Help with 10mm heavies for subsonic use...

[bigfelipe]

So, I know this goes the opposite direction most folks take 10mm, but I have fast boolits covered. Now I'm looking to design a boolit for subsonic work in a 10mm Glock. This will be a powder coated round most likely. Trying to figure out the max grain I can load under 1.260" OAL and have enough case volume to push it to 950-1000fps. Anyone made anything bigger than 220gr? I figure a really heavy round could still be effective and quiet. I'd love to push 275-300gr but I don't know what is practical. I guess it's a matter of how far into the case it can be seated?

What say you gurus of casting and loading?

[bigfelipe]

Was playing around on mountain molds... Lol. How about this beast?

[bigfelipe]

Anyone..?

[Outpost75]

I shoot my 10mm in a Ruger Blackhawk and use this design from Accurate. I load it with 3.5 grains of Bullseye and it gives performance like a .455 Eley.

Attachment 259233

[megasupermagnum]

I've never tried, but based on my own experiences, you could likely do well with a 240 grain. One bullet I know some people have tried is the HG #258, the 41 magnum Keith bullet, sized down. That is a 230 grain SWC. 1.260" is quite a limit, is that all the longer your magazine is? I've loaded longer than that in 45 acp.

[bigfelipe]

I shoot my 10mm in a Ruger Blackhawk and use this design from Accurate. I load it with 3.5 grains of Bullseye and it gives performance like a .455 Eley.

Attachment 259233

Is 252 the grain?

[bigfelipe]

I've never tried, but based on my own experiences, you could likely do well with a 240 grain. One bullet I know some people have tried is the HG #258, the 41 magnum Keith bullet, sized down. That is a 230 grain SWC. 1.260" is quite a limit, is that all the longer your magazine is? I've loaded longer than that in 45 acp.

That's the 10mm OAL. I don't know enough to know if a GLOCK 20 mag can be loaded longer or if it will function. It's definitely possible it can be longer...

[megasupermagnum]

A quick search finds my last 10mm loading were with the 180 grain XTP at 1.250" OAL. I don't know why I thought they would be longer, I guess they just look longer.

[Outpost75]

Is 252 the grain?

Yes. In the Ruger cylinder length there are no issues. I use also in my .40 S&W cylinder with 3 grains of Bullseye, also performs like a .455 MkII.

[44Blam]

I'm shooting an accurate mold 40-180H with no lube groves. It ends up being 188 grain with my alloy.
I'm shooting them with basically a full case of AA #9 and getting 1275 or so FPS. That'll stop a lot of things that walk this planet... It does certainly go BANG - but we're shooting guns... Bang is good, right?

[475AR]

I have been playing with this 240gr, I haven't settled on a load yet but it will load to work in your Glock and still do 1050fps. If you want I will dig up my starting loads.

[bigfelipe]

I'm shooting an accurate mold 40-180H with no lube groves. It ends up being 188 grain with my alloy.
I'm shooting them with basically a full case of AA #9 and getting 1275 or so FPS. That'll stop a lot of things that walk this planet... It does certainly go BANG - but we're shooting guns... Bang is good, right?

Bang is fine when you have ears... I prefer no bang. That's why I own so many suppressors...

[bigfelipe]

I have been playing with this 240gr, I haven't settled on a load yet but it will load to work in your Glock and still do 1050fps. If you want I will dig up my starting loads.

Any information would be greatly appreciated! If you have info on case capacity/fill with that projectile and your powder load it would be helpful for sure.

[475AR]

Any information would be greatly appreciated! If you have info on case capacity/fill with that projectile and your powder load it would be helpful for sure.

I will dig up the loads, I haven't done much with it in the last few months because of work, but I hope to get back to load development by the end of the month so I can hunt some hogs in May.

[lar45]

I do not have a 10mm, but I shot one once...
I do have an AMT Longslide Hardballer 45acp with 7" barrel that I shoot 270s from Hunter's Supply in.

To figure out how long of a bullet the 10mm case will accept,
take a bullet, measure the length,
seat it normally in an unprimed case and measure the outside of the case.
Remove the barrel from the gun and do a plunk test to ensure that the test round will chamber freely.
Next start seating the bullet deeper and deeper while measuring the outside of the case until it starts to bulge.
Now measure the length and use this to calculate the max shank depth.
Take you max loaded length subtract the case length and add the max shank depth.
This will give you the maximum bullet length.
Now go to www.mountainmolds.com and use his bullet design software to see what your max bullet will weigh.

The next step would be to take your bullet length, weight and loaded length and plug that into quickload.
Try several different powder burn rates until you get what you are looking for.

If you get the bullet length and weight, I would be more than happy to plug it into Quickload.

[bigfelipe]

I do not have a 10mm, but I shot one once...
I do have an AMT Longslide Hardballer 45acp with 7" barrel that I shoot 270s from Hunter's Supply in.

To figure out how long of a bullet the 10mm case will accept,
take a bullet, measure the length,
seat it normally in an unprimed case and measure the outside of the case.
Remove the barrel from the gun and do a plunk test to ensure that the test round will chamber freely.
Next start seating the bullet deeper and deeper while measuring the outside of the case until it starts to bulge.
Now measure the length and use this to calculate the max shank depth.
Take you max loaded length subtract the case length and add the max shank depth.
This will give you the maximum bullet length.
Now go to www.mountainmolds.com and use his bullet design software to see what your max bullet will weigh.

The next step would be to take your bullet length, weight and loaded length and plug that into quickload.
Try several different powder burn rates until you get what you are looking for.

If you get the bullet length and weight, I would be more than happy to plug it into Quickload.

Thanks. I'll get back to you when I have some numbers...

[bigfelipe]

I will dig up the loads, I haven't done much with it in the last few months because of work, but I hope to get back to load development by the end of the month so I can hunt some hogs in May.

Thanks. No rush. Look forward to seeing what you did...

[slam45]

what barrel are you using? in the glock 20 with a stock barrel key-holing is common with cast 200g+ boolits... case capacity goes away fast with heaver than 200g and most mags work best with an oal of 1.255 max... i have had good results with a 200(accurate 40-200B) grain mold that runs 205 to 210 with my alloy.. red dot produced a good shooting load that runs 965f/s from a stock length KKM barrel in my G20... i looked at going to heaver boolits, but i have other calibers that run heavy boolits much better with less problems... to shoot heaver than 200g boolits in a 10mm, i'd look at a revolver...