Sierra 107 TMK

[HuntTXhogs]

https://www.midsouthshooterssupply.com/item/000077407c/6halfmm-point264-diameter-107-grain-hollow-point-boat-tail-tmk-rifle-bullets-500-count

[Commander184]

[BluntForceTrauma]

HTXH, thanks much! But I'm too dang cheap. Midsouth wants $33.52/100. Cool. Shipping $11.87. Uh, maybe I'll wait until I combine a bunch of stuff. . . .

[bj139]

NR

[StoneHendge]

HTXH, thanks much! But I'm too dang cheap. Midsouth wants $33.52/100. Cool. Shipping $11.87. Uh, maybe I'll wait until I combine a bunch of stuff. . . .

Or when they do free or flat rate shipping!

[HowaGrendel]

HTXH, thanks much! But I'm too dang cheap. Midsouth wants $33.52/100. Cool. Shipping $11.87. Uh, maybe I'll wait until I combine a bunch of stuff. . . .

It's only money, keep it in circulation......lol

[Niles Coyote]

This just arrived...


Velocity testing 107 loaded to 2.258, this leaves them jumping .097" in my JP's chamber. 18" barrel, rifle gas.

[BluntForceTrauma]

NC, you win! First of the Horde to get these and test them!

Thanks for report.

How much of bearing surface or shank is out of the case mouth when loaded to 2.258? Trying to get an idea of nose length, bearing surface length, boattail length, overall length.

[thedudeabides]

Why do all the ones but for the far right in the picture appear to have flattened primers? Is that something with the CCI 400s having a thinner cup?

[xlcc]

I am curious as to why your case heads look black.Is it the photo or a feature of a gas gun?Your primers look like they are starting to flatten as well.How is the accuracy on your trials?
Those bullets certainly look like they'll do the job.Lucky you to receive a new product so quickly.

[Niles Coyote]

How much of bearing surface or shank is out of the case mouth when loaded to 2.258? Trying to get an idea of nose length, bearing surface length, boattail length, overall length.

Hope this helps. Its hard to get a measurement.


thedudeabides,
I think that is due to the lighting and angle of the picture, when I looked each one over with my magnifying glass they all appear to be the same. Some as noted below also have more black residue on them than others causing them to appear different too.

xlcc,
These cases have been fired a few times and because of that I used a black marker on the case head and primer (primer just cause it was there and in the way) so that way I would be able to see any new pressure signs. The primers all still have a good radius on them and are not flattened. For 28.9 & 29.2 I did see the beginnings of ejector marks, though I could likely delay those a bit by changing my gas setting, buffer weights and/or spring weight. I am using a first gen JP SCS while using the standard weight spring (black IIRC).

Also, this was strictly a velocity test watching the velocity curve, pressure and extreme spread. Shots were fired in my bullet trap, not at paper. Think of it as a different way to get the same results as an OCW. There are two likely nodes, the wider one between 28.0-28.3 (which probably will start around 27.8) and 28.9-29.2, the top one had me crushing into the powder a bit so I am going to try out the lower one first.

If things work out in the morning I will be punching some holes in paper with 27.8-28.4 in .2 grain steps. I've also loaded some extra at 28.1 to see where the BC falls at distant steel targets.

[Niles Coyote]

BluntForceTrauma, also I meant to add, my length to the lands with these are .057" longer in OAL compared to the 107 SMK, so these have a longer nose

[jackwagon]

Niles coyote , judging by your username/ location its nice to see another Grendel fan in the Michiana area.

[HuntTXhogs]

Evening all -

I loaded up some of these tonight with 1 grain less than max charge of TAC.

Took some measurements:

Bullet in a cutaway case to obtain distance to lands: 2.3985”

Subtract magazine length 2.260” which would indicate a jump of .1385”

The bullet itself is 1.2050” in length and .2635” in diameter

Using light behind the bullet I was able to trace over the part is the bullet that is ~ .2635” in diameter





Here is the bullet seated to mag length , the neck is properly positioned over the marked bearing surface



Here is an idea of case fill for an estimated load at 2630 FPS



I’m getting a Magnetospeed for Christmas so I’ll get velocities sometime over the next couple of weeks

[BluntForceTrauma]

Cool info, HTXH! I think I'm gonna like this bullet.

Although I wish they'd make them dead on 0.264. Bullet makers finesse their specs to account for out-of-spec barrels. Barrel makers finesse the specs of their bores to account for out-of-spec bullets. Round and round we go. Just make stuff to spec!