Hello fellow 10mm aficionados...
I'm looking to develop as heavy a 10mm subsonic round as possible. I realize this goes against the grain with most 10mm shooters but I have a reason. I have a threaded barrel and suppressor for my GLOCK 20. This is my RV gun when I travel. My "one gun" for that purpose. Something for everything. I want a heavy cast boolit for subsonic use. The thinking is it'll be quiet but still penetration will still be good. A sledgehammer round if you will.
I'm looking for something 250-300 grains @1000fps. The higher the weight, the better. I'm not sure what is possible while remaining stable with the slow twist of 10mm. I'm sure others have had similar thoughts. Can't find a mold anywhere close to what I want. I have played with Mountain Molds design page but it's limited. I do some coated boolits, hi-tek and PC. So, I think a tumble lube or no lube groove design.
I don't know what will fit in the case with enough room for powder to get enough velocity...
Thoughts?
Edit: not interested in just using 180-220gr projectiles and calling it good...
I worked this up on Mountain Molds...
Sorry. Wrong mold. That one was bumped up to 45 caliber by accident. It gives you an idea though.
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Maybe you're looking for a project, but if not, there's no point in reinventing the wheel.
Rim Rock 220 grain bullets generally run heavy...all mine have been 226 grains. Push it to 1000~1050 fps and you don't have to worry about k-booms. I'm sure it's possible to find and load heavier bullets, but don't see any point to it. If anything I think you'll just run into stabilization issues, as well as the potential for unsafe pressures.
Well if you want heavy without gaining length forget the lube groves, PC coat the bullets, also if bullets get too long you will likely see pressure spikes or the bulge where the bullet sits inside the case that may cause feeding issues... ::)
So, even though that Mountain Mold page starts with 10mm/40, the as cast diameters have been pushed up to 45ACP sized bullets.
If you trim the diameter back down to .403", then the in-case length gets well above 0.500". In my test at MM I came in at 0.567" inside the case with a 0.270 nose and a 270 grain bullet, two groove. (Shadow is right, if max weight is the goal, go no lube groove and powder coat, but Mountain Mold doesn't allow you to delete lube grooves.)
Here is my take...
A 220 grain loaded within published data doesn't get above 1000 fps, and the reported pressure at max is nearly 37,000 psi. So, a 220 grain gets you very subsonic.
Quote from: The_Shadow on March 29 2020 01:50:08 PM MDT
Well if you want heavy without gaining length forget the lube groves, PC coat the bullets, also if bullets get too long you will likely see pressure spikes or the bulge where the bullet sits inside the case that may cause feeding issues... ::)
Yup, I stated in the OP that I coat bullets and was looking so no lube grooves or at most tumble grooves. Obviously I don't want to blow up one of my guns. Been there with a case head failure that trashed the frame of a new Glock in the middle of a stage during competition. That's why I'm looking around for as much information as I can to make educated starting guesses. I was hoping being a 10mm dedicated forum someone may have been down this rabbit hole before. Maybe not...
Quote from: sqlbullet on March 30 2020 10:19:02 AM MDT
So, even though that Mountain Mold page starts with 10mm/40, the as cast diameters have been pushed up to 45ACP sized bullets.
If you trim the diameter back down to .403", then the in-case length gets well above 0.500". In my test at MM I came in at 0.567" inside the case with a 0.270 nose and a 270 grain bullet, two groove. (Shadow is right, if max weight is the goal, go no lube groove and powder coat, but Mountain Mold doesn't allow you to delete lube grooves.)
Here is my take...
A 220 grain loaded within published data doesn't get above 1000 fps, and the reported pressure at max is nearly 37,000 psi. So, a 220 grain gets you very subsonic.
Yeah. It was late and I had been messing with that mold site for awhile. Accidentally bumped up the diameter. It was just to give an idea. That site doesn't allow you to mock up PC-type rounds.
Quote from: sqlbullet on March 30 2020 10:19:02 AM MDT
...
A 220 grain loaded within published data doesn't get above 1000 fps, and the reported pressure at max is nearly 37,000 psi. So, a 220 grain gets you very subsonic.
Where did you find published load data for 220 grain bullets?
Muskrat, probably the data that was obtained in the pull down documentations as found in the UW, BB, DT ammos.
There was 205 grain data in the Accurate Arms in the past...
