Reproofing a BPE rifle to NE?

[matt85]

in my random searching for double rifles i stumbled across a rifle that apperently started life as a 577 BPE 3" and was later reproved to 577 NE 3" (100gr cordite under 750gr bullet). i was unaware people actually did this. personally it sounds dangerous but the company that sold the rifle is a well know manufacturer so i doubt they would sell something dangerous.

how difficult is it to reproof one of these old guns to NE levels? what kind of requirements must be met? i imagine it must have steel barrels and be VERY well made.

here is the link the the rifle that sold: http://wrusedguns.com/guns/rifles/11

-matt

 

[ikeda]

John Taylor talked about this very thing, and advised against it.
He was of the opinion that the shallow rifling in a BPE barrel would not stand up to much firing of "cordite" without erosion damaging the accuracy.
But he was concerned about a rifle standing up to thousands of rounds while being used by a professional.
Don't think that would be an issue with hunters today.
He told more than one story about certain unsophisticated hunters shooting NE shells in their BPE rifles simply because the original ammo was no longer available out in the bush. The regulation was of course terrible, but he never mentioned hearing of the rifle being damaged by the NE loads.
I guess as long as you were not dealing with a twist barrel, and as long as the gun is in good condition, it would certainly seem to be feasible.

 

[CTDolan]

Matt, the rifle (on WR's site) has a Jones underlever, doll's head third fastener, and lockwork which does not encroach upon the bar. Overall, it's a very strong design and should have no problem standing up to full nitro loads.

As for how difficult such things are to re-proof, it's something which must be taken on a case-by-case basis as there are so many factors. Some rifles are up to the task, others not.

 

[Red Leg]

SxS's are fairly regularly reproofed for nitro. However, unpitted, high quality Damascus (not the crap on the cheap Belgian imports which flooded this country at the opening of the last century!) is as strong as any compressed steel. And the more "modern" BP actions, such as the A&D and various sidelocks, are almost identical to their nitro brethren. They tend to withstand proof loads and inspection with ease. A rifle is a different thing entirely. Nitro pressures in a rifle have a very abrupt spike - nothing at all like the pressure curve in a BP load. I am not even sure Birmingham now days would attempt to fire a proof express load in a BP rifle. Loading nitro for black - a nitro based load with BP like pressures and velocity is another thing entirely. You can find numerous articles in the back issues of Double Gun Journal on that arcane science. Note, you would still be firing a BP loading - simply using a modern powder and dacron filler to achieve the original end.

 

[CTDolan]

Black powder actually has a more abrupt pressure spike than smokeless, but it's very short-lived.

 

[CTDolan]

The main issue is one of peak pressure.

 

[TallGrassHunter]

I believe the guys that regularly used the old doubles would send them back to be reproved, tightened on the face and a bit of refurbishing as needed/affordable. I've notice fair bit that were reproved for cordite/nitro. At the time of reproving they are usually re stamped to indicate such. I forget the codes but it shouldn't be too hard to get.
I just have this basic information on English reproving. Would be interesting to know if other countries used the same codes.

 

[Red Leg]

I believe the guys that regularly used the old doubles would send them back to be reproved, tightened on the face and a bit of refurbishing as needed/affordable. I've notice fair bit that were reproved for cordite/nitro. At the time of reproving they are usually re stamped to indicate such. I forget the codes but it shouldn't be too hard to get.
I just have this basic information on English reproving. Would be interesting to know if other countries used the same codes.

That is absolutely correct for sxs shotguns. Go to one of the classic double sites on line, and you will always find a few guns which went through re-proof for a 1 1/8 ounce nitro load. The barrel flats tell the whole history. I have never seen a BP express re-proofed to nitro. Doesn't mean there aren't any, but I haven't seen one. It would have to have proof marks , but would also have to be re-marked in the "new" caliber.

 

[matt85]

I have never seen a BP express re-proofed to nitro.

follow the link in the OP and you will find a BP rifle reproved to NE.

-matt

 

[Red Leg]

follow the link in the OP and you will find a BP rifle reproved to NE.

-matt

You are right. First that I have ever seen.

 

[sierraone]

This is a great post Matt. The back and forth between you and Red Leg is pure old double education for someone like me!

 

[matt85]

too bad that Manton was already sold... i would love a hammer 577 NE.

i found a 500 BPE 3" that looks like it might be a good candidate for converting to 500 NE. something about a double with hammers just calls to me, i wish modern makers would offer them! i saw in an older catalog that Verney Carron offered a small/medium bore double with hammers but the price was $40,000+ which is way above and beyond what i will ever be able to afford.

aside from worrying about pressures and the rifling another concern is that it would take a fair bit of work to make a BPE rifle into a serviceable NE rifle. example is the 500 BPE rifle i found only weighs 9.5 pounds and has a steel plate for a butt. i would have to have the gun regulated for NE ammunition and the stock would have to be shortened with a butt pad installed. also, at least 1 pound of lead would need to be added to make the gun heavy enough.

any one know of a company that would reproof a rifle?


