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300 Blackout reloading questions?
I finally pulled the trigger and bought a 300 Blackout upper and i'm in the process of building some reloads. My questions for those of you that load for this are the following.
1 Is case life about the same as 5.56 NATO? If not shorter or longer?
2 How many loadings do you get between having to trim cases?
I'm loading once fired Lake City 5.56 brass
I forgot to mention i'll be loading supersonic rounds with 150 gr FMJBT over H110 powder and CCI 400 primers
Good info J.c. thank you. I never even thought about a pad on the shell deflector to prevent dents on the shorter blackout cases. I'm going to work up some loads starting at 15 grs. Two of the manuals I have list 16.2 grs as max loads but online i've seen data with 17 grs. I don't need max velocity for plinking rounds. As long as they cycle properly i'm happy.
2 個解答
- J. cLv 46 年前最愛解答
If you're using converted 5.56 LC brass, you'll need to anneal before shooting since the annealed portion on 5.56 is mostly removed in trimming, but other than that it will last as long as any other rifle caliber of similar design and loading.
As always, as I'm sure you know, individual chamber dimensions and reloading details such as over sizing and loading hot loads, will affect brass life more than the design of the caliber. Semi-autos, and especially over gassed semi-autos, will shorten brass life by beating up the case rim. A stick on cushion on your AR brass deflector will help keep from denting brass as badly.
Don't over swage or over trim the primer pockets of the 5.56 brass, and they should last at least 10-20 loadings or more if you don't oversize them and anneal every 2-3 loads. You can try going longer between annealings, and if you get too many split cases, anneal more often.
The load you chose is an average plinking load. Watch for pressure signs above 16 grains of H110. LC 5.56mm brass usually has a slightly larger capacity than most commercial brass, so you can sometimes squeeze a little more powder in it, as some people have loaded them up to 17 or 18 grains with no over-pressure signs, but start checking at around 16 grain. Work up carefully.
- 6 年前
Haven't fire the round but based on it's design I'd wager case life will be similar to that of the .223/5.56 in a semi-auto rifle. There will be others with much more experience with that round who can be more exact with their info.
