What makes one bolt gun more "tough" than another?

SquarePizza

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I was reading a post the other night about accuracy international and someone referred to them as bombproof and tough as nails. Other than marketing hype, what really makes one bolt gun tougher than another? Say why is an AI more durable than a rem 700?

I have only focused on bolt guns my entire life and I can only think of the following problems that I have encountered:

1 - Lose action screws (could happen to any gun, my fault for not checking)

2 - Drifting pin (win model 70, the cap at the rear of the bolt, the retaining pin was almost lost during a PR1 course 10 years ago. Its starting to drift again now).

3 - Poor magazine feeding.
3a. - CDI bottom metal on my win 70 has never been better than 60% reliable with AICS mags. Therefore I would never trust this rifle with my life.
3b. - Howa mini has weak mag springs and can occasionally suffer from the bolt riding over the top of a cartridge.

4 - Poor controls (Mag release location on Howa mini often causes dropped mags, even with aftermarket solutions)

All of these examples that I can think of are more focused on reliability of components rather than the robustness of the rifle. I have never had something actually break off of a gun. Therefore, it makes me wonder if people saying X gun is war zone tough is more marketing and simply just liking one gun over another than actual robustness.
 

Winny94

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    Apparently the answer is "the price you pay"

    Cant tell you the amount of times ive been told my basement assembled rifle will basically just turn to dust since it doesnt have a fancy maker engraving on the barrel, but thousands of rounds in a switch barrel configuration shooting a wide variety of cartridges and no problems. :sneaky:
     

    Jackomason

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    Something steel head told me recently is early pressure signs. The action can actually stretch, the case will expand, then the actions will shrink down on the case.
     

    Supersubes

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    AI receivers are burly, and were epoxied and screwed to an aluminum chassis. They have a robust trigger that bolts to the receiver. The receiver and bolt were both nitrided, which was not common back then. It uses a full diameter bolt, with a large bolt stop/anti bind rail which combined with the clearances allow it to run well in dirty environments. They invented the current prefit fad 20 years before it became a fad as well. This made for easy barrel swaps by a regular armorer, as opposed to sending the whole gun back to AI or some depot level servicer.

    AI has added some features in the last decade, but the basic features date to the early 80’s. The reputation was built from that time.
     
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    Wiillk

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    XP-100. All you need to say. They put paper thin barrels on the early models but the action looks like something you would put on the end of a 16” Naval gun. Guess they were a bit concerned about the pressure levels of the little Fireball, which in its day was above normal.

    What makes one stronger? As said above, more steel, better mating of the locking lugs, more locking lugs (two is better than one and a third, ala the Mauser 98 is stronger than two, IF, the quality of the steel, the heat treating and the precision of the machining is matching or better.
     

    dimar1492

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    Another consideration, some trigger designs are more likely fail in dirty or extreme environmental conditions.

    There is always a lot of focus on the receiver and bolt. Clearances (often confused with tolerances) and similar talk. But if the trigger goes down, your fancy custom action is just as dead as any other.
     
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    Nik H

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    What makes one bolt gun "tougher" than another?
    1. Accurate specification of the use case requirements that it is supposed to function within. Also known as a PRD (Product requirements document)
    2. True engineering talent that understands how those product requirements drive the design of the various elements of the rifle
    3. Comprehensive and thorough multivariate testing to truly stress the design against the requirements
    4. Accelerated life testing to understand the limits of the design
    5. LRIP models in sufficient quantity tested by actual users to assess the correlation between field testing and internal testing and to identify gaps that were not predicted through the design process
    6. Improvement of the design based on the field testing
    7. Further testing in the field to validate the actual improvements
    8. Lots of engineering capital without real regard to the end cost.
     
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    Supersubes

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    There is NFW someone can actually measure that sort of behavior outside of a seriously well instrumented engineering lab.

    I call BS
    I agree that its impossible to measure precisely without specialized tools. You can experience this anecdotally though by the way a particular combo creates sticky extraction at modest pressures. 338 lapua in a standard remington action is frequently subject to this. Lots of variables involved of course.
     

    ma smith

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    I was reading a post the other night about accuracy international and someone referred to them as bombproof and tough as nails. Other than marketing hype, what really makes one bolt gun tougher than another? Say why is an AI more durable than a rem 700?

