington 7.5 in prepped LC cases. Both are absolutely lights out, and the TMK makes a great Antelope/Whitetail bullet out to 400 yards out of 5.56.

 

[Doom]

Agreed that the results of the calculations are potential. In this case the potential should be pretty accurate if you use JBM.

JBM is probably the most accurate Bal Calc you can use for free. If you run the two cases in JBM it will give you the predicted difference in drop due to Sierra’s data using the segmented BC data. Now, your actual DOPE will likely very some as the BC actually very between lots of the same bullets and possible errors in the measured velocity.

I ran the two bullets at 59F, 600 ft elevation and Sierra’s data looks like the TMK has about an 8.5” advantage at 600yds. Since both bullets are from Sierra the likelihood is that the actual performance will be comparable to predicted.

If we were trying to compare the TMK to a ELD-M then the comparison becomes more suspect due to differences in the testing of the bullets.

 

[sprad05]

Always seemed to have issues getting TMKs to group well