Information about munitions:
23.    Information gathered about the delivery systems used was essential for the investigation. Indeed, several surface to surface rockets capable of delivering significant chemical payloads were identified and recorded at the investigated sites. These were carefully measured, photographed and sampled. Samples later confirmed to contain Sarin werr recovered from a majority of the rockets or rocket fragments. For more detailed information and assessments see Appendix 5.

Environmental samples collected in Zamalka / Ein Tarma on 28 August 2013
Between 14:14 and 14:38 a number of samples were taken from the rockets and fragments.

Limitations:
The time necesary to conduct a detailed survey of both locations as well as take samples was very limited. The sites have been well travelled by other individuals both before and during the investigation. Fragments and other possible evidence have clearly been handled/moved prior to the arrival of the invetigation team.

Limitations:
As with other sites, the locations have been well travelled by other individuals prior to the arrival of the Mission. Time spent on the sites was well used but limited. During the time spent at these locations, individuals arrived carrying other suspected munitions indicating that such potential evidence is being moved and possibly manipulated.

U.N. report photo shows confirmation of sarin in Syria attack

(Reuters) - The U.N. investigators studied five impact sites and were able to determine the likely trajectory of the projectiles at two sites: Moadamiyah and Ein Tarma.

Eliot Higgins, who blogs under the name of Brown Moses and has been tracking videos of weapons used in the Syria conflict, wrote that he has not seen the opposition using the munitions identified in the report: a variant of the M14 artillery rocket and a 330 mm caliber artillery rocket.

But Amy Smithson, a chemical weapons expert at Monterey Institute, said the August 21 attack bore "so many hallmarks of a military trained in chemical warfare doctrine" and not an untrained force. She said the army has chemical delivery systems the rebels lack.

Brown Moses: Who Was Responsible For The August 21st Attack?

○ Mapping the Sarin Flight Path from UN report

The HRW report also mentions the use of artillery shells Soviet era BM-14 launchers for 140mm rockets. These have been around a very long time and used extensively in the Algerian civil war, Egypt and Sudan (etc.). IMO these 140mm rockets could be launched from homemade artillery. There are videos of rebel forces launching this diameter rocket, see one here.

'Sapere aude'