Failure to Feed Question

[Erik]

Hi, you guys have been so helpful in my quest to reload 7.62x39, and using cast bullets no less. I have just one more question (hopefully).

I have successfully loaded 7.62x39 cases with 155 grain lead bullets using 14.5 and 15.0 grains of Alliant 2400. I get reasonable accuracy with both loadings. Unfortunately, about one in three rounds failed to feed properly. Usually, they are getting caught about 3/4 of the way into the chamber. Twice, however, the rounds failed to clear the magazine.

Is this likely the result of me not crimping quite enough? If not, what is the most likely cause? It's really bothering me, because reliability is really important to me.

I also noticed the recoil on the reloaded rounds is about half the recoil with Wolf factory rounds. Is that to be expected?

Thanks so much for all of the help you've generously given me so far. I am fairly new to reloading.

[anachronism]

That's about a .357 mag level load, in a larger case, so I suppose it is pretty mild. As for the feeding issue, it could also be a sign that the rifle needs the bullets seated to a different overall length.

[Erik]

The length I seat to is 2.11 inches OAL. Do you think that's too short? Could it be a crimp issue?

[BillDan]

Sounds like the action is short-cycling due to low power loads. Switch to a slower powder and start at the minimum load to see if cycles the action reliably. Reduced cast bullet loads in auto-loaders just have problems with stock springs and gas ports.

[Maven]

Erik, I used the LBT version of the Lee bullet with essentially the same amount of #2400 as you and never had a feeding problem from my SKS. First, you may want to inspect the gas piston and then fill its grooves with white lithium grease for less friction between it and the gas tube. while you're at it, coat its face too. Second, make up some dummy rounds (NO powder & NO primer) and partially seat a CB in each. Put one in the follower and let the bolt chamber and seat the CB. Do the same with the others in order to establish the overall length for that CB in your rifle. Next time you reload, try making 1/2 your rounds (at the new OAL) without a crimp v. 1/2 with a crimp to see if they feed differently. Btw, I never crimp my CB rifle loads including those for a semi-auto rifle. Is there something I'm missing?

[ETG]

You never said what kind of rifle it is. I am assuming that wolf ammo cycles reliably in your gun. The first thing I would do is load a mag with alternating cast and wolf (top round being wolf). If the cast feed reliably and the wolf fails to feed you have your answer without looking any further - short cycle because of low pressure. That is what it sounds like.

[Junior1942]

You never said what kind of rifle it is. I am assuming that wolf ammo cycles reliably in your gun. The first thing I would do is load a mag with alternating cast and wolf (top round being wolf). If the cast feed reliably and the wolf fails to feed you have your answer without looking any further - short cycle because of low pressure. That is what it sounds like.The man is a genius. . . .

[Sprue]

Sounds like the action is short-cycling due to low power loads. Switch to a slower powder and start at the minimum load to see if cycles the action reliably. Reduced cast bullet loads in auto-loaders just have problems with stock springs and gas ports.

My thought as well.

[Maven]

I believe Erik mentioned in another thread that he had an AK-47.

[truckmsl]

Erik,

I load a 135 grain spitzer bullet in an ak with an overall length of 2.05 inches and experience no feeding problems. Remove the gas tube and clean the gas port. Check your scale with check weights, if that load feels that weak, you may not really have 15 grains in there. My AK feels pretty strong with 15 grains of 2400; not full power, but still plenty strong. Take your mag apart and clean it - mine was hanging when dirty. As far as crimping goes, my experience with my boolit is that a crimp is necessary - there is just not a lot to hang onto that boolit considering the short case neck and large lube groove. I use a .311 expander with a .314 boolit but the "push test" tells me I need a crimp. If someone can suggest a way to safely avoid the crimp in an autoloader I'd love to hear it, since ak brass has become spendy.

[MtGun44]

Crimping an autoloader is pretty much a key requirement. Sometimes with enough
case neck tension you can get away without it, so MAYBE you can polish the expander
ball a bit smaller and put a good flare on the case to prevent damaging the boolit,
but if you do you may resize the boolit in the case neck and start getting leading. Also,
if you put in much of a flare, you have to remove it at least back to straight or you will likely
have failure to chamber the last little bit.

Bill