Underwood 220gr HC

[sqlbullet]

I agree with Yondering.  I have giving up on recovering hard cast bullets in most media.  They just keep going and going.

[Intercooler]

    I'm going to send him a couple of HC 220's just for the hell of it. He said he can cut his blocks for a single 56" shot if we don't see anything in the first try.

The BCSP's will be interesting plus the others which have never been seen. If I had a DoubleTap Hard Cast to send him that would be neat to at least compare the channel of both.

[Intercooler]

   Bad with the good. I did the Chronograph on the 220's today out of the Match and the 1006. Both were totally cleaned inside and out prior to visiting with zero rounds through them. The 1006 made nice round holes and looked to hit where they should within reason given the sights. The Match seemed to not stabilize them like the Glocks if you ever watched Hickok's video. I think they both have Polygonal rifling where the 1006 doesn't. (chime in)

    My purpose for getting them was purely test and evaluation. I don't believe we have any critters around here for such a thing. My suggestion is try them in your pistol and see what you get. If you need to use them go for it but just realize they may make a square hole rather than round.

   I think me personally in my Match, Razorback and Hunter I would opt for the 200-220 TMJ's.

[sqlbullet]

I would think twist rate would have more effect on stabilization than rifling type.  The 1006 I believe is 15:1.  Glock reports 9.xx:1, don't know on the Witness.

[The_Shadow]

The S&W 10xx pistols are 16:1  if I can recall it's left hand twist

Glock right hand, hexagonal LENGTH OF TWIST 250 mm / 9.84 in.

[DM1906]

I would think twist rate would have more effect on stabilization than rifling type.  The 1006 I believe is 15:1.  Glock reports 9.xx:1, don't know on the Witness.

Not necessarily.  Any twist rate of 25:1 or faster, in any handgun, with any commonly available handgun projectile will stabilize (the margin is quite generous, and velocity is not a factor).  The actual ideal twist rate is closer to 30:1 for most bullets I've calculated (Greenhill formula), but I've not done all of the possible projectiles, and for the sake of argument, I'm not aware of any handgun barrel of similar caliber (.356 - .458) with a twist rate of less than 28:1, and none of the auto-pistols less than about 19:1.  The only extreme that I'm aware of is one series of .44 Mag with a rate of 38:1 (you'd know it if you had one), which have to be loaded accordingly, or they fail.   The problem is, we are seeing some combinations that do not appear to stabilize.  Some speculate rifle-stripping (the bullet actually strips over the lands, or slips in the case of polygonal barrels), but I don't buy it.  I think it's a timing issue.  A keyhole does not immediately indicate a bullet that didn't stabilize, it only indicates a bullet that isn't true in flight, which can be due to a number of reasons.  If a bullet is heeled at any time, it will continue flight with that attitude if it is stabilized.  An early/mistimed battery unlock can heel the bullet.  If it is, in fact, not stabilizing, the bore and recovered bullet will show clear evidence of it.

[Intercooler]

Keyholing right? I have only experienced that one other time out of a Bersa I had.


I'm in hopes someone else can shoot some of these and tell me what they get.

[harrygunner]

Wanted to get some chronograph results and see how the Underwood 220gr hard cast works in a Glock 29.
   
I decided to compare the spread of hits of the 220gr HC between my 1911 with its Bar-Sto barrel and my third generation Glock 29. The G29 is standard, except for a metal recoil rod assembly with a standard 17lb recoil spring.
   
I placed the target at 30 yards and shot slow strings with my hands resting on a shooting bag. Took lots of time to make sure my sights were aligned consistently. Each square on the target is 1x1". The group in the upper left is from the Glock. The better centered group is from the 1911. Proves in my mind that the Glock barrel does stabilize the 220gr ammo. Then I shot the Glock at a distinguishable formation on a berm about 60 yards away, standing off-hand. The hits were comfortably close to the target, showing again, the bullets stabilize.

Here are the chronograph results

Altitude: 3221 ft, Temperature: 48 degrees, Barometric pressure: 26.9 inHg

10mm Underwood ammo -

Glock 29

180gr XTP : 1263, 1266, 1255, 1253, 1299 : avg 1267 ft/s
200gr XTP : 1133, 1120, 1141, 1153, 1170 : avg 1143 ft/s
220gr HC  : 1075, 1082, 1084, 1104, 1094 : avg 1088 ft/s

1911 4.25" Barrel

180gr XTP : 1271, 1265, 1269, 1299, 1253 : avg 1271 ft/s
200gr XTP : 1181, 1187, 1199, 1183, 1167 : avg 1183 ft/s
220gr HC  : 1152, 1153, 1165, 1156, 1161 : avg 1157 ft/s

Also shot my S&W 640-1 in .357 Mag with Buffalo Bore's 158gr JHC. That J-frame has a 2.125" barrel. It's a smooth shooting load from that gun. Quite controllable and comforting as a BUG.

158gr JHC : 1242, 1231, 1226, 1260, 1255 : avg 1243 ft/s

Target attached:



[attachment deleted by admin]

[Intercooler]

Seems pretty comparible to what I get out of longer barrels.

[REDLINE]

Thanks harrygunner.  Great work.

[harrygunner]

'REDLINE' It was fun. Bought a tripod to hold the chronograph. Now, I "need" to test every load I have. 

[REDLINE]

I hear ya, me too!   Though lately I haven't been out much as times are a bit tough at the moment.   Hopefully that will change around tax return time (assuming Obama lets me have anything back).  And yeah, a tripod is way worth using.  Though for my CED M2 rail/skyscreens it's pratically a must to have a tripod.  You don't have to, but if you don't you pretty much need a special base.