.303 Brit to 54R conversion?

[Dr Prepper]

Recently came upon a fairly decent pile of .303 Brit brass.
Looking up the specs and dimensions it looks like it would be a candidate for conversion into 7.62x54R the only major concern is the rim is .03" smaller outside diameter.

Havent looked at SAAMI paperwork yet, or dug out some factory loaded 54r to compare more precisely. But figured i should post this asap and hopefully get some good responses in the meantime.

Looks like roughly same charges, same velocity etc, so i imagine the cases can hold roughly the same pressure.

Let me know what you think or if youve tried this before and have any advise/tips etc.

TIA!

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[orygun]

Interesting question. I'm going to hang out and see if I can learn a thing or two.

 

[Dr Prepper]

Interesting question. I'm going to hang out and see if I can learn a thing or two.

Grab a seat, I enjoy the company.

I should also state this would be my first foray into wild catting or caliber conversion. Some what new to reloading but currently wading through oceans of brass im processing for reloading. so im head first' Might as well hit the high dive.

 

[ma96782]

What will be the donor platform?
Are you willing to "work" to get it to feed and function correctly from the magazine?
And not to mention the cost of the project.
Then.....Rrrrright......
Like I'm really dying to have an SMLE in 7.62x54R. LOL.

But, of course a single shot is a different story.

Aloha, Mark

PS.....but speaking of conversions. A popular one {back in the day} was the Mauser K98k in 8mm to .30-06 conversion. Funny, that the value of an unmolested Mauser K98k is so high now a days. And, even then, there were "some problems" to over come. Rrrright.....everyone wanted to use a stripper clip. LOL.

 

[orygun]

Probably just looking for reloadable brass for the 54R.

 

[Dr Prepper]

PSL and mosin is what ill be running. I have quite the stockpile of donor mags i could modify. I bought about 15 of them for about $15 each in as is condition for parts. Some were pretty rough some are in great shape.

Cycling isnt necessarily the goal though. But would be desired. Single feeding if necessary isnt out if the question. Mainly trying to explore the upper most accuracy each of these rifles are capable of by tailoring a round for them.
My mosin is used and certainly not a safe queen my my one PSL looks totally virgin in unshot condition. Pristine bore.

 

[Dr Prepper]

What will be the donor platform?

Yeah no donor platforms just looking for reloadable brass as orygun stated.

Sorry i meant to add "brass" into the title. Looks like i missed it.

Im too lazy for all that. Im looking for the quick easy hack.

 

[Certaindeaf]

Do what I did and don't do that.


lol

 

[ma96782]

My son use to own a PSL. Actually, he has owned two of them.



He wasn't happy with them and sold them off. He said that he didn't care for the lack of accuracy vs. what he could get on a much cheaper platform. The PSL to him was a "novelty" (more than anything else). Yeah.....it's not like you run into them, all that often.

I figure, it was probably due to the construction and light barrel. But, who cares?

Speaking of which.....
I have several Mosin Nagant rifles.
But, I would not think of changing the caliber. Mostly, because of the expense. If I wanted something else. I'd just buy it. Probably, saving myself from the aggravation and possible disappointment of a Mosin in a different caliber. Yeah......like I really needed THAT?

Aloha, Mark

 

[03A3Sporter]

I know a guy that did a x54R conversion on a Semi Bren build to take advantage of the cheap at the time x54 ammo .. it seemed to work ok other than the occassional odd split case neck .

Just an FWIW a BREN ain't an enfield and the SMLE action is by no means as strong as a Mosin Nagant

 

[ma96782]

Wait a minuet? Were you talking about converting.......only the brass......from .303 to 7.62x54R?

OMG!

Cheap reloadable brass is available off the shelf for the 7.62x54R. Why would you want to go through the trouble?

Then.....
I believe that there is a market for the .303 brass (boxer primed). Being that.....there was a bunch of No4s, that have recently hit the market.

Aloha, Mark

 

[CLT65]

I've done a lot of stuff like this in the past. I've done a LOT of tinkering when it comes to case conversion and the like. I used to love doing that kind of thing just to see if it could be done. That, and reloadable brass in obscure calibers is much more readily available now than it was 30 years ago. For exapmle, I have a whole bunch of .284 Winchester brass that I converted to 7.5 Swiss. I still use it and it works fine, but if 7.5 brass were available back then like it is now, I never would have converted valuable .284 brass.

I believe it technically could be done, if you had to and there was no alternative, but you'd have a weak case that you'd only want to load very lightly to avoid a blowout. There's just too much difference in case diameter.

My advise, based on my experience, would be to sell your .303 brass and buy some reloadable 54R brass. The conversion would be a time-consuming hassle to make work, and you'd just end up with inferior ammo. You could probably get a good price for .303 brass, and it shouldn't be too hard to find 7.62x54R brass.

 

[homeuser6]

nope .030 will blow the case head

 

[Dr Prepper]

View attachment 845763
View attachment 845768



nope .030 will blow the case head

Hmm... Yeah i wasnt worried too much about the rim dia. Difference being .0015" on either side (radii) but the head difference being +.003" as well. AND the shoulder major diameter also being +.056" on the .54r is starting to make me think its not worth while.
Id have to blow out the case to dimensions (and waste powder and bullets) and then resize it to get the ultimate finished dimensions im looking for. Then do a ladder and fiddle with a load. And then do bullet jump after that.

Yeah, Sigh. I could use some extra $ and you are correct, would probably be cheaper over all in the end. Probably by quite a bit.
So where are you all seeing this reloadable 54r brass at? Esp recently? Seems ALL brass is sold out everywhere.
Im curious now because i havent seen a whole lot, which is why i kinda started thinking about doing this in the first place.

Foot note. The main reason i like PSL's and such are their surplus ammo. I didnt get it for the accuracy. Not a fan of ak's but i do like the rarer stuff like 8mm's PSL's and shotguns (until mine broke!) Its a longer range supressing fire type rig. That and it was $160 lol. Almost as cheap as my mosin.

 

[coop44]

Considered buying one of the heavy mg barrels in 7.62× 54r rechambering it to 303 on a p14 action but the barrels dried up.

 

[po18guy]

I would not. First, you would need to trim 2mm off the neck of the .303 and then size it in the 7.62 sizer to set the shoulder back to 54R spec. The problem then is the case diameter of the .303 is smaller at the rim than the 54R. In a 54R chamber, you are going to have bulged cases. Combined with likely extraction problems, and at 45,000PSI, I'd rather not.

Never a better time to sell the brass or trade for 54R.

 

[Dr Prepper]

Considered buying one of the heavy mg barrels in 7.62× 54r rechambering it to 303 on a p14 action but the barrels dried up.

I had one of those. A UK59 barrel i bought it from apex or TGI before they flopped i cant remember which. I wish i kept it. That sucker was nice and THICK. wanted to swap it on my PSL. Would have been an insane amount of work though and no lathe.

 

[Dr Prepper]

you are going to have bulged cases.

Yeah this is the main thing that worries me. I think its the nail in the coffin for this one.

Did a brief search for 54r brass last night. Didnt see anything actually for sale besides lapua and i think pederson which were both $1.50 a pop.
At that rate ill just pull some mil surp and mexican match some API and other custom loads.