heat treated vs. non treated receivers

[Dr. John H. Stone]

I just bought a receiver which I am using on a SMI smokeless barrel conversion.. I see posts directed that shotgun receivers cannot be used on rifles,, so I think mine is a shotgun receiver if so is this unsafe as pressures reach about 40,000 psi.??  SB2  vs SB1  , I can't find this designation on my receiver  just a NN serial number,. Someone please enlighten,,
thanks much '
Doc Stone :-)

[Fred M]

Doc Stone.
Only the barrel are marrked SB2 not the frame which I think is wrong both should be marke what they are.

As you realize shot shells are loaded in the 12kps range some gages a bit more.

So a shotgun frame is not designed to handle 40kpsi. What they are actually stand will not be devulged by H&R.

Now how you supposed to tell which is an SB2 and which is an SB1 if you have only one or the other without a barrel, I do not know.

You should forward this question to H&R to be sure..
I would not fire 40kpsi loads in a frame that I do not know what it is. Ser# will tell if you know what codes been used.

Both frames are made by investment casting. But the material used for one or the other must be different.
For the few pennies saved they should be all the same  strength.

[Dr. John H. Stone]

Thanks so much guys, I'm new to NEF and this board but you guys sure jump in to help. I'll call NEF asap to find out for sure what I've got..
I've got my  NEF survival rifle in 308 shooting in spades now w/ the rubber washer..  crazy...
Also the SMI smokeless barrel is shooting into MOA  @ 100 yds.. Life is goood!!!!!!
thanks,
Doc :-)

[trotterlg]

Out of curiosity a month or two back I did some frame load calculations with different cartridges both shotgun and rifle, I did post the calculations.  Seems there is some overlap in the actucal frame loads seen by the larger high power shotgun loads and the low pressure smaller centerfire rifle rounds.  I think a 30-30 is less than a 12 gauge magnum load.  I was just using the area of the cartridge and it's maximum pressure to calculate the load on the frame.  Some of the older Huntsman muzzel loaders used a push in breach plug that was held in by the frame, apparently these were discontinued when a few people were shot in the head by the breach plug when opening the rifle after a hang fire.  Larry

[Paul5388]

It seems like some of the rifle frames are case hardened, like the Buffalo Classic and some of the shotguns are blued.  That makes it close to impossible to look at a receiver and tell what it is.

As Tim said, calling NEF with the serial number is the only way to tell.

[Busta]

I just bought a receiver which I am using on a SMI smokeless barrel conversion.. I see posts directed that shotgun receivers cannot be used on rifles,, so I think mine is a shotgun receiver if so is this unsafe as pressures reach about 40,000 psi.??  SB2  vs SB1  , I can't find this designation on my receiver  just a NN serial number,. Someone please enlighten,,
thanks much '
Doc Stone :-)

Doc Stone,

You are fine with a SB-1 shotgun receiver for the SMI barrel, they have been putting them on those frames since 1984. The breech plug and barrel contain all the pressure, thus the whole frame and barrel recoil together. Now with high pressure center fire cartridges it would be another story since the cartridge case would recoil back into the standing breech and in due time your frame would stretch causing an unsafe condition. Give Ron or Joe Name a call at SMI to put your concerns to rest.

http://www.smokelessmuzzleloading.com/

[Busta]

Now how you supposed to tell which is an SB2 and which is an SB1 if you have only one or the other without a barrel, I do not know.

This post is for everyone, not just you Fred.

There are three things that stand out on a SB-2 rifle frame to be able to tell it apart from a SB-1 shotgun frame. Wish I had my new digital camera, maybe someone could take a pic of the differences and post them in the stickies. Quick? I know you don't have a shortage of frames. :grin:

The front of the SB-2 frame where the forend hinges has a lip machined around the radius to where the spacer only makes contact with the outer most edge. The SB-1 frame will have a uniform radius all the way accross. You will need to remove the forend to see this


The inside of the SB-2 frame is machined smooth while the SB-1 frame will show the casting marks from the mould. You will need to remove barrel from frame to see this.

The firing pin on the SB-2 frame is much smaller in diameter than the SB-1 frames shotgun sized firing pin. I believe the smaller rifle firing pin and firing pin hole is for keeping the high pressure rifle's primers from flowing back into this hole and therefore locking up the breech.

There may be other differences, but those are the ones that stand out to me. The older rifle frames may be different, my SB-2 example is about 5 years old and it is a Ultra Varmint. I also have several SB-1 examples and they are consistent.

Hopefully someone can post some pics of a side by side comparison of the two frames.

[quickdtoo]

Busta, I only have 2 SB1 frames, a Topper and a Pardner, the rest are late model SB2 frames. I'll check em to see if those differences stand out and take a pic if they do.

Thanks!!

[Dr. John H. Stone]

thanks guys , you're GREATTTTTTTTTTT, to quote Tony the Tiger..
stay tuned as I know I'll have other newbie questions..
Doc :-)

[quickdtoo]

I forgot, I have a '96 RMEF 35 Whelen, since it's pre '99, I'll see if there's any difference tween it and the post '99 high pressure SB2 frames. Pics to follow.... :wink:

[Mac11700]

Here's a look at one of the newer nickle receivers off a Topper Deluxe Classic...if this helps..



Mac

[Busta]

Thanks Mac, that is a SB-1 frame everyone. It will look the same weather it is blued, color case hardened or nickle in my examples.

Notice the large diameter firing pin hole and firing pin. The SB-2 has a much smaller diameter hole and pin.

