I am looking for anyone with experience loading the 375 X 2 1/2" Flanged Nitro Express. I do have the Wright book, and it provides a good starting point, but his doubles were proofed for the 270 grain bullet with 40 grains of cordite (14 TPI). Mine is a 320 grian bullet and 40 grains cordite proofed double (17 TPI). My current thoughts are to start with RL 15 and Varget with the 300 grain Hornady RN, but I would like to hear from anyone who has worked with this cartridge.

Thanks,
Jim

I've loaded a fair amount for the 14 tpi version and have come to prefer 3031 for the best combination of accuracy, velocity and pressure signs. The ones I have had have all been single barrel rifles, either bolt or single shot.

My current favorite load is 44 grs IMR3031 with a 270 gr Hornady loaded to an overall length of 3.375"; this gives an average vel of 2000 fps, pretty much like old 14 tpi factory loads. Pressure as calculated by QuickLoad is 33,000psi. I have some other loads if you would like them by email.

[ 03-15-2003, 19:28: Message edited by: bpesteve ]

bpesteve,

Many thanks for the informative reply. This is exactly the type of response that I was hoping for. I would certainly appreciate any data that you would be willing to share via email. Address: wootjlj@cybersouth.com

I particularly appreciate the pressure estimate, as I do not have a suitable software program to do this calculation. Are you pleased with the Quickload program, as I have been trying to decide which to go with? After 30 years of reloading it is finally time to go high tech I suppose .

Best regards,
Jim

Jim:

Proof marks that say "40 Cordite, 320 Max" (the .375 No. 2 load) mean that the rifle was proofed for that load but do not automatically mean that it was regulated for it. One of the oddities of this caliber is that so many doubles chambered for it were not regulated with the load for which they were proofed. Rifles with 320 grain proof marks with barrel legends indicating original regulation with 270 or 300 grain bullets abound. What does the barrel legend (the egraved script on top of the barrels as opposed to the proof marks stamped on the barrel flats) say? Out of curiousity, what maker is the rifle from?

If there is no bullet weight marking aside from the proof marks, you have to start somewhere and the 300 grain is as good as any. The Hornady may work but doesn't in some doubles due to differences in bearing surface, in which case you should try the Woodleigh which was designed to approximate the original Kynochs in profile. If it was regulated with the 320, you can get 320 grain .375 RNs from Hawk. It might shoot well with 300s anyway. My .400/.360 NE was regulated with 40 Cordite and 300 grain and shoots that weight best, but shoots well with 270 and 285 grain over the same charge as used with the 300.

There was a fairly decent article on the .375 2 1/2" in the Summer 2002 Double Gun Journal (Vol. 13, Issue 2) titled "Holland & Holland's Original .375 Bore Revisted" by David Gilmore and Robert Firth. The article is a compilation of notes on shooting six .375 2 1/2" rifles including a Thomas Bland proofed and regulated for the 320 grain load and a H & H Royal proofed for the 320 grain load but originally regulated with 270 grain.

A sidebar to the article lists:

270 Hawk RT 42.6 IMR 3031 2005fps
270 Hawk RT 43.5 IMR 4895 2010fps
270 Hawk RT 46.0 RL 15 2000fps
270 Woodleigh RN 44.0 IMR 3031 2005fps
270 Woodleigh RN 45.0 IMR 4895 2000fps
300 Hawk RT 43.0 IMR 4895 1990fps

A fine, useful cartridge for North American timber and brush hunting. Hope the above helps.
--------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

mbogo375 Once you find a good shooting load with the full weight bullet, please try the Hornady 220gr. and the Speer 235 with the same powder charge. I would like to see if the 75% rule will work for the 375 Flanged.
Elmer Keith thought the 375 Flanged with the 300gr. bullet made a dandy Elk rifle in the timber.

Thanks Gentlemen,

400 Nitro,
You may very well be correct concerning this rifle, but I won't be able to confirm the barrel markings until I actually receive it. I anxiously await the delivery on Wednesday. The former owner says it shoots very well with factory 270 grain loads (it is an H&H Dominion grade sidelock).

