Testing TWO groove barrels on the M1

[eclancy]

Gentlemen,
These files are for some of the new guys. The files below show testing done on 2 groove and 4 groove barrels for the M1 Garand. It also shows us some of the changes in velocity drops. I hope you find some of this data of interest.







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Thanks again for taking the time and effort to read this data. I hope you have learned a little of the history of the M1 Garand.
Clancy
ps Could use some hits. I hope to have both sites update in soon. Have fun hope you enjoy and learn.
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[Jeff F]

I can't say much about the m1's but I have a couple of Enfield with 2 groove barrels and they shoot by far the nicest groups.

 

[Slamfire]

This is not a test report, but a snap shot in time prior to completion in testing.

What I read from this is after 4080 rounds the two groove barrels are producing less velocity per barrel than when they were new. The four groove barrel with 2000 rounds is producing slightly higher velocity. We do not know what the 2 groove barrels were doing at 200o rounds. Since the barrel life of a 30 caliber is around 5000 rounds, the two groove barrels are at the end of their service life and the four groove is mid point. Making conclusions through comparison is not proper until both barrel types have hit 5000 rounds.

Any one got the final test report?