Fluting Model P Bolt?

[aaronraad]

Any opinions on the having a Barnard Model P bolt fluted?

Anyone with any experience?

Do modifications to bolt actions contravene the ruling? With regards to something in the rules about "a serial numbered action can only be used if there were at least 6 produced by the manufacturer"?

Does a bolt need to be heat treated again after being milled for fluting to get back to the manufacturer's original steel properties?

I figure that a gunsmith would not flute a bolt, for the same reasons they would not flute a barrel post-heat treatment?

Keith, Matt & others?

[AlanF]

I'm looking forward to Keith's answer on this .

[Matt P]

Aaron
I wouldn't suggest it mainly because they're just to hard, is there a reason or just so it looks good

Regards
Matt P

[aaronraad]

Aaron
I wouldn't suggest it mainly because they're just to hard, is there a reason or just so it looks good

Regards
Matt P

Shaving weight wherever I can...I'd backfill the scope with Helium if I thought it was going to save weight.

[KHGS]

Aaron
I wouldn't suggest it mainly because they're just to hard, is there a reason or just so it looks good

Regards
Matt P

This is not something that would be viable. The bolt as Matt has said is HARD!!! The core is around 34 to 37 RC but the rub is that they are nitrided to around 63 RC. So the bolt would need to be softened & reheat treated, not a good idea.
Keith H.

[williada]

Aaron, if I may add to what Keith says, as to why manufacturers use this method in precision actions. Some actions are ground to a finish with matching bolts likewise ground for alignment purposes. I have spoken before about that six o’clock locking lug wear. It destroys accuracy. This occurs overtime by abrasion, (captured grit mixed with cleaning oil and failure to grease your lugs leaving the area completely dry) with a sloppy bolt/ bolt race fit. It can be fixed by sleeving bolts.

The purpose of sleeving bolts, and turning them down to fit or placing rub screws at the rear of action or Borden bumps a bit behind the lugs was to achieve this near perfect alignment with tiny tolerances. It also maintains a perpendicular bolt face to the axis of the bore if the action threads are cut in alignment with the bolt race as is the lug contact area, action face - assuming the barrel threads are aligned with the bore. Better actions like the Barnard have taken that to a new level and virtually offer you that blueprinted action. That is why they are so good.

The hard surfaces prevent galling and resist abrasion from dust. There is a slight difference in action hardness and bolt hardness at the surface and usually the core with the action being harder particularly in the lug area to allow the bolt to wear in preference to the action. You would like to think the heat treater could repeat the hardness relationship between action and bolt.

Assuming a spiral could be cut on a milling machine, you could bet any heating marks to anneal it in order to mill it, re-harden and then draw a temper or machining ridges will be linished out on a grit belt, then polished. This will decrease the diameter of the bolt and contribute to a similar problem as mentioned earlier, but it would sure look good and be lighter.

Trivia.
In the past people had to restrict heat transfer, with aluminium heat sinks or heat control paste and protect the integrity of lugs and cocking area if they were working on the bolt with a torch.

May I also comment for those that lap their locking lugs having found a problem upon bluing them - beware of breaking through hard layers that are surface treated on some actions and bolts. You can get into the soft stuff pretty quickly as the surface hardness is measured in thousandths of inches. Otherwise that six o’clock lug problem will show up again or your headspace will grow. If you go too far, you just might have to shift that bolt handle. Never use diamond grit because it embeds and is a sure fouler if people lap with it. Do not confuse this with diamond honing in a barrel manufacturing process used by some.

[aaronraad]

Aaron
I wouldn't suggest it mainly because they're just to hard, is there a reason or just so it looks good

Regards
Matt P

This is not something that would be viable. The bolt as Matt has said is HARD!!! The core is around 34 to 37 RC but the rub is that they are nitrided to around 63 RC. So the bolt would need to be softened & reheat treated, not a good idea.
Keith H.

I'm surprised the bolt is nitrided so hard given that the receiver is only advertised as through hardened to HRC 38?

Does this include the locking lugs?

I thought the preference would be for the bolt to 'wear' as opposed to the receiver, as a replacement bolt is only about 40% of the cost of Model P? Isn't receiver wear is more critical given Barnard shooters have the option to use multiple bolts with difference bolt face options, toleranced to fit the same action?

Each action has its faults, is this a worthy criticism not that I've read any reports of receiver wear myself?

[AlanF]

One critcism of the Barnard is that its on the heavy side. Its a choice you make when you first buy it. If weight is critical then you might go for a Stolle. Personally, having a Barnard is one of the few things I'm prepared to sacrifice some barrel weight for.

[aaronraad]

One critcism of the Barnard is that its on the heavy side. Its a choice you make when you first buy it. If weight is critical then you might go for a Stolle. Personally, having a Barnard is one of the few things I'm prepared to sacrifice some barrel weight for.

I wouldn't even necessarily criticise it's weight, because realistically their designs were focused on TR shooting or tactical repeaters at the time, not BR or even F-Class.

