Stock Rifle HV "HOW"

[vzerone]

Geargnasher, I was searching on the internet as to why big cannons have such small rifling grooves. I didn't find an answer, but never the less I found some very interesting things, at least to me. Do you know what the rifling twist was on those 16 inch guns on the U.S. battleships? One turn in 25 inches. I was shocked. I thought it would be slower. The muzzle velocity for the AP rounds was around 2500 fps. The nuke rounds velocity was around 2700 fps. Number of shots before the rifling liner had to be replaced was around 394 for the AP rounds, little higher for the nuke rounds, and the practice rounds was a very high count. Now watch me swing this right into line with the cast bullet forum. Think of barrel life they would have gotten with cast projectiles! What do you think Geargnasher, single or multi-cavity mold? LOL Average weight of powder charge was 600 lbs. Wow! They must have had one heck of a huge powder measure.
The Navy certainly had enough Beeswax to make their own lube if they shot cast. So would we consider that HV?

[geargnasher]

Wow, 25"? That's pretty tight, but the Greenhill formula was developed for artillery in the first place so those boys knew what they were doing.

All I know about artillery is from a fired practice shell that used to be a door stop at work. It had a lead (alloy?) obturation ring and the 105mm barrel had made shallow engraves in that ring about 1/4" wide all the way around, lands and grooves the same width. The ring was only about an inch "long" and had a groove in the middle of it that I presume was filled with some sort of lube. The huge, steel shell was about all one man would want to pick up from the floor, and it didn't even have any explosives in it. Talk about small bearing surface!!! That little 1" band of lead didn't show any signs of stripping or gas cutting whatsoever, and I studied it very closely. Micro-groove indeed.

Gear

[vzerone]

Wow, 25"? That's pretty tight, but the Greenhill formula was developed for artillery in the first place so those boys knew what they were doing.

All I know about artillery is from a fired practice shell that used to be a door stop at work. It had a lead (alloy?) obturation ring and the 105mm barrel had made shallow engraves in that ring about 1/4" wide all the way around, lands and grooves the same width. The ring was only about an inch "long" and had a groove in the middle of it that I presume was filled with some sort of lube. The huge, steel shell was about all one man would want to pick up from the floor, and it didn't even have any explosives in it. Talk about small bearing surface!!! That little 1" band of lead didn't show any signs of stripping or gas cutting whatsoever, and I studied it very closely. Micro-groove indeed.

Gear

All of them that I have seen were bore riders. Yes I was wondering about the Greenhill formula too. If I'm not mistaken I believe those 16 inch projectiles were 72 inches long for the AP. The rifling was .150 deep and there were 94 of them around the bore. Yup, that's definitely Micro-Groove. Hey now all I have to find is the BC, ES, and SD LOL

[Hickok]

I believe I am just going to sit back and try and learn anything I can from the posts.

I am going to try to better my HV loads and go hopefully, happily along with my cast shooting.

Many times after posting loads results and targets that I am very happy with (and eager to show) after a lot of work and expense, I come away feeling worse than bird droppings on a pump handle after the critique takes away from the effort.

I am happy for and enjoy those who shoot bench matches and competition and give us their advice. I also like anything anyone posts about paper punching and 10 or 20 shots groups.

Me, I just like to shoot, and my main aim is to have a load in my rifles and handguns that will deliver on deer, bear, groundhogs, etc, and is accurate by my standards for general shooting and packing in the woods.

[newton]

Yes sir, such threads exist. Example: http://castboolits.gunloads.com/show...e-30XCB/page41

Many pages of specific loads, shot in several different rifles, complete with target and chrono data.

Thanks. Now I have a bit of reading to do.

I was actually thinking of a thread that didn't have all the small talk, so guys didn't have to weed through it all. I know it would be near impossible to do without heavy mod cutting, but would be cool anyways.

[TXGunNut]

I'm right there with you, Hickok. Well said.

This project is purely academic for me but I feel the things I'll learn in the pursuit of HV will benefit my other pursuits, in short help me to be a better caster, loader and shooter. The cars we drive utilize advances developed on race tracks, why should our rifles be any different? Now I need to go back and wade thru all the posts again to prioritize the many good points. Guess I should have been taking notes.

[popper]

Attachment 159608Attachment 159609Attachment 159610
150gr. jacketed @ 2000 fps, 145gr PB @ 2100 fps, 145gr. PB @ 2100 when the COAL is WRONG (short). 2nd pic was after 60 some rounds, shoulder started to wiggle a bit. Loads are past Hornady max jacket loads, just a tad, for BO. #3 show what happens when the boolit is NOT in the throat correctly.

[rockrat]

Looked down a few cannon barrels at Ft. Sill, OK and the twist of 1 in 25" didn't seem right from what I remember of the barrels of the smaller cannons there. Using the Greenhill formula for the 16" projectiles, I suspect the twist is 1 in 25 FEET , not 1 in 25 inches. Was checking online and saw the specs where the twist was 1 in 25 for the 16" guns, but curious as the tables didn't specify what the 25 was, so I figured to just plug it into the Greenhill formula. Got on the Mountain Molds website ,but their tables only went to 1 in 15 feet, but since the formula was there, I plugged in 300"(25 feet) as the twist. Came out to max. projectile length of 128", well over the 72" projectile length for the 16" AP round.