Here are the various Pull Down Documentations
DT Double Tap 230gr Hard Cast10mm Auto
Muzzle Velocity: 1120 fps
Muzzle Energy: 612 ft. lbs
LongShot Weight: 7.2 grains
UW Underwood 220gr Hi-Tek Coated Hard Cast FN 10mm Auto
Muzzle Velocity: 1200 fps
Muzzle Energy: 704 ft. lbs
BE-86 8.0
UW Underwood 220gr Cast WFN 10mm Auto
Muzzle Velocity: 1237 fps
Muzzle Energy: 747 ft. lbs
LongShot 8.4 grains
UW Underwood 220gr Hard Cast(reduced)
10mm Auto
Muzzle Velocity: 1240 fps
Muzzle Energy: 750 ft. lbs
LongShot Weight: 8.0 grains
BB Buffalo Bore 220gr Hard Cast 10mm Auto
Muzzle Velocity: 1175 fps
Muzzle Energy: 674 ft. lbs
Power Pistol Weight: 8.4 grains
Gotcha.
I gotta say, unless the round is for poaching rhinoceroses, I don't see a single reason for going heavier...and a lot of potential issues. Whatever winds your watch I guess.
I agree with you Muskrat, I do like the 200 grain bullets and my cast ones are about 208 grains.
I do also like several other weights for my purposes.
Just wanted to post the data found in the pull-downs of the commercially sold ammo as a reference
I like the idea of heavy for caliber bullets, ALWAYS HAVE at least since I have learned "better". :)
No need for subs in my house but I understand. I tried PP, Longshot and Blue Dot. For me although the others metered better, BLUE DOT was my champion.
I use GT bullets 220g HP. It's quite a long bullet. ZERO stabilization issues from factory G29, G20 @ G40 bbls or from aftermarket Lone Wolf Or KKM bbls.
I started at 7.0g and worked to 8.5. I stopped cause I hit my target velocity. But no problems AT ALL where witnessed. Cases are fine. Primers fine and pockets live for additional loadings just fine. (Some are on there third loading)
Of coarse your results can differ and always stark low and work up.
But I'm real happy with these results.
GT bullets offers many diameters and a couple hardnesses. I take there standard alloy it measures 12BHN and expands beautifully in wet paper at 1200 FPS ALMOST to base of HP shaft.
They also sell "AS CAST" and this is what I buy cause mine are all
Powder coated. Then sized .402.
CW
Quote from: Muskrat on March 30 2020 12:06:55 PM MDT
Where did you find published load data for 220 grain bullets?
Hodgdon reloading website (http://www.hodgdonreloading.com/data/pistol?&CartridgeName=10mm+Auto&OrderBW%5B%5D=220).
Just got my new Alliant 2020 manual and they show only one load for 220 cast FP coated using Sport Pistol Powder 4.7 grains @ 929 fps
They also show a load used in the 40S&W 220 cast FP coated using Sport Pistol Powder 2.9 grains @ 728 fps
Sport Pistol powder was said to not react with the coatings on the PC coated bullets
The sad thing is that they make no reference to barrel length for the test and still no pressure values... :(
Also there is no 200 grain Gold Dot or any other 200 grain bullets listed in the book only the 190 gr Federal JHP
Quote from: sqlbullet on March 31 2020 07:12:26 AM MDT
Quote from: Muskrat on March 30 2020 12:06:55 PM MDT
Where did you find published load data for 220 grain bullets?
Hodgdon reloading website (http://www.hodgdonreloading.com/data/pistol?&CartridgeName=10mm+Auto&OrderBW%5B%5D=220).
Thanks...wonder when they added that bullet to their charts?
Interesting that the go-to powders for 220 grain aftermarket loads (800X and Longshot) aren't even on the list. Also interesting that Hodgdon lists max pressures at velocities WAY below what Underwood is generating. From a 6" barrel I get 1,226 fps from the Underwood 220 hardcast...almost 25% faster than anything Hodgdon publishes.
Often when data is added it is for newer powders that get included in testing. But except for CFE Pistol none of those are new.
And, I agree that they aren't suited to heavy bullets either. Heavier bullets need slower powders. Longshot would be the obvious choice in the Hodgdon line, though I would favor AA#9 personally.
But, at least they have data!
I posted this back on Feb. 8th on a more local forum to me in GA. .40 sw brass loaded to 10mm oal @ subsonic speeds with GT Bullets 220gr Coated HP
Something like this.. I've been meaning to try the Sherwin Gloss Black.. GT Bullets 220gr HP. The seating depth actually works for a Lee factory crimp to put it right on the edge of a lube groove. I loaded up some at .40S&W pressure and some at 10mm.. for a 10mm. 500 ft lbs. Subsonic.