In the past I have shied away from 3031 for doubles as I have been working with larger cases which required excessive filler to prevent hangfires. On my first range session with my very first double, a 450/400 3", I actually had one 3031 load which did not ignite properly and lodged a bullet about 3" in front of the chamber. This experience led me to move to medium and slow powders, and fillers as appropriate (after much experimenting I found that I got the best results using the relatively hard and crumbly craft type foam cut to proper thickness to allow mild compression when seating the bullet). This is the reason that I was considering trying RL 15 and Varget, but the smaller case capacity of the 375x2 1/2 could be more appropriate for 3031 (it certainly seems to be the most commonly used).

NE 450,

I certainly intend to try the 220 and 235, as well as others. They should make interesting whitetail loads . That is half the fun of load development for doubles, finding new loads that regulate in vintage rifles!!!



Jim

mbogo If that is a picture of your rifle it looks like a nice one. I have used IMR3031,IMR4831, and RL-15 quite a bit in my 450 No2. All with fillers. I have had no problems with any of the powders. I am currently working with RL-15 with the 480 and 500gr. bullets. I have yet to chrono RL-15 but the pressure seems to be less. I still use 3031 with the 350 Hornadays. The 375 2 1/2" makes a great double for US use as there are so many different bullets available suitable for game form deer to elk and black bear. Keep us posted on how she shoots.

Ne450,

Yes, that is the new addition to the family (hey, it should be cheaper to feed and maintain than my daughter ).

Although I have tried many different powders, RL 15 has proven to be the most accurate and consistent in two 450/400's and a 450 BPE. Also not bad were Varget, IMR 4831, H 4831, IMR 4350. I have been slightly less happy with IMR 3031, IMR 4895, IMR 4320, and IMR 4064, but they could work better in other rifles.I wonder how some of the extremely slow powders like RL 25 and slower might work, but I haven't tried them yet (a good reason for more trips to the range .

Jim

Jim:

Nice. If the bores are as good as the rest, it should be a winner. I'm jealous.

Holland was pretty good about engraving the regulation load on the barrels (sometimes on the floor plate) so, hopefully, you won't have to guess. In my observation, Holland seems to have pushed the 270 grain for all of their .375 bore cartridges and I wouldn't be surprised if this one was regulated for that weight as well.

As noted in my previous post, my Evans .400/.360 is a 40 Cordite, 300 Max gun. I've used all of the powders mentioned in the sidebar above, with the same weight bullets. My final charge weights and velocities were VERY close to theirs. I wasn't crazy about 3031 either. Best results with the powders listed was with 46 grains RL 15, no filler, and 300 grain Hawk RT for 2010fps. I have always used Federal 210s.

One other thing - it would be a very good idea to slug the bores. These old British doubles are known for groove diameter variations and it is always best to use groove diameter bullets, although it may be a pain.

Best of luck with your new toy. Let us know how you progress. I would be very interested in hearing the details.
-------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Update:

I received my Holland today. Flats are marked 375 EX 40 Cordite-320 Max. Barrels are marked Holland & Holland, 98 New Bond Street London, and Winners Of All The Field Rifle Trials London. Bottom of action is marked Charge 40 Grains Of Cordite, 375 Cases, 2 1/2". The only other markings are British proofs on the flats, plus the serial number on barrels,water table,and forearm, plus Holland & Holland on the sidelocks. Looks like no help with the regulating load, but that was not unexpected.

The bores look to be very good plus, and are 7 land and groove like the Alex Henry. It's a bit hard to determine true groove diameter due to the odd numbered grooves, but if I rotate the slug it appears to be about .378". The chambers are rather tight at about .450 base diameter, so I won't be able to use 405 Win brass without turning the case heads(they come out of my dies at .458 to .459). I have ordered some Bertram brass, and will probably try some Westley Richards factory ammo as well (hopefully they will be smaller than the 405 brass).

If anyone has another source of brass, PLEASE let me know (I do know about Kynoch of course). Looks like I won't get to shoot my new toy until I get the new brass next week . Even then I won't be able to size the case heads to chamber base diameter, so it is a good thing that they are relatively low pressure loads, or I might have to get a custom sizing die made (more of the joys of vintage doubles ).

Well, it looks like things are just getting interesting .

Good shooting,
Jim

Unfortunate that they failed to mention bullet weight. Guess that will add to the adventure some.

Are you sure about the chamber measurement? According to Fleming, BRITISH SPORTING RIFLE CARTRIDGES, base diameter of original Kynoch (the old cordite stuff) ran .454 to .459 in this caliber. This data is not min/max standard but measurements of a variety of loaded samples from collections. Makes you wonder how the bores got that much wear if factory ammo wouldn't chamber.

