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Author Topic: Cartridge for Husqvarna RB sporting rifle  (Read 19870 times)

10. October 2007 kl. 3:08:19
Read 19870 times


Hello there,
I've just aquired a Husqvarna rolling block sporting rifle and need some help identifying the cartridge it's chambered for. It has a heavy oct barrel 31.5 inches long (marked Husqvarna on LH side, on top there is a large crown with the letters LH under it, while under the barrel - the serial number, a calibre stamp (?) of 15.4 and the letters HM and LLH). The sight is a 3 leaf with the two folding leaves marked 120 and 180 (meters ?). The action is colour case hardened and fitted with twin extractors. The two large action pins are locked in place using cap screws Sporting walnut stock.

Now to the cartridge - a brass 20 gauge shotgun cartridge trimmed to 1.875 inches fits the chamber nicely and the barrel has a 1 in 88 inch twist (8 narrow lands with wide grooves). I haven't slugged the bore yet but I would estimate it at about .60 cal.

The rifle is very nice original condition and I doubt it has been used much.

Have I got a black powder 20 gauge rifle ?
Any help would be greatly appreciated.

10. October 2007 kl. 9:20:00
Reply #1

jæger justnæs

I think you are right in assuming it is a 20 gauge rifle. Model 4 came in this caliber and are not very common. I have one myself, groove diameter .658. I have used .662 balls and have recently customized a mould to cast .658 short conicals due to the slow twist, approx. 1-72. I'll look into more details when I can find som spare time:-)
Best når det smeller!

10. October 2007 kl. 18:47:20
Reply #2


Lyman makes a nice hollow based 20-bore slug casting out at 345grs:

Their shoulders held the sky suspended;
They stood, and earth's foundations stay;
What God abandoned, these defended,
And saved the sum of things for pay.

A.E. Housman

11. October 2007 kl. 10:32:09
Reply #3


Jaeger & 303,
Thanks for the reply. I measured the twist again and it was closer to 1 in 72 as you suggested. I'll slug the bore just as soon as I can find a lead ball large enough to do the job. Making cases should not pose a problem but the length of 1.875 inches is strange...why not 2.5 inches which was standard for most of the old BP 20 gauge guns?

I am very familar with BP Remington RB rifles, I have been shooting them in various calibres for many years. The largest calibre I've loaded for (that is until the Husqvarna came along)was an early Remington No1 conversion with a Springfield muzzleloader barrel chambered for the .58 Berdan cartridge.

I especially like the twin extractor setup on the Husqvarna action. I wish the Remingtons had this feature!

I would also like to know if this is a Swedish or Norwegian rifle and a approximate period of manufacture. I definitely plan to get it shooting again.

Thanks for your help.

14. October 2007 kl. 7:08:28
Reply #4


Hello again.
I've just slugged the bore of the Husqvarna RB. Groove was

.662" and the bore .622". I am thinking of having a mold made up by NEI (USA). They offer a version of the 20 gauge Westley Richards Paradox slug

(often referred to as the "cotton reel bullet". I've seen them used here in Australia with rifled shotguns. Quite accurate out to 150 m. It measures

.630" and has a hollow base like a minie ball bullet. This slug will fit inside a 20 gauge case but I think there could be difficulties with a wider slug

(eg .660"). Do you think this undersized slug would expand enough with a charge of 60-70 grs FFg to fill the barrel's groove successfully?
« Last Edit: 14. October 2007 kl. 7:09:58 by 712 »

14. October 2007 kl. 19:36:46
Reply #5

jæger justnæs

I think you ought to concider what they used in the old days: brass shells. A .662 ball fits snugly into a 20 gauge brass shell. Slugs of modern days are made to fit in a plastic shell (with thicker walls), maybe even a shot cup and least but not last they are made small enough to pass the choke of a shotgun without dangerous pressure.

> Do you think this undersized slug would expand
> enough with a charge of 60-70 grs FFg to fill the barrel's groove successfully?

I wouldn't count on it, maybe you'd be better off throwing rocks...
Here's a clip of my first shots with it...
Best når det smeller!

16. October 2007 kl. 7:32:14
Reply #6


Thanks for the video. It looks like a fun rifle to shoot. Yes, yours is very similar to mine. Are your cases full length or did you have to shorten them?
What powder charge were you using with your round ball load?

> I think you ought to concider what they used in the old days: brass
> shells.

Yes I would use them if I could find them easily. Unfortunately Bruce Bertram does not make them (I called into his workshop last week to check). I will have to order some from the US (Rocky Mountain Cart, turned brass cases)but this is not an easy process as our Govt has placed restrictions on the importation of cartride case!

> I wouldn't count on it, maybe you'd be better off throwing rocks...

No I would borrow my son's homemade catapult to do that. I'd be very interested to get details of your conical slug.


16. October 2007 kl. 19:01:26
Reply #7

jæger justnæs

Sorry about your government's import restrictions, Spud!:no:
I got my CBC brass from Midway. Not very expensive at all. Specify whether you want Boxer or Berdan primer pockets. I shorten the cases to approx. 1.83"/46.5mm. My chamber wil accept no more than 47mm case length.
So far I have loaded it as if I were to load a 20 gauge shotshell and have kept within 60 and 70 grains BP. Over the powder I put a cardboard shilling and a wad. Different lubes and wads ought to be tested.

I heard of a conical slug made from a modified .600 Lee RB mould and put my local gunsmith to the task. The conical turns out as a kind of semi-wadcutter with a diameter of .658 and a length of .600.

Happy hunting!

Here are some pics to get you in the mood:

Best når det smeller!

18. October 2007 kl. 9:26:04
Reply #8


Thanks for the details on your load. You've certainly given me some ideas regarding the best bullet to use. The conical turns out as a kind of semi-wadcutter with a diameter of .658 and a length of .600.

Could you give me the approx weight of your conical? Have you experienced any leading when using it solely with lubed wads?

The length of the chamber still puzzled me so I made a chamber cast to check the dimensions. After some research I'm now fairly certain that my rifle (and yours) are actually chambered for the 18 gauge cartridge! The dimensions are close to those in "Cartridges of the world". It states that this cartridge was 1 7/8 inches in length (the deciding factor for me) and was used/loaded in Europe during the late 1800's. The 20 gauge cartridge is only slightly smaller and you've shown that it is certainly safe to use.

Do you have any additional information regarding the use of this cartridge in Norway or Sweden?


07. November 2007 kl. 22:47:54
Reply #9


I have a fullstocked No. 4 that shoots very well with a .662 round ball over a fiber wad and 70 gr FFG.  I actually get slightly better results with a .648 ball, but I have to patch it in the case and it is messier.  Still shoots MOD (Minute of Deer) easily at 100 yds.

30. January 2008 kl. 18:56:33
Reply #10


Hi to all

I have a couple of boxes of the CBC and Magtech Brass hulls that use the Large Rifle Berdan primers.

I can not find a good source for them.  I have tried midway, Grafs, Magtech, Midsouth shooters, PMC and others.

Who has the Berdan primers available?  I will buy in in groups of 1000 to 5000

I have one of the SXS 20 Gauge shotguns and I want to make a double rifle out of it.  

Thanks in advance

Charlie  a 22 Hornet fan.