Range session today, choreographed several 10mm loads out of my Glock G20. Yes, I spent lots of money on ammo today so you don't have to. Borrowed a buddy's Garmin C1 Xero Chronograph and was really impressed with it. Very easy to use and none of the finickiness of my Chrony with the screens and the PITA of setup. Really impressed with it and will be buying one for myself.

Getting my Glock G20 worked into the carry rotation. First part of my range session was sighting in the Holosun 509T I had mounted on it. Then it was trying out the different types of ammo for function and shooting them over the chronograph. My goal is to pick out two loads for the pistol that shoot to same point of aim; a hard cast or solid copper bullet for bear defense/woods carry and a hollow point for, "Urban Carry". This may be a challenge that requires further work, my group was one gigantic vertical string up and down the center of the target with the different types of ammo.

Apologies for the formatting, it doesn't carry over easily from Excel to forum. I did include the factory ratings at the top of each load. Also .22LR at the bottom that I used to set up and learn the chronograph operation with.

Some interesting results. The cheapest Winchester USA Ready produced some of the highest velocities. It's cheap (well, relative for 10mm) FMJ range ammo that's actually loaded to 10mm levels, I was surprised. Velocity differences between my 4.6" barrel Glock G20 and 4" barrel Smith & Wesson 610 is about 35fps slower in the revolver.

Biggest disappointment was the Hornady Critical Duty at well below 200fps of its rating. I thought this might be a replacement load for the 175gr. Winchester Silvertips I have carried for years but it's not.

Really impressed with the Double Tap 200gr hard cast. Almost as much energy as the Underwood and it is extremely consistent, I think max spread was something like 12fps.

The Underwood 200gr. Hard Cast performed to its advertised specs and was very consistent. It also had more energy than the 220gr. Buffalo Bore load. Unfortunately Underwood brass does not play well with the moon clips of my Smith & Wesson 610. The rounds are not held securely and just fall out of both the factory Smith & Wesson and TK Custom moon clips. This is the only 10mm ammo that I have had this issue with.

I will not be doing any additional shooting with the Buffalo Bore. Two of the five rounds fired had blown out primers. Fortunately no case bulging or any other signs of over pressure. I've had this same issue in the past using Buffalo Bore in my Dan Wesson Razorback. It's just not worth the risk.

For your enjoyment and perusal...

180gr Winchester USA Ready - Glock 20
Velocity Energy
Rated 1,250 624
1 1,206.4 582.0
2 1,176.8 553.0
3 1,235.4 610.0
4 1,214.2 589.0
5 1,221.6 596.0
Average 1,210.88fps 586.0ftlb

180gr Winchester USA Ready - S&W 610
Velocity Energy
Rated 1,250 624
1 1,195.8 571.0
2 1,221.4 596.0
3 1,108.3 491.0
4 1,171.6 549.0
5 1,173.7 551.0
Average 1,174.16fps 551.6ftlb

175gr Hornady Critical Duty - Glock 20
Velocity Energy
Rated 1,275 650
1 1,093.7 465.0
2 1,011.2 397.0
3 1,063.9 440.0
4 1,034.5 416.0
5 1,041.3 421.0
Average 1,048.92fps 427.8ftlb

185gr 49th CC XTreme Penetrator - Glock 20
Velocity Energy
Rated 1,105 501
1 1,011 420.0
2 1,006.6 416.0
3 1,107.5 504.0
4 1,011.8 421.0
5 1,025.7 432.0
Average 1,032.52fps 438.6ftlb

200gr Federal Solid Core - Glock 20
Velocity Energy
Rated 1,130 567
1 1,157.2 595.0
2 1,139.7 576.0
3 1,150.5 588.0
4 1,151.9 589.0
5 1,156.6 594.0
Average 1,151.18fps 588.4ftlb

200gr Federal HST - Glock 20
Velocity Energy
Rated 1,200 639
1 1,077.9 516.0
2 1,061.9 501.0
3 1,061.5 500.0
4 1,073.4 512.0
5 0 0.0
Average 1,068.675fps 507.3ftlb

200gr DoubleTap Hard Cast - Glock 20
Velocity Energy
Rated 1,200 639
1 1,188.2 627.0
2 1,189.7 629.0
3 1,182 620.0
4 1,189.4 628.0
5 1,176.7 615.0
Average 1,185.2fps 623.8ftlb

200gr Underwood Hard Cast - Glock 20
Velocity Energy
Rated 1,200 694
1 1,192.3 631.0
2 1,209.9 650.0
3 1,210 650.0
4 1,208.7 649.0
5 1,200.4 640.0
Average 1,204.26fps 644.0ftlb

220gr Buffalo Bore Hard Cast - Glock 20
Velocity Energy
Rated 1,200 703
1 1,138.6 633.0
2 1,129.9 624.0
3 1,149.9 646.0
4 1,122.7 616.0
5 1,143.8 639.0
Average 1,136.98fps 631.6ftlb

40gr Winchester Wildcat - S&W 617
Velocity Energy
Rated 1,255 140
1 1,054.5 99.0
2 1,062.4 100.0
3 1,075.4 103.0
4 1,072.2 102.0
5 1,083.9 104.0
Average 1,069.68fps 101.6ftlb

Good info, thanks for posting it.

