SBR rimfire chronoes

[ton45-II]

I thought I'd share some stuff I chronoed last month. Most were predictable but some was questionable.

Norinco SBR 13"

Win Wildcat (high velocity)
1268
1254
1300
1258
1269

Win T22 (standard vel)
1249
1237
1218
1220
1233

CCI Std Vel
1078
1057
1058
1070
1058

Rem Sub Sonic HP
979.7
927.7
969.5
959.4
900.5
858.5

Rem CBees
706.8
823.0
750.4
688.7
734.9

CCI Stingers
1582
1603
1598
1623
1600

CCI Sub Sonic HP
1122
1049
1074
1111
1088

Aguila Colibri
405.6
440.6
463.8
428.8
445.8


RUGER 10/22, 12.5" Dlask w/Levang compensator

Win Wildcat
1301
1282
1252
1251
1281

Win T22
1204
1217
1206
1225
1231

CCI Std Vel
1052
1032
1032
1030
1042

CCI SSHP
1082
1092
1028
1091
1085

Aguila SSS (only had five and only for this 10/22)
934.8
934.9
909.4
936.9
928.3

Rem SSHP
1016
914.4
986.1
997.0
1015

Stingers
1547
1595
1606
1626
1623

Rem Cbees
804.4
658.3
704.7
688.8
675.2

Aguila Colibri
398.1
402.7
415.9
397.5
391.8


So why are the CCI Subsonic HP flying faster than the CCI standard vel?
Why are Winchester T22 Standard vel not flying at standard vel?

My guess for the CCI subsonic is because it was measured with a long barrel
by the manufacturer. The Winchester T22 was probably measured with a pistol length barrel, 5", or a longer barrel, 22-24". The powder burn rate and barrel length is playing a factor with some of these velocities when the manufacturers measure them. A medium length short barrel is good!

This exercise has reinforced the consistency of CCI standard vel too me. Look at that deviation!

ton

 

[diopter]

Remind me to give some S&K Standard Plus to try.

 

[brnolvr]

I had 5 bricks of T-22 Winchester that shot velocities like you experienced, Was not impressed at all.

Sent 1 email to winchester with the lot number, they sent me a empty box with a shipping label and a envelope of coupons equivlent to the value of the ammo. redeemable at any gunstore.