Lee Enfield help .303/7.62 Nato

[351 WINCHESTER]

I found some interesting information regarding the conversion of no4 mk1 rifles to 7.62. I saw a picture with the proof of 19 tons. The Brits. use the long ton of 2240 lbs. which = 42,560 lbs. All .303 rifles were profed to 18.5 tons which = 41,440 lbs.

I thought the 7.62x51 nominal pressure was 50,000 lbs. I have always read and been told that the lee enfields were not very strong actions. I know the Indian enfields used modern steel and improved heat treating to allow them to use the 7.62 nato round.

How come the Brits. and Canadians rebarrelled some of their no4 mk1 rifles to the 7.62 nato round. I would think that after some period of firing that things would start to "give" under the added pressure.

 

[silverlance]

oh, dont forget that 308 is 60,000 cups. x51 is 50,000 CUPs.
(cubic units of pressure).

i believe cup is old standard now, but still applicable. 303 is likely much less than 50K cups.

so... ishapore safe for shooting 308 win? I don't know. dennis kroh at empire arms refuses to sell them. says that he personally saw a guy blow off a good part of his crotch when one went kaboom on him (although the rifle did give him many warning signs over overpressure - the extractor blew out real early and he continued to shoot by pushing a cleaning rod down the barrel to extract after each shot).

 

[DiN_BLiX]

i think .303 is around 40,000. Alot of people stay away from the indian built .308 enfields due to poor upkeep/beening imported as junk. I have seen some real nice ones, but they were most likley the exception.

 

[Jeremy2171]

Isapores 2As are good rifles and made specificaly for the 7.62(same as .308...really) round.

CUP stands for "Copper Units of Pressure" not "Cubic". CUP and PSI are used in stating pressure levels but the two don't equal each other and that is where part of the problem is. Some see "cup and think "psi" and it doesn't work that way...some have substituted "cup" FOR "psi" and that has led many to think .308 is unsafe in a 7.62.

 

[Ian Sean]

Ummm...guys...Ishy Enfields were built on NEW receivers....they were NOT .303's rechambered for .308, this is a common misconception.

Linky to info...http://enfieldrifles.profusehost.net/ri5.htm

 

[DMK]

I found some interesting information regarding the conversion of no4 mk1 rifles to 7.62...How come the Brits. and Canadians rebarrelled some of their no4 mk1 rifles to the 7.62 nato round.

Nobody reads posts anymore. The OP isn't asking about No.2 Ishys nor is he asking about .308, but about the No.4 7.62x51 rifles.

Honestly, I don't know how they rationalized the 7.62 conversions. However, they were sniper rifles, not service rifles. Perhaps they felt that since they would shoot a relatively low round count and would be maintained better, it was worth the risk. I've heard that they handpicked receivers for these. Perhaps the re-proofed them. Authentic 7.62 No.4s are kind of rare here in the US so generally little is known about them.

Shotgun News had an article about them a while back. I'll see if I can dig it out and see what they said.

 

[BruceB]

Does anyone REALLY think that a legitimate government is going to issue booby-traps to their personnel? Come ON, guys.

NO, the actions were not specially selected or manufactured. NO, the rifles were not a "low-round-count" concept.

Snipers do MORE shooting than almost any other soldiers, and their rifles are not restricted to limited firing use. The British L39 series of 7.62 NATO rifles based on #4 actions served well for many years, and some may well still be in service.

Thousands of other #4 rifles were modified to 7.62 NATO via commercial kits from such reputable makers as Parker-Hale. These kits were specifically intended to create 7.62x51 target rifles from .303 #4s, again not a "low-round-count" function. Kits included a barrel, a magazine, and small parts required to adapt the action to the newer round.

Enough 7.62mm #4s were around the competition circuit that Parker-Hale made a version of their fine #5C sight (which fits only the #4 Rifle) which is specifically calibrated for 7.62 NATO, and marked accordingly.

There are no strength issues involved when converting the #4 to 7.62 NATO, as long as the action being adapted is in correct serviceable condition.

 

[mnw42]

The Enfield L42 is basically a modified No.4 Mk.1 (T) built on converted receivers and new receivers designed specifically for the 7.62 NATO. I don't believe that their is any major difference between the two beyond the mag, ejector, and extractor.

Link1
Link2

 

[Fosbery]

Standard no.4 rifles converted to 7.62 (L8 rifles) are pretty rare but I don't believe there is any problem with them. The 7.62 sniper/target rifles (L39A1, L42A1 and the Enforcer) are fairly common and I've never heard or experienced any problem with them. They shoot well. Unlike the L8 rifles the L42 was issued to military combat snipers and the Enforcer to police snipers. The L39A1 was also used as a military target rifle and all three were sold to civillians during production and then as milsurps (and polsurps?) when they were replaced.

Ishapore Enfields are a whole other thing. They were built brand new rather than being converted to 7.62. I've not had any experience of them so I couldn't comment on quality.

 

[Topkick]

Lee Enfield help

OK fellas, with all the hubbub about pressure comparisons, so tell me please, if a reading of 50,000 cup's and a reading of 50,000 psi is reached what is the actual difference???

Topkick

 

[DrDremel]

The problem with #4 7.62 NATO Enfields are not so much the caliber as it is the feeding and extracting. I had two parker Hale converted rifles. Both would occasionally have bolt over base malfunctions when feeding and extraction was not reliable enough to be considered for defensive or hunting use. Going from rimmed to rimless made a great rifle mediocre at best. Even with a new mag, bolt head, extractor and ejector, it just was not the best. I ended up selling them as they were not reliable enough for me. They shot well and were great if you were to only use them for range shooting but not for any serious use.

