Several posters have mentioned just firing the 5.56 cartridge in a 7mm TCU firearm to form cases. My Contender just dents the primer. Is there any trick to getting 5.56 cartridges to fire in a TC 7mm TCU?
Thanks.
Several posters have mentioned just firing the 5.56 cartridge in a 7mm TCU firearm to form cases. My Contender just dents the primer. Is there any trick to getting 5.56 cartridges to fire in a TC 7mm TCU?
Thanks.
I always used 223 remington brass because the 5.56 didn't work for me. I made and reloaded about 650 rounds shooting silhouette. Even in 300 blackout I find 223 brass works better to.
kr54: No tricks required. You need to size the case until it JUST allows the action to close with a healthy snap. This keeps the case from moving forward with the firing pin and extends case life. Keep adjusting the sizing die down until you achieve the above. I fireform with a minimum published load and 140 grain bullets. I'm too lazy to anneal, so I lose some to split necks but I have thousands of donor cases so a few lost every once in a while is acceptable. There were a bunch of articles written by Bob Milek and Steve Herrett regarding the case sizing/fireforming process during their development of the .30 and .357 Herrett. Worth researching for scanned or PDF copies. I've used that process on just about every case I've reformed.
Not formed as 7mm, these are loaded 5.56 cartridges. They just won't fire. Sized primed 223's will fire the primers, but the 5.56, don't.
Could be that the hammer spring is on the light side or weak. Military cartridges generally use a harder primer to prevent slam fires. They may fire on a second attempt.
45_Colt
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |