.30 XCB wildcat, from scratch.

[geargnasher]

What we aught to do is a 358XCB. I'm not kidding. Just a little bit more powder capacity would put 3031 right in the drivers seat for 2400FPS.

So, have you given up sleep altogether, or cloned yourself?

PS, don't forget my Model 70 needs a new barrel in amongst all those projects you keep dreaming up! Guess I'd better get to barrel shopping before the "good idea faery" dumps another bucket of pixie dust on you....

Gear

[runfiverun]

yeah speaking of model 70's.
I got a push-feed action I need to send your way to have a purple 7mm barrel screwed onto it.
and a stock found and glued to that...and a bolt handle,,,,, and maybe a trigger.

a 35 XCB would be pretty dang good too...

[MBTcustom]

So, have you given up sleep altogether, or cloned yourself?

PS, don't forget my Model 70 needs a new barrel in amongst all those projects you keep dreaming up! Guess I'd better get to barrel shopping before the "good idea faery" dumps another bucket of pixie dust on you....

Gear

That would be a very good idea Ian. The sooner the better.

[felix]

I wonder if we shouldn't make these Mosin actions work for these single-shot projects. The actions are dime a dozen, and prolly still are. Jumptrap, a member here some time ago, did a destruction test with one and just couldn't make it budge with any overload tried. Massive pistol powder amounts. He used the string and tractor tire concept for the firing. Question, can the bolt-face be modified easily/cheaply? ... felix

[felix]

3031 is an excellent 30 caliber powder, and is very versatile with various payloads and GUNS. ... felix

[MBTcustom]

The big hurtle with the Mosin is that extractor. It's made for the Russian cartridge in the first place which is rimmed and larger than the 308/06/mauser cartridges. A custom extractor would have to be fabricated/modified for each one. I'll have to do some pondering to see if I can come up with something.

Hey Brad, your barrel is in the lathe.

[runfiverun]

I seen a 7mm made up on the 348 win case a number of years ago, it mocks the win wssm round super close in velocity.

anyway a super good barrel [properly chambered], a good trigger, on a mosin action modified to single shot, most likely wouldn't need a case change.
if good brass could be found....

[btroj]

The big hurtle with the Mosin is that extractor. It's made for the Russian cartridge in the first place which is rimmed and larger than the 308/06/mauser cartridges. A custom extractor would have to be fabricated/modified for each one. I'll have to do some pondering to see if I can come up with something.

Hey Brad, your barrel is in the lathe.

Awesome!

Thanks for the photos. Wife was sorta like, yeah? So what.

Women.....

[swheeler]

I seen a 7mm made up on the 348 win case a number of years ago, it mocks the win wssm round super close in velocity.

anyway a super good barrel [properly chambered], a good trigger, on a mosin action modified to single shot, most likely wouldn't need a case change.
if good brass could be found....

Sounds like the 7mm Gradle

[MBTcustom]

Well, at long last I am getting after the Technicolor 4X4.

As with all the XCB rifles, I took my time setting up the barrel in the lathe. Kriegers are such a pleasure to work with! Makes it really easy to get things perfect. Even for Kreiger, this barrel is exellent.
Here I am turning the tenon and cutting the threads with the barrel set up in the superbearing:
Attachment 97510

Attachment 97511

Perfect fit, with exactly .010 space between the bolt face and the end of the barrel. The bearing surface for the recoil lug will be cut later:
Attachment 97512

Next, I reamed the chamber stopping .020 short of perfect headspace, using my self-designed true-floating reamer holder. After reaming, I cleaned the chamber and the reamer very well, slipped the reamer back in the chamber and satisfied myself that I had reamed a perfectly tight chamber by checking deflection and comparing measurements taken from the rear of the chamber to the corresponding location on the reamer. Then the barrel was turned with the indicator placed on the shank of the reamer, in order to observe that the chamber was not only tight, but perfectly straight. This is one of the best ones yet as the needle barely quivered as the barrel and reamer were turned. I'll be conservative and call it .0004 runout.
Attachment 97513
So what does all that mean for Brad?
Means that sucker's going to shoot. That's what it means.
I might also mention that I checked the runout in the middle of the barrel with the barrel at rest and under no external stresses, and noted the high spot on the outside of the barrel, how much it was, and where it was. When this chamber was cut, that measurement was identical while trapped and fixtured in the lathe, as it was at rest. This means that I imparted no strain on the barrel whatsoever by holding and turning it in the lathe. I take great pride in my ability to do this!

Finally, I made the recoil lug, and surface ground it. I had to flip it about 7 times, but I got .000050 TIR that I was after. It's flat and parallel, and made of the same material that the barrel is (416 SS)
It was machined from billet, from a piece of certified steel
Attachment 97516

Good times.
Now that I am satisfied with the flatness of the lug, I will proceed to cut in the bearing surface for that piece.

[runfiverun]

Sounds like the 7mm Gradle

yep that's it.

[338RemUltraMag]

What variables would need to be considered to make an 8mm version? Would give numbers smack between the 30 and 35, I could get in on that!

[btroj]

An 8 mm version would be very similar to an 8 x 57. This is basically an 06 reamer run in short to give a case the same length as an 8 x 57 but with the shoulder, neck, and throat of an 06.

To do an 8 mm version one needs an 8 mm 06 reamer and an 8 mm barrel.

I think a 35 makes more sense but I don't own an 8 mm or any moulds for one so there isn't a saving there. I just like the 35 cal bullets available and think it makes sense to go 35.

[MBTcustom]

An 8 mm version would be very similar to an 8 x 57. This is basically an 06 reamer run in short to give a case the same length as an 8 x 57 but with the shoulder, neck, and throat of an 06.

To do an 8 mm version one needs an 8 mm 06 reamer and an 8 mm barrel.

I think a 35 makes more sense but I don't own an 8 mm or any moulds for one so there isn't a saving there. I just like the 35 cal bullets available and think it makes sense to go 35.

Not exactly Brad. 8mmXCB would have a longer neck than the 8mm Mauser cartridge, as well as more properly designed throat, and also it would get that inherently close tolerance fit between the FL sizing die and the chamber of the rifle.

The only variable to consider is neck diameter.
If you want such a thing to be built, we can make it happen. My vision is to have a whole line of XCB reamers in all different calibers.

[338RemUltraMag]

Tim,

I would Love an 8mm version, something easy like the 30 XCB, I would want to use a .321 bore because of the available slow twists (1-16 comes to mind) that will stabilize a 323471 at 1900 fps. I was going to have my local smith do this as an 8x57 but you guys would know how to ring out ALL the inherent accuracy for a cast boolit round.

As for my bore choice... Well... an 8mm vs 35 cal debate isnt for here but you can hazard a guess as to what size I will take.

As a final question, I want a very accurate rifle but hate scopes, could this be made up as a surplus look alike (based off of a M48) OR would the results be easier to come by if it were made like a varmint style rifle?

Can open sights be fitted to said rifle?

Now lay it on my, How far off kilter am I?

Joshua

[felix]

Just what we were talking about last night, Tim. You know what to do. ... felix

[runfiverun]

josh... 1900?
a 1-16 would be on the slow side for that, a 1-12 would be better suited for the 1800-2300 zone.
if you had a particular boolit in mind then the rifle 'could' be throated to it.

I'm thinking one boolit design.
one case design.
one throat design.
just different diameter holes.

that would simplify everything, and really help drive home the concept of fit, and function.

[338RemUltraMag]

That was MY thought as well, I will cut me a 323471 boolit mold, then have the rifle throated cut and made FOR that boolit.

I ran the numbers through the stability calculator and 1-16 will stabalize that pill at 1900 fps, I plan to shoot at full speed. The barrel company also offers a 1-14 twist bore which may be better suited as it offers stability down to 1300 fps.

I woukd like to start with a military action and work from there, either making it a sleeper target rifle in military dress or make a varmint rig from it with the ability to run a scope as well.

[runfiverun]

the 14 should stabilize 125 [and maybe 150] jacketed when pushed into the 2800+ range which the 8 version should easily be capable of.

[MBTcustom]

Tim,

I would Love an 8mm version, something easy like the 30 XCB, I would want to use a .321 bore because of the available slow twists (1-16 comes to mind) that will stabilize a 323471 at 1900 fps. I was going to have my local smith do this as an 8x57 but you guys would know how to ring out ALL the inherent accuracy for a cast boolit round.

As for my bore choice... Well... an 8mm vs 35 cal debate isnt for here but you can hazard a guess as to what size I will take.

As a final question, I want a very accurate rifle but hate scopes, could this be made up as a surplus look alike (based off of a M48) OR would the results be easier to come by if it were made like a varmint style rifle?

Can open sights be fitted to said rifle?

Now lay it on my, How far off kilter am I?

Joshua

Well, I can certainly make you a rifle that closely resembles a military mauser, but you have to understand that it would drive the cost up tremendously!
If you want iron sights, that can be easily aranged, as thats exactly what I will be producing for Lamar. However, if you are after irons AND glass, thats also percectly doable, albeit slightly more expensive. It just depends how much you want to invest in the project. Anything is possible.