Author Topic: rechambering .303's (Read 2599 times)

kevin.303 · « **on:** April 09, 2003, 09:55:25 AM »

i was wondering if you fellas could tell me what 7mm calibers it is possiable to rechamber a .303 in? i've seen .308's and gibbs makes a .45-70 based on a no.4mk.1.i've also heardof people firing .30-.30 and .30-40 krag in .303 enfields. any truth to this, i would think it is highly unsafe and bad for the chamber and barrel

jhm · « **Reply #1 on:** April 09, 2003, 10:14:54 AM »

I dont believe you can rechamber a 303 DOWN to a 7mm which is .284 vs .311 you might be able to rebarrel to 7x57 or 7-08 just a quick answer without looking any further, hope I was of some help.

JIM

John Traveler · « **Reply #2 on:** April 09, 2003, 10:15:07 AM »

Hi, Kevin!

I've only seen a few re-barrelled .303 Enfield rifles, and have never shot one. The aussies are famed for re-chambering and rebarrelling the .303 Lee-Enfield actions, probably for economy reasons. The wildcat calibers used (.17-303, etc) are downloaded because of the limited action strength.

First, are you referring to the Lee-Enfield design, or the P-14 Enfield (a mauser type) action? The P-14 is definitely much stronger and suitable to rebarreling to another caliber.

The .45-70 rebarrelled No. 4 rifles are practical because the WWII era No. 4 rifles are the strongest of the Lee-Enfields available.

As for the safety of firing a .30-40 Krag round in a .303 rifle. YES, it can be done, and at relatively little risk (the .30-40 bullet is smaller diameter than the .303 bore). However, this would strictly be an emergency thing to do, and not otherwise.

The reverse, firing a .303 cartridge in a .30-40 rifle is not possible. The .303 case has a longer head-to-shoulder dimension and will not fit. Even if it did fit, it would not be a good idea because the .303 bullet is oversize for the .30-40 bore.

As for rebarrelling a P-14 to 7mm magnum or other magnum calibers, it is one of the best and strongest actions for that purpose. Conversions to .30 Magnum, .338, .375, .458, etc are common.

HOWEVER, the .303 Lee-Enfield is NOT considered a good choice for rebarrelling to another caliber. The only possible rechambering I've seen or heard of is to the 7.62x39 Soviet cartridge, since both use the same bullet diameter (.311 inch).

So, there you have it: P-14 okay for rebarrelling or rechambering to magnum calibers, but not the .303 Lee-Enfield. Lee-Enfield okay for conversion to 7.62x39 Soviet only.

kevin.303 · « **Reply #3 on:** April 09, 2003, 10:25:24 AM »

i was referring to the lee-enfield and i guess i miss-typed because i was thinking of cartridges such as .308. 7.65 & 7.7 jap and some one even suggested the old and hard to find .307.and what about the 7.62x51 soviet cartridge? when i'd mentioned building custom rifles in a previous post i was wondering what calibers could be built on no.4mk.1 because compared to p-14/17 enfields theyare cheaper then free. :grin:

gunnut69 · « **Reply #4 on:** April 09, 2003, 01:05:33 PM »

The 7.62x51 is not a soviet cartridge it is the nato military version of the standard 308 win round. Also please note the 303 and the 7.62x39 russian use different diameter bullets. The Russian short uses the same bullet diameter as does the 7.62x54 russian rimmed and the 308(7.62x51), that is .308 inches. The Enfield's greatest limitation is it's design which makes changing to a rimless caliber almost impossible. The extractor on the Indian built version of the No1 chambered in 7.62 Nato is troublesome at best. Barely functional most of the time. It is possible to convert the No4 to rimless but the conversion is a PITA and not very reliable. I suggest rebarreling to rimmed calibers only. Actually the Aussies habit of wildcatting the 303 is probably more due to the design limits of the enfield action than for any other reason. There is little reason to alter an enfield's caliber. The 303 round is quite capable of handling most north american game and is effective easily to the range that the rifle is capable of. Rebarreling the enfiel to the 7.62x39 russian round would be difficult indeed primarily do to the difference in rim types and the extreme difference in cartridge lengths. Perhaps the endfield could be altered to 7.62x54 Russian but cartridge availability and performance issues would make one wonder, 'why go to the trouble'. Also the 303 and 7.62x54 use differing bullet diameters.. Accuracy of such a conversion would be abbismal. The enfield could be altered to several of the sharps cartridges most of which are fairly similar to the 45/70 although the 50 caliber rounds may not be able to be made to feed as repeaters. Regardless of caliber the pressures generated by any round in this rifle must NOT exceed the 303 British for safety reasons.

