I greatly appreciate all of your input. Im going to go over to Sportsmans at lunch and pick up a small base die. If that doesnt work I will pull 5 bullets and add a grain of powder.

Will get back to you guys next week end.

DHC, I was throwing each load out of a the powder dispenser. I did not weigh each load separately.

Slim, rounds are not crimped. I may also run a few rounds using imr 4895.

I'm thinking my problem is solved with a low base die, my buddy ran ten rounds through his winchester sx-ar with no problems. The M1A reloading article by Glen Zediker also pointed out that a low base is needed.

Thanks again. I'll follow up this week end.

I greatly appreciate all of your input. Im going to go over to Sportsmans at lunch and pick up a small base die. If that doesnt work I will pull 5 bullets and add a grain of powder.

Will get back to you guys next week end.

DHC, I was throwing each load out of a the powder dispenser. I did not weigh each load separately.

Slim, rounds are not crimped. I may also run a few rounds using imr 4895.

I'm thinking my problem is solved with a low base die, my buddy ran ten rounds through his winchester sx-ar with no problems. The M1A reloading article by Glen Zediker also pointed out that a low base is needed.

Thanks again. I'll follow up this week end.

Geland My extractor does leaves marks on the brass. Action of rifle is pretty brutal on the brass. But then again, I have no problems with store bought ammo.

Rich916 wrote:

Geland My extractor does leaves marks on the brass. Action of rifle is pretty brutal on the brass. But then again, I have no problems with store bought ammo.

Okay, does the extractor claw left marks on the factory ammo the same as the reloads?

Geland. Yes. It leaves the same marks on the factory ammo. I picked up an RCBS small base die at lunch. Got lucky, it was the last one they had. I'm also greatful I stocked up on about 15 diferent powders before the latest Obama panic that cleared all the shelves.

hmmm sounds interesting. I dont own a semi but have read somewhere of the problems they had with the M16 when it went into use because of the ball?? powder being used had a different burning rate to what was needed to make then function properly. maybe some thing along those lines..??
weird that factory is ok and your reloads arent. if you have acess to someone elses reloading gear do the same load through thier dies and see what happens.

All gas operated guns are designed to operate with a certain pressure curve, which is why they can be sensitive to types of powder.

Also, don't crimp.

Ok, I didn't do all this stuttering. I remember this happening once before may 18 months ago. Not sure why, this is a different computer.

Ok, the consensus is seems to favor changing powder loads.

Slim:
I don't load for semi rifles but I expect that day is coming. Your advise not to crimp perked my interest. Since I have only fired military or police semi's I have always used service ammo. Without exception it was all crimped. Even the 9mm was taper crimped. How does not crimping contribute to better cycling?

MacD, I also do crimp rounds for a semi-auto. If not, there is a big risc that the bullet would move into the barrel before you hit the primer and I don't like my bullet touching the rifling without me wanting it. Also when you don't fire such a round and try to unload the rifle, all powder is spread in the mechanism... and I don't like unburned powder surrounding my round when I fire it...

So for me: co crimp for a semi-auto because the bolt has usualy such a speed that it acts as an inert hammer.

But SJ could have better reason to not crimp...

If your going to crimp for a semi auto, you should have bullets with cannelures and your seating depth must be only at the point where the crimp locks into the cannelure.

I mistakenly tried crimping with bullets that didn't have a cannelure or seated where the neck didn't reach the cannelure (against Reddings recommendation). I can't locate my topic about it but I had issues with rounds not chambering in my six8 AR. When I stopped crimping, the rounds started chambering without issue. I think since my crimp didn't have anywhere to go, it was distorting the neck.

I also make sure I have enough neck tension to hold the bullet. I've even measured rounds after chambering to ensure COAL wasn't changing.

Anyway, if you have a semi-auto that is not chambering reliably with reloads, I would try not crimping and seeing if that helps.

Strange. I use the Lee factory crimp, also on bullets without a cannelure with no problems at all. I even noticed once that I pushed rather deep markings in a czech bullet without cannelure. I think that's not so good for accuracy.

Maybe there's a big difference in a semi-auto in a small caliber compared to one with .308 bullets.

There are two types of crimping dies, roll crimp and tapered crimp. Plus some dies (like mine) have the crimping feature built into the bullet seating die as the last part of the stroke instead of a dedicated die like yours. These can all be factors in why one may be and issue and another not.