Overall length question

[surfish95747]

Okay, I've been loading my 5.56 rounds using Xtreme bullets 55 grain bullets with Accurate 2015 22.3 grns seated to 2.2 overall length. My question is, the cannelure on the bullet is fully covered at 2.2 inches overall length. Someone once told me the bullet should be seated so that the case mouth is half way covering the cannelure? What is correct? Does it matter? This load works, accurate, easy to shoot, so I'm not terribly worried. Just curious. Thanks guys.

[T2C]

Unless you are firing a select fire carbine, I would not get too caught up with the cannelure on a reload. The cannelure is used in conjunction with the crimp and helps prevent bullet set back on a semi-automatic or automatic rifle during the recoil sequence. It is normally covered by the case mouth.

I would be more concerned about function and accuracy than the location of the cannelure. The last 5,000 Hornady .30 caliber bullets I purchased had an exposed cannelure when I loaded for optimum C.O.L. for my M1 Garands and it did not affect function or accuracy. Ignore the cannelure and set your C.O.L. for optimum function and accuracy.

[markm]

I set the seating depth to match the cannalure position assuming it also nets an OAL that is mag friendly. (in other words, not too long) The cannalure can be ignored as long as you don't have a "heavy" crimp that's squeezing the bullet. I put a light factory crimp on all my .223 rounds, OTM without cannalures and Ball blaster 62 gr fmj.

[B52U]

I set the seating depth to match the cannalure position assuming it also nets an OAL that is mag friendly. (in other words, not too long) The cannalure can be ignored as long as you don't have a "heavy" crimp that's squeezing the bullet. I put a light factory crimp on all my .223 rounds, OTM without cannalures and Ball blaster 62 gr fmj.

Mark what is your favorite TAC recipe for 62gr fmj? I have been developing a load with the new 62gr hornady fmjbt with CFE223 to get rid of it (too slow burning and carbon fouling for my tastes) and want to switch to TAC for 62gr.

[markm]

Mark what is your favorite TAC recipe for 62gr fmj? I have been developing a load with the new 62gr hornady fmjbt with CFE223 to get rid of it (too slow burning and carbon fouling for my tastes) and want to switch to TAC for 62gr.

I've never combined TAC and 62s. Although I'd probably just run the old 24.5 gr that made 55 gr shoot good for blasting. There was plenty of room for top end pressure with that load... enough to sub in a 62 gr without any worries.

[B52U]

I've never combined TAC and 62s. Although I'd probably just run the old 24.5 gr that made 55 gr shoot good for blasting. There was plenty of room for top end pressure with that load... enough to sub in a 62 gr without any worries.

Right on, and good point about the 24.5 55gr load, that recipe worked great for me.

[HomeGrownSPR223]

Hello all new to m4 carbine


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[surfish95747]

Thanks everybody.

[Bret]

Someone once told me the bullet should be seated so that the case mouth is half way covering the cannelure? What is correct?

If you are going to crimp, then you should typically have the case mouth covering most of the cannelure. There are basically two types of crimps for bottle necked rifle cartridges. The most common is a roll crimp. It's the middle one in the picture below. The key to having good consistent roll crimps is making sure that all of your cases are trimmed to the same length. The other type which is generally seen on military type FMJ ammunition is called a factory crimp. It's the right one in the picture below. The factory crimp is pressed in from the side as opposed to being rolled in to the cannelure. It's not as important to have the same length cases when using a factory crimp. When setting up for a factory crimp, find a longer case in the batch and seat the bullet until almost the entire cannelure is covered.


As has been pointed out, you don't need to crimp just because a cannelure is there. I like to when loading FMJ bullets just for the fun of it. If you decide to do a roll crimp, your seating die will generally have the ability to do this. However, I would recommend first seating only and then setting up the die to roll crimp only. Trying to do both at once makes it difficult to get things exactly right. If you decide to do a factory crimp, I'd recommend the Lee FCD for bottle necked rifle cartridges. It does a great job.

BTW, please don't take my recommendation of the Lee FCD for bottle necked rifle cartridges as a recommendation of the Lee FCD for straight walled pistol cartridges. The latter is wholly unnecessary for proper reloading and is a cover for poor reloading practices (in my opinion ). But that's a topic for another discussion.

[markm]

BTW, please don't take my recommendation of the Lee FCD for bottle necked rifle cartridges as a recommendation of the Lee FCD for straight walled pistol cartridges. The latter is wholly unnecessary for proper reloading and is a cover for poor reloading practices (in my opinion ). But that's a topic for another discussion.

I agree.

Back to rifle though... I keep meaning to test a taper crimp against the LEE Factory Crimp. In my set up, NO crimp vs. LEE Factory Crimp... I lost a ton of accuracy without the crimp. I think my group sizes doubled to like 1.5 moa.

I set my FCD up so it's barely visible. No where near what is pictured above. But I still want to see what a taper crimp would do.