TargetTalk

Hi,
The old OSP can be alive as a .22LR

1. New liner in the barrel.
2. Reshape grip to comply with rules.
3. Replace handles with those from a .32 to add weight.
4. Move front sight back to comply with rules. (Drill and thread)
5. New mag. (From an other GSP .22LR perhaps)
6. New trigger (From an other GSP .22LR perhaps)

With Lapua Pistol King it makes 255 m/s and works fine.

Kent

Yepps!

3. Probably only if newer style light slide/bolt (which is the correct name of it?).
6. Perhaps only a harder spring behind the trigger will do it

You do not have to do everything that I did. Check that .22LR magazines fit your pistol (some do not).

All you need is;
1. A stock .22LR barrel, .22LR magazines and a 1000g trigger from Walther.
2. The .32 caliber cocking handles (make them smaller so that they are not so heavy, or machine them like hers).
3. The plastic tubing (to act as a buffer). This is necessary.
4. Move the front sight back to be ISSF legal.
5. Modify the grip to be ISSF legal.

You will probably have to tune the weight of the cocking handles and the length of the buffer for the ammunition that you use. Easy to do. My modification works very well with all the match ammunition that we used but you should plan on fine tuning everything to your ammunition.

The Bo-Mar sight modification was done because for the Precision stage she used a sub six hold with a narrow blade opening and for the Duel stage she used a center hold with a wide blade opening. These are features that are not really necessary but were helpful for her particular needs.

The following are the photos and captions for the OSP/GSP Conversion
.
Print and line them up in groups as labeled.

A-1 The right side, showing World Cup & World Championship equipment control stickers.

A-2 The left side, note that Lauren has small hands, even for a 5’5” girl. She is a lefty.

A-3 Top view with grips removed (note the barrel, sights and charging handles).

B-1 Right side, note the chamfering and the lightening slots on front of frame.
Note the rear sight position.

B-2 Left side is the same. The serial number had to be relocated because of the
lightening slot
.
B-3 The Top of Slide Casing showing the chamfering and the lightening slot on the top.

C-1 Top barrel is Custom made by Falcon Machining Ltd. In Scottsdale, Arizona.
The sides have been milled to get the correct balance.
Bottom barrel is a Walther, with chamfers and the front turned down on a lathe.
It has lead wheel weights for more weight when she was older and stronger.

C-2 Top Barrel is the Walther with the wheel weights removed.
Bottom barrel is the Falcon.

C-3 The top one, the Falcon barrel, shows how the front sight is dovetailed on its length.
The bottom one, the Walther barrel shows how the front sight is dovetailed across.

D-1 The custom cocking handles on the .32 cal cocking handle bolt that goes through the breechblock. The recoil buffer is slotted to fit around the spring. It is a section of plastic tubing 3/8” I.D. X 9/16” O.D. (aprox. ¾ inch (19mm) long). It has thousands of rounds of use.

D-2 The other side of the cocking handles and an end view of the recoil buffer.

E-1 Top cocking handle is the custom one for the conversion,
(With the Allen bolts the pair weigh 51 grams).

The bottom one is a stock .32 cal from Walther,
(With the Allen bolts the pair weigh 73 grams).

On the left is a custom dovetailed front sight (not used on this pistol but shown so that you can see what it looks like milled for the Falcon barrel).
On the right is a new recoil buffer showing the slot to fit on the recoil spring.

E-2 Same as E-1 showing different views of the cocking handles, front sight and recoil buffer. Note the large Allen bolt holes on the Walther. The walls would be very thin and weak if milled to lighten them, therefore the custom cocking handles with smaller Allen bolts is better.

F-1 The custom Bo-Mar rear sight installation, slight top view.

F-2 Same as F-1, slight bottom view.
Note the detent in the sight to zero the sights when the changing sights..
Note the screw of the micro plunger in the frame for the detents.

Some pistol smiths may find this feature is challenging to machine and install. A small hex bolt on each side of the sight locks the sights down.

The sight modification works extremely well and the sights are always perfectly positioned after the change because of the small spring-loaded plunger in the frame and a detent centered in the bottom of each sight.

One sight is zeroed for sub 6 hold for the Precision Stage with a narrow slot.