 

[JesseL]

Doesn't a 7.62x51 case have a smaller area inside the rear of the case than .303 Brit? If so, then given equal pressures the 7.62 round would put less stress on the action than the .303 and the 7.62 could operate at higher pressures to achieve a level of stress equivalent to the .303.

 

[351 WINCHESTER]

Well I guess the no4 mk1 and 2 are much stronger than I was lead to believe. I know the .303's were profed at 18.5 tons (British ton is 2240 lbs.). The 7.62's were profed at 19 tons. Go figure.

What I don't know is if they profed in psi or cup or something else, but I believe the 7.62 nato is 50,000 psi. I don't think the Brits. or Canadians or any other govt. is going to issue unsafe weapons to their troops.

Some time ago I learned that Hornandy used to offer a light magnum ctg. for the .303. They still have some on hand and from what I know now this round would be safe in a no4 or possibly a no5. I can only assume that this load was loaded to higher pressure to get almost 2900fps with a 150 gr. .312 bullet.

 

[Limeyfellow]

The Lee Enfields designed to fire the 7.62mm nato rounds have much stronger bolt heads and other little modifications that got up the ability to handle 19 Tonnes of pressure. You can tell these bolt heads as they are marked with 19T on them and have a longer extraction claw. With the stronger bolt and barrel these modifications done for the L39, L42 etc can handle the extra pressure and work just fine.

The L42a1 in particular was still serving as a sniper rifle until the early 1990s.

I would love to get ahold of one of the Lee Enfield Envoy rifles.

 

[JesseL]

The Lee Enfields designed to fire the 7.62mm nato rounds have much stronger bolt heads and other little modifications that got up the ability to handle 19 Tonnes of pressure. You can tell these bolt heads as they are marked with 19T on them and have a longer extraction claw. With the stronger bolt and barrel these modifications done for the L39, L42 etc can handle the extra pressure and work just fine.

I would have thought that the bolt body (where the locking lugs are) and the receiver (where the lug recesses are) would be the weak points, rather than the bolt head (which is just under compression).

 

[Mk VII]

They are the same old bolt heads - just ones that have passed the higher pressure test (which is now 20 tons, by the way).
Many conversions continue in use on the club circuit, though serious competitors have discarded them by now. And yes, they have been known to break locking lugs in the rain.

 

[351 WINCHESTER]

"Break locking lugs in the rain?" Could you please enlighten me as what effect rain would have on the locking lugs?

 

[mightyike]

PO Ackley

Read PO Ackley's seminal work on pressure testing, blowing apart guns, etc...I do not think an Enfield is meant to be a 7.62 Nato....just because it can be done doesn't mean it should be done.

I remember that from the 1960's when I was in high school in Terry Montana.

It's a moot point. If you want to take the chance, it's yours to take.

 

[Mk VII]

Could you please enlighten me as what effect rain would have on the locking lugs?

wet ammo will increase the rearward thrust on the bolt.

 

[daniel (australia)]

Those pressure ratings aren't the proof load pressures but the rated standard working pressure. They were proof tested with loads at far higher pressure - up to something like 31 tons for the .303 IIRC.

In relation to the breaking of lugs in the rain the issue is essentially this: dry clean cartridges expand on firing and grip the chamber walls briefly as the pressure peaks, but wet cartridges (or even worse, oily ones) don't grip the chamber walls. The result is that with the wet (or oily) cartridges much more of the gas pressure is transfered to the bolt-face as the cartridge freely slides back in the chamber, and that significantly increased "backthrust" is in turn transferred to the locking lugs.

BTW this is a good reason why all case lube should be removed after reloading too.

 

[daniel (australia)]

I should also add that No 4s in 7.62 and also in 5.56 are still seen in Service Rifle competition here, as well as a fair few in .303. They seem to work just fine.

 

[351 WINCHESTER]

Well I"m impressed with everyones knowledge. I've just got an education. I have a no5 (sporter) and love it. I read somewhere that the chamber should be free of oil. I now know why.

Thanks for all of your input.

 

[Slamfire]

I have a L39A1 Target rifle in 308 Win. It obviously had been through a number of hands before I got my mitts on it.

Someone had bedded the action with an aluminum plate, under the action. Also, someone had installed a handstop and rail.

The action is way too sensitive to sling tension, which might be due to the plate. The zero of the rifle changes radically going from sitting, prone, and then moving as the tension changes.

Off the bench with a forend rest the rifle shoots ten shot groups under 1 MOA.

My rifle also springs the bolt with loads that are relatively mild. My M1a loads, of 168 SMK 41.5 grains IMR 4895 (just about 2600 fps in a M1a) causes a stiff bolt lift. Loads that chronograph at 2450 fps or less don't give a hard bolt life.

I had to spend big bucks to get a reliable feeding 308 magazine.

I wanted to shoot the thing across the course as a lark, but I never put the time or effort to debug the wandering zero issue, and then, if I can't push bullets faster, I am really hurting at 300 yards, and 600 yards. I shot it once at 500 yards, I did awful. The PH5A sights were canted. I finally got a good set of Twin Zero rears. That cost an arm, leg, and other body parts.

Outside of that, the rifle is well built. Fantastic trigger, smooth bolt, just feels slick all over.

 

[ArchAngelCD]

Just for the record, current SAAMI specs for the 303 British is 49,000 psi, the .308 Win is 62,000 psi. IMO that's a really big difference so caution is a great idea if you convert.

 

[Oohrah]

It seems to me the No.4s also beefed up the receivers also
for target. The biggest problem was at times were out shooting
the US teams. Their conversions did take some of the spring
out of the action and it was supposed to be more ridgit. I have
had a No.4 Sniper for many years in 303, and will never part with
it!