I've had good experiences with Underwood as well, and it's become my go-to outdoor revolver defensive load. That's unfortunate about the moon clips, but not really a concern for me as I don't use them.

I've never had problems with Buffalo Bore ammo, but your experiences are concerning.

Those Garmin chronographs certainly look nice. It's hard for me to justify the cost, but if my Chrony ever dies I'll be very tempted.

Very good info. Thank you.
The Underwood 200gr heaters are my favorite.

200gr JHP Underwood in my G20 and 29.

So more 10mm weirdness. One of the reasons I decided to test so many different 10mm loads is that I wanted something different than Underwood. I had shot it in my 610 before and the issue was the moon clips were not holding the cartridges securely, they would literally fall out of the moon clips. I’m talking just picking them up off the bench they would fall out. Almost defeats the purpose of moon clips. I did not have this issue with the moon clips for my Ruger GP100 revolver in 10mm.

So tonight, I got a wild hair and decided to test fit all of the 10mm ammo I chronographed into the moon clips for my 610. Some fit noticeably tighter than others. To my surprise the new box of Underwood I bought for testing fit just fine, while loose and wiggly the rounds do not fall out of the moon clips. The original Underwood ammo I used was an older box that was sitting around and had the bright red coating on the bullets. Underwood calls their newer ammo, “Black Cherry” and it is a very dark red almost black coating.

Then I got an even wilder hair and decided to see if the loaded moon clips would fit in the revolver. I had seen on Gun Sam Revolver’s YouTube channel that he had issues with some Double Tap ammo in his 610 not fitting in the cylinder properly. I have a similar issue, the cylinder required considerable effort to close and the rounds are tight and drag against the recoil shield making the cylinder very difficult to rotate. More concerning was that the moon clip did not want to eject after opening the cylinder, I had to use a punch from the front of the cylinder and tap on top of a round to get the loaded moon clip to fall free. Ok, so got out my Ruger GP100 and the Double Tap ammo seems to fit fine, the cylinder closes without extra effort and the cylinder rotates without binding. Weird.

Then tried the Buffalo Bore and the cylinder will not even close on both the 610 and the GP100. Even more weird.

No issues with any of the other ammo I tested. All moon clips were TK Custom who I believe is also the current OEM supplier to both Ruger and Smith. When issues were encountered another moon clip was tried to make sure the individual clip was not bent or damaged, the results did not change.

So yes, I love the 10mm but it just seems that it’s still a little out there and not standardized yet.

This has been a problem with moon clips forever. Different ammo headstamps may have slightly different rim thicknesses, and all moon clips aren't created equal, either. Without even getting into the durability issues, it's just a very finicky solution that requires vetting your ammo and clip selection very carefully, continuous care to not be d the clips, and special tools for mooning/de-mooning.

IMO, it's easier and more reliable to just stick with rimmed cartridges in revolvers and save the rimless stuff for the semi-autos they were designed for. I wanted a 9mm revolver for a long time, but ultimately gave up on the idea. There's nothing I can do with a 9mm that I can't do with .38+P/.357, just like there's nothing a 10mm will do out of a revolver that a .41 or .44 Mag can't do better.

Another thing to try while shooting handguns over a chrono.
If you point the pistol down, and slowly bring it up on target vs pointing the pistol up, and slowly bringing it down on target. you will see your velocities change. It's all about case volume, and where the powder is located. this test shows that a powder that mostly fills the case, is more consitant. Anyways, back on topic...

When I was shooting a 929 in Steel Challenge matches, I used the polymer Rimz moon clips. They were a godsend. So easy to load/unload, and they stayed straight. All types of brass easily worked in them.
I have not ordered some for my 610 yet…but they are on my short list and something to consider.
https://www.ezmoonclip.com/page_7.htm

I have a relative that does a small black bear guiding operation, MI. He often carries a 40 S&W for recovery, semi-auto shotgun if more concerned about a wounded bear.

He’s not really a ‘gun guy’ though he’s been around guns & hunting for decades. He’s actually finished off a bear or 2 with his Glock 22, in 40 S&W. He did grouse about the poor penetration of the hp ammo he used.

I bought him some 180 grn hardcast for his 40, not used yet but should penetrate better. When I assist I usually bring my 4.2” Redhawk in 45 Colt.

I do realize the 10mm is the quintessential ‘woods carry’ handgun, not trying to upset that apple cart. The other option is to get the better, specialized ammo for the gun you already have.

quote:

Originally posted by VictimNoMore:
When I was shooting a 929 in Steel Challenge matches, I used the polymer Rimz moon clips. They were a godsend. So easy to load/unload, and they stayed straight. All types of brass easily worked in them.
I have not ordered some for my 610 yet…but they are on my short list and something to consider.
https://www.ezmoonclip.com/page_7.htm

Yes,I have some of those for my 625’s. I keep meaning to order some for my 610 and my GP100.