From an F-Class perspective it will be interesting to see if Barnard comes up with a specific design. With reduced numbers in TR and consistent competition from other action makers there would have to be a critical point. Let alone that actions are not a wear item and they would just be accumulating each year in the 2nd hand TR classifieds. Maybe receiver wear from hard bolts lugs is the only way they can get them to fail at some sort of rate

The big risk would be that if Barnard tooled up and produced a specific F-Class action, would that compromise production, quality or sales volume of their current offerings?

[KHGS]

One critcism of the Barnard is that its on the heavy side. Its a choice you make when you first buy it. If weight is critical then you might go for a Stolle. Personally, having a Barnard is one of the few things I'm prepared to sacrifice some barrel weight for.

Spot on Alan!
Aaron, both bolt & receiver are nitrided, the core of both are around 34 to 38 RC. If you can find me a worn Barnard where normal use has been in play (not totally abused) I will buy it!!!! There are thousands in use around the world, in Australia have a look on any firing line to see the percentage of Barnards in use! There is no perfect target action, but the Barnard actions are as close as I have seen for the purpose they are used. I have built many "F" Class rifles both std & open on Barnard "P" actions & have not found weight to be a problem. I can assure you no matter how light the action was somebody would find weight issues!!!
Keith H

[aaronraad]

Aaron, both bolt & receiver are nitrided, the core of both are around 34 to 38 RC.

Okay, that makes sense having both nitrided to the same hardness. Probably all good technical information they should update their website with.

[williada]

Maybe Burnie or Barry could chime in. They have made actions for our sport. I am looking at the issue from an extreme accuracy perspective, and hopefully trying to document things you might not read about readily Aaron. So in responding to your thread I was also thinking of other people without Barnards. I also believe that Barnard has stringent quality control that sets them apart and they have run with new technologies such as nitriding and grinding. If you want absolute proof consult a metallurgist. They are not expensive. By the way a soft stone sharpens a tungsten bit.

My emphasis was if others changed the bolt they could stuff it up and have to rely on people using old technologies. The bloke doing the job would have to measure your action hardness. No heat treater would take that on face value if they were to configure the bolt hardness to your action. On many actions bolt hardness is a tad less for reasons given. I am in agreement with Alan and Keith with regard the Barnard. Also, from a marketing perspective they would have to consider their profits if there was demand for fluted bolts. That’s a business decision not an accuracy one.

So let’s assume bolt diameter got smaller and the bolt hardness was greater than the action then I would not be a fan of interchangeable bolts particularly with lug wear either. You would not want wear on the action from harder bolts, particularly if hardness also differs relatively between a small or large bolt head as well. So it is the bolt that must wear in preference so that the action can swing with multiple partners and their individual relationships are not compromised. Such would be the case for many who use Omarks with adapters if they went down that path. So many do not have Barnards and they are mostly club level shooters who are the bread and butter of the sport. One of the first things you should be verified is full engagement of the lugs. I’ve seen some crook ones. A good smith will always measure before they work and some have been caught before when tolerances have not been what they were meant to be. The last time I shot a Sydney, my neighbour in the camp from NSW was having an atrocious Queens coming to the last stage, having a freshly barrelled Musgrave by a well known NSW smith. I had my gear with me because my wife was shooting in the Victorian Women’s Team. I found the bloke was only working on the bottom lug and the headspace had crush which allowed us to lap it. I think he won the last stage in “C” grade. I wonder why he was in “C” grade? Also, just ask any barrel maker about heat treatment certification. Incidentally, my wife top scored with a Musgrave in the teams event a placed highly in the Queens shooting nine centres a one range with irons.

So the following comments are general comments that are not action specific but related to the bolt fit in the race as I was asked privately about that lug wear, so these are my thoughts and they will expand a bit so a few dots can be connected for others that may be interested. There is an upward force on the rear of the bolt when it is cammed home caused by the bent, that thing that slides through the bolt shroud on modern rifles (because of bolt spring pressure) on the trigger sear before trigger release. This means tilting at the opposite end which is the bolt face i.e. at 6 o’clock. This simply leads to fliers with lug wear.

Another problem can be can be exacerbated in loose chambers with factory ammunition (or new brass) because the round will sit due to gravity in the chamber at six o’clock hence a concentricity problem and bullet slap condition can arise. Also depending on the setup and how cockeyed the bolt is and how loose the chamber is with new brass and sideways tensions of extractors and ejection pins, sometimes the round can be cocked up at the neck and down at the head with that hint of angle due to extractors - an almost opposite effect. A fast lock time may reduce some of the variables if things apart from sighting and getting the shot away which it assists in the timing of. It is just so important that you measure headspace with all your reloads as the brass is constantly moving and don’t reduce that too far with over sizing or bumping the shoulder back to create your own loose chamber. It negates extreme accuracy. A modern chamber like an Ackley in the extreme will minimise brass flow.

Now if your cases are thinning in the body on one side it may be a sign that the case is resting at six o’clock, however if you notice your necks are thick or thinner with a bias to one side it just might be due to the case being cocked up at the neck and held down by the head not really be a banana case or an oval chamber or poor brass. You can check the case wall thickness with one of those RCBS tools. I combine case checking with this and a Neco tool.