John Traveler · « **Reply #5 on:** April 10, 2003, 05:08:14 AM »

I heartily agree with Gunut69's comments about rebarrelling the Lee-Enfield action. It might be an interesting exercise just to prove that you can do it, but rebarrelling to another caliber is just not too practical. The .303 is a great cartridge as-is, period!

To echo his remarks about unreliability with the No. 4 rebarreled to 7.62 NATO, I known a few Canadian competitive rifle shooters that had something to say about that. The 7.62 NATO converted rifles were notorious for faulty extraction and ejection of fired cases and unfired rounds. They didn't like it at all!

Rick Teal · « **Reply #6 on:** April 10, 2003, 10:54:39 AM »

Gunnut69:

The Russian 7.62X39 and 7.62X54 are cartridges that take a .311 bullet. I'm guessing they designated it as 7.62 because the bore was .30 calibre, but cut deeper grooves in the rifling that are common in the west. It wasn't until Ruger began producing mini 30's with undersized bores that you began seeing .308 bullets loaded in 7.62X39 ammunition.

I have a Globco 555 that was originally an SVT 40 in 7.62X54. These rifles were rechambered only (and not rebored or rebarrelled) to .303 British.

Rick

kevin.303 · « **Reply #7 on:** April 11, 2003, 05:51:16 AM »

so by cartrides similer to the 45/70 do you mean the 45/90 and the 45/110? a bolt action buffalo rifle would make an interesting conversation piece. i was reading about the .303 epps at www.303british.com and was thinking that instead of doing custom rifles in multiple calibers i could re-chamber them in .303 epps and use aftermarket parts to give them a bit more of the "sporting" look that some folks prefer

Rick Teal · « **Reply #8 on:** April 11, 2003, 09:15:11 AM »

You'll have to be careful in marketing No 4's chambered in .303 Epps. The cartridge can be loaded to much higher pressures than the No 4 is considered to be capable of handling. Perhaps some type of warning not to load it to pressures in excess of a certain psi limit.

In a P14 or Ross, the Epps can produce velocities in excess of 2800 fps with a 180 grain bullet, while its not considered prudent to load a No 4 much beyond 2650.

gunnut69 · « **Reply #9 on:** April 12, 2003, 05:57:35 AM »

The 7.62x39 Russian and the 7.62x54 are both shown on Clymer's reamer database as using 308 diameter bullets. The 303 Brit is shown as using 312 diameter bullets. Hornaday reloading manual Nuber 4 says the 7.62x54 is loaded with 308 diameter bullets while the 7.62x39 uses a 311 diameter bullet but is safely and accurately loaded using 308 diameter projectiles. The 303 British is shown as using 312 diameter bullets. As far as reloading pressures go you are very correct. The normal No.4 should not be hot rodded although the No.1 made by the Indian government in 7.62x51 (Nato) should be more robust. I would not advise pushing the limits too far. If more power is needed I would advise a different rifle. When I mentioned other cartridges like the 45/70 I was really refering more the rim diameters and configurations.. The 45/90 etc are simply longer cased 45/70s and the limit would be the magazine length of the Enfield action. WITHOUT measuring I would guess a 45/90 or 45/100 might be shoe horned in with some mods and proper bullet selection... Once again without measuring and remember the magazine length would be the limiting factor. One might also look at the various 40 caliber sharps rounds. They offer somewhat reduced recoil and maximum case lengths for these cases are shorter while the performance is not much reduced. I would be especially interested in the bottle necked 40 caliber Sharps rounds. Most use the 45/70 case head as a basis and still provide a most impressive look. Not too long ago a magazine pundit had an Enfield made into a magazine style express rifle and I believe he said the 45/90 was the length limit. remember we're relying on an aging memory bank here and age porosity has most assuredly set in, with a vengance. Still I believe a 40/100 bottleneck would be possible. This would be a most interesting weapon indeed.

Wildcat Crazy · « **Reply #10 on:** May 21, 2003, 05:14:09 AM »

You would probably need a hammer to chamber a .30/40 Krag in a .303 Enfield.
I just tried chambering one in my SMLE,it stops short by 3/16 inch.
The .30/40 Krag is .015 larger than the .303 British at the same distance
from the rim.
WC

gunnut69 · « **Reply #11 on:** May 21, 2003, 02:13:33 PM »

I must also remind you that the 7.62 Nato round even though it runs at a lower pressure than it's cousin the 308, was chambered in a No.1 using special metalurgy. Also those Indian 7.62 No.1's I've worked on have been a pain to get to feed and extract correctly.