Hi Power barrel change.

Jms920 · August 1, 2014, 12:33 PM

When replacing a FN Hi Power barrel with a stock FN barrel, is fitting required or is it simply a drop in job?

Dixie Gunsmithing · August 1, 2014, 11:03 PM

Ideally, it should fit, but it pays to check the locking lugs by using some layout fluid/layout blue, then working the action, and finally looking at the rub pattern on the barrels lugs to see the fit.

Why are you having to change out the barrel? The reason I ask is, I have had customers think the barrel was bad when they see a small crack around the chamber of the barrel. This will happen on about all Hi-Powers, and that shows up when the barrel stretches later on in its life, where the crack is from the joining of the breech/chamber end to the barrel, and was hidden by polishing. The barrel on these is safe, and I have seen plenty do this. I just thought I would throw that in for the others reading.

tangolima · August 2, 2014, 04:48 AM

I will check loose breech on the old barrel and the new. If they are both loose, damage has been done on the slide. Then you know what else needs to be replaced or fixed.

-TL

Dixie Gunsmithing · August 2, 2014, 10:24 AM

I forgot to add, earlier, that the Browning Hi-Power will not handle hot loaded +P high pressure rounds well at all. On my gun, I use regular ball ammo, by Federal, nothing fancy. The high pressure rounds will definitely batter the locking lugs on both the barrel and the slide. The gun was literally not designed for some of the rounds that are now being made. Some will change out the recoil spring to 18+ pound, but I stick with the lower pressure rounds. These pistols are too expensive of a gun to take the chance.

Jms920 · August 2, 2014, 10:32 AM

Thank you for the replies, good information.

tangolima · August 2, 2014, 12:04 PM

Quote:

Originally Posted by Dixie Gunsmithing

I forgot to add, earlier, that the Browning Hi-Power will not handle hot loaded +P high pressure rounds well at all. On my gun, I use regular ball ammo, by Federal, nothing fancy. The high pressure rounds will definitely batter the locking lugs on both the barrel and the slide. The gun was literally not designed for some of the rounds that are now being made. Some will change out the recoil spring to 18+ pound, but I stick with the lower pressure rounds. These pistols are too expensive of a gun to take the chance.

I heard that too. The metal tends to be a bit soft. Loose breech is usual issue.

-TL

Huffmanite · August 2, 2014, 02:41 PM

Jeeeez, must have been circa 1966, when I replaced the FN hi-power barrel in the pistol an uncle brought back from Europe in WWII....was a combat infantry man in 4th Div. Think the FN pistol was made around 1942. Anyway original barrel had a nice bulge, so bought a replacement FN made barrel for it....cost around $15.

Been too long ago, but recall it was pretty much a drop in fit....but their was a burr or something on the new barrel I had to deal with for the new barrel to fit and function properly. Minor file or metal sandpaper work was needed.

Still have the pistol and it still shoots well.

Jms920 · August 2, 2014, 05:40 PM

Thanks Huffmanite.

Dixie Gunsmithing · August 3, 2014, 09:51 AM

tangolima,

The Hi-Power was designed around the original 9mm Luger round, or 9×19mm Parabellum, with its original chamber pressure, and the design has essentially not changed since, unless they changed the steel type used in its manufacture. Anyhow, anything that ammo manufacturers do to raise the chamber pressure above the original specs on the cartridge, or increased recoil, will place extra stress on this gun.

John Browning was working on this gun when he died at Belgium, and its design, (GP-35), was finished by another FN designer, Dieudonné Saive, and Val Browning. They made the gun as light-weight as possible, to fit the hand better than the 1911, and with a larger magazine capacity. That was the requirements of the French Military, whom were wanting the new pistol. The problem with this, is that it is weak when handling anything other than the ammo it was designed to handle, or any new 9mm rounds after 1934-1935, that produced higher chamber pressures or higher recoil.

