New longrange Varmiter - Build Log
Posted: Sat Dec 21, 2013 7:28 pm
The Start
Some years back I would knock rabbits over with the humble 22LR and consider a 120m shot a long one. Then I moved on to my 6/223 which was very useful on rabbits out to 250m whenever I wanted it to work. When a friend gained access to a number of properties with wide open grassland, creeks and plenty of hills I found my little 6/223 was outranged.
So I took a spare Omark I had and using a pre-loved 223 fullbore barrel made it into a longrange 22/250 complete with 1:8 twist barrel - the Frankenrifle. Now due to the worn throat in that rifle I was able to get an honest to god 3650fps from the 75gn mtach bullets and scored my personal best of 512m on a completely unsuspecting bunny. Whilst the Frankenrifle did work well, I kept looking at the ballistics charts and the accelerated barrel wear and desired something I could shoot more, hit more predictably and suffer less in the wind.
What Cartridge?
We know the blokes who have built 6x47 Lapua chambered rifles, one with a 1:10 twist that throws 75gn VMAX bullets (Hi Andrew) the other for 105gn class bullets (Bergers/Sierras/AMAXs) from it's 1:8 twist barrel (Hi Jason). Whilst the cartridge choice was good, the barrel life is not materially better than the old 22/250. I like practicing, this means putting rounds downrange on a regular repetition. When the deer hunting tapers off in October, the varmit rifles come on until February.
So, if the 6mm calibre is a lock. What cartridge? I toyed with the 6x47 Lapua but went with the old favourite 6mm BR. I did consider the 6mm BR-X, 6mm Dasher and the 6mm LR but the simplicity of the 6mm BR brass from Lapua with a skim neck turn and primer pocket preparation is very alluring.
The BR is a shortened 308 case, originally starting as the 308x1.5 - being a 1.5inch (38mm) long cartridge modelled on the highly successful PPC, but fatter. This original Remingon case was intended for the 70gn match bullets popular at the time, but in the 1990s it was superceded by the 6mm BR Norma. A slightly different interpretation of the case, being 39mm long and the chamber being throated for the 105/107gn VLD bullets becoming available at the time.
Anyway, the 6mm BR will throw a 105gn bullet at a healthy 2800fps, sometimes topping out just under 3000fps using 30 point something grains of AR2208. In comparison a 6x47 Lapua will get 3100fps from a 26in barrel, the 243 is pretty much the same. Barrel life using these loads is expected to be around 3000 rounds for the BR, far short of the 308 or 223, but more than twice that expected from a 6x47 Lapua or 243.
What Rifle?
OK, so if you are going to build a 6mm BR for long range, what action do you use? Anyone who looks through my safe will quickly observe that I have a thing for Ruger No.1 rifles. There are six of them in there, some with outstanding accuracy by virtue of their custom barrels and careful construction. I did seriously toy with building on a No.1, in the Varmit profile. In the end I decided that I wanted something a little lighter, something a little more stainless steel, and something that was a repeater.
A repeater, well yes the BR case is not known for it's feeding properties from normal magazines. Short, fat and long bullet make for a complete nightmare feeding proposition. It is known to feed well from magazines that are single stack design, like the Tikkas, some Weatherby rifles, some Savages and several european wonders. There is even a specific magazine box offered for Remington 700 rifles that is designed to feed BR cases in a single stack configuration. A little research suggests that this magazine can be a little hit or miss and can sometimes fail utterly.
Googling helped a little and I found a description by a bloke who converted a plastic AI 223 magazine to feed the BR case. In effect the AI plastic magazine becomes a large single stack magazine for the BR case - it holds 7 in there with plenty of length for OAL loading. So, using a DBM was a possible avenue. But what action?
My first thought was to the Remington 700 action. Whilst not perfect, it offers a wide range of stocks, plenty of triggers and other go fast bits to cure the failings of the factory offering. So a Rem700 it was. Then some more $$ became available, and the desire for a lighter rifle took hold, and before I knew it I had placed a deposit on a Pierce Engineering action made entirely from Titanium!
Trigger
The problem with using an aftermarket action is that they don't come with even a shitty factory trigger. In fact, some don't even come with trigger pins!