-matt

 

[Red Leg]

I think we have two questions. The 500 you describe was clearly built as a stag and boar rifle. The true proof houses in The UK inspect and then final proove through firing. I am pretty sure a light rifle like this would be rejected without firing. So, it would first have to be "converted" into a nitro to pass the eye test. Hopefully, the gunmaker would have the skills and experience to determine if you have adequate chamber strength and a stout enough action before beginning. A lot of folks could do the stock work fairly easily.

I doubt if your intention is a formal re proof in the UK? So, that means someone here who could do the conversion to a heavier rifle - easy - and stand behind it as a nitro express - much rarer. He would also have to re-regulate rifle. With such different pressures, that almost certainly means true re-regulation rather than mere load development. That takes things from simple to expensive.

I know exactly one person in the US that I would trust with that work - JJ Perodeau. Heis in OK and regularly re-regulates doubles. Knows more about them than any man I have known. I have no idea if he would take on the conversion of a BPE to nitro, but I would urge a conversation with him as an informed starting place.

 

[CTDolan]

As mentioned, there's a mountain of factors to consider but, if the action is up to it yet the barrels not (the reasons could be legion, such as the condition of the bores), a monoblock (sleeving the chamber region) is one option.

 

[matt85]

thanks for the info Red Leg, ill contact him.

-matt

 

[rookhawk]

I'm not an expert but I do know there is a major flaw to the advice stated above.

A BPE is not the same gun as a NE. We today use three different terms that we made up in modern times for guns. BPE, Nitro for Black, and Nitro Express. They are just words made by modernists to describe loads.

The big difference is that those three guns had different barrels. Not just different proofs, but different barrels.


My weights may be off but let me illustrate:

A .500 Express "black powder express" may be regulated for a 340gr bullet at 1600fps and th barrels weigh 5 pounds.

A .500 Express "light nitro" which today is called a "nitro for black powder" is regulated for a 440gr bullet at 1900fps. The barrels weigh 7 pounds.

A .500 Express "nitro express" is regulated for a 570gr bullet at 2150fps and the barrels weigh 9 pounds.

All have the same brass case, but they were physically designed differently and were built for different things. A.) for stag, B.) for big cats, C.) for elephant as a simple example.

I couldn't care less if someone wants to use nitro powder in a BPE as long as you adhere to the service pressure and regulation of that load. A nitro for black powder is NOT simply doing the former, it is a hotter load at faster speed.

You can't. Reengineer a gun that was built to handle a particular pressure and load. How will you add weight to the barrels and their thickness?

Answer: you can't. You're putting a square peg in a round hole. I hope Cal Pappas chimes in as I think he'd concur.

 

[cal pappas]

Gents:
I've been away from AH for a while. For this topic, I have only seen two bpe doubles reproofed for nitro. One was a .577 2 3/4" bpe with new nitro proofs for the 90 grains and 650 load. NOT the full house load of 100-750. The second was a .500 bpe with newer nitro proofs for 70 grains of cordite and the nfb bullet of 440 grains, NOT the 570 grains bullet we all know and love.

Many shotguns that are bp originally and reproofed to nitro is fine as the shot charge is the same and velocity is the same. Not so with double rifles and the bpe load was far less pressure, hell, less everything, than the new full house nitro cartridges.

Remember, while the proof load, either black or nitro, is far in excess of the standard load, it is only proofed ONCE, and may not (read will not) stand up to repeated shootings with heavier loads of powder and lead.

Just my two cents.
As Arnold said, "I'm back."
Cal

 

[rookhawk]

Well said, Cal. Welcome back.

I'd add that shotgun barrels all weigh relatively the same. A 2-3/4" chambered black powder live pigeon gun easily passes proof for a 2-3/4" nitro load so that's often what you'll see.

A 9lb 500BPE rifle will not survive long reproved as a 500 Nitro for Black calling for a 440 bullet and 70 grains cordite because the latter is traditionally built as an 11lb gun.

 

[Thomas Rutledge]

These are the proofs on my newly acquired .577 Greener. Opinions please. Thanks.

 

[rookhawk]

The proofs show Nitro proofing at .577 express 3" and 2860 bar. I would make darn certain that a full nitro load is under the proof pressure of 2860 BAR. I would be very surprised if a 1400fps regulated load for a .577 express would regulate a full .577 Nitro Express load traveling over 2000fps EVEN IF the proof house says the barrels can handle the pressure.

Reproofing a black powder for nitro does not make it functional for nitro. It still may be under weight. It still may not have a stock that can endure the recoil. The sights may not aim correctly. The barrels are not regulated for the increased velocities.

Just a bad-bad-bad idea in my opinion. Others may disagree.