Sierra 107 TMK

[ricsmall]

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!

What fun would that be John?! ��

[HuntTXhogs]

I was getting inconsistent seating depth using brand new Hornady dies so I pulled the seating stem out and measured the depth and it was very close to bottoming out on the bullet tip

So.....

I drilled it deeper and FLITZ polished it using a TmK sacrificial bullet and now I shouldn’t see so much variance in seating since them stem now contacts only the ogive

[Effenpig]

I had already drilled one of my stems for use with the Amax so I'm using that

I've done the trick with a bullet and polishing compound to get "customize" a seating stem. I've never actually heard of anyone else doing it like that before now, I thought I was the only one

[Cornbread]

I allways measure bullets across the bearing surface not along it. Curious to see if you measured across what you would get. I have never measured a 6.5 bullet that didn't measure .264.

[HuntTXhogs]

I allways measure bullets across the bearing surface not along it. Curious to see if you measured across what you would get. I have never measured a 6.5 bullet that didn't measure .264.

[HuntTXhogs]

I’m having a hard time seating these 107 TMK consistently using a brand new Hornady seating die with the seating plug opened up for the longer tip.

I am seeing variance in bullet lengths by .008”




Which after seating can attribute to wildly varying COAL , some by .015”




I marked where the seating plug is engaging the Ogive and it doesn’t appear to be different on the two rounds loaded above

Recommendations ???

Can anybody else confirm the same

[HuntTXhogs]

[Sticks]

Is your COAL based on the ogive the same?

[Kilco]

I've ran into the same problem with 5.56 and 308 using the Hornady seating dies. Switched to a Redding and the problem went away.

I really don't know why Hornady seater exhibit this problem, but anytime I'm dealing with compressed loads I always get a COAL variance when using Hornady

[HuntTXhogs]

Is your COAL based on the ogive the same?

[HuntTXhogs]

So I bit and I bit hard...

LE Wilson chamber seating die with VLD seating stem AND a K&M arbor press have been ordered.

I’ll report back on whether this helps with seating these bullets with better consistency and I’ll spend the days waiting looking for my comparator gauge...

[HuntTXhogs]

Here is a 10 shot group, seated and bagged, at 100 yards with the Hornady seating die that was used to seat them all by COAL.

Charge was 29.5 grains of TAC, no pressure signs



I can’t record velocities , no chrono

[Niles Coyote]

Got out today, groups were okay but not great.


Dots are 1"... going to explore some slightly lower charges and 28.6 next. If that does do it I'll try 8208.

[bfk4lyfe]

8208 XBR data from today, about 48 degrees, sea level, attempted seating at 2.258, but like HuntTXhogs said it wasn't too consistent, LaRue 18" upper, 1x Hornady brass, Rem 7.5 primers:

28.5: 2578, SD 26
28.8: 2611, SD 14.5
29.1: 2639, SD 12.3
29.4: 2653, SD 8.7
29.7: 2663, SD 10.4

Unfortunately groups, or lack there of, were not worth mentioning. They were patterns at best until 29.4 where I had a slightly less than 1" group and 29.7 was around 1.75. Minor ejector marks at 29.4, but nothing crazy, 29.7 definitely had some. I would take pix but unfortunately I dropped the box and the spent casings got all jumbled up.

Any suggestions on where to go from here? 29.4 and play with seating depth..orrrr? I'm new to this reloading thing.

[grayfox]

You could confirm the node with 29.2, 29.4, 29.6 sets. The if SD's keep in single digits I'd take the 29.4 and, depending on how much freebore you have, 2.250, 2.260 and 2.270 for optimum coal... 29.4, 2650ish and 18" barrel seems to be right in a node-range combo I would expect personally.