Will O’Meara shares his thoughts and analysis on an upcoming rifle build, from calibre selection to stock type, bolt and barrel construction and magazine options.
The rifle build, a fortunate stroke of serendipity. It is a funny thing when the stars align in your favour. Only last month I was elbow deep in ballistic data writing an article on calibres.
A lot of research goes into these articles; research is necessary to support the conclusions that I have gained through experience over the years, and also to provide you with interesting facts, to help you draw your own conclusions.
So, last month we concluded that the .270 Win was an excellent hunting calibre, that its parent – the .30-06 was even better at the expense of very little extra recoil and that the .300 Win Mag (in a hunting-weight gun) was too much gun for a lot of people.
There was a gap in my data from an experience perspective, and that gap was the 7mm family. Sure, I’ve fired them, but I’ve never lived with one. Well, guess what? That’s about to change – we are building a 7mm. I recently met some very good people from Proof Research, Scott and Kelly.
I have for some time admired their barrels and sub half-MOA guarantee. I’ve also taken note of their growing popularity and have been eager to try them out for myself.
When I met the people behind the product, I was sold. They share the same passion for hunting and the outdoors and it was very cool to swap stories with them. So, a new rifle is to be built, next comes the difficult part… what rifle?
So, I sat down with a pen and paper and started making some notes. These are the first decisions to be made: purpose, calibre and weight. Firstly is the purpose; the answer is medium-sized game (deer), mostly on mountain terrain.
I have hunted with many calibres before, from .22-250 to .300 Win Mag. My current .270 Win is super smooth to shoot so I am thinking maybe it needs a big brother and so, with the help of last month’s article, it is decided: the 7mm Remington Magnum.
There are more impressive 7mm offerings out there, but a limited variety of ammunition availability in Ireland is what pushes me to the Rem Mag. The main criticism of this calibre seems to be the belted case, which some argue is without purpose.
The problem with belted cases is that they can have feeding issues, this was never a problem in my .300 Win Mag, so we will have to wait and see how the 7mm performs.
Let’s take a quick look at the performance of this calibre. I have compared it to the .30-06 (the other calibre I was tempted by) and my current calibre of choice, .270 Win, in the table that you’ll find further down in this article.
For this energy comparison I chose bullet weights and styles that I am likely to use. I compared like with like where possible from Federal, Winchester and Sako. What I am analysing with terminal energy; at what range does the bullet drop below 1300ft/lbs of energy?
In my experience this the minimum amount of energy required on medium-sized deer to consistently achieve an effective wound channel and exit wound.
The conclusion of the terminal energy comparison demonstrates that the 7mm Rem Mag is significantly more effective than the .270 Win, and gives you over 100 yards advantage of the .30-06 with 150gn rounds, but only 50 yards of benefit when we get into the 175-180gn category.
The bullets I chose to compare is based on what is most readily available from my local firearms dealer, JL Firearms.
For the recoil comparison I had my own experience, which tells me that the .30-06 has the slightest margin of extra recoil, which when shot with an effective moderator is so small that I would not consider it a negative factor.
We explored in a previous article how each rifle will transmit different perceived recoil – for me it’s all about how it works in reality, but when I am getting into a new calibre then it is useful to look at some data that might help predict felt recoil.
I went on to compare the difference in wind deflection for the 7mm versus the .30-06 and found that with hunting-style bullets and at ranges under 600 yards, the difference translated to the effect of a 0.5mph wind.
I don’t believe that anyone has the ability to judge the wind to this accuracy – where it counts and in a hunting scenario – and so this difference between the two calibres isn’t going to sway the decision for me.
Calibre decision confirmed! Moving on: what length barrel? I am going for the shortest barrel possible and I think that is going to be right at the 24-inch mark, and Proof Research have recommended a 1-in-9 twist rate.
I elected to go for the Sandero profile, which will work out 3oz heavier than the Sandero light that they offer. It will be threaded in 5/8×24 UNF and come fitted with a muzzle brake. I will more than likely use it mostly with a Hausken WD60 moderator.
