Attention: Model 07 Gurus, Semi-Gurus, and Virtual Gurus|Restoration, Repair and Maintenance|Forum|Winchester Collector

What I’m trying to do is determine whether I can take the 07 to the range and fire twenty rounds this weekend before tackling buffer replscement.  If I can find my thickness gauge set and measure the visible gap, that should tell me indirectly  how much buffer is left. I presume the washer’s counter is in contact with the upper face of the buffer and the larger diameter of the washer is being held off the rim of the buffer housing by the remaining thickness of the buffer. 

The unanswered question is how much gap is necessary to keep steel off steel on the recoil stroke? 

I take it from your measurements that the upper surface of the compressed buffer was .600. 0.060 below the rim of the cup.  The counterbore of the washer being only .097 thick, it could not reach far enough down to contact the buffer before the larger diameter of the washer interfered with the rim of the cup. Ergo, there was .504 airspace between the washer and the buffer, which meant the buffer received none of the transmitted force. The cup and connected bolt extension absorbed the entire blow. 

I need to scour my shop to find the little cardboard Starrett box that holds the gap gauge tool. It was my Dad’s. 

After I measure the thickness of the new buffer, i can calculate how wide the gap should be with it installed. Measuring the existing gap should give me an estimate of what’s left. 

I watched the same two videos again and one of them showed the gap with a new buffer installed — it didn’t look much different than what mine looks like now. 

All in all, it looks like a Rube Goldberg design for mounting a buffer. I wonder how much of the design was because of the Browning patents. 

I’ve done the measuring and have attached my calculations,  about which I’m always uneasy. Please correct my algebra as needed.  Here’s a summary of what I think I’ve found:

Using the measurement of interior height furnished by Midwest Crisis as close enough for my gun, Buffer cup height is assumed to be .360.  By measuring a new old stock factory original buffer and buffer washer, I get buffer thickness = .320 and washer counterbore = .100.  

By my calculations, the gap between the bottom of the outer diameter of the washer, and the rim of the buffer cup,

using a new buffer and washer, should be = .060.  My gap with existing buffer and washer installed is actually a measured .035.  

Using the formulae in the attachment, the calculated remaining thickness of my buffer is .295, which is 92% of a new one. 

The .O35 measured gap in my gun is 58% of the calculated .060 gap with a new buffer and new washer. EDIT: this ratio fails to consider the presence of the constant 0.10 thickness of the washer counterbore. To relate the effect of only buffer thickness to the size of the gap, we must remove the effect on the gap due to the presence of the 0.10, thus: 

A. New buffer thickness .320 + washer counterbore thickness .100 = .420;

B. Calculated installed buffer thickness .295 + washer counterbore thickness .100 = .395; 

The ratio B:A is .395:420 = .94

If we measure a gap of .035,  then solve for buffer thickness:  .320 x .94 = .300.

Which is close enough to .295 to be useful in the real World of measuring gaps with feeler gauges and calculating an implied, permanent buffer compression.  I don’t know how to account for momentary buffer compression, so I don’t know how much buffer thickness will avoid peening metal.  I suspect that anyone in New Haven who did know has since Departed. 

Advise if I need to repeat high school algebra. Resist adding images of prunes.  

Well, 92% of a new one should be able to handle more than 20 rounds. Jeez, how often did the factory expect these buffers to last?  Judging by the difficulty of replacing them,  surely they must have been good for a thousand rounds . 

I can now vouch for removing the barrel nut with a Knipex channel lock, provided the jaws are padded. The one I used has installable polymer jaw inserts that are more squishy than I’d like for really beefing down on a pipe joint. It would slip before I could get more than a quarter turn of the barrel nut but didn’t harm the finish. 

I’m going to re-measure the gap after a range session with the gun, to see if there’s been any change. I’ve got some reloading to do of another caliber before an upcoming range session, so I’m going to put off any gunsmithing of the 07 for at least a week. I probably need to see how you fare with the job when you get parts in hand. 

One other question – what do think the buffer washer is made of? The GPC one I’ve just taken out of its plastic seal doesn’t feel metallic at all. I’ve had it since 2005 and pretty sure its factory new old stock.