As to your brass problem, as I'm sure you're aware, Bertram can be a headache. I tried it in one of my doubles and found it non-functional. Base diameter was too large to fully enter the sizing die without pulling the rim off getting it out. It was extremely soft. NE.450 No. 2 has had good luck with it in his .450 No. 2 though. I hope it works for you.

Proceed very cautiously with the Westley ammo, which is loaded in Germany by Wolfgang Romey. I tried some of it in .400/.360 Purdey NE and velocities were 350 fps over standard external ballistics. Extraction was difficult and I'm glad I only fired two rounds. I dumped the rest of the loads to salvage the brass which is of decent quality, but not great. This could have been an isolated incident and just a bad lot, but be careful.

You might try Huntington's. I don't know if it is available in HDS or not. Another option would be Horneber and I'm fairly sure that they do make it. I seem to remember hearing somewhere that they make Romey's brass. The new Kynoch might be a good option. The batch that I tried in .450/.400 was good ammo and the brass is superb.

Good luck and good shooting!
-------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

mbogo375
Give us an update on that primo double.
Have you tried the 220 Hornadays or the 235 Speers yet? I am curious to see if the Rule of 75% works.

I worked with a Wilkes double in December 2000, but it consistently put the right barrel group about 4" above the left at 50 metres, so I passed on it eventually. Also, it was too heavy for the calibre at 10.5 lbs, and felt like a lead pipe (not all Brit doubles have good handling!). The loads I tested it with are as follows:

270 gr Hornady spitzer + 45gr AR2208 (Varget) = 1980 fps and 1 - 2" grp @ 50m

250 gr Taipan SP + 41gr AR2206 = ? fps and 1.5 to 4.5" grp @ 50m

300 gr Woodleigh RN + 44gr AR2208 (Varget) = ?fps and 1.2" grp (consistent) @ 50m.

The rifle flats were stamped "Cordite 40, 300 max".

Hope this contributes.

...and BTW, who do all you Bertram-knockers out there think Kynoch gets to make brass for them!!

NE 450 No2,

I am still in the load development process. The bores(groove diameter) on my double are .378+ as I mentioned before. I ordered a Walnut Hill press and point forming die in actual groove diameter to bump up the .375 bullets from Richard Corbin. I am also waiting on some .377 Hawks in 320 grains. So far all the loads that I have tried are still shooting apart, and I have gone as far as I feel comfortable pressure wise. Best composite groups so far have been with .377 Hawk 280 FN and 235 Speer, both with Varget and RL 15 (best individual barrel groups are with the Hawks and the 235 Speers as well). I have tried 200 Sierra, 235 Speer, 270 Hornady RN, 300 Hornady RN, 280 and 255 Hawk FN, and even the 270 Hornady SP and 300 Sierra BT to see if a different nose shape would change POI.

The closest to bringing the two barrels together at 50 yards is the .377 Hawk 280 FN, so I am hopeful that the .377 Hawk 320's will work better. I also think that bumping the other bullets to actual groove diameter will show further improvement. I have also tried IMR 3031, IMR 4350, VVN 540, VVN 560, and IMR 4895, and have varied cartridge OAL from 3.15" to 3.45" (long throat), and juggled charge weight commensurate with the corresponding changes in effective case capacity. All part of the fun of double rifles .

As to chamber dimensions,I was incorrect on the .450 (I was measuring slightly further into the chamber-it is actually .453 at the absolute end of the chamber with a very quick taper to .450). The Westley Richards factory ammo in too large at the base to chamber properly, but the Bertram brass works perfectly. I did have to use RCBS dies, as the CH dies were too large at the base for my chamber.

If you have any other suggestions I would be happy to hear them.

Jim

Marrakai,

Thanks for the post. What OAL were you using? I have actually gone a little over your loads in the 3.4" to 3.45" OAL due to the extra case capacity from seating the bullets further out, but it was no closer to regulation at 50 yards than seating to 3.15" and reducing charge weight to similar load levels to yours. Individual barrel groups are running under an inch if I do my part, with the right being about an inch lower than the left and about 2 to 3 inches apart horizontally.

Jim

Jim

You can always take the cordite load x 1.33 and come up with a starting load for IMR-4831 or corditd load x 1.19 for RL-15 for a starting load..

