Reaming 7.62 NATO to 7.62x54r

[Sniperhandle]

Thank you so much, that's extremely valuable information!

I don't know anything about welding, so I'll table the x54r based on your mag feeding test. It feels good to cross options off the list!

Yes, I was referring to the Dutch Mannlicher cartridge, which seems to have very similar external dimensions to the .303. Sorry I hadn't clarified. I think it could be viable because 6.5x54 Mannlicher-Schoenauer reamers and dies can be used, but I'd rather stick to a .308 bore if I can. Making the brass seems like a real pain, and I don't have an annealer right now.

I'm glad to know your 30-40 Krag feeds perfectly. That's my fallback chambering, so it's good to have it reconfirmed first-hand. Brass seems hard to come by at the moment though, so it's not my first choice.

I'm really excited to hear that the .307 Win works! In one of the initial pictures you posted in this thread, I think your .307 Win is wearing a 7.62 NATO conversion magazine, so I just assumed it wouldn't feed from a .303 Brit mag. It only has about 40% of the case taper of the .303 (though that's about double the taper of the 7.62 NATO.) How many .307 Win cartridges will fit in a standard .303 mag? Will it feed smoothly if loaded to capacity?

It seems the .307 may even headspace in a .308 chamber if I headspace off the shoulder. That means I might be able to screw a 2A1 barrel into my No.4, flip the front sight over, and call it a day! I'd obviously check headspace properly, but it seems plausible that it could work off the bat.

This represents some real progress. Thanks again for sharing all this knowledge!

Lawndart

Brass for the Krag can be formed out of 303 British Cases, I used to do that 30 years ago when 30-40 Krag was hard to find, And then it became available again from Winchester when the Ruger number 3 came out and Browning reproduced the 1895 Winchesters both chambered in Krag. The necks are a little short on the 303 when formed to Krag but I have never had an issue using them. I bought a bunch of 30-40 Krag Winchester brass a long time ago and so I no longer reform from 303 British. When Greek HXP Ammo was being unloaded on the US market in the 90's there was a lot of boxer primed 303 brass laying on the ground and I have buckets of that laying around here too.

Graf's had 30-40 Krag with their headstamp on it not too long ago and the price wasn't all too bad.

Yes the number 4 had a Sterling 7.62 mag in it, But I have since swapped it for a 303 mag when I switched over to 307 winchester.

The 308 worked ok when I first built that rifle and the extractor would pull it out, But it didn't always eject when it came back it would just slide right past the ejector screw, Hence the idea to switch to 307.

Edit to add: Another idea that had crossed my mind was 308 Marlin Express, Very similar to the 307 but at the time I could find 307 brass and 308 dies work fine too.

 

[S11033]

Brass for the Krag can be formed out of 303 British Cases, I used to do that 30 years ago when 30-40 Krag was hard to find, And then it became available again from Winchester when the Ruger number 3 came out and Browning reproduced the 1895 Winchesters both chambered in Krag. The necks are a little short on the 303 when formed to Krag but I have never had an issue using them. I bought a bunch of 30-40 Krag Winchester brass a long time ago and so I no longer reform from 303 British. When Greek HXP Ammo was being unloaded on the US market in the 90's there was a lot of boxer primed 303 brass laying on the ground and I have buckets of that laying around here too.

Graf's had 30-40 Krag with their headstamp on it not too long ago and the price wasn't all too bad.

Yes the number 4 had a Sterling 7.62 mag in it, But I have since swapped it for a 303 mag when I switched over to 307 winchester.

The 308 worked ok when I first built that rifle and the extractor would pull it out, But it didn't always eject when it came back it would just slide right past the ejector screw, Hence the idea to switch to 307.

Awesome, the .307 sounds like it’s the ideal answer! Any idea how many rounds fit in the mag?

 

[Sniperhandle]

I shoot from the bench mostly and I have never put more than 5 rounds at a time in, Never crossed my mind to fill the mag. Just make sure to load them with each rim in front of the last just like you do with 303 to prevent rimlock.

Edit to add: 307 Winchester is thicker brass and has a smaller internal volume, So like I said, Use 300 Savage data and you will be fine.

