AR Loading
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HTSmith
Silver $$ Contributor
I do not crimp and would not recommend crimping non-cannalured (sp?) bullets. My sizing die gives a good grip and I've not had any problems with bullets moving. Just one feller's experience.
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danny
Silver $$ Contributor
I have never crimped bullets for an AR, M1 or M1A/M14 and don't know of anyone that has.
Danny
Nope I use a cheap Lee fl die and like most of them they size the neck down so much I don't need to crimp. This sucks with bolt and other rifles but works good for a ar plateform.
I thought you crimp on canalure bullets of course not non canalure bullets but to keep the bullet secure from being moved by the violent action of the gun chambering a round?? As you can see many don't and many say it adversely effects accuracy. You will find most factory crimped and I apply a light crimp around the canalure.
Now getting the bullet seated to exactly the right length every time so the canalure is in the proper place to be crimped... Thats the problem..lol
When I set it up on one the next one is different.. Theres a ton of threads on why.. If your loading normal 55gr bullets by a manual you are under magazine length which means you should be way away from the lands of the barrel.
Now getting the bullet seated to exactly the right length every time so the canalure is in the proper place to be crimped... Thats the problem..lol
When I set it up on one the next one is different.. Theres a ton of threads on why.. If your loading normal 55gr bullets by a manual you are under magazine length which means you should be way away from the lands of the barrel.
Man my rcbs small base dies do the same thing..
I couldn't ever any kind of accuracy with my 243 die. I noticed how hard bullets were to seat so I checked and sure enough they were way to small. My bullet was acting as a expander.
When I bulk load for 3gun, I will trim and crimp my cannalured 55FMJ. For non cannalured, I go with the tight neck like the others here.
jepp2
Gold $$ Contributor
As others have mentioned, if you run enough neck tension (about 0.002") the bullet will not move during the chambering action. But my brass and practices might be different than yours.
Know you OAL of the next to last round added to the magazine. Fire the top round, and remove the chambered round and measure. If the OAL changed (and it can shorten or lengthen), then you don't have enough neck tension. Also measure the OD of your brass necks after sizing, and again after seating the bullet. This will define how much neck tension you are running.
As brass work hardens from subsequent firing and sizing, you will get more spring back, and the OD of the sized neck will be larger. You neck tension will decrease.
Improper crimping can degrade accuracy. So if you decide to crimp, do it correctly. I am including a picture showing a light crimp.
Know you OAL of the next to last round added to the magazine. Fire the top round, and remove the chambered round and measure. If the OAL changed (and it can shorten or lengthen), then you don't have enough neck tension. Also measure the OD of your brass necks after sizing, and again after seating the bullet. This will define how much neck tension you are running.
As brass work hardens from subsequent firing and sizing, you will get more spring back, and the OD of the sized neck will be larger. You neck tension will decrease.
Improper crimping can degrade accuracy. So if you decide to crimp, do it correctly. I am including a picture showing a light crimp.
You're going to be FL sizing for semi-auto. IF your bullet seating die will roll crimp and IF your rifle groups well with a bullet seating depth that allows you to take advantage of the cannelure, you may consider using the roll crimp from your seating die, even if it's slightly crimped. Doesn't take much to make that crimp.
None of the bullets I use have cannelures. I may use my Lee Factory Crimp Die for some applications.
Mulligan
Silver $$ Contributor
Brian,
The only .223 I have experience with are my Son's AR's used for service rifle/high power compition....both WOA 7 twist for the heavies. I've loaded pails full of 77 gr SMK....no crimp no worries. Lots of fantastic scores. Both Forester Bonanza micrometer match and RCBS micrometer match dies worked great.
CW
I thought it was just me.. Some bullets slide in and some pop in. I know that's not right. Maybe I should call rcbs?
My ar as with most have way more free bore than mag coal will allow anyhow. So that should not be a problem.
Thats why many of us use dies such as the redding full length bushing dies... you want to be able to control your necks to the neck tension you want.
On another note fl resize for an AR everytime. Annealing helps alot too. Good Case prep is paramount with an AR for consistancy
How are you sizing them and what die are you using?
jepp2
Gold $$ Contributor
This check doesn't have anything to do with mag coal length. It is a check to see if your bullet is moving during the violent chambering action. Bullets can move backwards (shorter OAL) if the force of hitting the feedramps drives them into the case, or they can move forward (longer OAL) if the inertia hammer effect of them stopping suddenly allows the bullet to shift forward. I have seen both happen.
That is a very good crimp. Which die did you use to do it?
Ok I see what you mean. I thought you were saying it was running into the lands.
I also agree with you that a improper crimp is bad for accuracy. When I first tried crimping I over did it and accuracy went south. Now I just don't do it at all even on my ar and hunting rounds.
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