I am still developing and testing loads for my .500 S&W 7.5" PC revolver. I found interesting phenomena:

With some loads, LR primer (CCI 200) generates lower pressure (this is obvious) but higher velocity than the same load using Fed GM215M.

Prime example:

Ares 400gr hardcast coated bullet + 36 gr H110
CCI 200: 1558 fps, cases really easy to extract
GM215M: 1552 fps, cases a little sticky to extract

CCI 200 + 38 gr H110: 1608 fps, cases easy to extract

These bullets are really tight in cases.

Another phenomena:

In this scenario, cases are not expanded after sizing. All loads crimped the same way.

Lehigh Defense 350gr bullet + 42 gr H110 + CCI 200
Brand new cases: 1850 fps with low SD ~ 9 fps
Few times used cases: ~ 1770 fps average, but one shot 1700 fps and another one 1830 fps or so. What the hell is this? So I tried Fed GM215M for proper ignition in used cases, but with the same 42 gr H110, I got "only" 1768 fps, SD ~12 fps, but there is some primer flattening.

Could anybody explain that behavior to me? What can I do to have the same velocity and SD from used cases with this particular bullet?

Thank you for advice.

Jiri

You don't need magnum primers in the 500 S&W with amounts of powder.

Pay more attention to how heavily and consistently you crimp the bullet.

Barstooler

i can guess -- i expect the rifle brisence is a tad slower than pistol .. and the cup is a tad longer

jeffeosso:

I use brass made for rifle primers. My question is LR or LRM . . .

Barstool(er):

Crimping is the same all time. The difference is new versus used brass. Bullet pull (without crimping) will be different and bullet pull out force added by crimping will be insignificant.

BTW Hodgdon recommend LRM (Winchester LRM) primers for .500 S&W.

But Federal GM215M could be a little bit overkill. Look at this website: http://www.castingstuff.com/pr...esting_reference.htm

You can see that GM215M power is 6.12, CCI 200 is 4.28, so Winchester LRM with 5.45 is somewhere in the middle.

Jiri

I see no need for a magnum primer in the 500 case.

quote:

Originally posted by p dog shooter:
I see no need for a magnum primer in the 500 case.

Yes and no, just my theory:

If it is for particular load (powder and bullet combination) too slow (I mean burning), the more powerful primer could provide faster ignition - pressure rises faster and/or higher. On the other hand, weaker primer could delay ignition, lower pressure peak, prolong burning etc.

I believe that selecting particular primer strength can be used for fine tuning of reloads, if you are seeking for top performance.

Jiri

There is a reason FA 454Casull brass uses small rifle primers.

my mistake - thank you for correcting that --
i wouldn't use LRM in a pistol case -- there's too much documented proof that LRM cause higher pressures -- and with less than 70gr of powder, i've never needed mags in rifle cases --

pistol powders aren't hard to ignite, and all are faster than rifle powders

Can you use large pistol magnum primers in the 500 Mag?

Most of not all the big S@W cases 460 and 500 are designed for rifle primers.

So no it is not a good idea pistol and rifle primers have different dimensions.

quote:

Originally posted by p dog shooter:
Most of not all the big S@W cases 460 and 500 are designed for rifle primers.

So no it is not a good idea pistol and rifle primers have different dimensions.

They're the same diameter but the rifle primers are a little bit taller. They fit fine but I was just wondering if they'd would fire the round.

The reason I ask is to see if anyone has ever tried them because I loaded 50 rounds of the 500 Mag yesterday and installed the large pistol magnum primers instead of the large rifle primers by accident.

If they will work for plinking I'll just leave them as they are rather than pulling the bullets and repriming. I guess the best way to find out is to just give them a try.

I'll let you all know how they work later today.

jeffeosso:

I will not use LRM in the most loads. But Hodgdon published reloading data are all for Winchester LRM primers.

Yes, LRM will cause higher pressure, precisely it will ignite more powder at the beginning. Everything else is the result of that. It will also generate "initial pressure". This will of course increase pressure when compared to the same load with LR primer.

But I still think it could optimize (fine tune) load where "powder on the slower end" for particular bullet is used, bullet has lower initial pressure to move etc.

On the other hand, I will use weakest LR primers for some loads to get best results.

Now, I have S&B LR primers (weak), CCI 200 (moderate) and Federal GM215M (strong). Can't find anything between here.

Jiri

quote:

The reason I ask is to see if anyone has ever tried them because I loaded 50 rounds of the 500 Mag yesterday and installed the large pistol magnum primers instead of the large rifle primers by accident.

Why not just run them through your die and remove them no trouble at all could have been done in the time it took to write about it.

quote:

Originally posted by p dog shooter:

quote:

The reason I ask is to see if anyone has ever tried them because I loaded 50 rounds of the 500 Mag yesterday and installed the large pistol magnum primers instead of the large rifle primers by accident.

Why not just run them through your die and remove them no trouble at all could have been done in the time it took to write about it.

You can pull bullets and dump the powder and reprime and then recharge the casing and then place the bullet and crimp it in the time it takes to type this?... then you're a genius. I'd like to see you do it. ha ha ha Makes no difference what forum you go to there's always a know it all smart ass!

By the way the large pistol magnum primers work just fine firing the 500 Mag cases. So I don't have to do anything to them.

So how does it work?

quote:

Originally posted by Rook49:

quote:

Originally posted by p dog shooter:

quote:

The reason I ask is to see if anyone has ever tried them because I loaded 50 rounds of the 500 Mag yesterday and installed the large pistol magnum primers instead of the large rifle primers by accident.

Why not just run them through your die and remove them no trouble at all could have been done in the time it took to write about it.

You can pull bullets and dump the powder and reprime and then recharge the casing and then place the bullet and crimp it in the time it takes to type this?... then you're a genius. I'd like to see you do it. ha ha ha Makes no difference what forum you go to there's always a know it all smart ass!

Wow this is a pretty rich response coming from a new 6 post member to the forum who just admitted he "accidentally" loaded 50 rounds of ammo with Large Pistol Magnum primers instead of Large Rifle. Did you actually put some powder in or "accidentally" forgot that too? Just how much loading have you done before you accuse others of being smart ass. Usually new members get welcomed to a forum, I'm not so sure in this case with that sort of attitude.