40 grs of cordite x 1.19 = 47.6 grs. of RL-19

40 grs. of crodite x 1.33= 53.2 grs. of IMR-4831

This applies to most, if not all, doubles and they have the cordite load stamped on the water table.

mbogo375
Exactly where are your shots hitting, ie how far apart are the right and left bbl groups hitting. [both vertical and horizontal] and at what distance.
I would try the following loads while you wait for the other bullets.
The 280 Hawk with IMR4831 start with 53 grains.
with RL-15 start with 47 grains.

NE 450 No2,

Here is a 30 yard group with 235 Speer (I have not tried this load at 50 yards yet).



Most of my 50 yard groups have been with 270, 280, and 300 grain bullets. Best group was 280 Hawk with 48.0 grains of Varget loaded to 3.25" OAL. Right barrel was 1 3/4 inches to the right and 1 inch below the left barrel. I thought that I was really on the way here, so I added 1 grain to try to bring the two barrels closer together and that group had the right barrel 2 1/2 inches lower and 3 inches right of the left barrel . I haven't had the opportunity to shoot the 48.0 grain load again (but I have never experienced this much shifting away from each other with a 1 grain INCREASE in powder charge). Incidentally 46.0 grains grouped to approximately the same point as the 49.0 grain load .

I have been waiting for the bump-up die and the 320 grain bullets before getting serious about more load development.

Jim

mbogo375
What happens if you shoot 47grains with the grain bullet. See my range results with the 450 No2. I dropped one grain of powder and my groups POI moved higher and the two bbls hit closer together. Also I recommend shooting your best load so far at 75 and 100 yards. Even at 100 yards my best loads have the right bbl hitting on the right and the left bbl on the left.
What shooting position are you using. I could live with the 235 Speer group if the shots remained that close together as the range increased. Try Rl-15 first then IMR 4831.
With individual bbl groups that good the rifle is bound to be a good shooter.

Mbogo,
You have a very accurate double there, remember a double will only shoot as well as its WORST barrel..

Your group spread is typical of the 375-2.5...What you need to do is up the load 1 gr, at a time until the groups come together at 50 yards..but with the 375-2.5" you must limit that to 2200 FPS and if at that velocity it doesn't come together then STOP...Now you must use another alternative and this is A typical with that caliber in doubles..so if the velocity gets too high without results then start trying different bullets and 9 times out of 10 a lighter bullet will solve the problem in the 375-2.5"..If this does not work then email me the groups and we will figure out where the problem exists...Always shoot your double off a bench with your hand under the forend...

A worst case secenario is re-regulation by an expert in that...I would suggest David Yale for regulating a double. He is the very best.

450 and Ray,

Thanks for the suggestions. I do shoot off the bench with the fore end supported by my hand, and the butt only touching my shoulder. No part of the rifle touches anything other than me.

The lighter bullets do come a little closer to regulating than the heavier ones, but groups do not move closer with increases in charge weight as much as you would expect. Rather than trying to describe the groups I will post representative photos below (all these groups were at 30 yards so that they may better be compared-aiming pasters are 1"). In all honesty, I suspect that re-regulation will be the final solution, but I want to work with groove diameter bullets first (I also will vary the seating depth and nose shape, as well as powder and primer type, etc.). As you can see, it is rather consistent in individual barrel grouping.





This group was fired with two Westley Richard cases and two reformed Hornady 405 cases, both were lathed to remove a bit of brass from the area just above the rim, plus the rims were turned to reduce thickness and diameter. I don't know if this was the cause of the individual barrel groups being slightly larger, or if the long throat and short bullets were the culprit (or maybe just my shooting ).







I am certainly open to further suggestions, as increasing charge weights would probably not be the answer given the weights that I have already tried (even though my rifle is proofed for the 17TPSI load).