As a note, I believe the barrel was changed later on from a one piece barrel, to a two piece construction to make it easier to manufacture. Here, they mated a chamber and lug piece to a barrel, and they were brazed together. This is why the gun shows the small crack/seam around the barrel, and it looks like it starts right at the end of the chamber, and the start of the rifling, or it appears to. When you inspect the inside, you can't see this seam. I have ran into this a lot on these pistols. I think firing hot rounds might be why this shows up early on some pistols as compared to others that did later on.

tangolima · August 3, 2014, 09:32 PM

Thanks. Good to know.

I was actually looking at the Kareen, the Israeli clone of the hi power. You think it handles the modern rounds better? It doesn't matter really as I hand load, and I don't load my rounds hot anyway.

-TL

James K · August 3, 2014, 10:10 PM

To put more icing on the cake, wartime HP's were often sabotaged by the Belgian workers by ruining the steel or "forgetting" to heat treat the slides and barrels; the guns just got by proof and inspection, but will peen and hang up after only a few rounds.

Jim

tangolima · August 3, 2014, 10:20 PM

There was such a hi power in good shape for sale. I backed out of the deal for the exact reason.

-TL

Dixie Gunsmithing · August 3, 2014, 11:03 PM

Not just the pistol, but anything that came from FN after the occupation, and until it was over, as the workers sabotaged everything. If it has a Nazi mark, its a wall hanger. I think this happened to some other manufacturers, too, and I can't remember which right off, but they were lower in numbers.

Dixie Gunsmithing · August 3, 2014, 11:13 PM

tangolima,

They would have to use a tougher/harder steel for it to work, in both the barrel and the slide. Changing the recoil spring does nothing for the lugs getting battered, it only keeps the slide from flying back so hard.

I owned a FEG copy, and was happy with it, and I'd say the Israeli version is just as good. A lot of these are showing up now, where they've been retired from M & P duty all over Europe.

Dixie Gunsmithing · August 7, 2014, 09:13 AM

All,

Here is a great AGI video about loose breech pistols and barrel lockup with damaged lugs, by Bob Dunlap and Ken Brooks. It shows how to check for this, and described battered lugs, plus, the Browning Hi-Power is mentioned.

https://www.youtube.com/watch?featur...&v=ZOotIqOWHik

tangolima · August 7, 2014, 12:42 PM

Oh no. You just gave away my secret.

Loose breech is the thing I check when I am taking interest to purchase a semi auto. Surprisingly a lot of people haven't even heard of the term.

There is a more precise method to measure it if you get to field strip the pistol. The same principle applies so it is not hard to figure it out.

A pistol with excessive loose breech, especially with damage on the side, is mostly a money pit. It can be fixed, but the gun will never be the same again.

-TL

Dixie Gunsmithing · August 7, 2014, 02:12 PM

If you notice on the S&W auto that they show, it had another problem besides for/aft movement of the breech, but up and down too. That is why it cut the lug recess in a taper. Most all designs, including the 1911, have a unlocking delay in the lugs, as the slide travels rearward, before the lugs start to disengage. The 1911 does it by the link swinging a little past top center. These other types have a delay space built into the cam, which should not allow the lugs very much downward movement at all, until the bullet leaves the barrel and the slide reaches a point where the barrel does move down. The S&W looked to me that the lugs tried to drop out as soon as the slide started going back, which means the cam is worn down, or it was machined wrong (too much slop). To be honest, I think it was, along with the barrel lug being to shallow too compound it. It wouldn't be the first S&W to leave the factory screwed up. I've heard about whole lots of revolvers having to be sent back, with out-of-line cranes, from a dealer.

Even the Walthers and the Berettas have the unlocking delay, they just do it a little differently. The Hi-Power was the first to use a cam in place of a link, that I can think of, but a lot of the other companies followed similar methods after the fact.

Cossack · August 7, 2014, 05:57 PM

Here's Stephen A Camp's take on +p in the Hi Power: http://www.hipowersandhandguns.com/B...essureAmmo.htm

Back to the original question - were there any changes to the barrel or slide that would limit interchangeability of the barrel or slide? For example, could a new barrel from a MK III work in a pre-war gun or vice versa?