Notice the rough texture and casting lines down inside the frame. The SB-2 frame will be much smoother with no visible casting lines.

Notice the leading edge of the frame has a uniform radius all the way accross. The SB-2 frame has a lip that protrudes slightly all the way around this contact point that is very noticable.

These are the three things that jump out at you. Of course the SB-2 frame is also much harder and just has a certain feel and sound to it when installing barrels.

Now if we had a side by side pic of both frames exactly the way Mac has posted this, the differences would be very evident to everyone. This would be nice to have in the FAQ's up in the stickies.

[quickdtoo]

Here they are, as promised!! :wink:  Frames left to right...'91 SB1 Pardner, '03 SB1 Topper, '96 SB2 Ultra, '04 SB2 Handi....

The bottom pic shows the major difference tween the two, the SB1 frame is solid at the stock mating surface while the SB2 is skeletonized.

[MSP Ret]

Great work Tim!!! Can you get that in the FAQ stickys?....<><.... :grin:

[Busta]

Thanks Quick!

By the looks of things, there may be a couple different variations of SB-2 frames out there. Mine is not exactly like either of your examples. Mine looks like the third one on the radiused part in the front, like your fourth one as far as firing pin and hole size but mine (2000 or 2001 Ultra) does not have a number or any other marking down inside. :?  

Another feature that is now apparent in your pics is the gap from the hinge pin to the front of the frame. It is much larger on the SB-2 frames.

All my SB-1 frames are just like your first two examples.

Very evident that the SB-2 frame is manufactured with a completely different process than the poured cast SB-1 frame is.

Not exactly sure of the process of manufacture for the SB-2 frame, but it appears to by a pressure injection molding type of casting probably similar to the way the G5 broadheads are made. This would make a much stronger casting and would minimize or eliminate any types of voids so common in old fasioned poured castings.

Thanks for the pics and sticky. It should be able to help people determine which frame they have in an instant.

[blackpowderbill]

A few years back I read someplace that the receiver of the SB-1 is made of cast ductile iron while the SB-2 is made of steel. I noticed that my 45-70 SB-2 has a nicely blued receiver indicating it would be steel, Iron does not blue well. All the SB-1s I have worked with have been either plated or flame coloured.

[quickdtoo]

SB2 frames are investment cast alloy that are heat treated. Rimfire SS1 frames are also blued as are many Pardner frames, the blued appearance, whether matte or gloss is not a good way to tell the difference.  The internal appearance is more telling, as is the large firing pin of the shotgun and Huntsman frames. But in the end, call H&R to determine what barrels can be used on the frame, that's the only safe way to know for sure.

Tim

[blacksan]

Hmmmm, what about this frame? A few days ago I finally picked up a 30-30 Handi from an owner that purchased it new just a few years ago and never fired it. It's marked SB-2 on the barrel but the frame has a NM designator. Just glancing over the frame it appears to be an SB-2 with the small firing pin hole, milled/recessed area at the front of the action and pretty smooth interior finish that does not display the rough casting of the SB-1 frame. I understand that the M designator donates an outsourced frame that was not manufactured in 30-30 configuration? It's feasible that this rifle sat for years on a dealers rack but I do know that it was new when purchased (I know the previous owner) and not assembled from parts after the fact. So, is this an SB-2 frame?

[Spanky]

If it came straight from the factory and the barrel is marked SB2 it is an SB2 frame.



Spanky

[D Humbarger]

(some of the rifle frames are case hardened, like the Buffalo Classic )

I would bet that those frames are actually "case colored"  rather than  "case hardened".

[quickdtoo]

Blacksan, the best way to tell an SB1 from and SB2 is to remove the stock, or at least loosen the stock bolt enough to see if the tang of the frame is solid around the bolt hole(SB1) or skeletonized(SB2). Even if you called H&R to check by serial number, they'd tell you they'd only fit the same barrels to it as an SB1.

The BC frame is the same heat treated investment cast alloy steel SB2 frame as the Handi, it just has a faux case coloring that doesn't look anything like a real color case hardened cast iron frame.

Tim

[medicdogg]

Tim,
Not to dispute you but I have a SB1 frame that is skeletonized.  I beleive it to be a pardner but I will check.  I know that it is a shotgun frame though.

[gcrank1]

Or, is it a shotgun on an SB-2 frame (that makes more sense than it being an SB-1 with SB-2 features).
Does it have a large shotgun type firing pin or the smaller rifle type pin?

[medicdogg]

I was wrong about it being a pardner, it is a topper 158, doesnt have a serial number and yes its a shotgun frame but they did make some 158's with rifle barrels if Im not mistaken.

Second pic doesnt show too well but it has a rough cast interior and larger firing pin.  I have changed the internal parts for ones from a pardner.

[quickdtoo]

The M158 is neither an SB1 or SB2, H&R Inc(went out of business in late 1986) didn't have any designation of frames other than model number, H&R1871 first started making them in very late 1986, that's the reason why they won't fit accessory barrels to frames made before 1987 that don't have two letter serial number prefixes that start with N or H. 

Tim

http://www.hr1871.com/Support/accessoryProgram.asp

Additional barrels may be added to firearms of our manufacture since 1987 only, with a serial number that begins with N or H. We do not install additional barrels on any other manufacturer’s firearms.

[medicdogg]

Yep, thats what I thought but isnt it odd that it is skeletonized like the SB2 frames.

[quickdtoo]

It really isn't tho, it's more like an SB1 with a couple small voids.

Tim