SB-1 Frame Internet Research

[yukonjim]

Well since there has been a lot of information posted on the different between sb-1 and sb-2 frames, I thought I would do a little research.  I wanted to find out exactly what the heat treatment is of the sb-1 frame and how much pressure it would handle.   Here is what information that I found.  It comes for the Internet sites referenced below and I assume no liability as to it’s the accuracy or how it is applied.

1) NEF is a member of the Sporting Arms and Ammunition Manufactures Institute (SAAMI).  Ref: http://www.chuckhawks.com/no_standards.htm  SAAMI is An Accredited Standards Developer For The American National Standards Institute (ANSI).  SAAMI sets the standard for proof tests.  Here is the link:  http://www.saami.org/ansi.html

2) SAAMI sets the standard for proof testing of firearms in ANSI Standard ANSI/SAAMI Z299.5-85.
 
3) NEF states in their barrel accessory program web page that: “Shotgun frames may be fitted with additional shotgun and muzzleloader barrels only.”  http://www.hr1871.com/barrelAcc/index.htm.  In their description of the .50 Caliber Sidekick and Huntsman Muzzleloaders it states that the finish is a:  “Color case-hardened frame”.  http://www.hr1871.com/firearms/index.php?cat=1

4) If NEF says that shotgun frames (sb-1) can be fitted with muzzleloader barrels then apparently they are strong enough to handle the same pressures as a muzzleloader.  The sb-1 shotgun frame looks, in the pictures, the same as the muzzleloader frame (i.e. color).  Therefore based on what NEF says and the color, the shotgun frame must be the same frame as the muzzleloader.  If this is true then apparently the shotgun frame is case-hardened and has the same strength as a muzzleloader frame.

5) The next question is what is the muzzleloader frame pressure rating.  Chuck Hawks Muzzleloader Information website has a section entitled “No Muzzleloading Standards”.  http://www.chuckhawks.com/no_standards.htm.  In the narrative the author, Randy Wakeman, states that: “The NEF Huntsman is based on a smokeless rated action, accepts center fire cartridge barrels, and is a form 4473 firearm as a result.”  Where the author got this information is unknown.  However if his information is correct then muzzleloader and shotgun frames could accept center fire rifle barrels.  I could not find any information on the Internet to verify this statement.  I believe it is incorrect and a rifle barrel should never be used on a sb-1 shotgun frame.

6) From the SAAMI proof test table as obtained from: http://home.sprynet.com/~frfrog2/miscellk.htm#proof, the minimum proof pressure test is 1.55 times the maximum average working pressure and the maximum proof test is 1.70 times the maximum average working pressure.  The maximum working pressure, as obtained from the same website, for a 12 gauge shot shell with a 3 inch chamber is 12,000psi.   Using the maximum working pressure of 12,000psi and rounding up for the minimum proof and down for the maximum proof pressures as suggested the proof test table. The minimum proof would be 12,000psi times 1.55 or 18,600psi.  The maximum proof pressure would be 11,000psi times 1.70 or 18,700psi.
 
7) Looking at the cartridge pressure tables on the above site, http://home.sprynet.com/~frfrog2/miscellk.htm#proof, it would appear that a NEF shotgun barrel should be capable of handing some of the popular pistol cartridges.

The information presented here was obtained from the above referenced Internet sites and is for information purposes only.   I assume no liability as its accuracy.  I also assume no liability as to how this information is used.

yukonjim

[Busta]

yukonjim,

The SB-1 frame is for the H&R/NEF Shotguns (.410-standard 12ga) and Huntsman Muzzleloaders. These frames CANNOT be fitted with CENTER FIRE RIFLE barrels period. Color Case Hardened SB-1 Frame is NOT a Hardened SB-2 Rifle frame.

The SB-2 Center fire Rifle Frame is a HARDENED Frame and CAN accept all ceneter fire rifle barrels, shotgun barrels and Huntsman Muzzleloader barrels.

There is also a SB-2 10ga Shotgun Frame that is a larger frame that accepts all 10ga barrels and the 12ga Ultra Slug Hunter barrel that is a 10ga blank bored to 12ga rifled.

There is one Huntsman .50 cal muzzleloader barrel/.243 center fire rifle barrel Combo that uses the SB-2 frame. The other Huntsman .50 cal/12 ga barreled combo's use the SB-1 Frame.

Now in the OLD DAYS they used to put low pressure center fire barrels on the same frame as the shotguns such as the .45-70, they NO LONGER will fit rifle barrels to shotgun SB-1 frames.