James K · August 7, 2014, 08:22 PM

On the two piece barrels, you can't see the seam inside because it isn't there. The full-length barrel is turned down at the back and the small end inserted into the part containing the lug. That allows barrels to be made in long lengths from bar stock, and then cut to size, a more economical system than making each barrel individually from a forging or from a large piece of bar stock.

I believe the parts are electric brazed together, not silver soldered.

Jim

Dixie Gunsmithing · August 8, 2014, 08:17 AM

Quote:

Back to the original question - were there any changes to the barrel or slide that would limit interchangeability of the barrel or slide? For example, could a new barrel from a MK III work in a pre-war gun or vice versa?

The only barrel change, is the two piece barrel, but the dimensional outside design hasn't changed, that I know of, but a call to Browning would verify that. Unless they made the newer barrels out of a better grade of steel, they would be the same. The main change between the first model to the MKIII are the sights and the safety. Here, a MKIII slide would not work on an older gun due to the firing pin safety. One might be able to convert it, but it might prove to be a big and expensive job. The MKIII supposed to handle +P, by some things I've read, and if the steel hasn't changed, then I don't see how.

Here is an article about the above:

http://milpas.cc/rifles/ZFiles/Pisto...gh%20Power.htm

Let me add that a barrel from a FEG, or an Israeli clone, might fit one as well, and save a good bit of money this way.

Cossack · August 8, 2014, 04:40 PM

Thanks for the link

Quote:

The MKIII supposed to handle +P, by some things I've read, and if the steel hasn't changed, then I don't see how.

The steel has changed - it's a cast frame on a MK III, which is supposedly much stronger. It's strong enough for .40 S&W, so I imagine it's also strong enough for 9mm +P.

Dixie Gunsmithing · August 8, 2014, 09:06 PM

Cossack,

Being cast shouldn't make a lot of difference, if it is the same material. It would still have the same yield and tensile strength properties. What would make a difference is the steel type, and now hard it was. Also, casting, without rolling, will not have the grain in the steel in the same direction. My guess is that they switched from something like carbon steel, similar to 1040, and used something like 4130 or 4140 Chromoly, which when quenched and tempered at its lowest, can get a yield of at least double, or around 100,000+ psi. Annealed, it runs around 60,000 psi. Anyhow, by casting, they save a bunch of work in machining, but the problem arises in heat treating, and controlling warpage of the part, which the gun makers have down pat pretty much anyhow. Generally, the part is made undersize, and is finish machined after its tempered, and with the tooling they have now, its not too hard. They didn't have this available in the later 1920's when the gun was first designed, and patented in the US.

The reason I say this, is I think the 40xx series of steels are war babies from WWII. This was developed for things such as aircraft tubing, and other parts of landing gear, engines, and in the newer rifles like the M-1. I am not sure what was available at Belgium in the 30's, though, but the war started not long after the guns release in 1935. They did have Nickel steel then.

On rolling of cast steel into billets, the steel takes a grain in the direction of the rolling. A mill just across the river, (HK Porter), came up with twisting red hot billets, making the grain spiral, and raised its toughness quite a bit. When cast, though, the direction can be every which way, which may not help, I'm not sure. Anyhow, they use this twisted steel in fork lift channels, which needs to be tough. It could be a combination of the two, using casting with different steel. If there is anyone on here working in metallurgy, I'd like to see a comment on it, as I always thought that rolled was tougher than cast due to the grain. Of course, if the steel was tough enough, I doubt it would matter.

Update:

Quote:

Grain Structure In Metal Rolling

In common industrial manufacturing industry, the ingot or continuous casting is hot rolled into a bloom or slab. In addition to producing a useful shape for further processing, the hot rolling process converts the cast grain structure into a wrought grain structure. The initial cast material will possess a non uniform grain structure, typically large columnar grains that grow in the direction of solidification. These structures are usually brittle with weak grain boundaries. Cast structure characteristically contains many defects such as porosity caused by gases, shrinkage cavities, and solid inclusions of foreign material that becomes trapped in the metal, such as metallic oxides.