[vzerone]

Looked down a few cannon barrels at Ft. Sill, OK and the twist of 1 in 25" didn't seem right from what I remember of the barrels of the smaller cannons there. Using the Greenhill formula for the 16" projectiles, I suspect the twist is 1 in 25 FEET , not 1 in 25 inches. Was checking online and saw the specs where the twist was 1 in 25 for the 16" guns, but curious as the tables didn't specify what the 25 was, so I figured to just plug it into the Greenhill formula. Got on the Mountain Molds website ,but their tables only went to 1 in 15 feet, but since the formula was there, I plugged in 300"(25 feet) as the twist. Came out to max. projectile length of 128", well over the 72" projectile length for the 16" AP round.

Thanks for pointing that out. Took a lot of research, but finally got it. It's 1 turn in 25 calibers. So I guess it's 25x50 since the gun is listed as a 16 inch 50 Cal Mark 7. Dang, it's a flintlock rifling twist!!!

What can I say, I use to small arms and their twists are in inches. You can tell I wasn't a gunner's mate! LOL

[popper]

Appears CBA match fps is in the 1600-1800 fps range for heavy, 170-190gr GC boolits (308W). Not very high fps for caliber. Most 1:10 twist.

[vzerone]

Thanks for pointing that out. Took a lot of research, but finally got it. It's 1 turn in 25 calibers. So I guess it's 25x50 since the gun is listed as a 16 inch 50 Cal Mark 7. Dang, it's a flintlock rifling twist!!!

What can I say, I use to small arms and their twists are in inches. You can tell I wasn't a gunner's mate! LOL

Actually I was wrong again. The caliber is 16 inches so it would be 16x25 which is 400 inches. I found this too:
The rifling of this gun was right-handed, which means that the projectile will rotate clockwise when viewed from the rear. Early 16-inch guns had "gain twist rifling" that had an initial twist of 1 turn in 50 caliber that increased to 1 turn in 25 caliber at a point 2 calibers (32 inches) down the barrel. The rifling remained at 1 turn in 25 caliber twist throughout the remainder of the barrel. This special type of rifling acted to reduce the strain on the soft copper rotating band of the projectile during the maximum acceleration near the breech, but was found to be impractical due to manufacturing difficulties and the fact that this actually increased the drag on the projectile in the barrel. Later guns were produced with rifling of uniform twist.

[David2011]

I may see what I can get from the 375 H&H too. I have had it over 1800 with accuracy easily. Never gone faster with good results but have learned much since then.

I'm toying with shooting my .375 H&H in that velocity range using the 250 gr RCBS mold. Do you have any alloy recommendations? Powder recommendations? I was thinking H-4895 for the reduced power loads.

What's the recoil like at 1800 fps? I would expect mild but I've been surprised before.

David

[runfiverun]

I'd imagine more manageable than a 435gr 45-70 at the same velocity.

[btroj]

A 265 at 1800 fps is a ***** cat. I used 27-29 gr of 2400 with a Dacron fill for those loads. Sub 2 inches at 100 for 5 shots all day long. Shooting 50 from the bench in a single sitting was no big deal.
4895 wouldn't be a bad choice at all. Here is some good info. http://www.castpics.net/subsite2/ByC...0375%20H_H.pdf

[btroj]

I'd imagine more manageable than a 435gr 45-70 at the same velocity.

ummmm, yes? A 435 at 1800 in a 45-70 isn't something I care to fire from the bench.

[vzerone]

One of my friends has that same mold for 375 for various 375 caliber rifles he has. One of them being the 375 H&H. I believe he was loading it around 2000 fps or more and it was very pleasant to shoot. The rifle was very accurate too. I think he was using WW's. He nailed a crow one day with it at the shooting range at 150 yards. The rifle had an old cloudy Weaver 4X scope on it.

[wmitty]

Crow with a .375? I love it!

[popper]

soft copper rotating band Not that soft but the 5 & 8" still use it, they are 'micro-groove' so to speak. If you call 1/2 - 1' deep V grooves 'micro'.

[cainttype]

I'm toying with shooting my .375 H&H in that velocity range using the 250 gr RCBS mold. Do you have any alloy recommendations? Powder recommendations? I was thinking H-4895 for the reduced power loads.

What's the recoil like at 1800 fps? I would expect mild but I've been surprised before.

David

A case full of WC872 surplus pushes a 275 gr LBT LFN to 2380-2390fps in my 24" Shilen barrelled Browning A-bolt. A small kicker of 4198 cleans the burn up a little (not absolutely necessary) and can boost those numbers a little. 1.5 MOA, or better, 5 shot groups at 100yds has been easy to get with nothing more than a good fit to throat and NEW casings. Alloy was lino-Pb 1-3, LBT blue lube was used... I haven't tried it with the fire-formed casings yet.
I'm certain that can be improved on, but it already delivers more than I require of it so I'm not likely too devote much effort there unless I get really bored.
This type load isn't for the recoil-sensitive.

[vzerone]

A case full of WC872 surplus pushes a 275 gr LBT LFN to 2380-2390fps in my 24" Shilen barrelled Browning A-bolt. A small kicker of 4198 cleans the burn up a little (not absolutely necessary) and can boost those numbers a little. 1.5 MOA, or better, 5 shot groups at 100yds has been easy to get with nothing more than a good fit to throat and NEW casings. Alloy was lino-Pb 1-3, LBT blue lube was used... I haven't tried it with the fire-formed casings yet.
I'm certain that can be improved on, but it already delivers more than I require of it so I'm not likely too devote much effort there unless I get really bored.
This type load isn't for the recoil-sensitive.

Yes that load is getting up there so I imagine it has a good punch. Does your rifle have the boss on it? The .375 seems like a very easy one to get shoot with cast and accurate too.