 

[S11033]

I shoot from the bench mostly and I have never put more than 5 rounds at a time in, Never crossed my mind to fill the mag. Just make sure to load them with each rim in front of the last just like you do with 303 to prevent rimlock.

Cool, good to know it will take at least 5 rounds!

The reason I was asking is that we run some PRS-style matches out to 600yd at my range, and it would be super cool to show up with a steampunk Enfield. For those matches, the more rounds I can fit in a mag the better. If you happen to have your stuff out sometime and can test the number that would fit, I'd really appreciate it, but otherwise I can just figure that out down the road.

As soon as I have access to my rifles, I'll crank the sporter 7.62 NATO barrel off my 2A1 and see if I can get proper headspace by just torquing it into my No.4.

Thanks again for all the help!

Lawndart

 

[Sniperhandle]

Cool, good to know it will take at least 5 rounds!

The reason I was asking is that we run some PRS-style matches out to 600yd at my range, and it would be super cool to show up with a steampunk Enfield. For those matches, the more rounds I can fit in a mag the better. If you happen to have your stuff out sometime and can test the number that would fit, I'd really appreciate it, but otherwise I can just figure that out down the road.

As soon as I have access to my rifles, I'll crank the sporter 7.62 NATO barrel off my 2A1 and see if I can get proper headspace by just torquing it into my No.4.

Thanks again for all the help!

Law

No 1 Mk 3 or 2A barrels are not a direct fit to a No 4, They can be done, But it will require machine work. They are all 14 threads per inch 55 degree whitworth threads, But they are different. It may screw on but thats about it.

 

[S11033]

No 1 Mk 3 or 2A barrels are not a direct fit to a No 4, They can be done, But it will require machine work. They are all 14 threads per inch 55 degree whitworth threads, But they are different. It may screw on but thats about it.

Yeah, I was told that a No.1 barrel will screw in, but will bottom out 180 degrees from the correct timing (upside down).

I’m not sure if the thread starts at the same point on the 2A as the No.1. Assuming it does, I’ll have options, and the right one will depend on where I’m at with headspace.

If headspace is too long and a longer bolt head won’t fix it, I can turn 1/28” (since threading is 14 tpi) off the shoulder. That would shorten headspace by 35.7 thou.

If headspace is too short, I can use a 1mm spacer that’s sold on GB and sand it down until I’m correctly timed. 1mm is 39.4 thou, which would be just over half a turn.

If headspace is just right, I can rotate the front sight 180 degrees about the bore axis and re-pin it. I’ll also have to file a new extractor cut.

Lawndart

 

[S11033]

By my calculations, the total difference in the height of a 10-round cartridge stack at the .307 Win's larger shoulder should be right about 6mm. At least 9 rounds should fit, but it's plausible that the full 10 might fit. At the rim, the .307 Win stack should be shorter by around 2mm. The follower will be more tilted, but these variances seem relatively small.

 

[XTR]

I can chamber a barrel in 30-40 Krag, which is almost identical to the .303 Brit and has a .308" bore, but I
think that would be a pretty boring conversion.

Your call, but the 30-40 is essentially a 308 with a rim and a long neck, and if your feeling wildcatish you can AI it and come pretty close to 30-06 capacity.

unless the cartridge just doesn’t appeal it may be worth another look at the ballistics that are available in a rifle that can handle the pressure. The limiting factor of the K-J was the single lug bolt.

 

[S11033]

Your call, but the 30-40 is essentially a 308 with a rim and a long neck, and if your feeling wildcatish you can AI it and come pretty close to 30-06 capacity.

unless the cartridge just doesn’t appeal it may be worth another look at the ballistics that are available in a rifle that can handle the pressure. The limiting factor of the K-J was the single lug bolt.

Yeah, 30-40 is definitely adequate. I’d avoid improved versions because the taper will 100% work in an unmodified .303 mag.

There are two things that make it less appealing than .307 Win right now. First, brass is out of stock, as is any brass I could reasonably make it from. I see .307 Win in a couple places, and can form it from Starline .444 Marlin in a single pass. Second, I’d have to order a custom barrel whereas I could use a cheap 2A1 barrel for the .307.