Jim

mbogo375
With the individual bbl groups touching most of the time, I would say there is nothing wrong with your shooting.
In a recent test of my 450 No2 I dropped the powder charge 1 grain [RL-15] and saw a noticeable RISE in the point of impact at 100 yards, the left and right bbl groups moved closer together also. Do not worry about puplished velocities for the Nitro ctgs, I think there was a little "blue sky" in the factory numbers. This would/did result in such a slight amount of difference as to be unnoticeable at 35 yards. [My Accuracy International 308, scoped, hits low at 25 yards, I need to move the scope "up" four minutes of angle to be dead on at 25 yards. This would cause me to shoot four inches high at 100 yards. You may be hitting low at 30 yards and spot on at 100] It may be that you need more barrel time. It looks like that 50gr. of Varget with the 235 Speer's hit HIGHER on the target than 53gr. of Varget.
Try IMR4831 with the 270 and 300gr bullets.
Start with 50gr. and increase each load one grain at a time. Shoot these loads at 30 yards and 100 yards.
Have you shot the rifle with any load at 30 yards and 100 yards, if so what were the results.
If that double shoots a 2" horizontal at 30 yards and maintains that same 2" spread at 100 yards, I would just go and look for some wild pigs.
If you are concerned about bullet expansion at 375 Flanged velocities I would definately shoot Hawk bullets with the .025jkt[I have used them in my 450/400] for deer and pigs, moving up to .035jkt [used them in the 9,3x74R, both have given excellent expansion and penetration, very few pigs have even taken one step, none have run over 20/25 yards] for elk and black bear.
Even though I really like my Chapuis 9,3 I would like to have a small to medium bore British double. After all there is nothing like
"BRITISH AND BEST"
Keep trying, check the rifle at 100 yards.

I'll vote for shooting it 100 yards...

30 yards, with a scoped rifle, will be off, and it's not 2 barrels meant to converge.

The 375, will a big medium, is still a light gun, meant to be shot further... try it further out...

please
jeffe

mbogo375
Have you had a chance to get back to the range?

I did get back to the range last Saturday. I wanted to chronograph a few loads, so I did not get to try longer range groups. I tried seating the bullets about as far out as possible (still not touching the lands) to see how that might affect convergence. From the appearance of the groups pictured I think that I am going to have to wait for the bump-up die to compare the longer .375 bullets, as it does well with the .377 Hawk FN 280's, but not nearly as well with the .375 Hornady RN 270's. Lighter bullets (235 Speer, 220 Hornady, and 200 Sierra) seem to do well also. It seems that the longer bullets are less forgiving of the larger bore diameter than the smaller ones (maybe due to the shorter bullets having a longer bearing surface in comparison to their overall length?). Although I have not checked twist rate yet I don't think that this is causing these convergence problems. The larger diameter bullets, while not having the best individual barrel groups, just seem to converge better than the smaller diameter ones so far.

Another interesting observation that I made over the weekend is that the bores have a perceptible taper (smaller near the muzzle naturally)that is not due to wear or erosion. I am beginning to suspect that this rifle was originally set up to shoot paper patched bullets, although it is definitely a nitro gun.

280 Hawk FN(.377 dia.) with 50 grains of Varget at 2170 fps (3.425" OAL)



220 Hornadt FN with 52 grains of Varget at 2350 fps (3.245" OAL)



270 Hornady RN with 50.0 grains of Varget at 2160 fps (3.503" OAL)



Jim

mbogo375
Your rifle consistantly shoots the right bbl groups lower and to the left. The individual bbl groups are very good.
Just as an experiment try the Hawk 280gr with 48,49, and 51 grains of Varget [watch for pressure]. and the 220 Hornadys with 50,51, and 53gr. of Varget. I am curious as to how the Individual and joint bbl groups move when JUST the powder charge is changed. Also shoot some of the best loads with each bullet at 100 yards. As your bbls have not crossed, the rounds might hit closer together at the longer distance.
What jacket thickness is the Hawk 280gr?

mbogo375
I have already posted my excellent results with the Hawk Bullets.
I have taken a few deer with the 375 H&H and the 220gr Hornady. It has worked very well, muzzle velocity @2400fps [reduced load]. I shot one deer facing me at 175 to 180 yards. The bullet traveled through the heart and landed in the rear ham. It was expanded perfectly , and had done about as much damage to the heart as I have ever seen. I figure the impact velocity at that distance to be somewhere around 1700 fps.
I have also used the 235 Speer in a reduced load to shoot a few deer with good results, but have not recovered any bullets from that load.

NE 450 No2,

The Hawks are .025 jacket thickness (I went with the thinner jackets, hoping that they would expand to groove diameter on firing better than the thicker jacket).

I have only a few of the 280's left, and have been waiting on the 320's before ordering more.

Jim