I need some help guys, lots to learn...please help me understand...
I own a RPR 6.5Cm with 60Rd through it. The bolt was recently reworked by AD Arms, bushing for SM firing pin, cocking piece and fluting to match anarchy shroud and coating. They did a beautiful perfect job.
My understanding is that the machinist has to run at least a very minimal “cleanup run” across the surface of the bolt head, so I thought it would be better to check head space after receiving the bolt back.
I'm relatively inexperienced in measuring head space, other than some FAL rifles I've build from kits in the past.
I had no gauges, so first I tried a ones fired case from this rifle (Hornady Factory load).
With one layer of scotch tape the bolt closes, with two layers it does not close all the way.
I found this method not trustworthy at all so I ordered a Forster go and no go gauge.
The bolt closes fine on the go of course but will not close on the no go no, not even starting to close if that makes any sense (Extractor not removed). So I thing this rifle should be safe to shoot?
Last week I ordered a Wilson case gauge to get a better understanding of chamber dimensions.
By compering fired case and both head space gauges in this Wilson case gauge the go gauge is very slightly below the first step, the no go in the middle between both steps and the fired case without tape of course is about 0.001-0.002 above the second step. For those of you who don't know, this gauge has a 0.005 cut machined into the surface.
Now what I do not understand is that the Forster no go measures about 0.002-0.003 shorter than the fired case. How come that the bolt closes with ease on the fired case(and 1 layer tape) but not on the no go gauge?
Is rifle brass that “springy” ?
My apologies for any errors, English is not my native language...
Thanks, Torsten
I own a RPR 6.5Cm with 60Rd through it. The bolt was recently reworked by AD Arms, bushing for SM firing pin, cocking piece and fluting to match anarchy shroud and coating. They did a beautiful perfect job.
My understanding is that the machinist has to run at least a very minimal “cleanup run” across the surface of the bolt head, so I thought it would be better to check head space after receiving the bolt back.
I'm relatively inexperienced in measuring head space, other than some FAL rifles I've build from kits in the past.
I had no gauges, so first I tried a ones fired case from this rifle (Hornady Factory load).
With one layer of scotch tape the bolt closes, with two layers it does not close all the way.
I found this method not trustworthy at all so I ordered a Forster go and no go gauge.
The bolt closes fine on the go of course but will not close on the no go no, not even starting to close if that makes any sense (Extractor not removed). So I thing this rifle should be safe to shoot?
Last week I ordered a Wilson case gauge to get a better understanding of chamber dimensions.
By compering fired case and both head space gauges in this Wilson case gauge the go gauge is very slightly below the first step, the no go in the middle between both steps and the fired case without tape of course is about 0.001-0.002 above the second step. For those of you who don't know, this gauge has a 0.005 cut machined into the surface.
Now what I do not understand is that the Forster no go measures about 0.002-0.003 shorter than the fired case. How come that the bolt closes with ease on the fired case(and 1 layer tape) but not on the no go gauge?
Is rifle brass that “springy” ?
My apologies for any errors, English is not my native language...
Thanks, Torsten
