308 Handi rifle with 41gr of imr4064 and the primers are flat as heck. (165 gr partion) whats up? rifle has 140 rnds down it. can you help me. thanks Mike

Are you using new brass in the loads where you see your flat primers?? If yes, try to resize (neck size, preferably) a few pieces (one?) of the brass, which gave you flat primers, and try it again.

If new brass is a tad short in the head - shoulder dimension, primers will come out flat, even if the load is not excessive.

Have you used this load before in the rifle in question without any pressure signs?? Have you switched any components?? Any other pressure signs?? How did the gun open, do primer pockets stay tight??

- mike

quote:

Originally posted by mike61:
308 Handi rifle with 41gr of imr4064 and the primers are flat as heck. (165 gr partion) whats up? rifle has 140 rnds down it. can you help me. thanks Mike

I have a Ruger M-77 MKII in 7.62 X 39 m/m that does the same thing. To fix this I just neck-size my cases. In my Remington M-673 in .308; I use 45.0 grains of IMR-4064, and have no problems with flatten or sightly backed-out primers. Lots of times these cartridges developed for semi-auto are sized a litle smaller and when used in a bolt action they show signs of this primer flatening, even though the load is not excessive.

the brass is once fired factory loads. fired in that gun that i fl sized because of the break action. these are the first hand loads fired. i trimmed to length and i am not into the lands. are you saying that i am bumping the shoulder back to far causing headspace issues?
gun opened fine but i did have a stuck case. thanks mike

IF...you are having flattened primers, and IF...you are having stuck cases, you are having pressure problems regardless of what the tons of reloading manuals state.

They are not using your firearm, they are not using your bullets/primers/brass/powder when they are printing their books.

I have used:
IMR-4064 From 36.1 grains to 46.0 grains
Remington 9-1/2 Primer
without any difficulty, but that was in a new Ruger 77, not a Handi-Gun.

When you open the action after firing does the button feel different than with factory loads? My 243 handi sticks the button, and sometimes sticks cases in the chamber, with too hot loads. Sometimes loads well below book maximum.

most people don't do well necksizing with a handi. Long headspace affects lockup.

One of my reloading manuals (I think its Speer) states that you can get flat primers with low pressure loads. IMR's website shows 41 grains 1 gr below the min starting load.

I dont remember the exact reason why low pressure causes flat primers. It had something to do with the load not having enough pressure to expand the brass to fit the chamber, but enough pressure to force the primer out. I'd call IMR tech support. It would be very dangerous to assume you have a low pressure situation when it's really high pressure.

I had the same hting happen to me with a handi rifle in 223. I was developing some light loads and used the minimum powder charge from one of my manuals. I got a lot of unburned powder and flat primers. I called Hogdon and they suggested I add a grain and a half to the load and it worked fine (there was a discrepency between Hodgdon's data and my Hornady book, I was below Hodgdons's suggested min).

quote:

Originally posted by mike61:
Are you saying that i am bumping the shoulder back to far causing headspace issues?
gun opened fine but i did have a stuck case. thanks mike

Mike, yes if you set the shoulder back this can cause excessive headspace problems. All-in-all, I've found my best performing loads are achieved by simply just "necksizing" the cases.

I don't know how you have adjusted your seating die. The "regular" procedure to perform "partial FL sizing" (sizing case until it chambers with just a hint of resistance) probably does not work in a break-top action - which is what I assume your gun is. There is, however, a very cheap gadget by Stoney Point, which will allow you to measure the head-shoulder dimensions on both fired and sized cases. No, it is not perfect, but is a darn site better than guessing. www.sinclairintl.com. Ideally, you'll want your shoulder set back just .001" by your sizing operation.

I naturally can't state categorically, that excessive sizing of your cases is the problem. But I do know flattened primers show up if cases are a tad short in the head-shoulder dimension. Although, there could be other reasons as well...

- mike