I like 2-stage triggers on my precision rifles. I find them easier to use than the Jewells favoured by others. For my heavy varmiter I use a Huber Concepts two stage adjusted for a 2lb let off. The first stage is 1lb, which makes the second stage feel like 1lb. It is great, I can take up the weight and once I get to that second stage, I KNOW it is about to go BANG.
So I ordered a second Huber Concepts adjusted exactly the same as the first one.
The Barrel
Well, it was clear that a 6mm bore with a 1:8 twist was called for. But what profile, how many lands, and what length?
Length first. My previous experience with the 6mm BR has shown me that much past 22inches is wasted. Yes you do gain velicity, but not much and at the expense of portability and increased weight. So I'm getting the barrel cut at 23inches, with all of the shank being used so that I can set it back an inch and get another couple of thousand rounds out of it before needing another one.
Lands? Well most barrel makers today offer their 1:8 6mm barrels with 3, 5, 6 and 8 rifling grooves. This does not include polygonal, canted or other special rifling styles. After thinking, researching and comparing past barrels I decided on a 3 groove barrel from Lilja. The 3 groove is supposed to offer less resistance and bullet disruption as the bullet goes through the bore, because the lands are larger they last a little longer. These positives do have one down side and that is the bullet is not as stabilised as a traditional 5 groove setup. The thing is, the difference is only noticeable by a highly tuned benchrest rifle, so I was happy with the compromise.
Profile. A normal profile would be a Remington Varmit, but I was wanting to keep the rifle lighter than heavier, aiming for something in the mid-7lb zone to encourage my kids to use it as they transition from 22s into big rifles during their teenage years. Doing some quick maths using the Lilja calculator I worked out that a 23in barrel profiled in a #4 profile will deliver a muzzle of about .7in - plenty of meat when you consider it only has a 243 hole down the middle.
Stock
I wanted lightweight. A little flashy was also good. I already have an AICS, light they are not. Handled my fair share of Manners and McMillan, they leave me cold. HS Precision stocks are nice, but oh so common.
Last year I bought a nice hunting stock from a bloke in Canada for my ultralight 7/08. After a few emails back and forth I managed to secure his last VARTAC stock with clear gelcoat and full carbon fibre construction. Ka-SchWING! Lightweight AND flashy in one go.
At 2lb fully finished there is no stock available from the major manufacturers that approaches this stock for practicality and performance.
I still needed it fitted up with a DBM, and I had spotted one I really liked. The Battle Arms Development DBM is somewhat different by design, incorporating a magazine lever that is integral with the triggerguard instead of poking out below like so many Badger M5 copies. Unfortunately BAD does not have an export permit and I had ZERO chance of getting one of their DBMs legally. So I talked to the bloke from AtlasWorx in WA and convinced him to build one for me that was in line with the BAD design. GregT did his usual brilliant inlet for it.
Scope & Mounting
I cheated a bit here. A couple of years ago I was looking at a Nightforce 5.5-22 and a friend suggested I look at a March instead. Well it didn't take long before I realised that the March 2.5-25 was a better buy than the Nightforce, so I went one better an bought the 3-24FFP March. This is a great little scope with outstanding glass, light weight and brilliant adjustments.
This scope has been the scope on my heavy 7mm SAUM, but I reckon that it will work better on the 6mm BR. So that is where it will go, Nightforce Ti rings and all.
The Pierce action can be optioned with either a rail or a set of Talley-like rings. I ordered the rail, with a 10MOA cant, constructed entirely of - Titanium ('cause I could).
Case, Dies, Bullets
Lapua brass - Check.
Bullets - 105 AMAX, 107 Scenar, 105 Berger, 107 Custom Comp, !08 Berger and 107 Copperheads - Check.
Powder - I buy AR2208 by the 4kg bottle - Check.
Dies - Forster Micrometer Seating Die, Redding Micrometer Bushing Neck Die, Redding Body Die. Check.
Barrel is with the gunsmith.
Action was sent to gunsmith on Thursday.
Stock, trigger and scope will be delivered next week.
With a little luck I will have it back in late January or early February, just in time for deer season (yes that is a sick joke). Fingers crossed.
