6XC hunting/spotlighting build

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6XC hunting/spotlighting build

Post by Chronos » 02 Feb 2016, 10:02 am

For the past few months I've been collecting components for a build to fill a gap in the safe.

I wanted something in 6mm for spotlighting and fox shooting and although I have a .243W barrel for my Tikka it's a pain to change barrels and sight in.

While my 6PPC/6BR switch barrel target fun would be almost ideal it's single shot and too heavy for hunting on foot so I started looking for ideas.

The requirements for the cartridge were it needs to be 6mm and capable of .243 like performance with 65-95gr bullets. It needs to be a repeater action and reliably feed from a magazine, something the 6BR case isn't known for.

There's a good number of cartridges that fit the bill, Lapuas 6.5X47 case is commonly necked down to 6mm but I already have one necked up to 7mm and I'd rather not risk the confusion of having two guns running the same brass. Then there's the 6.5mm Creedmore case, again commonly necked down. Then there's .243 and .243AI. Good performance and the factory ammo option but the eventual winner for me was the 6XC case. Norma brass although a little expensive is good quality and availability is ok. The 6XC delivers similar performance to the .243W case but with better barrel life.

I originally ordered a carbon wrapped varmint profile 6mm barrel but when it didn't arrive in the shipment and was scheduled for delivery in another 8 weeks I cancelled the order and went back to looking for a blank locally. When a No3 profile Maddco barrel with a 200 round count appeared really cheap but chambered in 6mm Remmington I hit the books to see if it was usable. Indeed it was, the short fat nature of the XC case meant the reamer would clean up the entire chamber meaning the gunsmith could simply cut off the existing thread and cut a new thread then chamber as normal. While David Tubb developed the 6XC to shoot 115gr bullets normally they use fast twist barrels but mine is a 1:10" twist like most .243's but seeing as I'll be only hunting with mine I'm not interested in shooting bullets over 100gr so it should be fine.

Seddo's Guns had Stiller Tac30 actions in stock so the order was placed and the action sent to my local gun smith. I chose this action because being a clone of a Remmington action it would be easy to get stocks, a trigger and other components for. While not capable of the precision of a single shot benchrest style action the Tac30 will feed from a magazine and ha a bit more clearance built into it so it will still function should you get a bit of dirt or dust in it in the field.

I have a customised factory Remmington trigger I took off my BR rifle to fit a 1.5oz trigger which I hope will fit. It's been worked down to a crisp 6-8 Oz break and should allow excellent trigger control

When it came to a stock for it I initially purchased a silhouette style stock from Hatchers rifle stocks here in Australia but the more I thought about it the more I realised although it would have been fantastic to shoot standing it wasn't the best shape to shoot off a rest or bipod so I held off on doing the final sanding and finishing. I purchased an Atlasworks Aluminium bottom metal thinking I would use AICS magazines but when I saw Magpul P mags were around $40 I changed my mind and started looking at the Magpul polymer bottom metal which comes with a 5 round P mag.

While researching the Magpul mags and DBM I watched a clip on their Hunter 700 synthetic stock. This the ticked a few boxes for me with its full length bedding block that goes down into the pistol grip and the flexibility of their M lock system. As it turned out Magnum sports had both the DBM and the Hunter 700 in stock and the deal was done.

The action comes complete with a Pic rail and given the long range potential of the 6XC cartridge I started looking for options for optics. I really wanted a scope in the 4-16 or 6.5-20 mag range because even if you don't use that much magnification in the field it's nice to have when developing loads on a bench at the range when conditions are ideal.

I watched the second hand market pretty closely and when a Minox ZA5 4-20x50 came up second hand under $500 I grabbed it. Minox use the same SCHOTT AG glass used in the Zeiss Conquest range and have a reputation for reliable mechanicals as well as having 4 power at the lower end rather than 6.5. Though only a 1" main tube they have 80moa of adjustment life time warrantee. Good buying I think and I'm keen to test it out.

So now it's all coming together and the barrel is going to the gunsmith to get chambered. While he's been waiting for a new reamer to arrive I ordered 200 Norma cases before the price goes up. I managed to pick up a five boxes of Berger 69gr High BC flat base varmint bullets. These have a G1 BC of .308 which is pretty impressive compared say a 65gr Vmax which is .280 and the Bergers flat base should stabilise it better at hunting ranges which tend to be under 300m.

I also picked up three boxes of Noslers 80gr ballistic tips. These have a G1 BC of .329 which should make them a good choice for longer ranges, some research shows some American coyote shooters using them successfully out to 800y.

I already had some 65gr Vmax to try and some 85gr Hornsdy Interbonds. These are a bonded core bullet with a tapered jacket and are suited to heavier hall game than the other varmint pills. Their BC is approaching .400 and no doubt ill be Playing with them as an option for goats, pigs and even fallow deer.