Rolling a metal above its recrystallization temperature breaks apart the old grain structure and reforms a new one. Grain boundaries are destroyed and new tougher ones are formed, along with a more uniform grain structure. Metal rolling pushes material, closing up vacancies and cavities within the metal. In addition, hot rolling breaks up inclusions and distributes their material throughout the work.

From here:

http://thelibraryofmanufacturing.com/metal_rolling.html

James K · August 8, 2014, 10:24 PM

It is worth noting that there were at least two modifications to the barrel bottom lug. The first was replacement of the circular cam area with a squared off type. I believe the receiver cam was not changed and the barrels are interchangeable. That change was done at about the beginning of WWII before the German occupation.

The second change was made c. 1950, and involved dimensional changes to both the barrel bottom lug and the cam in the frame. Barrels from before and after the change are not interchangeable because the frames differ.

Note also that both the changes described were made only to FN pistols, with the first also being made to Inglis pistols; clone makers might or might not have incorporated either change, depending on the age of the BHP that they copied.

Jim

Cossack · August 9, 2014, 12:08 AM

Thanks, Jim, that tells me what I was looking for.

Dixie, I also appreciate the explanation. I figured there was more to it than cast vs. forged, especially since I usually hear of cast being less desirable, as in rifle receivers and pistol slides. The metal must be different, then. Thanks for explaining.

Dixie Gunsmithing · August 9, 2014, 12:37 AM

I read a little more about the history on the 40xx steel, and it is hard to dig up. Anyhow, they had this steel in the mid to late twenties, when it was first introduced for use in airplane frames as tubing that we were trying to copy from Fokker, after WWI. That was about all it was used for at the time, as they were using 1020, with 4130 sparingly for the high strength applications. Finally, they started using it solely later on, but its major use came about during WWII, when engineers started to design things stronger, but lighter. I think that was its first use in firearms, unless someone did earlier that I don't know about.

Since Browning is using a casting, it would have to be something way tougher than mild steel, or what they were using without changing the design, and something that would not crack or fail easily. I know the 40xx steels were being used a good amount through the 1950's, so I would say that may be what they converted to, unless they got into the 43xx steel. Anyhow, that's my guess at it. I enjoyed looking this up, as it never really occurred to me what the history was behind it.

August 1, 2014, 12:33 PM	#1
Jms920 Member Join Date: February 28, 2014 Posts: 27	Hi Power barrel change. When replacing a FN Hi Power barrel with a stock FN barrel, is fitting required or is it simply a drop in job?

August 2, 2014, 04:48 AM	#3
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,816	I will check loose breech on the old barrel and the new. If they are both loose, damage has been done on the slide. Then you know what else needs to be replaced or fixed. -TL Last edited by tangolima; August 2, 2014 at 12:01 PM.

August 3, 2014, 09:32 PM	#10
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,816	Thanks. Good to know. I was actually looking at the Kareen, the Israeli clone of the hi power. You think it handles the modern rounds better? It doesn't matter really as I hand load, and I don't load my rounds hot anyway. -TL Last edited by tangolima; August 3, 2014 at 10:18 PM.

August 1, 2014, 11:03 PM	#2
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	Ideally, it should fit, but it pays to check the locking lugs by using some layout fluid/layout blue, then working the action, and finally looking at the rub pattern on the barrels lugs to see the fit. Why are you having to change out the barrel? The reason I ask is, I have had customers think the barrel was bad when they see a small crack around the chamber of the barrel. This will happen on about all Hi-Powers, and that shows up when the barrel stretches later on in its life, where the crack is from the joining of the breech/chamber end to the barrel, and was hidden by polishing. The barrel on these is safe, and I have seen plenty do this. I just thought I would throw that in for the others reading.

August 2, 2014, 10:24 AM	#4
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	I forgot to add, earlier, that the Browning Hi-Power will not handle hot loaded +P high pressure rounds well at all. On my gun, I use regular ball ammo, by Federal, nothing fancy. The high pressure rounds will definitely batter the locking lugs on both the barrel and the slide. The gun was literally not designed for some of the rounds that are now being made. Some will change out the recoil spring to 18+ pound, but I stick with the lower pressure rounds. These pistols are too expensive of a gun to take the chance.

