The Accurate Reloading Forums
Barrel dimensions
11 November 2020, 20:57
Duane Wiebe (CG&R)Barrel dimensions
The project is a light weight 375 H&H bolt gun.
Douglas is adamant on nothing less than a # 4 contour...that comes to 3 1/2 pounds!
Anyone out there with a 375 double?
I'd really like length, muzzle diameter and diameter a about 7" from the breech end.
Reasoning is that doubles ususally have about the lightest practical barrels...I can use those dimensions as a guide.
Thanks much seeya
12 November 2020, 01:03
Duane Wiebe (CG&R)I did receive the desired information...in this case from Butch Searcy..Thanks much.
Both Douglas and Kreiger will only go down to #4 contour...which is:
Muzzle .650 neck (7"from breech end) .835
Searcy 375 double barrel dimension is:
Muzzle .540 Neck .675
Any thoughts..logic..guesses?
12 November 2020, 01:43
butchlambertDuane, who are you dealing with at Douglas?
12 November 2020, 02:03
Duane Wiebe (CG&R)Th guy who answered the phone..Name???dunno
12 November 2020, 02:05
Nick HughesI have always used .125 min wall at the muzzle as my rule of thumb. Don't know what I referenced for that info but I will do some research. I would think you could go down to .600 at the muzzle no problem. Why don't you ask John Kreiger? he will surely have a good answer at least to back up their limitations on the min contour.
12 November 2020, 02:57
Duane Wiebe (CG&R)Well..I'd bet legal influence. I've heard that minimum also from yrs ago...don't know who invented it. Also heard ,.100 don't remember where I heard that either.
12 November 2020, 04:56
TimanI used a K&P #4 medium sporter crowned @24" on that 7lb 5oz titanium 375 H$H I posted in this forum a while back.
It's good balance .630 muzzle/.830neck at 6 inches.
12 November 2020, 06:20
loud-n-boomerWhen Danny Peterson rebored and rechambered a certain .270 barrel to .30-06 he told me that the minimum wall thickness he would do was 0.125 inches.
One morning I shot an elephant in my pajamas. How he got into my pajamas I'll never know. - Groucho Marx
12 November 2020, 07:02
dpcdThe Manager at Douglas is named Stan Taylor; he is who you talk to when you order barrels. Only him. They, and Krieger and others, are just being overly cautions so they won't get sued from idiots. Of course, double rifles have very thin wall diameters; far less than .125; that is way overkill at the muzzle.
So, yes, it is their lawyer; not a real life minimum.
Chrome moly steel is very strong; I think it was Hatcher who turned an 03 barrel down to .125 over the chamber and fired it without incident; had to use proof loads to crack it, and that was not chrome moly.
You could have a muzzle of .075 easily and .25 of meat over anything in front of the chamber; my opinion but I am right.
12 November 2020, 16:48
ozark hunterI have a Brux .375 barrel that is a #3 contour and the muzzle of the blank measures .630
12 November 2020, 17:32
Mike_Dettorrefrom pp 201-202 of Hatcher's Notebook
“I collected some first-hand information by turning a Springfield barrel to 1/8-inch wall thickness and firing it with regular and high pressure cartridges. As the results were not visible, I turned the barrel down so that it was only 1/16-inch thick over the chamber. It held three regular service cartridges perfectly. I then put in a 75,000 psi proof cartridge which blew a piece out of the side of the chamber.”
MikeLegistine actu quod scripsi?
Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.
What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
12 November 2020, 18:37
setters5Lothar Walther will do a .375 lightweight sporter contour, .575 muzzle and .760 heel.
12 November 2020, 18:44
butchlambertquote:
Originally posted by dpcd:
The Manager at Douglas is named Stan Taylor; he is who you talk to when you order barrels. Only him. They, and Krieger and others, are just being overly cautions so they won't get sued from idiots. Of course, double rifles have very thin wall diameters; far less than .125; that is way overkill at the muzzle.
So, yes, it is their lawyer; not a real life minimum.
Chrome moly steel is very strong; I think it was Hatcher who turned an 03 barrel down to .125 over the chamber and fired it without incident; had to use proof loads to crack it, and that was not chrome moly.
You could have a muzzle of .075 easily and .25 of meat over anything in front of the chamber; my opinion but I am right.
