XP-100 7mm Int ... Help appreciated.

[Unofficialgunaddict]

Hello all,

I've just purchased a gun I've wanted since I was a kid, a 7mm xp100. The issue I'm having is that I purchased on short notice because the price was right, came with dies and brass, but now after doing a little more research, I'm not sure what I've got on my hands.

Here's the deal. This xp100 was originally a 7mm BR, but rechambered to a 7mm INT (which is what the barrel stamp indicates). "7mm Int". The issue is that in researching loads, I've come across a number of posts that suggest there were issues when rechambering the BR to INT... And that the INT-X or 7R is the result of the problems encountered when attempting to take a 7br and make it a 7int.

So... The gun is not yet here... Will be sent to my FFL shortly, but I'm thinking I need to get some advice before doing anything with this gun. It does come with 7mm IHMSA dies, fl, neck, reamer, seater, etc. but I'm wondering if I bought a gun that I can't or should use?

Anyone know anything about these?

 

[Outrider27]

There is no problem using it, you will just have to determine exactly where you're at with the chamber. If the brass you're getting has been fired at least once and doesn't look like it has developed a belt, you're home free - it's probably actually a 7mm Int. X. Unfortunately, both writers and sometimes gunsmiths referred to both the 7mm International and the 7mm International X interchangeably. The X, as you have probably already read, dealt with the problems resulting from rechambering a BR to 7mm International by changing the cartridge taper slightly, which dealt with the problem in the area near the extractor groove when using a cartridge based on the 300 Savage necked down to 7mm and using a modified shoulder angle in a chamber redone from a BR chamber. When blank barrels were chambered for either the 7mm Int. or the 7mm Int. X and fitted to XPs, there weren't any problems with either chambering as long as the shooter knew which reamer was used and had the correct dies; the problem was with some factory XPs in 7BR whose barrels were rechambered to 7mm Int. If once fired brass shows the belt, you can probably get the barrel set back a short amount and rechambered (again) with a 7 Int. reamer, or you'll have to rebarrel and you get to choose the caliber you want. Or you may just get lucky with the original rechambering job - some did.

The 7R is a rimmed 7mm based (if memory serves), on the 30-30 Win. case and is a predecessor to the 70-30 Waters. You'll probably find the 7R chambering more in Contenders rather than XPs.

Hope this helps.

Mike

 

[Unofficialgunaddict]

Outrider... That's a huge amount of help and more information than I've been able to find all evening. I appreciate your sharing your knowledge on the caliber, as well as your helpful suggestions about identifying the issue and resolutions as well. Thank you!!

 

[boltfluter]

There is no problem using it, you will just have to determine exactly where you're at with the chamber. If the brass you're getting has been fired at least once and doesn't look like it has developed a belt, you're home free - it's probably actually a 7mm Int. X. Unfortunately, both writers and sometimes gunsmiths referred to both the 7mm International and the 7mm International X interchangeably. The X, as you have probably already read, dealt with the problems resulting from rechambering a BR to 7mm International by changing the cartridge taper slightly, which dealt with the problem in the area near the extractor groove when using a cartridge based on the 300 Savage necked down to 7mm and using a modified shoulder angle in a chamber redone from a BR chamber. When blank barrels were chambered for either the 7mm Int. or the 7mm Int. X and fitted to XPs, there weren't any problems with either chambering as long as the shooter knew which reamer was used and had the correct dies; the problem was with some factory XPs in 7BR whose barrels were rechambered to 7mm Int. If once fired brass shows the belt, you can probably get the barrel set back a short amount and rechambered (again) with a 7 Int. reamer, or you'll have to rebarrel and you get to choose the caliber you want. Or you may just get lucky with the original rechambering job - some did.

The 7R is a rimmed 7mm based (if memory serves), on the 30-30 Win. case and is a predecessor to the 70-30 Waters. You'll probably find the 7R chambering more in Contenders rather than XPs.

Hope this helps.

Mike

Some great guys on this site.