With factory ammunition there was a trend to put .002” crush on the case with a tight headspace a way back which a well known mate of mine in Victoria was armouring up for some Australian team members. It occurred by accident having discussed the issue with him because he had forgotten to allow .002”-.003” crush on the threads when drawing up a barrel when I drew it to his attention.

However, what the positive effect could have been was the case head centralised the bolt and improved the concentricity of the setup. It also preloaded the threads to give consistent barrel vibrations. So by accident accuracy improved.

But you can come unstuck if the issued ammunition due to size variance won’t go home, or the brass hardness varies and influence vibration patterns through changes in thread tension.

With sorted Winchester rounds by weight during testing, I found in .308 that a headspace of 1.631” was better. In the case of RG (British), a headspace of 1.633” would be a better solution because of the quality control was not as good. For example, one of my test rounds went well over 3000 fps for RG. I thought it was a chronograph error until I checked Corby’s pressure tester sourced from Border Barrels and found it was indeed a hot round. The lesson for issued ammunition is on the other side of the equation. You have to manage larger groups and know how to read conditions because a flyer is more common than not. Managing variable pressures by allowing the case to expand can take the edge off the extreme. Longer throats can take the edge of variable primer spikes. A normal primer contributes about 5000 psi. There are trade- offs with compensation but that is another issue already discussed.

With reloads and Lapua in .308, I go with minimum headspace of 1.630”, not the maximum of 1.634”. It does not matter if you fire-form, you will match the chamber and headspace is not an issue within reason. Some have used maximum headspace on reloads to creep a few extra kernals in for long range fire-formed cases. I have heard of people cheating by running in the reamer further and fire-forming with a 30-06 and scrubbing the head stamp off. However, if you full length re-size without matching your chamber, you will once again start the process for the 6 o’clock lug issue unless your projectile is jammed in the throat. Awhile back we had a rule change and we have to cycle the bolt. I saw photos of the catastrophic failure that led to the rule change but also noticed the lug wear as a separate issue on the bolt. If a pin protrudes you can be in trouble trying to force a tight round home in the case of jamming bullets into the lands or trying to crush fit brass which varies too much to go home. But from an accuracy viewpoint the lugs cop it. I don't jam rounds unless I fire-form at home because I would not like to spew powder in the guts of the action and waste everyone's time.

We all know properly reloaded ammunition is better than factory. To maximise this you do not want the tension in the system except to maintain the sound action/barrel fit, because it affects vibrations for fine tuning. So use the minimum headspace and only bump the case shoulder back ½ - 1 thou” for reloads after they have been shot a couple of times.

Warner developed the Palma reamer for the Winchester case, and there have been modifications in throat length to accommodate new allowable projectiles because in the past only Sierra’s could be used. If you use Lapua, get a reamer cut for the brass measurements and get a re-size reamer that is matched (slightly undersized to allow for brass spring back) and have your smith make the dies.

So with a modern action like a Barnard which is made to exacting tolerances, or a blueprinted action, your results will be consistently better with correctly reloaded ammunition and you don’t have to fudge with the variables created by a sloppy bolt etc.

For those that use switch barrels without lubricant, you wear the barrel threads and you may impart a crush and if you draw up to a register mark your setup will develop a loose fit and be subject to fliers. It’s not if, but when. I’m not a fan.

David.

[Cameron Mc]

Dave

Really appreciate all that information. I love the technical side of our sport.
Just a simple comment with regard to Barnard actions. The fact that the Barnard has gained a foot hold in the USA speaks volumes.
The yanks have always prided themselves with homegrown gear. Another example are the SEB Rests....they are lined up for these.
I have tried many different actions over the years. The lastest so called custom actions coming from the USA leave a little to be desired. I feel the high demand has pushed quality control down which is a pity.
Some trivia. I have 2 Maddco actions and really like them. Both are around 17 years old and show very little wear on all critical surfaces. The receivers are nitrided to around 20 thou in depth and are extremely hard.
The bolts are electroless nickel coated and hard as well. This makes for a very slick movement between bolt and receiver. The lugs on our Maddco's remain unmarked. A rough estimate would be 20,000 rounds through each.
These actions have been the best from a pressure handling perspective that I have used. Note, I have not used a Barnard.

Cam

[6.5x55ai]

Just one comment on nitriding - it is hardly new technology. I have 3 modern Barnards and 1 "Kiwi". The Kiwi is 1981 vintage (I think their website says they began in 1983...) and is one of Peter's early actions pre-dating his use of his surname as the brand. My Kiwi action is nitrided.

[Cameron Mc]

Just one comment on nitriding - it is hardly new technology. I have 3 modern Barnards and 1 "Kiwi". The Kiwi is 1981 vintage (I think their website says they began in 1983...) and is one of Peter's early actions pre-dating his use of his surname as the brand. My Kiwi action is nitrided.

Totally agree. But there are different methods of "nitriding"

Cam