    I have only focused on bolt guns my entire life and I can only think of the following problems that I have encountered:

    1 - Lose action screws (could happen to any gun, my fault for not checking)

    2 - Drifting pin (win model 70, the cap at the rear of the bolt, the retaining pin was almost lost during a PR1 course 10 years ago. Its starting to drift again now).

    3 - Poor magazine feeding.
    3a. - CDI bottom metal on my win 70 has never been better than 60% reliable with AICS mags. Therefore I would never trust this rifle with my life.
    3b. - Howa mini has weak mag springs and can occasionally suffer from the bolt riding over the top of a cartridge.

    4 - Poor controls (Mag release location on Howa mini often causes dropped mags, even with aftermarket solutions)

    All of these examples that I can think of are more focused on reliability of components rather than the robustness of the rifle. I have never had something actually break off of a gun. Therefore, it makes me wonder if people saying X gun is war zone tough is more marketing and simply just liking one gun over another than actual robustness.
    Not every action can withstand high pressure as safely as the next...

    So max psi / containment/ failure mode/safety is a legit variable, especially for .mil applications (due to contamination, temp spikes, duress, etc)

    Theres also tons of testing on wear, dirt, hot/cold, etc they do.

    All the small parts kits that are true .mil spec w/ coatings and heat treatments.

    Not every action is also as field serviceble, as robust to shock when set in stock/ chassis, has as solid a pic rail, etc as the next

    If talking expensive gear maybe we take thus for granted, but an AI vs a $500 rifle, even a tikka, isn't really fair comparison.

    Tikka bolt stops will break, for example...the overall action isn't as strong.

    But another question is do you have the $100,000 in ammo to shoot out the 100k rnd service life of an AI?
     

    308pirate

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    I agree that its impossible to measure precisely without specialized tools. You can experience this anecdotally though by the way a particular combo creates sticky extraction at modest pressures. 338 lapua in a standard remington action is frequently subject to this. Lots of variables involved of course.

    Read again what that guy posted, carefully: The action can actually stretch, the case will expand, then the actions will shrink down on the case.

    Then there's the little detail of plastic vs elastic deformation of the chamber and the case. None of which anyone here can measure, let alone calculate.

    Sticky extraction at modest pressures = shitty chamber wall surface finish (chatter marks) is the most likely explanation. Then there's less likely causes like a chamber machined off center to the bore and/or receiver centerline, etc, etc, etc.....
     

    Supersubes

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    Read again what that guy posted, carefully: The action can actually stretch, the case will expand, then the actions will shrink down on the case.

    Then there's the little detail of plastic vs elastic deformation of the chamber and the case. None of which anyone here can measure, let alone calculate.
    I know, I was agreeing with you.
     

    diverdon

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    Feeding and extraction. Robust trigger. Once a close friend had the trigger on a production rifle snap on a fly in Alaska hunt. The pilot gave him a piece of Aviation safety wire to jury rig into a trigger. It worked, but other things being equal I prefer a trigger not made from cast pot metal.
     
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    hafejd30

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    Savage = Accuracy International
    PSA = KAC
    Barska = Nightforce

    A couple things that would make my AI’s tougher than my 700’s at a glance are

    - Bonded/flat/4 screw action of the AI vs torqued 2 screws on the Rem

    - The AI scope rail design is much more robust vs my 700. I’ve personally seen scopes shear off all four 6-48 screws on a Rem 700 under recoil

    - Bolt design on the AI is beefed up and 6 lugs vs the Rem

    If you compare the two side by side the Rem feels like a toy compared to the tank like feeling of an AI. But that comes at cost of weight

    The AI from its double stack mags and butter smooth bolt just runs like a tuned machine. This doesn’t necessarily make it tougher though

    Own both/shoot both and the AI does feel bomb proof compared to the Rem 700

    But google issues with both AI and 700 and you’ll find examples of failures of each. More so with the Rem due to quality control issues and the fact that there’s more 700 owners than AI

    You can buy a AI chassis for Rem 700 so there’s things that make the chassis tougher than some others but other than the bonding/screw to the action you can enjoy the same chassis on either platform if it’s your thing
     

    cas6969

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    "Wouldn't the same barrel on two different actions tell you that?"

