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Discussion Starter · #1 · (Edited)
I'd like to hear from people who have swapped higher=pressure cartridges onto these (edited to specify "SB2") SB2 frames that [email protected] would refuse to fit higher pressure cartridge barrels to.

Any issues with frames loosening up, etc?

I like the idea of a .308, or ??? barrel but do not want to put my only receiver in jeopardy.
 

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If you're speaking about sb2 frames that were originally fit to high pressure rifle cartridges like my original .243 from 1996 then I say no problem. If it's been proof tested for over 20 years that means something to me.

Let's ask Tim. He knows all.
 

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I made a subtle correction in your question, anything made in 1986 will have a cast iron frame, NEF started making SB2 frames in 1987. H&R's standard for high pressure barrel fits to the early SB2 frames had more to do with "who" made them than metallurgy.

Tim
 

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Take your stock off. SB1 (low pressure) on left. SB2 (high pressure) on right.
Auto part Machine Metal Gas Household hardware
 

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I have similarly thought about all of us who have converted to 357 Max on an SB-1 frame. Is there any evidence of the early 30-30 guns or the SB-1 converted guns getting frame stretch? I don't think they would blow up in a literal sense but do think the softer iron will stretch. In our Handi it sees about 1K 38Spc. and 357 Mag a year and about 200 357 Max loads working up to deer season. After 10 years and six kids I have not noticed any appreciable wear.
 

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357 max and 30-30 both are less pressure and bolt thrust than 44 mag iirc. I am not hugely concerned with my 357 max on sb1 equivalent. Especially since my supply of 357 max brass means I won't ever be shooting that many rounds of it off much like you.
 

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I have similarly thought about all of us who have converted to 357 Max on an SB-1 frame. Is there any evidence of the early 30-30 guns or the SB-1 converted guns getting frame stretch?
There were no SB1 (or SB2) frames before 1987, all their single shot frames were ductile cast iron similar to SB1, both the Maxi and 44 Mag were factory options on the M258 Handy Gun II combos 1982-86. I think frame stretch is a Contender thing, never seen such on any H&R, the internal action is where the flex happens, specifically the pin that supports the barrel catch, the weaker point on all of them is the underlug which is soft, probably designed that way from looking at how they're made.

Tim
 

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357 max and 30-30 both are less pressure and bolt thrust than 44 mag iirc. I am not hugely concerned with my 357 max on sb1 equivalent. Especially since my supply of 357 max brass means I won't ever be shooting that many rounds of it off much like you.
Pressure isn't the only factor to consider, internal case head area and pressure determine breech thrust, for a relative ball park comparison here are breech thrust figures based on external diameter of the case head and SAAMI pressure for the 3 rounds, actual pressure would be less since the calculation is based on the internal case head area, not the OD, but they're still relative. The case head size and pressure is why there were no magnum rifle chamberings offered by H&R, or why no one makes short mag chamberings for the Encore, the huge .555" case head and 65kpsi pressure are just too much for the platform.

Tim

30-30 .422" @ 42kpsi = 5874psi
357 Max .379" @ 40kpsi = 4513psi
44mag .457" @ 36kpsi =5905psi

Max Chamber Pressure - SAAMI Specs (lasc.us)

A Look at Bolt Lug Strength - Lilja : Lilja (riflebarrels.com)
 

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Tim, I am surprised to hear that the barrel lug is the weak point on these. I would have though frame stretch and then you would see some headspace issues. Have you actually seen any evidence of lugs separating?
 

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If you're speaking about sb2 frames that were originally fit to high pressure rifle cartridges like my original .243 from 1996 then I say no problem. If it's been proof tested for over 20 years that means something to me.

Let's ask Tim. He knows all.
Sorry, Dave, but, I had to lol at what you said. "Give it to Timmy. He hates everything!
<pause> He likes it! Timmy likes it!"
(You may not be old enough to get it either)
 

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I have a topper cast iron frame that has a round depression in the breech face where the case head rests against it. I'm thinking that could be a weak spot where the breech wall deformed from the stress of the cartridge pressure.

Either that or it was made that way and I never noticed it before!
 

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Tim, I am surprised to hear that the barrel lug is the weak point on these. I would have though frame stretch and then you would see some headspace issues. Have you actually seen any evidence of lugs separating?
There ya go with that frame stretch myth again, no such thing on an SB2, the underlug is the relief point for excess pressure, there have been many reports of loose barrels due to underlug setback and wear on well used guns, one 38-55 owners shot the barrel loose after 3000+ rounds, most likely just from wear over the years, how many here lube the pivot on their guns? Here's an extreme example of frame strength when a 7.62x39 round was fired in a 243, barrel wouldn't break open after the shot, was sent to H&R, underlug was setback, but frame was fine, they put a new barrel on it and returned it.

Tim



Guys...Guys...this was easily cleared up...I just got off the phone too with Gordon at H&R...and asked him exactly what was bent on the barrel,and as Matt had already stated...the reciever was fine..it wasn't stretched..nor was the hinge pin bent...it was the underlug...the barrel itself was fine...they had already checked the chamber and rifling...all seem ok to them...so they were in the process of putting it back on the reciever to test fire it when they found it to just wobble and wouldn't lock back up....He did say that a piece of the case was missing...and don't know if it just fell out or went down the barrel...but everything else was fine otherwise.This just goes to show you that the gun is a lot stronger than it is normally thought to be...and I for one am glad it has been worked out for the concerned parties involved.

As with any serious mishap like this...the most preudent thing one can do is to call the company and see what appropiate steps are to be taken.NEF ...and the folks who work in the customer service department are easy to work with and go out of their way to make things right for us,even when it's our own fault.

:D


Mac
 
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