The other sight is zeroed for the Duel Stage using a center hold. It has a wider slot making it easier to see the front sight against the black of the target.

Changing the sights takes less than 20 seconds to make. It is done on the line between stages while the other shooters are trying to adjust their sights by counting clicks.

The photos are self-explanatory instructions. Have a competent pistol smith that is familiar with Walthers do the conversion.

www.targettalk.org/images/Attachments/OSPConv/A-1.jpg
www.targettalk.org/images/Attachments/OSPConv/A-2.jpg
www.targettalk.org/images/Attachments/OSPConv/A-3.jpg
www.targettalk.org/images/Attachments/OSPConv/B-1.jpg
www.targettalk.org/images/Attachments/OSPConv/B-2.jpg
www.targettalk.org/images/Attachments/OSPConv/B-3.jpg
www.targettalk.org/images/Attachments/OSPConv/C-1.jpg
www.targettalk.org/images/Attachments/OSPConv/C-2.jpg
www.targettalk.org/images/Attachments/OSPConv/C-3.jpg
www.targettalk.org/images/Attachments/OSPConv/D-1.jpg
www.targettalk.org/images/Attachments/OSPConv/D-2.jpg
www.targettalk.org/images/Attachments/OSPConv/E-1.jpg
www.targettalk.org/images/Attachments/OSPConv/E-2.jpg
www.targettalk.org/images/Attachments/OSPConv/F-1.jpg
www.targettalk.org/images/Attachments/OSPConv/F-2.jpg

Sandy Santibanez

Sandy wrote:You do not have to do everything that I did. Check that .22LR magazines fit your pistol (some do not).

All you need is;
1. A stock .22LR barrel, .22LR magazines and a 1000g trigger from Walther.
2. The .32 caliber cocking handles (make them smaller so that they are not so heavy, or machine them like hers).
3. The plastic tubing (to act as a buffer). This is necessary.
4. Move the front sight back to be ISSF legal.
5. Modify the grip to be ISSF legal.

You will probably have to tune the weight of the cocking handles and the length of the buffer for the ammunition that you use. Easy to do. My modification works very well with all the match ammunition that we used but you should plan on fine tuning everything to your ammunition.

Looks very functional!! Some people wants it shiny and all bling-bling, but I think it is looks very good when everything is just function, just like this OSP ;-)

Actually the heavy (or lightend) .32 cocking handles are not used in the 2-3 swedish modified OSP that I know of, only the iron bar that goes through the slide/bolt (that is the correct term in english?) is used and it seems to work ok. But the lifespan is unknown while those are modified just last year. What parameters do you look at when adjusting for different ammos? What can happen if it goes wrong or at least not optimal?

The extra weight of the charging handles will slow the speed of the cycling. With no extra weight it will cycle very rapidly possibly stressing everything and eventually damaging the slide or charging handle bolt. It will also have a a more pronounced recoil snap.
With too much weight it will cycle very slowly, affecting function and reliability.

The plastic buffer absorbs much of the energy of the bolt as it slams back during recoil and assists the return spring in its function. It also makes the overall function smoother with a less pronounced snap as the bolt hits the end of its travel and returns to battery. The plastic buffer is a key element in the conversion.

There is a lot of latitude in the interplay of the components of the modification and for optimum function you should consider fine tuning everything. Match the weight of the charging handles, the ammunition you use, the resiliancy of the plastic buffer (how hard/soft and how resilient it is), the lenghth of the buffer and the lenght/strenghth of the recoil spring.

Her pistol was much lighter than a stock OSP/GSP with more apparent recoil since it had less mass. After tuning, the pistol actually cycled faster with less recoil than my stock GSP. It just took a little tuning to get everything adjusted just right.

Sandy, that pistol looks rather familiar..:)

Yes, it should.
We re-machined the charging bolt handle, the barrel and the front sight. The buffer was changed using a different plastic tubing that was a little longer with more resiliancy (the original was reinforced with a cloth center and split).
This post was started because there have been many people intrested in this conversion. OSPs make great door-stops but the conversion makes an excellent .22LR pistol for 25m and Rapid Fire.
I would like to talk to you about your timer, 858 484-7624.