5) The next question is what is the muzzleloader frame pressure rating. Chuck Hawks Muzzleloader Information website has a section entitled “No Muzzleloading Standards”. http://www.chuckhawks.com/no_standards.htm. In the narrative the author, Randy Wakeman, states that: “The NEF Huntsman is based on a smokeless rated action, accepts center fire cartridge barrels, and is a form 4473 firearm as a result.” Where the author got this information is unknown. However if his information is correct then muzzleloader and shotgun frames will accept center fire rifle barrels. I could not find any information on the Internet to verify this statement.

The statement that the Huntsman accepts center fire cartridge barrels is JUST NOT SO, unless it is the SB-2 Frame from the Huntsman/.243 COMBO previously mentioned above.

I hope that answers your questions.

[yukonjim]

Busta,

Apparently when you read the post you didn't understand it.  Nowhere did it say the sb-1 and sb-2 frames were the same.  In additional it was clearly stated that in the article referenced from Chuck Hawks Muzzleloader Information site about Huntsman muzzleloaders accepting rifle barrels could not be verified.  The reference stated Huntsman Muzzleloader not sb-1 frame.  All the information quoted is referenced with links so you can verify where it was obtained and draw your on conclusion.  Nowhere in the post was a clarification asked for.

Your statement that: "The SB-2 Center fire Rifle Frame is a HARDENED Frame and CAN accept all ceneter fire rifle barrels, shotgun barrels and Huntsman Muzzleloader barrels."  Both sb-1 and sb-2 are hardened frames.  The difference being the heat treatment process.  Sb-1 frames are case hardened per the NEF website.  In addition your statement that: "These frames CANNOT be fitted with CENTER FIRE RIFLE barrels period. " is not intirely correct.  Dimensionally the frames are identical.

As for case hardening it is a form of heat treatment.  Case hardening is a process of surface hardening involving a change in the composition of the outer layer of an iron-based alloy by inward diffusion from a gas or liquid followed by appropriate thermal treatment.  Typical hardening processes are carburizing, cyanding, carbo-nitriding, and nitriding. Ref: Modern Steels and Their Properties, Bethlehem Steel, Sixth Edition, 1967.

yukonjim

[Busta]

yukonjim,

Well, I didn't mean to step on your toes. I drew my own conclusion, and concluded that some of your information was misleading. We do have people that are new to these H&R/NEF's and I didn't want someone to have to challenge your disclaimer FOR SAFETY SAKE. The company will not put center fire Rifle barrels on SB-1 frames and DOES NOT recommend it is what I should have said.

Of course the rifle barrels will fit a SB-1 receiver but that doesn't mean that they should try it. The SB-1 receiver has not went through the same hardening process as a SB-2 Center Fire Rifle receiver and would more than likely lead to frame stretch, not to mention an UNSAFE CONDITION.

The information from Chuck Hawks is not correct and I didn't want some new guy putting a high chamber pressure center fire rifle barrel on a frame that may not be up to the task, that's all. Safety first!

This is from your first post, would you clarify please?

Well since there has been a lot of information posted on the different between sb-1 and sb-1 frames, I thought I would do a little research.

[yukonjim]

Busta,

No problem. I corrected the second sb-1 to sb-2 on my writeup.  Thanks for pointing out the mistake.  I know there are a lot of new guys on the site and they probably read post after post about sb-1 and sb-2 frames.  The intent was to provide as much info as possible on the sb-1 frame to help clarify things.  That is the reason for all the links where I obtained the info.  That way people can go there and see for themselves.  I agree that no one should put a rifle barrel on a NEF shotgun sb-1 frame.  Dangerous to say the least.  As I stated, I could not find anything on the Internet to collaberate the statement from Chuck Hawks site about the Huntsman Muzzleloader.  I believe it is incorrect and added a statement as such.

(Edited orginal post 11/27/2004)

yukonjim

[Cement Man]

I think Randy Wakeman's statement, as you quoted it, is entirely correct and he was not suggesting at all that rifle barrels should be installed on the shotgun frames.   As you quote - " a smokeless rated action, accepts centerfire cartridge barrels, makes it a 4473 firearm", that is correct. As  much as we have become used to using the term cartridge to mean a single projectile loaded in a case, the literal definition of a cartridge is " a tube of metal, paper, or both containing a complete charge for a firearm and usually an initiating device such as a primer". (Webster)  This would include shotshells.  I usually don't refer to shotshells as cartridges either, but by definition they are, and that is what makes it a 4473 firearm.  We all agree that the rifle barrels belong only on the rifle frames.  From reading many posts over the years, I know some folks push the limits when it comes to swapping barrels, tapping for scope mounts, etc., etc. but I don't think its a good idea.  Anyway, I am looking forward to someday owning a Sidekick.  Good shootin' and Happy Holidays to you.