Once the troops started cleaning the weapon properly (even with the dirtier powder) the Vietnam era M-16 turned out to be a good weapon for the purpose it was being used for.
1	Once	once	SCONJ	IN	_	4	mark	4:mark	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	3:det	_
3	troops	troops	NOUN	NNS	Number=Plur	4	nsubj	4:nsubj|5:nsubj:xsubj	_
4	started	start	VERB	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	22	advcl	22:advcl:once	_
5	cleaning	clean	VERB	VBG	VerbForm=Ger	4	xcomp	4:xcomp	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	7:det	_
7	weapon	weapon	NOUN	NN	Number=Sing	5	obj	5:obj	_
8	properly	properly	ADV	RB	_	5	advmod	5:advmod	_
9	(	(	PUNCT	-LRB-	_	14	punct	14:punct	SpaceAfter=No
10	even	even	ADV	RB	_	14	advmod	14:advmod	_
11	with	with	ADP	IN	_	14	case	14:case	_
12	the	the	DET	DT	Definite=Def|PronType=Art	14	det	14:det	_
13	dirtier	dirty	ADJ	JJR	Degree=Cmp	14	amod	14:amod	_
14	powder	powder	NOUN	NN	Number=Sing	5	obl	5:obl:with	SpaceAfter=No
15	)	)	PUNCT	-RRB-	_	14	punct	14:punct	_
16	the	the	DET	DT	Definite=Def|PronType=Art	19	det	19:det	_
17	Vietnam	Vietnam	PROPN	NNP	Number=Sing	18	compound	18:compound	_
18	era	era	PROPN	NNP	Number=Sing	19	compound	19:compound	_
19	M	M	NOUN	NN	Number=Sing	22	nsubj	22:nsubj|28:nsubj:xsubj	SpaceAfter=No
20	-	-	PUNCT	HYPH	_	19	punct	19:punct	SpaceAfter=No
21	16	16	NUM	CD	NumForm=Digit|NumType=Card	19	nummod	19:nummod	_
22	turned	turn	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	0:root	_
23	out	out	ADP	RP	_	22	compound:prt	22:compound:prt	_
24	to	to	PART	TO	_	28	mark	28:mark	_
25	be	be	AUX	VB	VerbForm=Inf	28	cop	28:cop	_
26	a	a	DET	DT	Definite=Ind|PronType=Art	28	det	28:det	_
27	good	good	ADJ	JJ	Degree=Pos	28	amod	28:amod	_
28	weapon	weapon	NOUN	NN	Number=Sing	22	xcomp	22:xcomp	_
29	for	for	ADP	IN	_	31	case	31:case	_
30	the	the	DET	DT	Definite=Def|PronType=Art	31	det	31:det	_
31	purpose	purpose	NOUN	NN	Number=Sing	28	nmod	28:nmod:for	_
32	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	35	nsubj:pass	35:nsubj:pass	_
33	was	be	AUX	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	35	aux	35:aux	_
34	being	be	AUX	VBG	VerbForm=Ger	35	aux:pass	35:aux:pass	_
35	used	use	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	31	acl:relcl	31:acl:relcl	_
36	for	for	ADP	IN	_	35	obl	35:obl	SpaceAfter=No
37	.	.	PUNCT	.	_	22	punct	22:punct	_