More to follow.
Some years back I would knock rabbits over with the humble 22LR and consider a 120m shot a long one. Then I moved on to my 6/223 which was very useful on rabbits out to 250m whenever I wanted it to work. When a friend gained access to a number of properties with wide open grassland, creeks and plenty of hills I found my little 6/223 was outranged.
So I took a spare Omark I had and using a pre-loved 223 fullbore barrel made it into a longrange 22/250 complete with 1:8 twist barrel - the Frankenrifle. Now due to the worn throat in that rifle I was able to get an honest to god 3650fps from the 75gn mtach bullets and scored my personal best of 512m on a completely unsuspecting bunny. Whilst the Frankenrifle did work well, I kept looking at the ballistics charts and the accelerated barrel wear and desired something I could shoot more, hit more predictably and suffer less in the wind.
What Cartridge?
We know the blokes who have built 6x47 Lapua chambered rifles, one with a 1:10 twist that throws 75gn VMAX bullets (Hi Andrew) the other for 105gn class bullets (Bergers/Sierras/AMAXs) from it's 1:8 twist barrel (Hi Jason). Whilst the cartridge choice was good, the barrel life is not materially better than the old 22/250. I like practicing, this means putting rounds downrange on a regular repetition. When the deer hunting tapers off in October, the varmit rifles come on until February.
So, if the 6mm calibre is a lock. What cartridge? I toyed with the 6x47 Lapua but went with the old favourite 6mm BR. I did consider the 6mm BR-X, 6mm Dasher and the 6mm LR but the simplicity of the 6mm BR brass from Lapua with a skim neck turn and primer pocket preparation is very alluring.
The BR is a shortened 308 case, originally starting as the 308x1.5 - being a 1.5inch (38mm) long cartridge modelled on the highly successful PPC, but fatter. This original Remingon case was intended for the 70gn match bullets popular at the time, but in the 1990s it was superceded by the 6mm BR Norma. A slightly different interpretation of the case, being 39mm long and the chamber being throated for the 105/107gn VLD bullets becoming available at the time.
Anyway, the 6mm BR will throw a 105gn bullet at a healthy 2800fps, sometimes topping out just under 3000fps using 30 point something grains of AR2208. In comparison a 6x47 Lapua will get 3100fps from a 26in barrel, the 243 is pretty much the same. Barrel life using these loads is expected to be around 3000 rounds for the BR, far short of the 308 or 223, but more than twice that expected from a 6x47 Lapua or 243.
What Rifle?
OK, so if you are going to build a 6mm BR for long range, what action do you use? Anyone who looks through my safe will quickly observe that I have a thing for Ruger No.1 rifles. There are six of them in there, some with outstanding accuracy by virtue of their custom barrels and careful construction. I did seriously toy with building on a No.1, in the Varmit profile. In the end I decided that I wanted something a little lighter, something a little more stainless steel, and something that was a repeater.
A repeater, well yes the BR case is not known for it's feeding properties from normal magazines. Short, fat and long bullet make for a complete nightmare feeding proposition. It is known to feed well from magazines that are single stack design, like the Tikkas, some Weatherby rifles, some Savages and several european wonders. There is even a specific magazine box offered for Remington 700 rifles that is designed to feed BR cases in a single stack configuration. A little research suggests that this magazine can be a little hit or miss and can sometimes fail utterly.
Googling helped a little and I found a description by a bloke who converted a plastic AI 223 magazine to feed the BR case. In effect the AI plastic magazine becomes a large single stack magazine for the BR case - it holds 7 in there with plenty of length for OAL loading. So, using a DBM was a possible avenue. But what action?
My first thought was to the Remington 700 action. Whilst not perfect, it offers a wide range of stocks, plenty of triggers and other go fast bits to cure the failings of the factory offering. So a Rem700 it was. Then some more $$ became available, and the desire for a lighter rifle took hold, and before I knew it I had placed a deposit on a Pierce Engineering action made entirely from Titanium!
Trigger
The problem with using an aftermarket action is that they don't come with even a shitty factory trigger. In fact, some don't even come with trigger pins!
