This morning I shot my newly built up G20 for hunting. It is a gen 3 G20, polished internal trigger parts, "-" connector, KKM 6" bbl, L&M Precision Gunworks mounted RMR 3.25 MOA, Wolff guide rod and springs.
I shot 50 rounds of Undwerwood 220gr hardcast from 3 different magazines. In total I had 5 FTF's. All 5 were in the same magazine, and it fed most of the way, but didnt totally lock into battery. I used only the Wolff 24# spring, which flung brass 15-25 ft away.
Another oddball thing, about 50% of the time across all 3 magazines, before the last round would load, the slide would lock open. The round was never stripped from the mag, and the slide lock engaged. Any ideas what would cause this?
Accuracy was crazy. Same hole, over and over again from a rest at 50 ft.
I also had 1 round that recoiled significantly less, and was alot quieter, but it didnt squib when I checked the bbl after field stripping.
Also, a couple light primer strikes related to the ftf's.
There have been quite a few reports with the Wide Nose Flat Points not feeding completely in the G-20's and not just Underwood...I think it has to do with the angle of feeding and the bullets nose shape as the rear of the cartridge is being lifted as the slide returns to battery. I think I read where DT shortened the COAL to 1.242" to improve feed and function. I don't know what COAL Underwood is loading to with his stuff.
Sometimes with the stronger recoil spring if there isn't enough slide velocity and/or travel to the rear a round may pop up to the top of the magazine, to be stripped by the recoil energy. Using less spring may help, letting the slide travel all the way to the rear long enough to have the cartridge pop up into position and be pushed forward by the slide to chamber.
Check out the info contained at this link...http://www.38super.net/Pages/Overall%20Length.html (http://www.38super.net/Pages/Overall%20Length.html)
Good luck!
I don't think the recoil spring is too strong, with the symptoms edhead35 described, and especially not with this load. Failure to completely go into battery is more likely a weak recoil spring (not in this case), or tight fit of the round in the chamber, either because of fouling, oversized ammo dimensions, or tight chamber.
The slide locking back is probably a combination of recoil and one of your thumbs hitting the slide stop lever.
A tangent or secant ogive on the bullet nose would be better for feeding than the TC shape though.
Received my order of Underwood 220gr hard cast.
I've attached a photo with a Double Tap 215gr hard cast round. The DT round is on the left.
The metplate is larger on the DT bullet. Don't know if it shows, the UW bullet is a medium gray color. The UW bullet may be denser since it looks a tiny bit smaller than the DT bullet.
The UW box rates it at 1200 ft/s. Intercooler recorded one of my DT 215gr at 1201 ft/s from his Witness.
What do you think?
BTW, guests (not logged in) will see no indication there's an attachment.
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Good question. When I spoke to Kevin he said the wider nose could create issues in some platforms. I guess whichever one works best in your platform is the one to go with.
The 215gr I tested looks discontinued by DoubleTap. I only see a 200gr. @ $48.19/50 and a 230gr. @ $48.19/50.
Underwood has the 220's for $33.00/50.
I searched around and found many use the Rimrock Hard Cast bullets.
By appearance, the Underwood rounds will feed well. The DT, with its larger metplate, feeds 100% in both my Glock and 1911.
In reference to the 215gr DT, it was available some time between 2005 and 2007. That's one of the rounds I mailed you this April. DT dropped that weight around 2007.
I'll be chronographing the Underwood rounds.
I'm trying to see how far the Gel can be extended out for testing. If he can get like 32" I want to send him a couple Hard Cast 220's to see just how far they travel. You think a piece of plywood or 2x4 in front would help tell us anything?
Other than the Gel being enough to hold the travel. Can you guys offer up some suggestions on how to set this test up? I'm sending chopinbloc some different ammos to try this week. I have never seen a Hard Cast Gel test so it has me interested.
I found one. If that little .380 goes 31" we need something to give us what we are looking for in using this 220 in the field.
Depends a lot on the bullet, but you'll need a lot of gel to stop something like that Underwood 220gr.
For comparison: Using water filled milk jugs for an example, most hollow points won't penetrate more than 3-4 jugs (assuming they expand). In my testing, a mild non-expanding cast bullet will penetrate 12-14 jugs at least. In compact wet paper catalogs, where several good hollow point jacketed loads penetrated 6-8", my 215gr 10mm bullet at 1250 fps penetrated all 17" and was not recovered. The Lee 180gr TC bullet at 1300 fps penetrated 16".
Maybe Hard Cast just isn't worth testing. I'm sending at least one of the MFG's using the Zero HP and the MAC Razorbacks which I don't know what HP that is. Nobody has done Kevin's screaming 155gr. so sending that too and Cor-Bon 180gr BCSP.
Quote from: Intercooler on October 31 2012 12:47:57 PM MDT
Maybe Hard Cast just isn't worth testing.
For gel testing of hard cast bullets, I recommend looking at the size of the wound channel, and just assuming the penetration is plenty deep enough. That way you don't have to worry about capturing the bullet, just set up enough gel blocks to tell you what you want to know.
I agree with Yondering. I have giving up on recovering hard cast bullets in most media. They just keep going and going.
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.
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.
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 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.
Quote from: sqlbullet on November 02 2012 08:29:22 AM MDT
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.
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.
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:
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Seems pretty comparible to what I get out of longer barrels.
Thanks harrygunner. Great work.
'REDLINE' It was fun. Bought a tripod to hold the chronograph. Now, I "need" to test every load I have. :)
I hear ya, me too! 8) 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.