    Mind blown.
    (Totally off topic, but now all I want to do is get a barrel blank and put actions at both ends. Two actions, two scopes. Cut two stocks so they meet in the middle. Say maybe .308 on one side, 300 Win Mag on the other. Talk about versatility! Oh man it's gonna be great. Where's my sawzall?)

    (yeah obviously you're going to have to remember to take the other bolt out, duh)

    ETA: If I use two different action types in the same caliber, I can do a side by side comparison of which is tougher. And we're back on topic. You can thank me later.
     
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    Mike Casselton

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    Everyone is full of shit.
    The one and only thing that makes an action tough is the name scribed on the side of it.

    Check these out:

    Bighorn: Everyone knows how tough a Bighorn ram is.

    Defiant: I fukkin dare you to try and break me.

    Come on, those names scream, I'm fucking tough.

    Japanese Arisakas notwithstanding.
     

    Thorbeast

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    Most custom actions these days are pretty tough and incorporate features which address known weak points on the rem 700.

    Improved/one piece bolt handles
    Integral or pinned recoil lugs
    Integral or pinned scope rails
    Side bolt release/bolt stop

    Almost all customs actions have the features above.

    Beyond that there are differences in custom actions regarding design philosophy (feeding/extraction/ejection) and quality of life improvements (prefit barrels, trigger hangers, anti bind rails, ect).
     

    Mech Eng

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    Read again what that guy posted, carefully: The action can actually stretch, the case will expand, then the actions will shrink down on the case.

    Then there's the little detail of plastic vs elastic deformation of the chamber and the case. None of which anyone here can measure, let alone calculate.

    Sticky extraction at modest pressures = shitty chamber wall surface finish (chatter marks) is the most likely explanation. Then there's less likely causes like a chamber machined off center to the bore and/or receiver centerline, etc, etc, etc.....
    I don't mean to stir up drama but are you saying the steel doesn't stretch?
     

    st1650

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    I feel my Nuke is a very very tough action. Probably one of the best R700 styled action. But even though I never really had issues with the trigger, I feel that all R700 triggers are definitely not as forgiving in bad weather.

    As much as love my trigger tech - I doubt it’s design is as rugged as the Sako TRG or the AI.

    I don’t really compete and I don’t crawl in the mud so I’m perfectly fine with the limits of my rifle.... but I wish I could afford an AT-X
     

    TurdFerguson

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    I think we forget that AI's main goal was a military contract not competition or recreation. Their submission was a new design using new ideas. The TRG was also created for military applications. If you look at the 700, model 70, sako a7's, 75's, 85's ect, they weren't initially designed for fighting, they were designed for hunters and lack a lot of the features many of the early milsurp bolt actions and modern bolt actions have. A hunter in the 60's/70's wasn't looking for a side bolt release or the ability to use a mag.

    The 700 was a product of the 50's/60's and the model 70 was a product of the 30's. Comparing them to a modern action like the TRG a product of the late 80's and complaining about the lack of features is a waste. The AI and TRG are more modern actions that align better with the times. As much as we bitch about the 700, 70, 75, and some others, they were a decent design to have stayed as relevantish as they have.

    Not dumping on the 700, 70, ect just saying they are an older design developed at a time closer to the 03 springfield and fit the sensibilities and needs of that era. They still work, just not as well as some of the modern designs that are designed around modern ideas and sensibilities.

    Meh flame suit on. ETA the age of the action does not excuse the manufacturer's lack of innovation and modernization.
     

    308pirate

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    I don't mean to stir up drama but are you saying the steel doesn't stretch?

    Steel stretches. The "action" meaning the receiver doesn't really expand radially much, if any. The chamber is part of the barrel, not part of the receiver.

    There's a lot more wrong with the post I was replying to but I didn't feel like wasting my time with a technically rigorous explanation.
     

    Mech Eng

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    Steel stretches. The "action" meaning the receiver doesn't really expand radially much, if any. The chamber is part of the barrel, not part of the receiver.

    There's a lot more wrong with the post I was replying to but I didn't feel like wasting my time with a technically rigorous explanation.
    Yes I agree that under normal pressures the chamber doesn't expand much. I did a bunch of FEA on an action I was designing for fun just to see what the forces would be.
     

    cas6969

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    Honestly I've only heard tell.
    But I've also seen people beat on them with blocks of wood or bang them on the shooting bench to get the bolt open without any troubles.
     