I've seated all 4 bullets as dummies and took some measurements. By doing this you can compare different bullet shapes and how their shape changes their seating depth for a given over all length or base to ogive length. Having this information allows you to choose how much Freebore you want (distance from the case mouth to the lands) no point making the Freebore too short and needing to seat heavier bullets really deep in the case but silly to make the Freebore long enough to seat a long bullet right out then having the lighter ones jumping right out of the case before they reach the lands.

I worked off having a minimum of 75% bore diameter of bullet in the neck, so about 4.5mm for a 6mm bore. This is probably enough to keep a bullet straight in the case when it feeds out of a magazine. A lot of people say 1 caliber is about right but remember I'm looking at a bare minimum for a short bullet, a longer one will be more. I seated all 4 bullets with around .160" (4mm) in the neck, this takes a bit of fiddling because of the different shapes and measured them from the base of the case to the ogive with a hornady OAL gauge. Then I looked at the lightest bullet and roll nder it down to give a bit more neck engagement and for a number around .220" Freebore (bullet touching the lands). I calculated that the heaviest bullet seated to the same base to ogive length (and there for the same distance off the lands) would give it an extra .130" or so in the neck. Remembering that's from the start of the boat tail not the base of the bullet.

Now I have my Freebore length my gunsmith can cut the chamber then cut the throat. Of course it's always better to err on the short side with Freebore because it's easy to cut it a bit deeper later on if required, not so easy to put it back :lol:

Pick and figures later on, a lot of info here but thanks for reading

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Re: 6XC hunting/spotlighting build

Post by Gwion » 02 Feb 2016, 10:50 am

Very interesting write up and project, Chronos. Looking forward to seeing pics and updates of performance.

I have never heard of the 6XC cartridge.
Thanks for taking the time.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 02 Feb 2016, 11:53 am

Thanks G,

More on the cartridge here from one of the people responsible.

http://www.6mmbr.com/6xc.html

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Re: 6XC hunting/spotlighting build

Post by Chronos » 02 Feb 2016, 2:00 pm

Here's everything ready for a trip to the smith

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Re: 6XC hunting/spotlighting build

Post by Gwion » 02 Feb 2016, 2:49 pm

:thumbsup: :drinks:

Looks the goods. DO you have an estimate for final weight?
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Re: 6XC hunting/spotlighting build

Post by Chronos » 02 Feb 2016, 5:53 pm

bentaz wrote:Sounds pretty fancy, glad I'm not a game species up your way.



hahaha, maybe I should just call it .243 short :lol:

"Looks the goods. DO you have an estimate for final weight?"


I'm not a huge fan of the "tacticool" look but the stock feels comfy and if a fair bit less flexible than any other synthetic I've handled which has to be a good thing when it comes to bolting the Atlas bipod onto it :thumbsup:
It was meant to be a light weight build but it's getting heavier with everything I add :lol:

No Idea on what the final weight will be but if it's over 4.5Kg it'll be going on a diet :thumbsup:

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Re: 6XC hunting/spotlighting build

Post by Swarm » 16 Feb 2016, 9:59 am

Chronos wrote:I'd rather not risk the confusion of having two guns running the same brass.


Tough to say isn't it.

On one hand you're not an idiot and you could say 'just be careful and pay attention' which you already obviously do. On the 1 in 10000 chance something got confused though it could go real bad :|
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Re: 6XC hunting/spotlighting build

Post by Lorgar » 16 Feb 2016, 10:49 am

It could happen, and only needs to happen once.

My primary rifle was a .308, now replaced with a 7mm-08 but I still have the .308 as a backup.

I kept ≈50 cartridges on hand for the .308 and the other 400 odd have been necked down for the 7mm-08, so all my brass is stamped .308.

I only use 1 load in each rifle and luckily one takes red-tipped ballistics tips and the other takes soft point so it's easy to tell them apart through that. I reckon you'd be stretching the truth a bit to say you can regularly spot the different between a .308 and 7mm-08 neck/projectile if you had a cartridge of each with the same projectile.

I take mates (not experienced shooters) to the range now and then and it would be easy for them to mistakenly chamber the wrong round.

I usually stick to having people on the 7mm-08 but if I do take the .308 I make sure there is only one box of ammo (50 rounds) for it, and as soon as it's finished being used any remaining ammo is locked away in the travel container so it's out of the way.

No problem when I'm shooting solo as I only have the one rifle, but it is a bit of a hassle when both are out and I've got to watch them like a hawk.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 16 Feb 2016, 1:28 pm

Swarm wrote:
Chronos wrote:I'd rather not risk the confusion of having two guns running the same brass.


Tough to say isn't it.