The benefits of a carbon-wrapped barrel are numerous. You can achieve a heavier profile for a lighter weight over a traditional steel barrel, they don’t get as hot, and they do a good job of dissipating heat, too. The benefit of less heat is that you are less likely to have a point of impact shift due to a hot barrel – this is unlikely to be a factor in a hunting scenario, though.
The carbon barrels also transmit vibration in a different manner to steel, though I guess I will only find out the real life benefits of this when I start to shoot it.
These barrels are cut rifled-style and are individually prepared by hand lapping and inspection before going out the door. Each rifle is also test fired prior to delivery to ensure that it meets the half-MOA or less guarantee.
My next decision was on the action. The actions in these Proof Research rifles are super impressive; the rail and recoil lug are all part of the action, machined from one piece.
The bolt handle is also machined as part of the bolt and not attached afterwards, as is the norm. These features mean rigidity and reliability, which, in turn, means accurate and dependable for hunting.
I knew I wanted the round ball bolt knob that Proof offers, but the action itself was a bigger decision. Both the hunter action and the tactical action have a built-in picatinny rail, but only the hunter action can be loaded by top feed. Why is this a problem?
Well, the only magazine on offer is the tactical-style AI box magazines with the paddle release. For me this is not a suitable solution for the style of hunting that I do. When you mix a paddle release with a pack and lots of crawling it is inevitable that at some point you will lose a mag – so they are not for me.
This quandary had me surfing the web looking for a hunting-style bottom metal, with a discrete release system and a flush-fitting mag – such a system, it seems, is in short supply. I did find one, but with a price tag of £500. Back to the drawing board.
A quick email to Dennis at Proof Research had me back on track and that conversation answered two questions for me. Dennis told me that his own rifle is a hunter action with a BDL hinged floorplate fitted in a TAC II Stock. Would he build me one? He’d love to!
This, as I mentioned, solved two problems for me, the second issue being the stock. Proof Research offer three stocks: the Summit, which weighs 18oz; the Terminus, which weighs 25oz; and the Tac II, which weighs 40oz.
If I was building a 6.5mm or a 6mm I think I would go for the Summit, I like the straight stock design and the light weight is appealing. I liked where the Terminus stock sat weight-wise, and liked the longer pistol grip and its forend design, but what I didn’t like is the butt; the Monte Carlo-style raised cheek piece makes it difficult to fit an adjustable cheek piece that can be built up or adjusted to fit the individual.
I also think that a stock should be as straight and as in-line with the bore as possible – the Monte Carlo design means that butt pad sits very low below the bore line, which I believe leads to increased perceived recoil. So the Tac II stock it is.
This stock is a little more “tactical” than I would normally favour for hunting, but it has a nice slim forend, an adjustable cheek piece, and is by normal standards still truly in the lightweight class.
I am a big fan of carbon fibre stocks. My experience is that they are kind to the shooter from a recoil perspective as well as being half the weight of a traditional composite stock.
What else is there? Well it is trigger time – time to decide on the trigger, that is. Trigger Tech, Timmony or Jewell? I chose the Jewell based on it being what I use in my other gun, so I think keeping it the same can only be good for repeatability.
So what does this all weigh in at? Well, that depends on what’s hanging off it. Proof Research advertises the weights for bare rifles as follows: Summit, 5.5lbs; Terminus, 6.5 lbs; and Tac II, 8.5lbs. My build will be a hybrid – how appropriate – so it should come in at the 7.5lbs mark bare.
I will be adding the larger Hausken mod, which will add an extra 1.1 lbs. I use a Spartan Precision 300 bipod, which is a feather weight 160 grams (0.36 oz), and then it’s just a case of deciding on a scope.
I reckon that the final build will come in under 10.5 lbs with a medium-range, hunting-style scope (4-16×50) and just over 11lbs with a tactical or larger hunting scope (5-25×56).
So now for the waiting game, I’ve done my homework; it’s time to wait for the Proof…
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