I’ll definitely do one in the future though if brass becomes available and Criterion will sell me an unchambered barrel with a .308” bore.

Lawndart

 

[XTR]

Yeah, 30-40 is definitely adequate. I’d avoid improved versions because the taper will 100% work in an unmodified .303 mag.

There are two things that make it less appealing than .307 Win right now. First, brass is out of stock, as is any brass I could reasonably make it from. I see .307 Win in a couple places, and can form it from Starline .444 Marlin in a single pass. Second, I’d have to order a custom barrel whereas I could use a cheap 2A1 barrel for the .307.

I’ll definitely do one in the future though if brass becomes available and Criterion will sell me an unchambered barrel with a .308” bore.

Lawndart

How much brass are you looking for? I could spare 50 for sure, might be talked into 100

I‘d have to check. Mine is a rebarreled Ruger #3. I don’t recall if I ordered 150 or 200 from Graffs a while back. I’d have to look And see how many unopened bags I have, I don’t need too many for a falling block.

 

[S11033]

How much brass are you looking for? I could spare 50 for sure, might be talked into 100

I‘d have to check. Mine is a rebarreled Ruger #3. I don’t recall if I ordered 150 or 200 from Graffs a while back. I’d have to look And see how many unopened bags I have, I don’t need too many for a falling block.

Thanks a lot for the offer. I'm pretty set on .307 for my first build because of how cheap and easy it will be to source a barrel, but I'll definitely keep that in mind as I plan my next build. If I can get Criterion to send me an unchambered .308" bore barrel, I will definitely take you up on it!

A falling block sounds super cool though...

Lawndart

 

[Sniperhandle]

Here is some pics of the bushed and trued bolt face etc. And mandrels I machined for doing pre ww2 rec with the internal "C-Ring" and ww2 and after rec without the c-ring.

 

[S11033]

Here is some pics of the bushed and trued bolt face etc. And mandrels I machined for doing pre ww2 rec with the internal "C-Ring" and ww2 and after rec without the c-ring.

That's super cool... I wish I had the knowledge and tools to take on projects like that. Someday!

I got in touch with Ray Gross at Manson Reamers, and he's got a print for a 30-303. Ray told me that freebore in the 30-40 Krag will be longer than ideal. If for some reason I can't get .307 Win to work properly, 30-303 will make a perfect fallback.

I'd just have to find a source of .303 brass. It seems to be out of stock in all my usual spots.

Lawndart

 

[Sniperhandle]

That's super cool... I wish I had the knowledge and tools to take on projects like that. Maybe someday!

I got in touch with Ray Gross at Manson Reamers, and he's got a print for a 30-303. Ray told me that freebore in the 30-40 Krag will be longer than ideal. If for some reason I can't get .307 Win to work properly, 30-303 will make a perfect fallback.

I'd just have to find a source of .303 brass. It seems to be out of stock in all my usual spots.

Lawndart

Knowledge comes from DOING, Living in such a time as this there is so much knowledge at our fingertips, Imagine John Browning, Whatever knowledge he had came from scarce books and by DOING. The only person holding you back from DOING is yourself, Don't be afraid of DOING, Many successful people failed miserably many times but they never gave up until they got it right by DOING.

 

[S11033]

Knowledge comes from DOING, Living in such a time as this there is so much knowledge at our fingertips, Imagine John Browning, Whatever knowledge he had came from scarce books and by DOING. The only person holding you back from DOING is yourself, Don't be afraid of DOING, Many successful people failed miserably many times but they never gave up until they got it right by DOING.

100% agreed.

I'm certainly not afraid of messing up as I learn. I'm going to buy myself a little mill and a lathe as soon as I move somewhere that I can have a garage. Right now we're stuck in downtown Boston until my girlfriend finishes medical school. Until then, most of my jobs get done as favors by friends, so I try to make sure I have my I's crossed and my T's dotted ( ) before I show up at their shops saying I need an adult.

I'll get there eventually though...