    918v

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    AI vs 700? Bigger parts made out of harder steel, premium barrel, shoots awesome out of the box. The 700 needs work and is inferior in every way with the exception of looks.
     

    MarinePMI

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    Honestly I've only heard tell.
    But I've also seen people beat on them with blocks of wood or bang them on the shooting bench to get the bolt open without any troubles.
    I've seen it. Twice. One gun was literally straight out of the box. First round fired, and when the guy went to cycle the bolt, the handle just popped off.

    As to the AI and it's testament of durability? SHC 2015. That comp was held in absolutely miserable conditions. Mud, rain, dirt, laying in shooting positions that had become gumbo after 240+ shooters cycled through (it was the largest comp at the time ever held). Only saw one AI go down, and that was from a popped primer and wet ammunition. We unscrewed the barrel behind the line, shook out the loose primer from the bolt lug recess, and then screwed the barrel back on. Next stage was out to 850yds, and that shooter (JByrd IIRC) damn near cleaned the stage. Meanwhile, we watched gun after gun start to go down when that silty mud started getting into the triggers. By the end of the first day they were tossing straw in the shooting positions, it had gotten so bad. It was miserable. But it was an awesome match, that really pushed shooter, skill and gear beyond what most ever experience.

    It's hard to justify and explain why people say AI's are bombproof...until you have to shoot in some really shitty conditions. Then the cost is all but forgotten, and your confidence in AI becomes damned near absolute.
    SHC_2015.jpg


    This particular stage was 10 shots with pistol (two per target) while seated in the car, out the passenger window. Then egress the car and retrieve your rifle from the back seat. Engage four targets, near to far, prone through the hay bale loophole, then four targets far to near, off the hood. (I cheated on the pistol targets; was shooting an FN FiveseveN).
     
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    308pirate

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    What makes one bolt gun "tougher" than another?
    1. Accurate specification of the use case requirements that it is supposed to function within. Also known as a PRD (Product requirements document)
    2. True engineering talent that understands how those product requirements drive the design of the various elements of the rifle
    3. Comprehensive and thorough multivariate testing to truly stress the design against the requirements
    4. Accelerated life testing to understand the limits of the design
    5. LRIP models in sufficient quantity tested by actual users to assess the correlation between field testing and internal testing and to identify gaps that were not predicted through the design process
    6. Improvement of the design based on the field testing
    7. Further testing in the field to validate the actual improvements
    8. Lots of engineering capital without real regard to the end cost.

    APQP
     
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    OREGUN

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    I keep hearing about AT-X triggers going down. How does that figure in?
     

    Aftermath

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    The mainest thing that makes one bolt gun more tougher than another is the nut behind the wheel. If he's wearing skinny jeans, that's not to be considered a tough bolt action.
     

    Aftermath

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    I feel my Nuke is a very very tough action. Probably one of the best R700 styled action. But even though I never really had issues with the trigger, I feel that all R700 triggers are definitely not as forgiving in bad weather.

    As much as love my trigger tech - I doubt it’s design is as rugged as the Sako TRG or the AI.

    I don’t really compete and I don’t crawl in the mud so I’m perfectly fine with the limits of my rifle.... but I wish I could afford an AT-X
    I agree with all of this with one exception.
    I don't do "real" comps or matches due to my work load (primarily) and my rural home AO. Not much in that nature close by at all. I'd love to and maybe I will enter a geriatric league in the future but will likely do so with the arms I already own as long as the arms the creator gave me continue to function. I say "real" because I do have some friends and we shoot against each other for bragging rights and beer.
    I'll soon complete 61 revolutions around the star we call the sun, I figure I am well past the days of crawling through mud, kicking in doors and asses. At least I hope I am. If that need ever arises again, I figure my 700 rifles and the customs based on that design will serve me just fine while I provide either overwatch or partake in repelling an invading force for as long as I don't leak enough plasma to create a fatal low blood pressure situation. In that case, I will be found with a hot barrel and some spent brass piled neatly where they were ejected nearby.
    I CAN afford an AI but I sure wouldn't to carry the damned thing very far!
    ETA: I REALLY do have some friends.
    EETA: I don't own any skinny jeans. Really. I mean, for real. Honest, I don't. Those 700's I own are some DAMNED tough rifles.
     
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