7.62x39

[Flash]

Is there any real advantage to using cases with large primers as opposed to cases that have small primers? I am working up a cast load in a single shot and have a mixture of both so I'm wondering.

[spinafish]

I have loaded quite a few of both and have not noticed any difference!

[woodchukhntr]

I haven't noticed any difference with my CZ527

[res45]

Haven't seen any difference between the two in my cast loads I use in my SKS rifles.

[Lloyd Smale]

ive loaded both and it will change group size to switch from one to another but no differnt then switching primer maker. For me it made just to big a project out of working up loads so i got rid of all the small rifle primer brass just to standardize. I have a buddy though that swears hes had better luck with the small primer brass overall in his guns. It makes a little sense as most small rounds like that do use small primers.

[Larry Gibson]

I also have both and have found the LR cases (Win & IMI) take 1/2 - 1 gr less powder, depending on the powder, to equal the same velocity as with R-P cases using SR primers.  Probably won't notice much difference in the run of the mill AK/SKS but in a good bolt gun the difference is obvious.  I use the R-P cases in my Mini MK X bolt action and the LR cases in my SKS.  My standard load with 123-125 gr .310 - .312 bullets is with H4227; 22.5 gr in the Win/IMI cases with LR primers and 23 gr in the R-P cases with SR primers.  I prefer the Hornady & Sierra 123 gr bullets for their accuracy in both the bolt action and quality SKS's.
Larry Gibson

[SHOOTALL]

I read an article that stated that to be lead free some rounds that had large primers are now being produced with small primer pockets. They put less lead out ( note some primer compounds are now lead free and require a larger flash hole but can be loaded with conventional primers in many cases  ). After testing on 45 acp it was noticed the small primers had less spread so the company went with all small primers on target loads in an effort to cut inventory. There law enforcement ammo will retain large primers for now. Bench Rest cases often have small rifle primers . From What I read small primers give better accuracy in most cases .