Best Bullet Weight for 1:7 Twist?

**wingspar** · 06-04-16, 14:57

I’ve never loaded .223 before, but have decided to start loading some. I already have powder I can use from my .308 reloading and it is IMR 4895 and Varget. I have primers and dies on order. The rifle is a Colt 6920 that I’ve had for a few years. I have a ton of range ammo, but since I’ve put a scope on it and recently installed a Geissele SSA Trigger, I’d like to start reloading for those times I want some real accuracy. I’ll keep on buying cheap range ammo for plinking. I don’t plan to load large amounts, maybe 100 at a time.

What appeals to me so far, and I have not done much research on this yet, but 55 grain FMJ X-Treme bullets look tempting. 55 grain bullets are all I’ve shot with a few 62 grain M855's thrown into the mix. My groups at 100 yards with the scope at 4x are pathetic. I can do better with my .308 at 300 yards. What bullet weight is popular for accuracy out of my 1:7 twist 16-inch barrel?

**larryp** · 06-04-16, 14:59

My personal AR with 1 in 7 twist does best with bullets 69gr and up. The 55 and 62 gr usually have groups twice as large.

**fledge** · 06-04-16, 15:11

Here's reliable info on 55gr with 1:7 twist which shatters a few myths.

https://www.m4carbine.net/showthread...-Twist-Barrels

**ColtSeavers** · 06-04-16, 15:44

It's not just bullet weight, but bullet shape and construction. Then there's specific barrels/builds liking some ammo more than others...

Steer away from lightly constructed and/or lightweight bullets and you'll be fine. There's been plenty of testing done to show no derimental affects using a high twist rate barrel with light weight ullets save for those that are so lightly constructed that they rotate themselves apart in flight.

**HKGuns** · 06-04-16, 15:47

I've pretty much reached the conclusion that unless there is a specific purpose in mind, like varmit hunting, there is really no good reason for me to load anything but 77gr SMK's or TMK's with an occasional Hornady 75gr thrown in because they shoot well too. They all load to magazine length.

ETA: I4895 is a great general purpose powder, I always have it in stock and it works well on ~50-69gr bullets. If you are going to shoot heavier you will want CFE223, TAC or XBR to get decent levels of velocity.

4895 and Varget are both long-ish stick powders that can be challenging to meter. CFE is a ball that meters easy and XBR is a short stick that meters great.

**.46caliber** · 06-04-16, 16:31

Skip the Varget on .223, it's a pain due to the long grains. Never worked with IMR 4895.

Guys have gotten great results with the heavies, 69+gr HPBTs. There are plenty that report great results with the little 50s.

If I was in your shoes, I'd grab a few different heavies, load up test loads with varying charges and see what the barrel likes best.

**T2C** · 06-04-16, 17:33

I use to load with H335 for shooting High Power matches at reduced distances (200 to 300 yards max.) It worked well with Hornady 55g FMJ bullets and Winchester small rifle primers.

Attached is a group I shot this afternoon with an iron sighted 16" carbine and reloads from 2008. I shot it for reference before shooting offhand. Now that I am approaching 60 years old, my eyesight is not what it use to be. I am certain that there are a lot of people who could shoot a better group with the load.

**fedupflyer** · 06-04-16, 17:50

I am getting much better results with AR-Comp and CFE-223 with 55g Hornday.

I am hovering right around an inch at 100 yds with a Wylde chamber w/1:8.

With a mil-spec 1:7 barrel and 77 SMK using RL-15, under 1/4 inch at 100 yds, using a fixed x10 scope.