Undersized Sierra 95 grain TMKs
#1
I really expect better from Sierra. Was loading a test set of 95 grain TMKs at 28.2 grains of Varget and neck tension was light. I used the wrong bushing sizing a fresh batch of brass, but that was only half the problem. The box of 100 bullets I paid $38 for off of Sportsman's Warehouse's shelf:

   

I can even get it to read .2420 if I push hard.

Had a few 95 grain SMKs from a year or so ago on my bench and figured I'd check if it is measurement error (a Hornady caliper afte all is the same as the made in China calipers you get in an auto parts store with $10 of red paint Smile ):

   

I cannot get it to read .2425 pushing hard. I measured 10 of each and at least they were all consistent.

I'm wondering what size the 500 I ordered from Midway will be.....
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#2
Measured some of my other 6mm bullets. Berger 105 Hybrid Targets measure .243 and don't respond to a push. Nosler 105 RDFs and 70 BTVs measure .243 and will go to .2425 with a squeeze. Note that all subject bullets that register lower with a squeeze spring back to Un measurement.
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#3
Well it looks like the real culprit I had with some neck tension issues wasn't the bullets, but some pretty wide lot to lot inconsistency from Hornady brass. I converted about 300 pieces from 2x fired 6.5G and most of that had come from factory ammo. Some of it may have been Black and some the old Amax, and probably a few different lots of each. Necking down amplifies neck brass thickness differences and random measurements were giving me .002" differential. Luckily I have 400 that I bought new and are consistent.

I did call Sierra today just to confirm how to confirm lot #s on their boxes and mentioned the undersized bullets. He said to send them back. I thanked him but said it probably wasn't worth the time and shipping for one box since I can still put them to use.
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#4
SH, thanks for reports and updates. Good stuff.
:: 6mmARC Target Cartridge with Hunting Capability :: 6.5 GRENDEL Hunting Cartridge with Target Capability :: 
:: I Drank the Water :: Revelation 21:6 ::
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#5
I had the same problems with the Sierra 95gr TMK when i first started loading them. Now i have a note that indicates to use a smaller sizing bushing for the brass when loading them.
What COAL/CBTO are you using to load the 95gr TMKs?
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#6
I tried that but the expander ball takes it right back out. I might just buy a set of ARC dies since my 6mm PPC seating die has almost no clearance loading light bullets. When the die is screwed up high enough to clear the shoulder, a have the stem pretty much bottomed out to seat 80s.

I've been seating the TMKs at a 2.26 COAL. - I just kept the same CBTO I had been using for the SMKs which were a 2.25" COAL.

Do you have a G7 you use for them? I can't find one on a Google search. The SMK's are spot on at .232 for me. I've got a competition Saturday and have no time to test but was probably going to put in .234. Probably doesn't really matter because the 600-700 yard targets are usually pretty big.
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#7
I don't use the expander ball when I resize and only use the specific bushing (depending on the Brass being used). I've been using the SAC seating die for about a month now and they are spot on. Been able to use the same seating die for the ARC, Grendel, Creedmoor, .308 Winchester and even for the .223.

are you using a ballistic calculator (Strelock Pro). I believe it might have the G7 information in it.

I tried them at 2.250 and 2.260 and my groups were bad. I've got them down to .5 MOA loading them out to 2.287.
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#8
I ordered a set of L.E. Wilson 6mm ARC bushing sizing & seating dies from Brownells. They didn't have the bushings I needed so I ordered .265" & .266" bushings from the L. E Wilson website. Depending on brand of brass, those two sizes should be sufficient. It's kinda weird Brownells has these dies but they're nowhere to be found on the Wilson site. You'll need an arbor press for the seating die.

I was already using the Wilson dies for sizing my 6.5 Grendel brass. I prefer them for match type loads but still use Hornady dies for range fodder.
The trick is growing up without growing old. -- Casey Stengal
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#9
Skyrep, I like using the expander ball because in theory, it will give the most consistent ID, especially with brass that's inconsistent. I tried sizing a bunch without it a few years ago but got pretty inconsistent results and my SDs went up so I actually ended up running the ball through the rest of that lot.

I don't use Strelock - use Shooter on my phone and go off my Kestrel when it matters.

I'm a 243 LBC btw, I try to say that whenever it matters.
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