Modification of a Standard Upper to .22

John Sabato · 02-27-2008, 12:49 PM

Thanks for the feedback Bill...

I just learned something new... the conversion breechblock does NOT fit in a standard upper receiver! It goes about 2/3's the way into the fork and screeches to a halt about 1 inch from the chamber... This may be just different tolerance in parts or the conversion upper may have been opened up to accept the conversion breechblock... I will spend some time on this measuring everything with my digital caliper, ... if I can find it!

It has been a long time since I did any mechanical engineering and I am sure I put it in a very safe place... I just don't remember where... senior moment I guess.

02-27-2008, 12:49 PM	#27
John Sabato Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: The Capital of the Free World Posts: 10,156 Thanks: 3,003 Thanked 2,309 Times in 1,098 Posts	Thanks for the feedback Bill... I just learned something new... the conversion breechblock does NOT fit in a standard upper receiver! It goes about 2/3's the way into the fork and screeches to a halt about 1 inch from the chamber... This may be just different tolerance in parts or the conversion upper may have been opened up to accept the conversion breechblock... I will spend some time on this measuring everything with my digital caliper, ... if I can find it! It has been a long time since I did any mechanical engineering and I am sure I put it in a very safe place... I just don't remember where... senior moment I guess. __________________ regards, -John S "...We hold these truths to be self-evident that ALL men are created EQUAL *and are endowed by their Creator* with certain UNALIENABLE* rights, and among these are life, LIBERTY, and the pursuit of happiness..."*