On one hand you're not an idiot and you could say 'just be careful and pay attention' which you already obviously do. On the 1 in 10000 chance something got confused though it could go real bad :|


Just common sense really. The risk of firing a 6mm down a 7mm bore is a missed shot and some head scratching. Chambering a 7mm round in a 6mm bore would be disastrous. Generally you couldn't chamber the 7mm in the 6mm chamber because the neck simply wouldn't chamber in the smaller rifles neck.

The real reason I wouldn't do it is simply because I'd end up with them mixed in the tumbler or on the reloading bench and end up trying to seat a flat based 7mm bullet in a case sized for 6mm and bugger the case mouth

Just for an update the smith had a reamer in order from the US of A but they contacted him to say due to tightening export laws they would not be shipping reamers overseas effective immediately. A quick hunt around turned up an unused reamer here in Oz that the owner generously sold and has posted it to the gunsmith. The upside is there won't be a 4-6 week wait for the reamer and I could have the gun by the end of the month

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Re: 6XC hunting/spotlighting build

Post by ebr love » 22 Feb 2016, 2:07 pm

Chronos wrote:Just for an update the smith had a reamer in order from the US of A but they contacted him to say due to tightening export laws they would not be shipping reamers overseas effective immediately.


:roll:

We're not going to be able to import water soon because it's used to cool the metal when reaming a barrel.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 22 Feb 2016, 3:56 pm

ebr love wrote:
Chronos wrote:Just for an update the smith had a reamer in order from the US of A but they contacted him to say due to tightening export laws they would not be shipping reamers overseas effective immediately.


:roll:

We're not going to be able to import water soon because it's used to cool the metal when reaming a barrel.


Speaking to him over the weekend it seems it all stems from an over enthusiastic US customs agent who had no idea what he was looking at and reported an outbound package containing reamers as "gun parts" no doubt causing Apache helicopters and a battalions worth of operators to descend on fast ropes on protect 'Murica

Anyhoo the smith now has a reamer from another source and it'll be up and running soon

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Re: 6XC hunting/spotlighting build

Post by brett1868 » 22 Feb 2016, 4:06 pm

Was it Pacific Tool & Gauge by any chance? I might have gotten lucky with my reamers being delivered week before last.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 22 Feb 2016, 6:09 pm

brett1868 wrote:Was it Pacific Tool & Gauge by any chance? I might have gotten lucky with my reamers being delivered week before last.



Nah Brett, JGS. I had one delivered a while back without issue its just a series of events that led one company to suspend exports while they sort it out

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Re: 6XC hunting/spotlighting build

Post by Rocker » 01 Mar 2016, 2:41 pm

How goes the progress Chronos?
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Re: 6XC hunting/spotlighting build

Post by MalleeFarmer » 10 Mar 2016, 4:26 pm

Yea I was just researching on tha interwebs about a cartridge to chamber my long range varmint/target build in since my Gunsmith after listening to me and my needs/wants told me I should be going for a .243 instead of a .22-250 I'm not a fan of the .243 so I had a look around and found this 6xc and after reading up about it sounds like a good compromise between barrel life and .243 like performance.
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Re: 6XC hunting/spotlighting build

Post by happyhunter » 10 Mar 2016, 5:50 pm

MalleeFarmer wrote:Yea I was just researching on tha interwebs about a cartridge to chamber my long range varmint/target build in since my Gunsmith after listening to me and my needs/wants told me I should be going for a .243 instead of a .22-250 I'm not a fan of the .243 so I had a look around and found this 6xc and after reading up about it sounds like a good compromise between barrel life and .243 like performance.


That's great advice by your smithy.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 19 Mar 2016, 7:26 pm

Well it's finished....almost. Need to paint the barrel and work up a load for it now

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Re: 6XC hunting/spotlighting build

Post by bigfellascott » 19 Mar 2016, 8:15 pm

Looks nice Steve, should do the job nicely mate.
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Re: 6XC hunting/spotlighting build

Post by Chronos » 19 Mar 2016, 8:22 pm

bigfellascott wrote:Looks nice Steve, should do the job nicely mate.


Hard to think it wouldn't but we'll see. The round is supposed to do everything a .243 will do so it should get a little 6mm pill along alright. Overkill for many thinks with fur but fun none the less :thumbsup:

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Re: 6XC hunting/spotlighting build

Post by bigfellascott » 19 Mar 2016, 8:25 pm

Yep it should smash the fur well. :D
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Re: 6XC hunting/spotlighting build

Post by Vati » 07 Apr 2016, 4:05 pm

Chronos wrote:Speaking to him over the weekend it seems it all stems from an over enthusiastic US customs agent who had no idea what he was looking at and reported an outbound package containing reamers as "gun parts" no doubt causing Apache helicopters and a battalions worth of operators to descend on fast ropes on protect 'Murica

Anyhoo the smith now has a reamer from another source and it'll be up and running soon


Label them as 'drill bit' in future maybe.

True enough ;)
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