Reloading 10mm?

[*chris*]

Had a strange experience at the range today. Just bought a S&W 610 10mm revolver. I shot a few clips of 40s&w and the gun shot like a dream. I also had some 10mm that I reloaded with 9.5 grains of 800x powder behind a 180 gn berry bullet. It was a fire belching round and I could see flames coming out the cylinder gap. Pretty typical for magnum loads out of a revolver.

Problem was the brass was hard to extract, the primers were flattened and 2 out of the 6 cases split in the center maybe 1/2 way around the case. Super over pressure it seems. I don't know the history of the brass. The load was compressed. The hornady manual lists 10.5 as the max load. I used a light taper crimp due to the plated bullet and seated them at 1.26" COL.

what do you guys think?

I'll post photos of the cases later.

Chris

 

[EddieCoyle]

Was it "A USA" headstamp brass by any chance?

 

[thormx538]

I don't have my notebook in front of me, but I have gone above [STRIKE=10.5]10.5gr[/STRIKE] ETA: 10.2gr of 800-X w/ 180gr plated HPs and have never seen any pressure signs in either a stock Glock barrel, or LWD Glock barrel. I only use Starline, and Underwood brass (which I think is Starline as well).

My guess is the brass had issues, rather than your load being too thermonuclear.

ETA -- looked at my notes, most I ever did was 10.2gr under a 180gr plated HP.

 

[*chris*]

EC, nope Federal brass.

800x is pretty hard hitting and I am used to seeing flattened primers. The stuck extraction worried me a little bit. I start my loads at 10% below the maximum listed in the Hornday manual and this is no different. Here is the brass that is cracked including a clip of 40 S&W that I also shot flawlessly.

This revolver has a 6.5" barrel, is that allowing too much pressure to build up? I shoot 15 grains of 800x in my 4" 44MAG all the time and it is no where near the high end.

I am looking at the factory federal ammo on the right and the primers are also flattened.

 

[drgrant]

800x? Try PowerPistol or something like that. That'll rock out on 10mm and I bet it doesn't blow the cases up like that.

-Mike

 

[*chris*]

Interesting, the Hodgdon website lists 8.7gn as the maximum charge for a 180 gn projectile with 800x.

8.7 1,210 30,000 PSI

I did weigh every charge, but it looks like the Hornady manual maybe wrong?

Chris

 

[hv55maxx]

On 10mm. Why the fark would someone make small pistol primer cases? Ordered some and half was small primer. Kinda pissed. At least 45 it's advertised if it's mixed primer size.


Would it be better to use magnum primers for this? I can't see an easy transition from simple small pistol primer to the required large pistol primer. I feel a small magnum would be more fitting.

 

[EddieCoyle]

If they're Norma small primer, I'll trade you two large primer cases for each one.

 

[thormx538]

800x? Try PowerPistol or something like that. That'll rock out on 10mm and I bet it doesn't blow the cases up like that.

-Mike

800X is slower than Power Pistol, should perform better in his 6.5" bbl

 

[*chris*]

800X is slower than Power Pistol, should perform better in his 6.5" bbl

What do you think of my load? The Hornady manual states that 10.2 gn is the max yet IMR states 8.7gn is the max. Are my 9.5gn safe?

I have never had a problem with the Hornady manual, I am sort of disappointed.

Chris

 

[EddieCoyle]

800X is slower than Power Pistol, should perform better in his 6.5" bbl

Why?

 

[thormx538]

What do you think of my load? The Hornady manual states that 10.2 gn is the max yet IMR states 8.7gn is the max. Are my 9.5gn safe?

I have never had a problem with the Hornady manual, I am sort of disappointed.

Chris

I updated my first post. I have gone to 10.2gr before and have not seen any pressure signs.

Manuals tend to be conservative with 10mm if they were printed in the last 20yrs or so. SAAMI spec on the 10mm Auto chamber is 37,500psi, but Lyman 47 and 48 max loads are under 30,000psi (8.4gr 800X/180gr JHP is 28,000psi, for example)

Why?

That question coming from you implies that I'm wrong (), but I always thought that since the longer barrel allows more burn time, the slower powder will get you a faster velocity given the same chamber pressure, ie, you can get more speed out of it before reaching unsafe pressures. But as I look through Lyman 47 and 48 right now, out of a 5" barrel they are measuring more velocity and lower pressure with Blue Dot and Power Pistol than they are with 800X.

 

[1903Collector]

On the newer revolvers the area where the firing pin protrudes from the frame is a bit convex, Which I think contributes to the primers looking flatter. I experienced this with my 629s. I was shooting 44 mags that were potent, around 17 grains of Blue Dot but well under max.

FYI, My standard cast 10mm load is 9.6 grains of Blue Dot under a 180 grain LFP out of G20. also works for the 165 grain jacketed. You got a 610.....so jealous!!