New to 223 Flat Base Bullets

[Camper]

I suppose that we should ask; what sizing die are you using, and what's your before and after bullet seating neck diameter? Reason I ask, as I load for 222 I've found that if I have that copper ring shaved off the bullet, accuracy drops. I resolved this with chamfer depth and neck tension by acquiring a different bushing.

They say that for ARs you want 3-4 thou if neck tension; for flat based bullets, I'd argue that you'd want 2-3thou; however, I do know that loading for ARs various dies often overwork, and undersize necks of 223. I'm curious what an anneal, or a post sizing neck mandrel could do for you.

-Mac

I use an RCBS FL die.

I'm actually going to use new brass run through the FL die with my first batch of these. I haven't done any yet. I'm halfway through a batch of 200 55gr fmjbt. I just had a feeling I would not get a good fit ahead of time and wanted to get some advice on how others do it and other equipment that will help me not mess it up. lol

 

[Camper]

You shouldn't be crimping any cases. The bullets probably don't have a crimping grove. You might be distorting the bullet shape? You should always chamfer the case o.d. and i.d. You don't need a heavy bevel. Buy a Redding FL bushing die so you can control the neck diameter. Standard FL dies size the necks way to small. Like someone else said I hold the bullet on the case with my fingers till it enters the die. Been reloading for small varmint hunting groups for 50 years.

Not even the ones for my AR?

 

[mac86951]

Not even the ones for my AR?

You don't need to crimp for your AR; but it depends on what you want your ammo to do.

Typically most of us don't. There's always an odd here or there where it helped; so feel free to experiment, but for range shooting neck tension alone works great for a large portion of us. In other words, don't think that you're required to crimp just because it's your AR ammo

 

[Camper]

You don't need to crimp for your AR; but it depends on what you want your ammo to do.

Typically most of us don't. There's always an odd here or there where it helped; so feel free to experiment, but for range shooting neck tension alone works great for a large portion of us. In other words, don't think that you're required to crimp just because it's your AR ammo

Got it. I'll do some experimenting with some that are crimped and not crimped. I guess I'll have to see for myself if it's worth not crimping in the AR. I'll keep 10 uncrimped on the bottom and then measure them after I fire 20 that are.

I'm not a competition guy. I know competition guys never crimp, but till this point I was always under the impression if it's going in an AR it should be crimped to prevent crimp jump in the magazine. Believe me, I know I don't know everything. lol

 

[gunsandgunsmithing]

You shouldn't be crimping any cases. The bullets probably don't have a crimping grove. You might be distorting the bullet shape? You should always chamfer the case o.d. and i.d. You don't need a heavy bevel. Buy a Redding FL bushing die so you can control the neck diameter. Standard FL dies size the necks way to small. Like someone else said I hold the bullet on the case with my fingers till it enters the die. Been reloading for small varmint hunting groups for 50 years.

I've crimped bullets without a cannelure(sp) for a few reasons before but never when accuracy was the MAIN goal from it. I agree that it can't be good in that regard. At least not as a whole.

 

[gunsandgunsmithing]

Got it. I'll do some experimenting with some that are crimped and not crimped. I guess I'll have to see for myself if it's worth not crimping in the AR. I'll keep 10 uncrimped on the bottom and then measure them after I fire 20 that are.

I'm not a competition guy. I know competition guys never crimp, but till this point I was always under the impression if it's going in an AR it should be crimped to prevent crimp jump in the magazine. Believe me, I know I don't know everything. lol

Watch closely for bullet setback from a magazine. I agree that you probably don't need to crimp but it will reek havok on groups if they get pushed back in the mag and it can have a big effect on pressures if it moves enough.

 

[Coyotefurharvester]

I keep enough shtf ammo on hand for my AR's, all loaded with cannelured bullets,all get a light crimp. This will be used first if need arises, none of it is fmj, and all of it very accurate.

 

[CaptJim]

I had the same problem with the 62 Nosler varmint bullet. luckily I had just bought the Frankford arsenal bullet seater set, just drop a bullet onto the die and pull the Handel. Die is micro adjustable for seating depth. I believe RCBS makes a seater die with a window that you can drop a bullet into? Food for thought. E

RCBS Matchmaster

 

[Camper]

I keep enough shtf ammo on hand for my AR's, all loaded with cannelured bullets,all get a light crimp. This will be used first if need arises, none of it is fmj, and all of it very accurate.

What projectiles do you use in your ARs?

 

[Cfshooter]

I always chamfer rifle cases and the Frankford Arsenal Universal Seating Die is one of my favorite tools. The RCBS window die is tits too, but can buy multiple FA’s for same price.

 

[ebb]

69 grain SMK

 

[MisterHelix]

I'm not a competition guy. I know competition guys never crimp,

That’s often the case, but not necessarily always true. Some folks crimp their competition ammo, and some folks might even shoot issued mk262 that has a factory crimp.

 

[Camper]

Finished my first batch of 60 grain Vmax. The RCBS 223 Matchmaster seating die made life easier. Thanks to everyone for the advice on the products and additional info on working with the flat base bullets.

 

[Xerothermic]

I use the "M" dies for 9mm pistol and 6mm rifle. Both are flat based. The case necks are quickly chamfered, one twist, and I bell with the "M" die just enough to get the projectiles started by hand. Seat and finish up with enough crimp to remove the bell. Make noise.