.223/5.56

[Thumper1991]

Recently got a couple ar15s. Never reloaded for one. I initially took the approach as if reloading for an handgun. crimping the rounds. My die is a roll crimp. So being kinda lazy I didn't want to trim anything less than 1.760. This obviously results in crimp issues. Looking around town for either an t/c or an lee factory crimp. Most of the shops are saying crimping for an ar isn't required. Any one thoughts on this please. Right now I'm just trimming 1000 rounds. Because I can't find the dies. I'll order one but thoughts on a good crimping die would also be appreciated.
Thanks

 

[sourdough44]

When reloading for a semi-auto proper case resizing is of utmost importance, that's one important issue. With a bolt gun it's easy to 'feel' when a round isn't chambering correctly. On a semi that round can easily get stuck as it's almost chambered. That can ruin your day if out & about.

I don't like absolutes with the crimp or no crimp debate. You do need good bullet tension to avoid any setback. Much/most of the time, normal bullet-to-case fit is enough, no special crimp. I have some 30cal 147 FMJ military bullets that are a bit loose in many cases. I've loaded some of these in 30-06 & 300WSM cases. I did give them a touch of crimp to hold them tight.

One can open a can of worms with talk about the Lee 'factory crimp die'. Yes, most any seating die can be adjusted to provide crimp. The Lee FCD does it as a separate step and is more forgiving with variations in case length. The Lee FCD is also infinitely adjustable, you can adjust it so you add little to almost no crimp. When I feel the need to crimp, I like to do it as an additional step. There are many tools for reloading one may find useful and the next guy will pass.

Read up on your prospective reloading project. Only load up a smaller amount until you test the loads. Always cross check your data from several sources.

 

[Kennibear]

Before I sold them to move to WA I loaded for a couple of M16's and a MSR (still have the MSR). Use a small base sizing die every time. I switched to a Lee FC and have never looked back. If I feel the need, I buy a Lee FC in that caliber but I should point out I do not crimp unless absolutely needed. The Lee will crimp too short and too long cases with the same setting. They can be set to just turn back the neck into an un-cannelured bullet removing any case flare.

Just remember that the MRS's ram the ammo into a feed ramp pretty aggressively and that will jam a bullet back into the case. That can raise pressure a bunch! Although I shot DCM matches with smooth sided 69gr Sierra MK's I load cannelured bullets if they are available in the style I want. Nosler especially runs batches of their bullets with a crimping cannelure.

I trim to 1.752" as the Lee trimmer setup cuts that length. It takes about four reloads before the cases need to be re-trimmed. I find H322 about ideal for any bullet under 60 grains and even the 55gr FMJBT bullets shoot well past 500 meters.

Enjoy your MSR's.

KB