bruce moulds wrote:rod,
i wasn't having a go.
just taking a neutral standpoint.
i am no engineering and design expert, but i do know what i want in an action. since you question my knowledge here it is.
in order of priority i look for these things.
safety, reliability, longevity, and lastly features which promote accuracy, which also includes user friendliness.
we all know why we have to do a trigger test prior to shooting. i could be wrong, but i believe it is due to a firing pin design which allowed a situation where a premature discharge occurred.
i have heard that an action using washers for a firing pin spring has problems maintaining constant trigger adjustment.
the longer the boltlift, the more powerful extraction becomes, assuming a well designed extraction cam. this means a 2 lug bolt. the same camming power might be what can get a queens winning shot into a chamber, as opposed to disabling a rifle.
i want maximum case life from my brass, and rear locking actions that i have used, although accurate, were not as good as front lockers.
i believe that a lot of good design features have been lost from bolt actions in order to make manufacturing easier.
as people have stated, history will decide whether or not yours will succeed.
i hope it does, and admire you for sticking your neck out
should you ever come to sa, or i to wa, i would look forward to meeting you, both in conversation and in competition.
you have here a golden marketing opportunity to sell the product you make.
all the best,
bruce moulds.
Bruce,
At least some technical points I can reply, using my modest knowledge :
1°) Safety ; A True 2-stage trigger is much safer than a single stage, as its cocks at a maximum of engagement. The single-stage can be (mis)-adjusted up to the point there is not enough engagement to satisfy a safety check….
2°) Reliability; This as a lot to do with materials and treatments used. Metal used in the first RPA, Millenium and INCH is 3 times the cost of the steel used by others. Same for this point: it is available at the next door here, but need to be ordered in quantity abroad whne in Australia. It is an aircraft quality abslolutely warp free and hardening at a level much higher than the commonly used 4140 or similar. This is one only of the details I could develop…
3°)Longevity: Choice of materials and processes as noted above are the determinant factor here.. All the important parts of the Inch are treated to 52 HRC as compared to the 38 HRC of so many others…and what to say about the nitride coating wear and corrosion resistant, also friction-free rated at 85 to 95 HRC, depending of the color choosen??.
4°) Accuracy ; the firing system allowing 1,3 to 1,4 milliseconds of locktime is unequalled. This exist since the RPA of 1994, just improved after 2 more generations. The three designs have already quite a record and I can include the Inch in that despite its short career….
5°) User friendliness: a reduction of 25% of bot pull travel is not user friendly when shooting either F-Class or mostly from the sling??. No interference with a cheekpieec who can correspondingly be extended forward…. Number of lugs has nothing to do with that…..Hearsays again.
6°) Firing pin design cause of the safety checks: YES, but it is bot the FP, but the coking piece instead, and the Single Stage function and the sloped cocking piece who caused premature discharges…Not the case for a good 2-stage trigger and a 90° square cocking piece. A good saf trigger also has a cost….
7°)Quote: “ I have heard that an action using washers for a firing pin spring has problems maintaining constant trigger adjustment’.
I prefer to use your own words here ‘You have heard’’. I do not think I have technically to comment hearsays!!.
8°) Primary extraction; A GOOD primary extraction is when it allows 2mm of Bolt pull at end of the opening cycle. I will not enter in geometry and cinematics here, but this is achieved under a very small segment of the bolt totation, and the more the ramp is away from the axis, the shorter the camming angle can be…..
9°) Queens prize winner: I do not understand clearly here…The Bisley Queens at least had been won by both the RPA and the Millenium (I 2008). Same year,in the same Queens prize an Inch prototype ended 1 point behind the winner, with the best score at 1000 yards of all the range!!!.... and well in the Grand asw ell….
10°) Case life; you are still thinking in terms of spongy SMLE actions. I can prove this is anon-sense in a purpose designed single shot action…. The inch was shot .338 LM with no observations to be made on this aspect…hearsay again.;;and misknowledge of metallurgy…
At least, despite my challenged competence, this one is at least sufficient to be able to determine important sections and stresses and general resistance of a part like a single shot receiver and bolt.
R.G.C
R.G.C.