Bolt Rifle Slop/Wiggle

[dak0ta]

How important is the wiggle/slop of the bolt in a bolt-action rifle when being pulled out of battery? Mauser has quite a bit at full retraction whereas some others have better guide ribs which make the bolt slide like glass along its track. Does this affect reliability and accuracy at all or just a tolerances thing?

 

[jdavis123]

Some slop is not unusual even on certain new rifles. The important thing is that the bolt locks up securely.

 

[ontarget]

Check out most of the current production budget rifles. So sloppy it feels like they might just fall out. However many of them are fine rifles.

 

[Tirod]

Tolerances are the amount of allowable difference because parts can't be made perfectly. The variance comes up because of operator skill, temperature differences at the time of machining, hardness of that particular lot of material, sharpness of the tooling, etc etc. Tolerances can stack up in assembly to the point that the parts have too much or even no space at all between them.

Clearances are the deliberately designed amount of space between parts to keep things working in extreme temperatures or conditions so that the parts don't bind to the point of stopping the action. Clearances keep the tolerance stack from jamming the weapon. Most combat bolt actions had enough clearance to function in artic conditions where the cold dimensions of the gun still require some space to operate the bolt.

Slop is a completely non engineering emotional based assessment that is frequently discussed as the owner wants to prevent another fellow shooter from criticizing their choice as being "low quality." The accepted myth is that a top tier gun has no "slop," all the parts are fitted closely because that is a representation high manufacturing quality, and that the ones so closely fitted they seem to have perfect parts and nearly magical fit are the most highly ranked socially. Therefore the owner must be from a higher order of superior human being.

Nothing could be further from the truth.

Take the 1911 for a case example. New out of the box samples from the beginning rattled and had plenty of clearance to function in a dirty environment, but still shot adequately to point of aim. They did so with ball ammo and were considered the epitome of combat pistols in the day.

Fast forward to the '60s when competitor's started tweaking them, and all the clearances were tightened up in an attempt to make them more accurate. Another 40 years of gunsmithing and they are now cranky and finicky pistols which can shoot some kinds of ammunition never intended for them, to a high degree of accuracy, but which could not get "over the beach" without jamming. They are race guns, impractical for actual hard use. The 1911 shooting community accepts they may need a return trip to get them working right yet still praises them for their superlative quality manufacturing.

Because they have no "slop." IE they make the owner look good. All because of a wide spread notion of what constitutes quality among a buying public that doesn't know engineering but does practice ranking each other socially on a minute by minute basis.

I'm glad I'm old enough now I don't care one bit about that nonsense.

 

[Longhorn 76]

In Tirod I have found a kindred spirit.

I do some pistol work, and have been capable of fitting parts with minimum clearance. But pistols fitted thusly can be jammed up with a single grain of unburnt powder or dirt.

 

[tahoe2]

All of my Mauser bolt rifles (ex-military) are sloppy out of battery, some more than others, but they are tight in lockup, and pretty accurate to boot.
They are not competition guns and therefore not 1/2" MOA or less, most are 1"- 2" MOA and some are still in military dress. All are 100% reliable and
not to finicky with ammo, a few are over 100+ years old and still do their job very well. Modern machining methods does create tighter tolerances, but I don't worry about it.

 

[chicharrones]

Some of this bolt slop is due to how much support the bolt has from the receiver when the bolt is open. Some bolts only have a half inch or so of open bolt support while others have much, much more.

 

[Welding Rod]

The problem with too much slop in a rifle bolt to receiver fit is if the shooter side loads or vertically loads the bolt handle while pushing the bolt forward it can bind significantly, sometimes even to a complete stop. It is not common to have this much slop on a modern rifle of reasonable quality, but I have seen it on at least one Ruger Hawkeye and Ruger Magnum.

The solution of course is to be sure to only push straight forward, or simply buy a better made rifle.

 

[Arizona_Mike]

True story, circa '93 at a range a guy took a shot with my sporterized Mauser, opened the bolt and then handed it back to me with a look of concern on his face saying "I didn't break it, I swear!".

Mike

 

[Slamfire]

This sure sounds like an echo from the past. When the M1903 was the American service rifle and target shooters were very familiar with the thing, American shooters were very proud of the thing. They rightly viewed the Mauser action as a rival and in print, pointed out differences between the Mauser 98 and the 03 Springfield to make the case that the American made and designed 03 Springfield was superior to the Mauser. The primary focus of the hype was the claim that the 'superior" workmanship of the 03 Springfield made it a superior action and bolt "slop" was one of those criteria they used back then to determine the perfection of an action. The M1903 action had less bolt slop, when the bolt was open, than the M98 Mauser. Ergo, to the American mind, that was proof that the M1903 was superior to the M98.

Having shot both M1903's and M98's, I have a M98 match rifle, I can say that in every point of departure from the M98 Mauser action, the American M1903 is an inferior action. I have broken firing pins, cocking pieces, firing pin collars, ejectors, and extractors in the M1903. I have replaced a number of gouged bolt stops and bolts with battered left locking lugs. The Mauser has a nice cushioned bolt stop, whereas the M1903 uses just the tip of the lugs against a hard bolt stop. The M1903 is a very unreliable action. The M1903 has about zero shooter protection features in case of gas release. I shot my first Colombian Mauser enough to wear out the case hardened surface in the bolt cocking cam, and that was the only part that wore out. I operated the thing in rapid fire sequences for years and I can't say that bolt wobble made that much of a difference in operation.

I do like my M70 action and that action was designed in the era when Americans decided an action was good or bad, based on the amount of bolt wobble. My M70 has very little bolt wobble. I like the M70 action as it is smooth and slick in operation. Bolt wobble gets to be a problem when there is too much wear in the receiver and the bolt cramps. The one rifle I have that has this problem is a Rock Island Arsenal M1903 Sporter. The receiver is worn and the bolt cramps and I can't push it as fast as I want.