August 2, 2014, 10:32 AM	#5
Jms920 Member Join Date: February 28, 2014 Posts: 27	Thank you for the replies, good information.

August 2, 2014, 02:41 PM	#7
Huffmanite Senior Member Join Date: February 17, 2006 Location: Northeast of Houston, Tx Posts: 393	Jeeeez, must have been circa 1966, when I replaced the FN hi-power barrel in the pistol an uncle brought back from Europe in WWII....was a combat infantry man in 4th Div. Think the FN pistol was made around 1942. Anyway original barrel had a nice bulge, so bought a replacement FN made barrel for it....cost around $15. Been too long ago, but recall it was pretty much a drop in fit....but their was a burr or something on the new barrel I had to deal with for the new barrel to fit and function properly. Minor file or metal sandpaper work was needed. Still have the pistol and it still shoots well.

August 2, 2014, 05:40 PM	#8
Jms920 Member Join Date: February 28, 2014 Posts: 27	Thanks Huffmanite.

August 3, 2014, 09:51 AM	#9
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	tangolima, The Hi-Power was designed around the original 9mm Luger round, or 9×19mm Parabellum, with its original chamber pressure, and the design has essentially not changed since, unless they changed the steel type used in its manufacture. Anyhow, anything that ammo manufacturers do to raise the chamber pressure above the original specs on the cartridge, or increased recoil, will place extra stress on this gun. John Browning was working on this gun when he died at Belgium, and its design, (GP-35), was finished by another FN designer, Dieudonné Saive, and Val Browning. They made the gun as light-weight as possible, to fit the hand better than the 1911, and with a larger magazine capacity. That was the requirements of the French Military, whom were wanting the new pistol. The problem with this, is that it is weak when handling anything other than the ammo it was designed to handle, or any new 9mm rounds after 1934-1935, that produced higher chamber pressures or higher recoil. As a note, I believe the barrel was changed later on from a one piece barrel, to a two piece construction to make it easier to manufacture. Here, they mated a chamber and lug piece to a barrel, and they were brazed together. This is why the gun shows the small crack/seam around the barrel, and it looks like it starts right at the end of the chamber, and the start of the rifling, or it appears to. When you inspect the inside, you can't see this seam. I have ran into this a lot on these pistols. I think firing hot rounds might be why this shows up early on some pistols as compared to others that did later on.

August 3, 2014, 10:10 PM	#11
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	To put more icing on the cake, wartime HP's were often sabotaged by the Belgian workers by ruining the steel or "forgetting" to heat treat the slides and barrels; the guns just got by proof and inspection, but will peen and hang up after only a few rounds. Jim

August 3, 2014, 10:20 PM	#12
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,816	There was such a hi power in good shape for sale. I backed out of the deal for the exact reason. -TL

August 3, 2014, 11:03 PM	#13
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	Not just the pistol, but anything that came from FN after the occupation, and until it was over, as the workers sabotaged everything. If it has a Nazi mark, its a wall hanger. I think this happened to some other manufacturers, too, and I can't remember which right off, but they were lower in numbers.

August 3, 2014, 11:13 PM	#14
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	tangolima, They would have to use a tougher/harder steel for it to work, in both the barrel and the slide. Changing the recoil spring does nothing for the lugs getting battered, it only keeps the slide from flying back so hard. I owned a FEG copy, and was happy with it, and I'd say the Israeli version is just as good. A lot of these are showing up now, where they've been retired from M & P duty all over Europe.