I like 2-stage triggers on my precision rifles. I find them easier to use than the Jewells favoured by others. For my heavy varmiter I use a Huber Concepts two stage adjusted for a 2lb let off. The first stage is 1lb, which makes the second stage feel like 1lb. It is great, I can take up the weight and once I get to that second stage, I KNOW it is about to go BANG.
So I ordered a second Huber Concepts adjusted exactly the same as the first one.
The Barrel
Well, it was clear that a 6mm bore with a 1:8 twist was called for. But what profile, how many lands, and what length?
Length first. My previous experience with the 6mm BR has shown me that much past 22inches is wasted. Yes you do gain velicity, but not much and at the expense of portability and increased weight. So I'm getting the barrel cut at 23inches, with all of the shank being used so that I can set it back an inch and get another couple of thousand rounds out of it before needing another one.
Lands? Well most barrel makers today offer their 1:8 6mm barrels with 3, 5, 6 and 8 rifling grooves. This does not include polygonal, canted or other special rifling styles. After thinking, researching and comparing past barrels I decided on a 3 groove barrel from Lilja. The 3 groove is supposed to offer less resistance and bullet disruption as the bullet goes through the bore, because the lands are larger they last a little longer. These positives do have one down side and that is the bullet is not as stabilised as a traditional 5 groove setup. The thing is, the difference is only noticeable by a highly tuned benchrest rifle, so I was happy with the compromise.
Profile. A normal profile would be a Remington Varmit, but I was wanting to keep the rifle lighter than heavier, aiming for something in the mid-7lb zone to encourage my kids to use it as they transition from 22s into big rifles during their teenage years. Doing some quick maths using the Lilja calculator I worked out that a 23in barrel profiled in a #4 profile will deliver a muzzle of about .7in - plenty of meat when you consider it only has a 243 hole down the middle.
Stock
I wanted lightweight. A little flashy was also good. I already have an AICS, light they are not. Handled my fair share of Manners and McMillan, they leave me cold. HS Precision stocks are nice, but oh so common.
Last year I bought a nice hunting stock from a bloke in Canada for my ultralight 7/08. After a few emails back and forth I managed to secure his last VARTAC stock with clear gelcoat and full carbon fibre construction. Ka-SchWING! Lightweight AND flashy in one go.
At 2lb fully finished there is no stock available from the major manufacturers that approaches this stock for practicality and performance.
I still needed it fitted up with a DBM, and I had spotted one I really liked. The Battle Arms Development DBM is somewhat different by design, incorporating a magazine lever that is integral with the triggerguard instead of poking out below like so many Badger M5 copies. Unfortunately BAD does not have an export permit and I had ZERO chance of getting one of their DBMs legally. So I talked to the bloke from AtlasWorx in WA and convinced him to build one for me that was in line with the BAD design. GregT did his usual brilliant inlet for it.
Scope & Mounting
I cheated a bit here. A couple of years ago I was looking at a Nightforce 5.5-22 and a friend suggested I look at a March instead. Well it didn't take long before I realised that the March 2.5-25 was a better buy than the Nightforce, so I went one better an bought the 3-24FFP March. This is a great little scope with outstanding glass, light weight and brilliant adjustments.
This scope has been the scope on my heavy 7mm SAUM, but I reckon that it will work better on the 6mm BR. So that is where it will go, Nightforce Ti rings and all.
The Pierce action can be optioned with either a rail or a set of Talley-like rings. I ordered the rail, with a 10MOA cant, constructed entirely of - Titanium ('cause I could).
Case, Dies, Bullets
Lapua brass - Check.
Bullets - 105 AMAX, 107 Scenar, 105 Berger, 107 Custom Comp, !08 Berger and 107 Copperheads - Check.
Powder - I buy AR2208 by the 4kg bottle - Check.
Dies - Forster Micrometer Seating Die, Redding Micrometer Bushing Neck Die, Redding Body Die. Check.
Barrel is with the gunsmith.
Action was sent to gunsmith on Thursday.
Stock, trigger and scope will be delivered next week.
With a little luck I will have it back in late January or early February, just in time for deer season (yes that is a sick joke). Fingers crossed.
More to follow.
