IMR4350 In British .303 Enfield MK4

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loose noose

loose noose

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Has anyone used IMR4350 powder behind a 174grn Sierra SP/BT/HP projectile. If so how much powder (starting-Maximum) OAL, and the primer and case used. Reason I'm asking is I've got an abundance of IMR4350 powder and would like to use some up in my British .303 Enfield rifle.

So far haven't found any loading data on that powder from Dupont for the .303 British. Any help will be greatly appreciated.
 
I thank you folks, reckon I'll try to start with 42 grains and work my way up to say 46 grains very slowly, I do love that rifle, I did find a load it really likes, so now I'm just testing the waters so to speak.
 
I cannot remember any specifics as this was a long time ago, but I do remember that powder worked quite well and the old mil surp rifle shot better than I thought it could, especially with cast bullets.
 
Maybe 35 whelen will chime in here. If not you might message him. He has done some shooting with the brit round.
I have only worked with 4198 and varget in that round. So i am not much help lol
 
I think you'll like IMR4350 in the .303 British. 46.0gr looks to be reasonable and will duplicate the mil-spec velocity of 2,400fps with the 174gr bullets.

I personally use BLC2 for the reason that it gives the highest velocities with lowest pressures consistent with original ballistics. This prolongs the life of the brass.
Most midrange burning rate rifle powders will reach the nominal specs of 2,700fps with 150gr and 2,400fps with 174's.
IMR 4350 does it likewise, but at expense of +/-2gr more powder. My experience is though that you will see good accuracy.

You do need to slug your bore and see what you are dealing with.
I got real lucky that I got a 1943 Fazerkerley that was arsenal reworked some time in the '50's. It's got a pristine barrel that mikes .311-.312".
With 150gr PPU soft points (Grafs.com) it shoots ~2" at 100yds (5-shots). 47.0gr BLC2 @ 2,700fps.
It shoots even slightly better with either the Hornady 174gr BTHP or PPU 174gr BTHP. 43gr BLC2.
Remember, what you're dealing with is that with a rear locking bolt, and frequently "generous" chambers, case stretching and case failure after just a few loadings. I've only had one case fail, and it was a range pick up with an unknown history. (Be sure to take with you a .410 shotgun brush and cleaning rod. Thats how you remove a separated case). The Remington and PPU brass I've been using are doing really well. I expect to get 10+ loadings from them. Anything that has been trimmed twice goes in the cast-load box...

I really enjoy my Brit. I plan to shoot it in the military rifle match next month at Talladega CMP match.
I replaced the "dog-leg" rear sight with a Fazerkerly correct milled vernier rear sight. I've got it marked for elevation with both jacketed and cast bullets facilitating cheap practice with cast bullets. Got some stripper clips, extra magazine, and even a correct sling.
I have a special place for the .303 as it was the first centerfire rifle I ever fired, now 50yrs ago!
 
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Just a hair off subject, but has anyone tried blackpowder and cast bullets in their 303?
I would like to duplicate the original loading some time and give it a go.
 
I don't now about blackpowder loads that could be really dangerous. I did it myself though it was in a mauser 98 action , I didn't blow myself up and it ended up being a pretty nice load for the old 8mm with a cast bullet. I do remember being a little hesitant on that first shot. Back to Subject I'm trying to remember but I think I used H335 and 150gr interlocks. I still have probably 100 ready to shoot. I'm pretty sure it was H335, if not it would have Been imr4320. I'll look at my notes and post again. I may have a load built up with 4350 since I use so much of it.
 
Goose Gestapo, I really appreciate your insight on the IMR4350 powder, I did slug the barrel and it was right at .311 and is in pristine shape, very sharp lands and grooves. Mine was made in 1955, and I believe it sat in the Armory for quite a few years. (very good condition) I bought mine just this year from an older gentleman that "just wanted it to go to a good home" per se. I posted pictures of it on this forum back around February or March of this year. I found my accuracy load to be 39.5 grains of H335, using a Federal Magnum Rifle primer, and 174grn Sierra SP/BT/HP projectile, the OAL was right at 3.085 in Sellier & Bellot casings. My best groups came right at 1.25" at 100 yards, using a portable shooting bench, and a lead sled, however at 200 yards they opened up considerably to 3", which I believe is my old eyes. Hopefully if the wind stays down this weekend I'll try the IMR4350 as I've loaded up several rounds using 42.0 all the way up to 45.5 grains. If the 43.0 and up show pressure problems I'll just pull the remainder, as I only have 5 of each, all in Remington cases (20 once fired). BTW I've got a bunch of PPU cases loaded up with H335 powder also and plan on taking my youngest son (40 years young) out with me later this weekend, as he has a lot better eyes than I have, and see what he can do with both loads. Reckon I'm going to have to order some .303 bullet molds for my Enfield and try cast bullets, it finally got cool enough out here lately that I can resume casting. What molds do you recommend?
 
46.0 grains of IMR4350 is more like 2250 FPS.
No magnum primer required for H335 either.
There are some cast loads on .303british.com.
 
Sunray, I'm aware of the fact that H335, doesn't require magnum primers, but that was the only large rifle primers I had at the time so I had to do with what I had. I did have some large rifle primers made in Bosnia, called "Unis "Ginex" Gorazde" but they didn't want to seat in the primer pocket, in fact if anyone has the opportunity to buy some just forget it, they are junk. (If I remember right they were like $20.00 per 1000) BTW thanks for the .303british.com I'll be looking into that for sure.
 
Suray, where did you get the 2,250fps figure. Most data disagrees with you.
re: Hodgdon, Hornady.
Perhaps you had an oversized bore/worn barrel???
 
I have been loading a 174gr Hornady InterLock bullet over 43.6gr BL-C(2) and it seems to be the most accurate load I have tried so far. I'm guessing the 174gr Sierra MatchKing bullets would be more accurate but they cost too much so I'm waiting for a sale.
 
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