Tom, Stan is looking for Duane to call this morning. He will do what he can for him.
12 November 2020, 20:58
Duane Wiebe (CG&R)quote:
Originally posted by setters5:
Lothar Walther will do a .375 lightweight sporter contour, .575 muzzle and .760 heel.
YEP!
12 November 2020, 23:21
Aaron Little.100” wall thickness at muzzle and up to half barrel length is very common with double rifles. I contour most of mine as such.
Sabatti 9.3x74R doubles have around .065”-.070” wall thickness at muzzles.
12 November 2020, 23:31
Duane Wiebe (CG&R)quote:
Originally posted by Aaron Little:
.100” wall thickness at muzzle and up to half barrel length is very common with double rifles. I contour most of mine as such.
Sabatti 9.3x74R doubles have around .065”-.070” wall thickness at muzzles.
Thanks Aaron...about in line with Searcy
12 November 2020, 23:33
Duane Wiebe (CG&R)quote:
Originally posted by loud-n-boomer:
When Danny Peterson rebored and rechambered a certain .270 barrel to .30-06 he told me that the minimum wall thickness he would do was 0.125 inches.
Where is that measurement taken?
13 November 2020, 00:22
lindy2As you all know, I don't know a damn thing about gunsmithing.
However, I would think that the answer to the question presented is relative to a number of variables, and therefore any one answer would be incorrect.
1. bullet diameters
2. powder charge.
3. type and quality of the steel
4. the type of rifling.
5. type of twist of rifling
6. Probably a whole host of other physical attributes I know nothing about, but I would look for if somebody got hurt or killed shooting a barrel that was claimed to be too thin!
13 November 2020, 00:42
butchlambertquote:
Originally posted by lindy2:
As you all know, I don't know a damn thing about gunsmithing.
However, I would think that the answer to the question presented is relative to a number of variables, and therefore any one answer would be incorrect.
1. bullet diameters
2. powder charge.
3. type and quality of the steel
4. the type of rifling.
5. type of twist of rifling
6. Probably a whole host of other physical attributes I know nothing about, but I would look for if somebody got hurt or killed shooting a barrel that was claimed to be too thin!
Chuckle chuckle chuckle
13 November 2020, 03:46
skl1Using a commercial barrel as the model is the best way to go, I think. But this may be a good reference also.
When I was drilling for a rear sight, barrel company suggested leaving .025 per 10K of pressure minimum wall thickness from the groove diameter. This made sense to me since with old shotguns you are targeting over .022 wall thickness to the groove diameter to hold around $12K of pressure. And those old shotguns are really low carbon steels usually.
This is all mostly important down at the high pressure (chamber) end. Hoop stress (which is what you're worrying about) models are slightly different depending on thin wall vs thick wall.
But the rule of thumb is something I look at when cutting contours or screw holes or whatever on barrels.
Rifle barrels I've tested average around Rc 28, which has a yield strength around 117,000 psi. But hoop stress can be higher than the 65,000 psi chamber pressures depending on wall thickness. There are models online if you want to try them.
HTH
13 November 2020, 19:25
Timanquote:
Originally posted by setters5:
Lothar Walther will do a .375 lightweight sporter contour, .575 muzzle and .760 heel.
I've used this barrel in 375 H&H as well. The rifle was based on one of my own actions in chromoly steel
But small ring design with 1.0 x 16 barrel thread.
That rifle was light as well 7lbs 10oz unscoped.
I put that one in a McMillan Mark X stock with dual fill.
Medium fill around the action area, light fill everywhere else.
The recoil was pretty snappy with the 270gr bullets. Strangely, the 300gr bullets felt like less recoil, maybe because they had less velocity? Anyway not important, just and opinion from my shoulder.
Still, you're looking at .100 wall on the muzzle. In looking at a .575 muzzle with a 375 hole in it initial thoughts are, damn......thats light, because it is.
13 November 2020, 22:42
Mike_DettorreI have a deeply fluted 8.59 galaxy and by measurements wall thickness is .19 3.5 inches from the breech face at the bottom of the flutes.
Out towards the muzzle wall thickness is .125 at the bottom of the flutes.
MikeLegistine actu quod scripsi?
Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue. What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
14 November 2020, 02:57
J WisnerHave a Interarms, Whitworth ( Zastava ) Mauser currently in my shop that I am putting sights on for the customer.
