SP20 .32 ammo

[ruig]

Hi,

Brainstorm needed.

Pistol — Hämmerli SP20 .32 S&W Long (not RSS version, SN 053xx).
Ammo — reloaded CBC cartridge case (the same load was used with Walther GSP .32 S&W without any troubles). I have bought this load since owner didn't need it anymore and I looked for cheap ammo.

Yesterday, during the match I got surprises. I was able to finish precision stage with couple of troubles with repetition and I already knew what expected me next.

May be has someone of you «white paper» or written specification about .32 S&W Long wad cutter standard? Dimensions? Maximal height?

I suppose, that bullet's outdent is the reason of yesterday's «pain».

Bullet must be completely sunk into cartridge case, mustn't it?

[JamesH]

Given its somebody elses surplus reloads for some other gun is it worth worrying about? If it were your own reloads and you were trying to troubleshoot then maybe.

Otherwise need more info, what was the nature of the malfunction for a start.

[buonvento]

I don't like CBC cases, I think they're too hard.
I normally use Fiocchi's cases which I find softer, but I'm in Italy.
The OAL depends from the bullet, with Fiocchi's I use 23.5 mm, with Lapua you must seat at 24.6 mm.

[ruig]

Otherwise need more info, what was the nature of the malfunction for a start.

Previous case properly ejected. Next cartridge is jammed on the way from magazine to chamber.
Solution for now - pull slide a little back and cartridge comes properly into chamber.

[Guest]

Does the same problem happen with a different magazine?

Would that jam still happen if the cartridge OAL was longer?

Would that jam still happen if the powder charge is increased a little bit?

Would that jam still happen with a shorter recoil spring?

Is the frame of this Hammerli SP20 in good shape?

Does any other load work flawlessly with this pistol?

Hope you find a cure for this soon.

[ruig]

The OAL depends from the bullet, with Fiocchi's I use 23.5 mm, with Lapua you must seat at 24.6 mm.

Overall cartridge length: approx. 24.5 mm.
Case length: 22.5 mm.

Today I got answer from one my friend - he has RSS version and he has already won CISM medal with it (also, he is trusted info source). He says - I must change recoil spring, or as alternative - remove one from them... or shorten both. They are too strong. Or I try to shoot with stronger ammo.

[Guest]

Does the cartridge rim slide well under the hook of the extractor?

[ruig]

Does the cartridge rim slide well under the hook of the extractor?

Yes. At least I think so.

Today I have removed firing pin (for my own safety) and did extract-load tests. About 10 magazines (x50 extract-load actions). No jams. Clean extract. Clean load. No problems.
But I think I wasn't fast enough to simulate real state of business after shot occurs.
I have even tested extract-load using empty cases - works too.

I have ordered now on e-bay 150mm x 3mm (strength 0.4mm) two springs for next tests.

Current spring length - 105mm. Diameter - 3.5mm (strength 0.4).
I will try to decrease springs' length starting from 105... and we look if it helps.


Unfortunately I didn't tested other ammo... Our local shops haven't such rare ammo. But I could try to order Magtech from Germany. It's not a problem.

[RB6]

I pattern my reloads after factory Lapua wadcutters without problems although they aren't shot from an sp20

Lapua seats the bullet very deep in the case ,the button of the bullet is
0.70 mm below the case rim and the case rim is heavily roll crimped to a diameter at the mouth to 8.21 mm . Lapua factory loaded case diameter at the middle of the case is 8.46 mm. The roll crimp is significant and I have patterned my reloads exactly as described.
Looking at the round it is obvious that when the pistol loads, it is loading an empty round so to speak. there is no bullet showing at all as it is recessed 0.70 mm below rim edge... I suppose the critical part of loading the pistol into battery is the overall length and that is why they roll crimp the case rim so much, the roll of the case wont catch anypart of the chamber and it is shorter than a round that has the bullet exposed any amount. The roll crimp doesn't even contact the bullet at all. the bullet is below the crimp
Before you cut any springs, just reseat the bullets 0.70 mm below the case rim and roll crimp to 8.21mm and that alone may assist in the round to load into the sweet spot. Just an opinion but what do i know

[buonvento]

My cartridges are the same in your pictures, and I haven't any jam, they group quite well, but I have a Pardini HP new.
What is the powder, load and primer?
P.S. I think your cartridges need a little more roll crimp.
Try this before working on springs...

[David M]

Check your overall length, some .32 auto loaders will not function with any lead exposed out of the case. Have a close look at a loaded magazine to check clearance, then look a the bullet feed.
Use a clamp or a vice (a .32 seater die in a press is prefered) to press a few bullets further into the case and try the feed.

[ruig]

Before you cut any springs, just reseat the bullets 0.70 mm below the case rim and roll crimp to 8.21mm and that alone may assist in the round to load into the sweet spot.

I will try... but I don't know when I'll reach loader.
Now I must find solution for 1000 already loaded and bought rounds.

Of course, next time, we will prepare small batch - 10-30 rounds... trying different configuration to be able to find best batch for SP20.

[ruig]

My cartridges are the same in your pictures, and I haven't any jam, they group quite well, but I have a Pardini HP new.
What is the powder, load and primer?
P.S. I think your cartridges need a little more roll crimp.
Try this before working on springs...

Yes, overall length lays in bounds of .32 S&W Long WC standard.

But seems that every manufacturer has own standard for chamber diameter etc.

I get exact info about my loads from this week.

[ruig]

then look a the bullet feed

I tested it manually yesterday. About 10 magazines.

In comparision to .22 lr AW93 (where slide speed plays no role during feed - cartridge will be always loaded properly) - slide's speed is very important - if I was to slow - jammed.

I see three interrelated factors - O.C.L, crimp and slide speed (recoil spring length).

[buonvento]

I think you must buy a cheap single stage press (and dies...). You can't shoot .32 without it (but it depends on your wallet...)!

[David Levene]

Like David M, I would suspect that the problem is that there is lead protruding from the case edge. This would normally mean that the bullets just need to be seated a little deeper.

I certainly wouldn't start messing around with spring tensions until I had tried the obvious.

[FredB]

This is a long shot, but it sounds like the SP20 is new to you. Are you sure that the little extra feed ramp for .32 has been properly installed? Problems with that can make feeding very difficult.

HTH,
FredB

[buonvento]

I don't think that the lead protruding the case could be a problem.
In the C.I.P. rules we read:
L3 (max. overall case lenght): 23.27 mm.
L6 (max. cartridge overall lenght): 25.40 mm.
If you seat at 23.50 mm. (Fiocchi's reloading manual for 100 gr. LHBWC) or 24.60 mm. (Lapua reloading data for 98 gr. LHBWC) you'll have always a little bit of lead out of the case.

[RB6]

Pistol jams..........
Pistol uses ammo with exposed lead.......
Pistol jams with exposed lead hitting top of chamber......
Lapua factory loaded ammo no use exposed lead.....
Hmmmm, maybe try ammo without exposed lead.........
Hmmmm, maybe good idea, cheap tooo

[David Levene]

If you seat at 23.50 mm. (Fiocchi's reloading manual for 100 gr. LHBWC) or 24.60 mm. (Lapua reloading data for 98 gr. LHBWC) you'll have always a little bit of lead out of the case.

Strange that the Lapua web site has pictures clearly showing the edge of the bullet flush with the end of the case.

I cannot remember seeing target quality .32SWL from any of the leading manufacturers with the bullet edge proud of the case, frequently seeing the bullets recessed slightly.