August 7, 2014, 09:13 AM	#15
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	All, Here is a great AGI video about loose breech pistols and barrel lockup with damaged lugs, by Bob Dunlap and Ken Brooks. It shows how to check for this, and described battered lugs, plus, the Browning Hi-Power is mentioned. https://www.youtube.com/watch?featur...&v=ZOotIqOWHik

August 7, 2014, 12:42 PM	#16
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,816	Oh no. You just gave away my secret. Loose breech is the thing I check when I am taking interest to purchase a semi auto. Surprisingly a lot of people haven't even heard of the term. There is a more precise method to measure it if you get to field strip the pistol. The same principle applies so it is not hard to figure it out. A pistol with excessive loose breech, especially with damage on the side, is mostly a money pit. It can be fixed, but the gun will never be the same again. -TL

August 7, 2014, 02:12 PM	#17
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	If you notice on the S&W auto that they show, it had another problem besides for/aft movement of the breech, but up and down too. That is why it cut the lug recess in a taper. Most all designs, including the 1911, have a unlocking delay in the lugs, as the slide travels rearward, before the lugs start to disengage. The 1911 does it by the link swinging a little past top center. These other types have a delay space built into the cam, which should not allow the lugs very much downward movement at all, until the bullet leaves the barrel and the slide reaches a point where the barrel does move down. The S&W looked to me that the lugs tried to drop out as soon as the slide started going back, which means the cam is worn down, or it was machined wrong (too much slop). To be honest, I think it was, along with the barrel lug being to shallow too compound it. It wouldn't be the first S&W to leave the factory screwed up. I've heard about whole lots of revolvers having to be sent back, with out-of-line cranes, from a dealer. Even the Walthers and the Berettas have the unlocking delay, they just do it a little differently. The Hi-Power was the first to use a cam in place of a link, that I can think of, but a lot of the other companies followed similar methods after the fact.

August 7, 2014, 05:57 PM	#18
Cossack Senior Member Join Date: May 2, 2006 Posts: 260	Here's Stephen A Camp's take on +p in the Hi Power: http://www.hipowersandhandguns.com/B...essureAmmo.htm Back to the original question - were there any changes to the barrel or slide that would limit interchangeability of the barrel or slide? For example, could a new barrel from a MK III work in a pre-war gun or vice versa?

August 7, 2014, 08:22 PM	#19
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	On the two piece barrels, you can't see the seam inside because it isn't there. The full-length barrel is turned down at the back and the small end inserted into the part containing the lug. That allows barrels to be made in long lengths from bar stock, and then cut to size, a more economical system than making each barrel individually from a forging or from a large piece of bar stock. I believe the parts are electric brazed together, not silver soldered. Jim

August 8, 2014, 10:24 PM	#23
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	It is worth noting that there were at least two modifications to the barrel bottom lug. The first was replacement of the circular cam area with a squared off type. I believe the receiver cam was not changed and the barrels are interchangeable. That change was done at about the beginning of WWII before the German occupation. The second change was made c. 1950, and involved dimensional changes to both the barrel bottom lug and the cam in the frame. Barrels from before and after the change are not interchangeable because the frames differ. Note also that both the changes described were made only to FN pistols, with the first also being made to Inglis pistols; clone makers might or might not have incorporated either change, depending on the age of the BHP that they copied. Jim

August 9, 2014, 12:08 AM	#24
Cossack Senior Member Join Date: May 2, 2006 Posts: 260	Thanks, Jim, that tells me what I was looking for. Dixie, I also appreciate the explanation. I figured there was more to it than cast vs. forged, especially since I usually hear of cast being less desirable, as in rifle receivers and pistol slides. The metal must be different, then. Thanks for explaining.

August 9, 2014, 12:37 AM	#25
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	I read a little more about the history on the 40xx steel, and it is hard to dig up. Anyhow, they had this steel in the mid to late twenties, when it was first introduced for use in airplane frames as tubing that we were trying to copy from Fokker, after WWI. That was about all it was used for at the time, as they were using 1020, with 4130 sparingly for the high strength applications. Finally, they started using it solely later on, but its major use came about during WWII, when engineers started to design things stronger, but lighter. I think that was its first use in firearms, unless someone did earlier that I don't know about. Since Browning is using a casting, it would have to be something way tougher than mild steel, or what they were using without changing the design, and something that would not crack or fail easily. I know the 40xx steels were being used a good amount through the 1950's, so I would say that may be what they converted to, unless they got into the 43xx steel. Anyhow, that's my guess at it. I enjoyed looking this up, as it never really occurred to me what the history was behind it.