Caliber is .458 Win Mag, muzzle diameter is .672", doing the math that is .107" wall thickness at the muzzle with a .0055 taper per inch going rear toward the breech for a while, then at 18" from the muzzle the barrel measures a whopping 1.010" in diameter.
Have the band ramp all made and fitted, now need to set up and drill and tap two # 6x48 screw holes for the rear sight.
When I tap holes like that I try to leave a min of .125" wall thickness, more is better it depends on the barrel and caliber
J Wisner
14 November 2020, 04:38
loud-n-boomerThe rebored barrel I have is .558 (.125 wall thickness) at the muzzle and .700 at the chamber throat.
One morning I shot an elephant in my pajamas. How he got into my pajamas I'll never know. - Groucho Marx
14 November 2020, 21:00
Duane Wiebe (CG&R)quote:
Originally posted by J Wisner:
Have a Interarms, Whitworth ( Zastava ) Mauser currently in my shop that I am putting sights on for the customer.
Caliber is .458 Win Mag, muzzle diameter is .672", doing the math that is .107" wall thickness at the muzzle with a .0055 taper per inch going rear toward the breech for a while, then at 18" from the muzzle the barrel measures a whopping 1.010" in diameter.
Have the band ramp all made and fitted, now need to set up and drill and tap two # 6x48 screw holes for the rear sight.
When I tap holes like that I try to leave a min of .125" wall thickness, more is better it depends on the barrel and caliber
J Wisner
I would guess those dimensions would satisfy any lawyer
15 November 2020, 02:15
ColoradoMattFor what it’s worth, my Lipsey’s 2019 Ruger African 9.3x62 measures .556 at the muzzle. That makes for 0.095 muzzle wall thickness. I can’t imagine a thinner barrel in this caliber. I measured two Oberndorf Mauser “Type A” 9.3x62 barrels just behind the front sight bases at 0.590”(the barrel band bases are blended to the crown).
Matt
FISH!!
Heed the words of Winston Smith in Orwell's 1984:
"Every record has been destroyed or falsified, every book rewritten, every picture has been repainted, every statue and street building has been renamed, every date has been altered. And the process is continuing day by day and minute by minute. History has stopped. Nothing exists except an endless present in which the Party is always right."
16 November 2020, 10:57
JBrownI have a Sako 375H&H. It is an early model built on the FN Mauser 98 commercial action.
It’s barrel is .575 at the muzzle.
Jason
"You're not hard-core, unless you live hard-core."
_______________________
Hunting in Africa is an adventure. The number of variables involved preclude the possibility of a perfect hunt. Some problems will arise. How you decide to handle them will determine how much you enjoy your hunt.
Just tell yourself, "it's all part of the adventure." Remember, if Robert Ruark had gotten upset every time problems with Harry
Selby's flat bed truck delayed the safari, Horn of the Hunter would have read like an indictment of Selby. But Ruark rolled with the punches, poured some gin, and enjoyed the adventure.
-Jason Brown
27 December 2020, 05:42
lee440Back in the mid-eighties, when McGowen was still in lllinois, I had them make me a #4 contour for a .416 Hoffman that I still have. It is .630 at the muzzle with .107 wall thickness. It has had hundreds of rounds sent downrange over the years. It would seem that a .375 would be no problem.
DRSS(We Band of Bubba's Div.)
N.R.A (Life)
T.S.R.A (Life)
D.S.C.
27 December 2020, 18:53
steve505Might be of interest. We did this analysis of hoop stress along a barrel profile we are thinking of selling.
01 January 2021, 03:29
Chuck NelsonProfile it to whatever dimension you feel is appropriate.
02 January 2021, 01:57
RockdocDuane I had a lightweight 375H&H Belted Mag made on my Mod 70 Classic. Had the barrel contoured the same as my old takedown (1913) H&H which made for a nice light contour without looking skinny.
I could get the dimensions if you still want them. Rifle is with Gordon being restocked.
Cheers Chris
DRSS
02 January 2021, 02:01
RockdocDoh, my Mod 70 is here so I can measure that
Need another coffee....
DRSS
02 January 2021, 02:11
RockdocAnd I can measure my H&H 375 Flanged Mag barrels too.
DRSS