Thanks again for all your help on this!

 

[Sniperhandle]

You're Welcome! When you get home, Message me and I will send you two .307 Winchester dummy rounds.

 

[S11033]

You're Welcome! When you get home, Message me and I will send you two .307 Winchester dummy rounds.

That's very generous, thanks a lot! It will be the middle of May. I'll certainly message you.

Cheers,

Steve

 

[Ggmac]

Hey guys, I have a question for people that know about chamber reaming and neck sizes.

I have a sporterized Enfield No.4 that I want to accurize, and I'm trying to avoid having to load .303 Brit. The action is already set up to run rimmed cartridges. I will have to make some tweaks to the magazine, but the bolt shouldn't require any changes.

I have a 7.62 NATO barrel that will fit into the action, but that won't reliably feed and cycle the rimless rounds, which is why I'm looking to the x54r or x54r. I'd like to know if I can ream the barrel to x54r without having to set the chamber back. It looks to me like all dimensions are larger in the x54r up to the case neck, where the NATO is larger. The neck dimension I see for the NATO is .343", whereas it's .336" for the x54r. (Also, keep in mind that x54r dimensions is using a .310" projectile whereas I plan to use a .308".) The neck of the x54r begins 1.657" and ends 2.043" from the breech face. On the NATO, it begins 1.560" and ends 1.863" from the breech face.

I'm very surprised by how much thicker the spec on the NATO case is than the x54r. I'm not going for benchrest accuracy here, since I'll just be using a 4x scope. But I want to get good case life, and don't like the idea of having a sloppy chamber. I assume the NATO chamber probably has some clearance built in already. Can you guys please let me know your thoughts on whether I need to set this barrel back or not? I don't know what a normal clearance is in the neck.

Thanks!

You could use 307 brass and not modify anything. If you can find 307 anymore. 100 rds should last a life time.
Hint 307 was the 308 win with a rim . Made for the lever action mid eighties I think. Seems like just last year . Yikes 40 yrs ago , dang Im old
I have some Parker hale barrels that were modified for the 4 . Or you could buy the rifle already made with Parker hale barrel and rear scope base .
Sorry I didnt read the entire thread . 307 will work and eject . Some work on extractor tension and ejectoe length may help with the 308 win . The extractor tension is what pushes or slides the fired case over to the receiver wall toward the ejector . If you feel and look on the left receiver wall youll see how the case must be pushed from chamber center to left side so it hitsthe ejector .

 

[S11033]

You could use 307 brass and not modify anything. If you can find 307 anymore. 100 rds should last a life time.
Hint 307 was the 308 win with a rim . Made for the lever action mid eighties I think. Seems like just last year . Yikes 40 yrs ago , dang Im old
I have some Parker hale barrels that were modified for the 4 . Or you could buy the rifle already made with Parker hale barrel and rear scope base .

That's exactly the conclusion we arrived to! Always good to have your solution validated.

I see brass in stock in a couple places, but learned that I can run Starline's .444 Marlin brass through a .308 die to form .307 in a single pass! It just needs to be trimmed a bit. I think that brass will be around for quite a while, because it's used to form a number of cartridges. It's cheap to boot!

I'd love to find one of those barrels, but it seems I'd probably need to have a clone made if I wanted it. Right now the plan is to try an Ishapore 2A1 barrel and just see how it does.

Lawndart

 

[Ggmac]

That's exactly the conclusion we arrived to! Always good to have your solution validated.

I see brass in stock in a couple places, but learned that I can run Starline's .444 Marlin brass through a .308 die to form .307 in a single pass! It just needs to be trimmed a bit. I think that brass will be around for quite a while, because it's used to form a number of cartridges. It's cheap to boot!

I'd love to find one of those barrels, but it seems I'd probably need to have a clone made if I wanted it. Right now the plan is to try an Ishapore 2A1 barrel and just see how it does.

Lawndart

Ive got about 12 barrels remaining in std mauser thread and one in no 4 thread .
I added some material to my previous post about making the rifle eject with std 308 .
Remember the 2 ishapores were for the 7.62 nato and very long throat to keep pressure low .