Type 97 NSR Rail Wear (pictures)
- Thread starter BigDerp
- Start date
shadow sniper
CGN Regular
- Location
- Quebec city.
####kkkk !!!!
- Location
- Southern ontario
well it is a softer aluminium receiver and that anodizing will only hold up for so long. hows the reliability been with the rifle? any pushed in bullets?
AFAIK that area of the receiver isn't aluminium but steel, but I may be mistaken.
As for reliability, had a small break in period of about 100-200 rounds where some of the bullets were pushed in. The last 400+ rounds occurred without a single failure. I suspect the initial rounds forced a path into the bullet guide that the latter ones can follow without as much resistance.
- Location
- Southern ontario
that entire black part of the reciever is aluminium test it with a magnet, and i believe these rifles really benefit from using grease type lubricants.
Ya, that's pretty heavy 'wear' after just 600 rounds! Yikes!
Clobbersauras
CGN Ultra frequent flyer
- Location
- Waaay out west.
Your rail wear is normal. Here is a pic of my old one with about 600-800rnds through it.
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It's important to note the service life of these rifles is in the 6k range (at least that's what it said in the old manual). Receivers wear out first. Lube and clean the crap out of the rails. The OP's look very dry.
It's important to note the service life of these rifles is in the 6k range (at least that's what it said in the old manual). Receivers wear out first. Lube and clean the crap out of the rails. The OP's look very dry.
Meh, I saw wear like that in my xcr-m inside of 400 rounds, and it sells for a lot more than the type 97 !
Ar180shooter
CGN Ultra frequent flyer
- Location
- Ottawa, ON
Quite often wear like that will go to a point, then stop. The wear in the OP's pic isn't alarming.
My xcr had 5k through it and barely showed any signs of wear, absolutely no impact/preening of any aluminum and just slightly wore through the anodizing in a few places but very smoothly, almost as if one polished their way through.
Here is my guess since i am only looking at pictures and diagrams. However, most rails in the receivers are not load bearing. They are there to guide the direction of the bolt.
The bolt is not forced to rotate when it travels down the rail, so any wear on the rail will be limited.
The rail got worn out a bit at near the steel extension probably due to the timing in matching up cam pin travel (bolt rotation) and linear movement of the bolt as it goes back and forth between the aluminum receiver and the steel extension. The area of the receiver, where it is close to the steel extension, is the transition zone where the bolt is forced to initiate its rotation, and hence the aluminum receiver is forced to conform to the path of the bolt nut driven d by the cam pin path. It is in a way similar in nature to the wear in the cam pin recess in the upper receiver of an AR15. Once the speed bump is removed, it won't go any deeper.
The bolt is not forced to rotate when it travels down the rail, so any wear on the rail will be limited.
The rail got worn out a bit at near the steel extension probably due to the timing in matching up cam pin travel (bolt rotation) and linear movement of the bolt as it goes back and forth between the aluminum receiver and the steel extension. The area of the receiver, where it is close to the steel extension, is the transition zone where the bolt is forced to initiate its rotation, and hence the aluminum receiver is forced to conform to the path of the bolt nut driven d by the cam pin path. It is in a way similar in nature to the wear in the cam pin recess in the upper receiver of an AR15. Once the speed bump is removed, it won't go any deeper.
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The only AR that wears out because of the cam pin wear groove is one with a piston.
The forces in a proper AR are linear and in line with the movement. Residual pressure in the bolt counter acts the early rotation of the cam pin.
This is not true with a piston. Add to that the bending moment inherent in every piston system on opening and that makes for some wear.
Properly designed piston guns have steel guide rails for a reason. AK, MAG 58 etc.
The forces in a proper AR are linear and in line with the movement. Residual pressure in the bolt counter acts the early rotation of the cam pin.
This is not true with a piston. Add to that the bending moment inherent in every piston system on opening and that makes for some wear.
Properly designed piston guns have steel guide rails for a reason. AK, MAG 58 etc.