.40S&W Nickel Brass Sized & Gauged 12 Pieces Avg. .844"
Powder: MP275/Longshot
Primer: CCI No. 550 Magnum Small Pistol
Bullet: GT 220gr Stripped/Cleaned Powder Coated
Weight: 216.63gr AVG. Length: .701" AVG.
COAL: 1.260" Seating Depth .285"
.40S&W SAAMMI CASE MAX IS 35,000 PSI/10MM 37,500 PSI
SPEED OF SOUND DEG F 12 - 1064FPS 32 - 1086FPS 52 - 1108FPS 72 - 1130FPS 92 - 1151FPS SPREAD OF 65FPS
Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time % Grains fps ft.lbs psi psi % ms
70 7.36 1025 506 30720 3939 98.6 0.594 ! Near Maximum !
71 7.44 1035 515 31541 3978 98.8 0.587 ! Near Maximum !
71 7.52 1044 524 32379 4015 98.9 0.580 ! Near Maximum !
72 7.60 1053 533 33235 4051 99.1 0.573 ! Near Maximum !
73 7.68 1062 542 34109 4086 99.2 0.567 ! Near Maximum !
74 7.76 1071 552 35002 4121 99.4 0.560 !DANGEROUS LOAD-DO NOT USE!
75 7.84 1080 561 35913 4155 99.5 0.554 !DANGEROUS LOAD-DO NOT USE!
75 7.92 1089 570 36844 4187 99.6 0.548 !DANGEROUS LOAD-DO NOT USE!
76 8.00 1098 580 37795 4219 99.7 0.542 !DANGEROUS LOAD-DO NOT USE!
77 8.08 1106 589 38765 4250 99.8 0.536 !DANGEROUS LOAD-DO NOT USE!
Both load pressures tested fed, shot, and ejected great out of my 5" 1911 & 16" PCC. Very pleased with accuracy, aside from more drop at longer ranges :)
I LOVE GT BULLETS! Powder coated and loaded all sorts of ways.. I sent out an email looking to purchase 3k unsized/unlubed last week and haven't heard anything back as of yet.. (damn virus) I have loaded the "220's" (actually 216ish) all sorts of ways. My 16" PCC Loves them at 1,350 15.-2" groups @ 50yd and Clay pigeons @ 100yd all day. I have been toying around with some other ideas and will be using various other bullets.. Most of which will be .41's sized down to .401. I have tried PP, Clays, 2400, MP275/Longshot, 800X, & NO. 9..
Here are a few links.
.41 Caliber 295 Grain Truncated Cone Bevel Base SSK
https://www.pennbullets.com/41/41-caliber.html (https://www.pennbullets.com/41/41-caliber.html)
GT Bullets 250 Grain Wide Hollow Point bullets 41 caliber
https://www.gtbullets.com/index.php?main_page=product_info&cPath=6&products_id=47 (https://www.gtbullets.com/index.php?main_page=product_info&cPath=6&products_id=47)
Missouri Reloading Bullets .41 Magnum 41 Outlaw 225 Grain Round Nose Flat Point
https://www.lg-outdoors.com/Product/Details/5661099?source=A10001 (https://www.lg-outdoors.com/Product/Details/5661099?source=A10001)
I actually just traded 100 - .308 168gr SMK's & 200 New Starline 10mm Brass for 4lbs Sealed Hodgdon Universal. Quickload is showing me fantastic numbers as far as case fill vs. the subsonic velocities I want. Still lots of combos to try out, another reason to Love the 10. There's not a whole lot of info out about this kind of stuff and I never thought anyone else was as interested as I am.. Like you said, against the Grain..
Happy & Safe Reloading to you! -Ben
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Quote from: sqlbullet on March 31 2020 12:43:06 PM MDT
Often when data is added it is for newer powders that get included in testing. But except for CFE Pistol none of those are new.
And, I agree that they aren't suited to heavy bullets either. Heavier bullets need slower powders. Longshot would be the obvious choice in the Hodgdon line, though I would favor AA#9 personally.
But, at least they have data!
Ya, I couldn't make heads or tails out of the powders they list for the 220 Rim Rock...Other Hodgdon powders have proven to be much better.
I've got several pounds of AA#9 to play with, so I'll work up some loads. I previously stopped at 9.5 grains...not sure why, but I was probably looking for USPSA loads for my 10mm. That load gave me just shy of 1000 fps, with very good accuracy. Now I just shoot .40 S&W for USPSA, as I got tired of loosing so much 10mm brass every match.
The nice thing about #9 is it is just barely fast enough for 10mm. Pretty much if you can seat a bullet on the charge without it backing out, it is still safe. Not that this is a valid reload technique :P