Barrel to Frame Gap on Break Open Guns

ckpj99 · June 7, 2015, 12:59 PM

I'm trying to understand barrel to frame gap on break open guns.

From what I understand a little gap is generally fine (maybe even expected?).

I recently bought a H&R Buffalo Classic in 45/70. It's was used, but LNIB. I've put about 20 rounds through it. It's surprisingly accurate with my reloads, which were originally developed for another gun.

It locks up tight. I've sort of fallen in love with the gun already.

That being said, there is a small gap between the barrel and recoil shield/frame/whatever-you-want-to-call it when you close the gun.

Is this a big problem? Will it cause the gun to wear faster?

Drm50 · June 7, 2015, 09:45 PM

I have some experience with the NEF/H&R and Savage 24s. The only problems
with the NEF was the forearm bushing. They are prone to come off,this usually
happens in just a few rounds. If it is bad weld job it comes off, if not stays on forever, this is true in all calibre and gauges. Having said that I have never had trouble with headspace in low pressure cartridges, 45/70 44mg even 30/30.
I did have to return several in 243 & 270. They were busting primers and throwing fire & smoke. The savage 24 with 223 barrel on top of shotgun was
the worst for this. It was so bad I quit selling them and refunded customers
money when they brought them in with complaints. The distributor I was buying
them from was making it good with his dealers. I "think" metal in NEF will take
the pressure, the gap is just design. The Savage reciever is soft, it will actually
get worse with use.

Axelwik · June 14, 2015, 09:17 AM

I have a Thompson Center Encore which is a break-open. There should be a bit of a gap. As long as the action locks and there's no excessive headspace it should be fine.

I shoot 270 Win. to 375 H&H Mag with that gun with no problems.

darkgael · June 16, 2015, 08:07 AM

Gap? What gap? How much of a gap are we talking about? I have a dozen break open guns...shotguns, rifles, pistols.....there is no observable gap on any of them.
I just checked two break open guns - a BT-99 and a T/C Contender (two barrels) - there is no observable gap to be seen when the gun is closed.
A gap between the standing breech and the barrel means that the barrel is "off the face" ....this is not normal. Firing a cartridge "off the face" allows the case to stretch so as to fill the space between the barrel and the standing breech. Case stretching at the head of the case will eventually cause case head failure (if you reload the cases). As to the gun itself...have you ever heard of a crack getting smaller?
Pete

Jim Watson · June 16, 2015, 09:36 AM

A quality break action gun should close hard on a piece of tissue paper, if at all. A gap there is known as being "off the face" and is a sign of wear or low quality.

mapsjanhere · June 16, 2015, 05:20 PM

The important question is - does the gap affect the head space of the gun? AKA does the gap also exist between the cartridge and the breech face? Take an unprimered case, load firmly, and cock. Then insert a feeler gage. If you can't get in between case and breech face, you're good. If the gap is all the way down you have a head space issue, and I would consider the gun unsafe.

James K · June 16, 2015, 08:36 PM

First, we need to understand that the barrels swing down, so there has to be some clearance at the standing breech in order to do that; barrels that fitted the breech tightly could not open. Very precisely fitted double guns have the breech slightly concave and the barrels slightly convex, so they are arcs of a circle centered on the hinge pin. But you don't get that kind of fitting for $19.95 (which is what an H&R or IJ single barrel shotgun cost when I started working in a gun shop. So there has to be some gap to allow the gun to function.

As long as the gap is small and does not increase, there probably is no problem.

Jim

June 7, 2015, 12:59 PM	#1
ckpj99 Senior Member Join Date: January 24, 2011 Posts: 386	Barrel to Frame Gap on Break Open Guns I'm trying to understand barrel to frame gap on break open guns. From what I understand a little gap is generally fine (maybe even expected?). I recently bought a H&R Buffalo Classic in 45/70. It's was used, but LNIB. I've put about 20 rounds through it. It's surprisingly accurate with my reloads, which were originally developed for another gun. It locks up tight. I've sort of fallen in love with the gun already. That being said, there is a small gap between the barrel and recoil shield/frame/whatever-you-want-to-call it when you close the gun. Is this a big problem? Will it cause the gun to wear faster?

June 7, 2015, 09:45 PM	#2
Drm50 Senior Member Join Date: November 10, 2014 Posts: 1,382	Break opens I have some experience with the NEF/H&R and Savage 24s. The only problems with the NEF was the forearm bushing. They are prone to come off,this usually happens in just a few rounds. If it is bad weld job it comes off, if not stays on forever, this is true in all calibre and gauges. Having said that I have never had trouble with headspace in low pressure cartridges, 45/70 44mg even 30/30. I did have to return several in 243 & 270. They were busting primers and throwing fire & smoke. The savage 24 with 223 barrel on top of shotgun was the worst for this. It was so bad I quit selling them and refunded customers money when they brought them in with complaints. The distributor I was buying them from was making it good with his dealers. I "think" metal in NEF will take the pressure, the gap is just design. The Savage reciever is soft, it will actually get worse with use.

June 16, 2015, 08:07 AM	#4
darkgael Senior Member Join Date: February 9, 2006 Location: Homes in Brooklyn, NY and in Pennsylvania. Posts: 5,473	Gap? Gap? What gap? How much of a gap are we talking about? I have a dozen break open guns...shotguns, rifles, pistols.....there is no observable gap on any of them. I just checked two break open guns - a BT-99 and a T/C Contender (two barrels) - there is no observable gap to be seen when the gun is closed. A gap between the standing breech and the barrel means that the barrel is "off the face" ....this is not normal. Firing a cartridge "off the face" allows the case to stretch so as to fill the space between the barrel and the standing breech. Case stretching at the head of the case will eventually cause case head failure (if you reload the cases). As to the gun itself...have you ever heard of a crack getting smaller? Pete __________________ “Auto racing, bull fighting, and mountain climbing are the only real sports ... all others are games.” Ernest Hemingway ... NRA Life Member

June 16, 2015, 05:20 PM	#6
mapsjanhere Senior Member Join Date: August 6, 2009 Location: Albuquerque Posts: 2,832	The important question is - does the gap affect the head space of the gun? AKA does the gap also exist between the cartridge and the breech face? Take an unprimered case, load firmly, and cock. Then insert a feeler gage. If you can't get in between case and breech face, you're good. If the gap is all the way down you have a head space issue, and I would consider the gun unsafe. __________________ I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.

June 14, 2015, 09:17 AM	#3
Axelwik Senior Member Join Date: March 12, 2012 Location: Land of Enchantment Posts: 436	I have a Thompson Center Encore which is a break-open. There should be a bit of a gap. As long as the action locks and there's no excessive headspace it should be fine. I shoot 270 Win. to 375 H&H Mag with that gun with no problems.

June 16, 2015, 09:36 AM	#5
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	A quality break action gun should close hard on a piece of tissue paper, if at all. A gap there is known as being "off the face" and is a sign of wear or low quality.

June 16, 2015, 08:36 PM	#7
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	First, we need to understand that the barrels swing down, so there has to be some clearance at the standing breech in order to do that; barrels that fitted the breech tightly could not open. Very precisely fitted double guns have the breech slightly concave and the barrels slightly convex, so they are arcs of a circle centered on the hinge pin. But you don't get that kind of fitting for $19.95 (which is what an H&R or IJ single barrel shotgun cost when I started working in a gun shop. So there has to be some gap to allow the gun to function. As long as the gap is small and does not increase, there probably is no problem. Jim