P14/P17 Conversion to 311 300 mag. ? Need Help ? (Pic Heavy)

ljones

ljones

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I was given what I believe is a P17 Enfield converted to .311- .300 Magnum. The fellow who had it didn't know much about it. I know that some were converted to other calibers to varying degrees of success and good to bad quality of work done. If the knowledgeable here could give me some info on this one. I know thw few handloads that came with it are shorter than standard .300 mag rounds as the bullet has to be set further into the casing to be short enough to work for magwell length. The stock forend is free floated and looks to have been glass bedded, and the action is snug when inserted into the stock with no movement. Weaver scope bases have been installed. The barrel is left hand twist. I have taken detailed overall pictures and detailed individual parts pictures and stampings pictures so those with some knowledge might be able to give me an idea what I have here and possibly a retail value as I have no need for this one. I know they were a strong action and would like to know if these are safe to use. It functions well and has been fired by the previous owner. Obviously whoever would buy it would have to handload for it as the bullets would have to be set a little deeper in the casing to fit the magazine. Also what would your evaluation be on the quality of the work? Anyone know who might have done it?

I also have a question about the round. It indicates that it is 311 300 mag. What would the 311 refer to. The previous owner said it was rechambered from .303 but it is stamped '17 thus I was thinking it was a P17. But the P17 was .30-06. The P14 was chambered for the .303. The serial of the barrel looks different to the receiver so I assume a P14 barrel was used on a P17 receiver? I don't know much about the differences between the two. I am also not a handloader so don't know all the details that would be needed to make these rounds. The handloads that came with it are .303 diameter bullets. Also not sure if the bolt is a P14 or P17. Any info would be appreciated and if anyone is interested in it PM me and we can work a deal. Thank you for the assistance.

Here are the Overall pictures:




Detailed pictures of Parts and Stamps:

 
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shredder said:
Your best bet would be to take it to a gunsmith and get a chamber cast done. That would be definitive.
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I have the handloads that came with it. The bullets are .308 (edited. I measured them while they were seated in the case) diameter. They are set in a bit further to be able to work in the magazine. But otherwise are regular .300 mag rounds. Now the fellow indicated that it wasn't that accurate. Not horrible accuracy but not sub MOA. I assume because the loads are using the .30 caliber bullets rather than the .311 diameter that a .303 would use. I assume that the 311 before the 300 mag stamp means to use .311 diameter bullets (.303 cal) in the 300 mag casings. I assume it would be more accurate with the .303 bullet than the .30 caliber bullet. But not being a hand loader I don't know if that would work. He was also using an old scope that could be hooped so that may have been the accuracy issue as well.
 
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I have done such things. I have a 308 british. (303 brass with 308 bullets) made by running a 303 reamer into a 308 barrel.

Yours is same idea. Run a 300 Mag reamer into a 303 barrel. Ordinary 300 Mag loading data will work.

It is a crude sporter and I would say it would be worth more if it had been left unmolested.

If I had it I would be happy to get $300 for it.
 
Ganderite said:
I have done such things. I have a 308 british. (303 brass with 308 bullets) made by running a 303 reamer into a 308 barrel.

Yours is same idea. Run a 300 Mag reamer into a 303 barrel. Ordinary 300 Mag loading data will work.

It is a crude sporter and I would say it would be worth more if it had been left unmolested.

If I had it I would be happy to get $300 for it.
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Thanks for the reply Ganderite. I thought it would be worth a little less than the $300 so I was close on estimate. Yes it would have been worth more if left as original but this was done years ago. No idea when. So it should be fine to run the .30 caliber bullets in the .303 bore?
 
Ganderite said:
I have done such things. I have a 308 british. (303 brass with 308 bullets) made by running a 303 reamer into a 308 barrel.

Yours is same idea. Run a 300 Mag reamer into a 303 barrel. Ordinary 300 Mag loading data will work.

It is a crude sporter and I would say it would be worth more if it had been left unmolested.

If I had it I would be happy to get $300 for it.
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I've looked into 303-300 win mag and my understanding is as above, just a 303 British P14 with a 300 win mag reamer run through it, and then whatever changes are needed to the magazine.

Why the OP's barrel is marked 17 I don't know for sure. The P17 (30-06) Enfields I have owned (a handful), never had this marking.

I've actually got a P14 sporter I'm still kind of considering doing this to....
 
Well - Its got a M1917 action, and a Pattern 14 bolt and barrel. Not sure why anyone would have bothered to assemble this combination, perhaps the magazine box for the M1917 gives more cartridge length. Too bad they didn't stick with the M1917 barrel...
 
cosmic said:
Well - Its got a M1917 action, and a Pattern 14 bolt and barrel. Not sure why anyone would have bothered to assemble this combination, perhaps the magazine box for the M1917 gives more cartridge length. Too bad they didn't stick with the M1917 barrel...
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From what I understand the old fellow who had it made had it as a short/medium range thumper rifle for the West coast here. So the smaller diameter bullet shot out of the slightly larger bore likely wasn't an issue. It wasn't made to be a sub MOA long range shooter. He had it for Grizzly while on the trapline and such. The gunsmith likely made it out of parts he had available for what worked for the intended use.
 
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Ganderite said:
It would shoot better with 174 to 180 gr 312 bullets.

I would be an excellent and cheap moose rifle.
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Would it make chambering the round too tight using the .312 bullet? If it was chambered using a regular 300 mag reamer would there be enough room in the neck to use those bullets and have it chamber properly?
 
The .302/.303 diameter bullet is a bit strange.I assume you measured the bullet diameter with the bullet seated in the case?I would pull a bullet and measure the diameter.You should have a chamber cast done to check chamber dimensions.You could also seat a .312 bullet in the case and see if will chamber.If I owned the rifle I would install a magnum length magazine box.
 
Ken T2 said:
The .302/.303 diameter bullet is a bit strange.I assume you measured the bullet diameter with the bullet seated in the case?I would pull a bullet and measure the diameter.You should have a chamber cast done to check chamber dimensions.You could also seat a .312 bullet in the case and see if will chamber.If I owned the rifle I would install a magnum length magazine box.
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Yes I measured it while it is in the case. It is a .308 bullet, not .303. I can't seat a bullet as I am not a handloader and have no equipment. I am looking to sell the rifle as I have no ability to do all that and I am a lefty shooter so it is not the best for me. I was looking for info so I could sell it with information.
 
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That is a good point about the chamber neck not being big enough to take a 312 bullet.

Measure the diameter of the neck of a fired case. That will give you an idea of how big the chamber neck is.

Measure the neck of a case with a 308 bullet in it. Add 4 thou to this number. That would be the size with a 312 bullet. If this is smaller than the fired case neck, you are good to go.
 
Ganderite said:
That is a good point about the chamber neck not being big enough to take a 312 bullet.

Measure the diameter of the neck of a fired case. That will give you an idea of how big the chamber neck is.

Measure the neck of a case with a 308 bullet in it. Add 4 thou to this number. That would be the size with a 312 bullet. If this is smaller than the fired case neck, you are good to go.
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inside diameter of the fired case nack os .308 and the outside diameter is .340. So probably no room for a .311 bullet.
 
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