Regards, Paul

www.boltfluting.com

 

[TC260]

There is no problem using it, you will just have to determine exactly where you're at with the chamber. If the brass you're getting has been fired at least once and doesn't look like it has developed a belt, you're home free - it's probably actually a 7mm Int. X. Unfortunately, both writers and sometimes gunsmiths referred to both the 7mm International and the 7mm International X interchangeably. The X, as you have probably already read, dealt with the problems resulting from rechambering a BR to 7mm International by changing the cartridge taper slightly, which dealt with the problem in the area near the extractor groove when using a cartridge based on the 300 Savage necked down to 7mm and using a modified shoulder angle in a chamber redone from a BR chamber. When blank barrels were chambered for either the 7mm Int. or the 7mm Int. X and fitted to XPs, there weren't any problems with either chambering as long as the shooter knew which reamer was used and had the correct dies; the problem was with some factory XPs in 7BR whose barrels were rechambered to 7mm Int. If once fired brass shows the belt, you can probably get the barrel set back a short amount and rechambered (again) with a 7 Int. reamer, or you'll have to rebarrel and you get to choose the caliber you want. Or you may just get lucky with the original rechambering job - some did.

The 7R is a rimmed 7mm based (if memory serves), on the 30-30 Win. case and is a predecessor to the 70-30 Waters. You'll probably find the 7R chambering more in Contenders rather than XPs.

Hope this helps.

Mike

My understanding of the situation is slightly different. The 7mm international rimmed has nothing to with XP's. The confusion was in relation to the 7mm IHMSA and the 7mm international-x which are very close to each other. Some people may have in fact confused the int-r with the int-x but if that's the case they were completely lost . When the 7mm BR's were being rechambered to the 7mm IHMSA the chambers wouldn't always clean-up properly so the body was straightened out slightly to make the 7mm Int-x which would clean-up the chambers.

The 7mm IHMSA dies may work but they're not the correct dies if it's actually a 7 int-x. A chamber cast would be a good next step to get everything straight.

 

[Outrider27]

Spoken like a man that has never seen a 7R XP. ;D

I have no idea why the owner did it (there's no accounting for taste and he liked it), but since the XP is a single shot feeding isn't an issue, and it shot quite well at 200 meters. Don't know how many more are out there (he claimed his wasn't the only one, but I never saw another in IHMSA competition); certainly Contenders are the obvious home for rimmed cartridges in a pistol shooting what is basically a rifle cartridge. Which is why I worded the reply as I did. The big fun with the 7mm BR was case forming for a number of years - we called it Little Orphan Ammo - so when Elgin Gates started down the 7I/7I-X path, which gave much easier case forming, many "jumped ship" and went to them. Us hardcore BR guys had, by then, formed so many cartridges that there was no reason to switch, so when Remington finally started making 7BR brass, even that made no difference to us. One thing I never understood was some of the horror stories around at the time about losing lots of brass while forming 7BR cases, but I always used the Remington .308 URBR brass and just followed the instructions that came with the RCBS forming die set, plus maybe I just got lucky. :

 

[TC260]

Spoken like a man that has never seen a 7R XP. ;D

I have no idea why the owner did it (there's no accounting for taste and he liked it), but since the XP is a single shot feeding isn't an issue, and it shot quite well at 200 meters. Don't know how many more are out there (he claimed his wasn't the only one, but I never saw another in IHMSA competition)

Fair enough. You've got one. That's a rebarreled gun not a rechamber like the OP's barrel. Either that or they put the wrong stamp on the barrel. A 7 int-r is so much smaller in diameter than a 7BR it doesn't make any sense that's what the OP's barrels been rechambered to.

 

[Outrider27]

Fair enough. You've got one. That's a rebarreled gun not a rechamber like the OP's barrel. Either that or they put the wrong stamp on the barrel. A 7 int-r is so much smaller in diameter than a 7BR it doesn't make any sense that's what the OP's barrels been rechambered to.

Never said I had one, only that I'd seen one - specifically, I competed against the owner in several IHMSA matches. Never said it wasn't rebarreled; my original discussion of the 7R was in reply to the OP's mention of the 7R as one of three 7mm International cartridges he'd found in researching the name. You said the 7R didn't exist in XPs, so I simply mentioned that I had seen one, and the owner of that one claimed that a few more existed, something I couldn't verify then or now. Once the OP new of the origin of the 7R, I'm sure one look at the brass that came with his let him know that version of the 7mm IHMSA Internationals was off the table.

 

[TC260]

Fair enough. A mutual misunderstanding. I was referring to the 7BR rechambers, not every XP that's ever been constructed.