The frame was narrower . They were made for low pressure rounds and usually are found with rimfire chambers.  The ones I've seen in shops, gun shows are in very good condition. 

There may be more differences than what I stated.  The barrel shank is probably smaller and the lower tang may be longer and and. Been a long time since studying them.

        Joe.

Thanks guys, this is very interesting, I bet I'm not the only singleshot nut that didn't know the difference between the #1 and the #1 1/2. The # 1 Military and the # 2 are easy to identify but these other models are confusing.    ledball

You've already got some conflicting information, and I think that is because what makes a 1 1/2 is not readily defined.  The early rolling blocks had several variations, among what I will call the sporting rifle.  I won't label it #1 or # 1 1/2.

The first sporting rifles, near as I can tell, in large bore calibers, had the same barrel shank as a military rifle.  They had the stepped receiver ring, octagon shape.  They had a long, sculpted trigger guard.  They had a narrower width than the military rifle.  In my belief, all of them had a sporter breech block and hammer, with an acorn shaped shield in it instead of the knurling or checkering of a military hammer/block.  I'm going to digress here on a pet peeve of mine.  I see many early sporter rifles being sold as 100% original with a military breech block.  The seller always says "early RB's had this type of block".  THIS IS A BLATANT FALSEHOOD.  My opinion of the origin of these rifles is the fact that almost all early rolling blocks were rimfire.  Look at the old catalogs and you will see this is a fact.  When those early, large bore rimfires became obsolete, nearly all were replaced with centerfire reloadable versions.  AT THIS TIME, MANY USERS CONVERTED THEIR RIFLES, USING MILITARY PARTS.  Over the years, this has continued, by users wanting to shoot therir rifles, or collectors/dealers/speculators trying to enhance the value by making it have some hope of being usable. 

The next type of sporting rifle that I can clearly define is an early model .22 rimfire.  These early rifles have the same outside dimensions of the frame, tang, etc, but have a slightly smaller barrel shank.  As far as I can tell, that is the only difference, other than being .22 rimfire.   

The next type of sporting rifle is what I call the 1 1/2.  Every version I have owned has been in .22 rf or .32 rf.  I have seen others for sale in larger rimfire, but have not examined them to see what they are.

More in another post   

Continuation of my last post.

The military shotgun has a shorter, wider lower tang.  The barrel thread diameter on this is the same as the sporter shotgun, I believe, about halfway between a #1 sporter and a #5 military.  The military shotgun has the patent info stamped on the tang similar to the military.

Where I see some of the confusion coming from is parts swapping between the models.  The shotgun stock can be switched to the #1 military.  I think some #1's have had lower tangs and stocks switched from shotguns, to allow the sporter tang to be used on a more valuable large bore rifle being made from a military frame.  I also think a lot of the #1 shotguns have had their parts switched into military receivers that were recontoured to look like sporters.  The military parts were then switched onto the shotguns.  The result is two mixed parentage rifles to muddy the collectors knowledge.

Remington also may have mixed parts at the factory to meet orders.  I know Grant shows examples of sporter/military engraved rifles that he swears are factory.  That is, military frames, sporter hammer/block, and factory engraving.  Some of the lower utility grade guns may have had military parts installed into them to make orders at a low price with parts on hand.  This may explain some of the military lower tangs on shotguns and #1 1/2's, in addition to users switching parts.

Throughout all of this, the one thing that is nearly constant is breechblock/hammer width and size.  Most will interchange, regardless of model.  I find a few early sporters that the breechblock is different, and will not headspace.  

Hope I haven't muddled this up too much more.  Remember, this is all my opinion, based on the ones I have seen and worked on.  That is a small sample of the millions of rolling blocks that were made.  I certainly see new things all the time that I haven't seen before.  

dave

Regarding threads on RB's. I only know of three threads that were used (not including the 4's) and were all square threads.

1.055 X 12, Smokeless military and sporters

.975 x 12, square, BP military, sporters and Hepburns

.850 x 12, #1 1/2 and #2

My 1897 is 1.055, my Shot gun is .975, my #1 1/2 is .850

The DeHaas book shows a shot gun with even tangs. Mine apprears to be original with remants of CC on both frame and tang. The tang on mine has a stamp "BK" any ideals as that that means?

Frank

J. Louis,  Was the shotgun a sporter, or a military?  I seem to remember having a military that I thought was a 16 gage some time ago.  I shot some low base 16 through it, also, and am glad I lived through it.  I might be confusing it with a H&A medium frame, though,  I shot one or the other, and thought better of it later.  I have built rifles on several of the sporter shotgun actions, and/or salvaged the lower tang and breechblock and hammer to make sporters.  Every one I have owned has been 20 ga.  Not that I have had an extensive sample to go from!  With a minor diameter of .940, the barrel would be getting kind of thin for a 16 ga at .740.  But, Husqvarna made numerous 16 ga shotguns, and I measured them and they're 1.050 like a #5, so only about .040 bigger than the remington shotguns. 

I measured the minor diameter of a shotgun action (too lazy to pull the barrel to measure the major dia) and it is .040" larger than the #1 action.  I measured several #1 and #5 actions and barrels to check them.

Given that, I would agree with the numbers that Frnkeore gives, at .970 and 1.050 for the #1 and #5, and 1.010 is what I calculate for the shotgun action.  Mine has the long, thin sporter bottom tang, as well as the narrow top tang.  But, has the patent markings on the top tang, undisturbed, so it was not thinned from a military.

dave

Dave I don't know if it was a sporter or a military action, I don't have any knowledge at all when it comes to the Rolling Blocks.

J.Louis