doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com 20 Bore Simson Paradox...finally shooting bullets!

The Simson 20 bore Paradox!

Let me start by saying THANK YOU again to Marty Sands for sending me some 20 bore 2-1/2” Paradox loads to try in my Simson Paradox gun. Marty was kind enough to send them to me in November of 2008. I finally had an opportunity to try some of them out today!



My observations are as follows:

I shot form a makeshift stand up bench and let the gun recoil freely. I am confident a sitting bench rest would make this little bugger untenable to shoot without developing a flinch. As it stands the large bruise on my shoulder is from firing only four rounds!

The Simson is very light at about 6 pounds and the stock has a narrow butt with no pad. The 440 grain Paradox bullet at 1350fps moves the gun around briskly. (It just plain hurts.) I am waiting a week or so to finish my testing with the 1550fps loads he also sent. (I will be slipping a recoil pad on my shoulder too!)

The composite group measured 6 and 3/4 inches at 50 meters. The right barrel is dead nuts punching 2 holes exactly where I was aiming about an inch and a half apart. (Easily “minute of deer” accuracy”.) The left barrel shoots to the right +5-3/4” and south -3-3/4” of the right barrel.

Hopefully the 1550fps loads will bring the composite group down enough so that I would be confident a second shot would be meaningful.

Dave,

Why are you trying hotter loads rather than going the other direction? It sounds brutal now, and surely will be more so at 200fps more with same bullet!

My interest is not casual. James Tucker is restoring a 16 Paradox H & H for me, so I may have the same issues. It was only slightly heavier than your Simson, but the new stock may add a couple of ounces. The H & H may have a bit more area on the butt, but it is not a big gun. This may require a little "Tom Sawyer" like deception of fellow posters to get a load worked up!

Hey Terry! I'm trying the heavier loads because that's all I have at the moment.

If they don't shoot any better then I'll start reducing the powder charge on the first load to see if that makes a differrence.

I wanted to give both the loads that Marty sent a fair shake. The hotter loads contain an OEM powder that is not readily available.

I'm kinda hoping reducing the power in the first load will do it as it's a standard over the counter powder.

The other reason is that I don't have any 20 bore bullets to reload. I did buy a mould and hope to learn how to cast. It's more of an available time kinda thing. This year has been pretty crazy with the economy, 2 heading for college and the wife being out of sorts for a three months with some upper GI issues.

Dave,
What are the details of your Simson gun, rifled chokes or?

The chokes are rifled with late style Paradox rifling (more similar to conventional rifling.

Not the initial rachet H&H style.)

The gun was built in 1930's.

Dave-

First things first, know my best wishes are with you and your family, hoping your wife's doing well.


On the 20-bore

With the handful of light bore-rifles I've gotten running, one trend has shown up with each of them during load development.
With the same bullet weight, adding powder brings the point of impact together, from there adding more brings them down.

If you're seeing a significant amount of crossing, I'd suggest your next move would be to either add bullet weight or bring the charge down.
Heavier bullets will give a more substantial initial recoil impulse, swinging the gun in the direction of the barrel fired (and up).
Heavier charges of powder tend to decrease barrel time (higher velocity) getting you less swing during the 'internal ballistics' microsecond of firing the gun.
Hope that makes sense.

That's just simple and general, and your gun may or may not follow the pattern. I've heard from quite a few other guys that their bore rifles tend to behave in a similar fashion.

A .620 ball of pure lead will weigh about 359grains
You're running a somewhat heavier conical.
Is that the NEI mould you're using?
Try backing off the powder a bit with that bullet and see how it prints.
Even at 1200fpsMV it'd be a great deer killing gun.
Also consider trying roundball in your load development.



Good luck with getting the gun going.



Cheers
Tinker

The 20's for the big makers of paradoxes Holland and Westley, they were late guns. Westley's had a three groove ratchet style, I have never examined a Holland 20 but Holland changed the rifling on some of their 12s sometime after 1910 to a 9 groove still ratchet style but looked more conventional. Westley's shot the capped 425 bullet at 1500fps. I have heard Holland may have had two loadings for their 20s. You would think the Simson being made in the 30's would have been regulated for a readily available 20 bore paradox loading.

Dave, I have to agree with Tinker. It looks like you need to bring that load down to about 1100-1200 hundred f.p.s. Regards Rich

Dave-

One more note.
It's very important that the gun mounts naturally on your shoulder, with the sights lining up perfectly -- AND that the stock heads up to the action perfectly, no gaps, no looseness.

Close your eyes, snap the gun to your shoulder three of four times with your eyes closed - then again and open your eyes.
That front sight should be in the groove of the rear sight.
If it's not, make haste to your favorite stock man and have it bent to fit you.
You'll be chasing your groups for ever until you get it to fit perfectly.

Any slop in the stock head to metal fit will also screw you and the gun eternally on an endless (and fruitless) path to a regulation load.





Cheers
Tinker

Sorry Guys...Had to take the number one son to college. The gun is in great shape.

No issue with wood metal...etc. I've also shot skeet and chuckar with the Simson and it seems to point just fine. The targets broke and the birds flopped....as well as with any other gun I've shot.

(I'm not a Olympic class shooter. However, If I had to hunt for my food I wouldn't go hungry...Although I'd never get fat either!)

I will be screwing with my 9.3x74R Merkel while the Simson is back burnered till I can get some loads squared up for it again.)