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Senior Member
That neck/mandrel/whatever is DEFINITELY the way to set neck tension in my opinion.Originally Posted by MarshallDodge
I think I tested my Dillon crimp die too. That may have been a different test... I was looking for pressure/velocity variances. For me no measurable differences in velocity were found with or without any kind of crimp.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
Senior Member
Double-post
Last edited by MegademiC; 04-02-22 at 23:27.
Senior Member
Ok, so I got a chrono and got out finally.
2.25"-ish COAL
24.2 gr TAC
77g CC
light/med crimp
2600fps out of a 14.5" CL
I loaded up some 24.4gr to try again later. I'm seeing some light ejector swipes so I may switch powders.
I may try H322 and XBR.
Edit: I just realized I'm comparing my 14.5" barrel to 18" velocities.
I have some 24.4s ready to try, hoping to get to 2650 but it seems Im around 556 pressure now so I wont be going any hotter past the 24.4gr.
Last edited by MegademiC; 04-03-22 at 13:01.
Senior Member
TAC is a touch on the slow side. H322 and 8208XBR may not give you better velocities but they may help with the bolt swipe issue.
"The sword is more important than the shield, and skill is more important than either. The final weapon is the brain. All else is supplemental." John Steinbeck
Senior Member
I have no reference point for the velocities out of a 14.5. I shoot a ton of 14.5, but we chrono everything on a 20" barrel for comparability.
And, yes. TAC is slower, so theoretically it will perform best in a longer barrel so you get more burn.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
Member
Velocity seems about right with 24.2 TAC load and a 14.5". The same load out of my 16" CL is around 2630-2650 depending on the lot of TAC. Definitely whacks steel harder than the 55 or 62gr plinker loads I use!
Member
IMR 8208 @ 23.8
77 MK
CCI 41 primer in LC brass
2750 fps in 18” MK 12
Very Accurate load
Crimp with Lee Factory Crimp Die
COAL: 2.246”
IMR 8208 powder of choice for Aussie Def Force MK262 Ammo with 77MK.
Last edited by RedTeam98; 04-08-22 at 21:46.
Senior Member
Interesting. I never heard of anyone using 8208 with 77s outside of us here.
And your 23.8 gr was our original formula, but it blew primers when I changes powder lots. Next time I can get at least 8 pounds of it, I'm going to calibrate it to that lot.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
Senior Member
I had a similar issue, that load trashed primer pockets. I have turned my load down to 23.1, and see better SD numbers.
"The sword is more important than the shield, and skill is more important than either. The final weapon is the brain. All else is supplemental." John Steinbeck
Member
The 23.8 load of 8208 duplicates the 2750 fps
I have settled on 23.3 that is accurate and still very close to my Leupold 2.5x8 Mark 4 scope dope.
I started with TAC years ago when Black Hills started production of the MK262. I noticed TAC likes it hot close to max.
Black Hills uses a variant of TAC but the burn rate is very very close to TAC. I used TAC until 8208 was introduced to the public. IMR 8208 is gaining ground among Match shooters And I consider it the best for heavier bullets in the 5.56 for me.
I have noticed in my MK12 that it leaves a black sut film in the bore just like TAC I believe this is part of anti copper additives to the powder.
I am glad ADI decided to bring the 8208 back to the market after a 55 years of absence.
Last edited by RedTeam98; 04-09-22 at 10:33.
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