375/45 Sabot?

[alphaburnt]

Anyone know of a manufacturer that makes a .375/.45 sabot? Would paper patching these up to .40 cal be an option? It would be about the same as the 44/50 as far as sabot material between bore and bullet. I have noticed the velocities Lane has posted using Blackhorn 209 elsewhere and Speer makes .375 Semi Spitzer SP weighing 235 grains, Hot Cor construction and has a BC of .317. Hornady has some that look promising as well. It seems like a good bullet for long range, but who knows if they would be accurate or perform on game?

 

[NimrodRx]

45/.355,.357 MMP is as close as you will get.

Still looking for a bullet that they will shoot accurately. Twist of most production 45s seems too slow. YMMV.

 

[alphaburnt]

Using a program for the Greenhill Twist rate formula, .375 diameter and 1:30 twist rate as a goal, the optimum bullet length would be .70 or roughly 23/32" length for the .375. I played around with the calculator to find out the optimum length for the .40 XTP and it was .81" and the .358 came in at .64". I did not know how accurate this calculator would be so I plugged in some numbers from my new pet load in my .50 ( .430 300 gn XTP) with a goal of 1:28 and it is .99" which seems pretty darn close. Can anyone measure some .375, .400 and .430 bullets and tell me what lengths you get for differing grain bullet weights?

 

[wayles]

.375 in the .45?

I have some sierra 200 grain pro hunters that measure .374x .837 and some hornadys I borrowed from a friend are 270 gr, .374 x 1.277. I do not intend to try the 270 grain but when hunting season is over I intend to try the 200 gr pro hunters. I have found a material to wrap around the bullet once that comes off with the sabot. It gives a very tight fit. This combo will be a shooter I am confident as long as the sabot does not blow out. We will see. A .40 cal 200 gr sst measures .40 x .977. I would like to see what your formula says about the 200 gr pro hunter. The .40 sst shoots great out of my .45
Wayles

 

[santoslhalper]

To answer your original question, I know of two places you can buy a .357/.45 sabot - MMP makes one- you can order direct from them. You can also buy a .357/.45 sabot from Precision Rifle (www.prbullet.com). I think that MMP also makes that sabot for them, but it is a different design.

 

[Critter]

.375/45 not .357/45

 

[alphaburnt]

Wayles, the bullet you gave the info for (.374x.837) calls for a 1:25 twist, the 270 grain calls for a 1:16 twist. Can you tell what you will be patching these with? And the process? Thanks

 

[alphaburnt]

To try out the Greenhill formula, I sat down last night and mic'd several bullet lengths and figured out what it says the optimum twist would be. They are as follows:

.452 Hornady XTP 250- .662 length- TR 1:49

.4505 Parker 250 Hydracon- .792 length- TR 1:38

Barnes ( .451?) 250 TMZ- 1.115 length- TR 1:27

.4505 Parker 275 BE- 1.040 length- TR 1:29

Barnes (.451?) 250 EX- .9005 length- TR 1:33

.452 Hornady XTP 300- .780 length- TR 1:39

Barnes (.451?) 290 TMZ- 1.220 length- TR 1:25

.430 Hornady XTP 300- .875 length- TR 1:31

.400 Hornady XTP 200- .685 length- TR 1:35

.400 TC Shockwave 200- .945 length- TR 1:25

After doing this and trying to remember how certain bullets shot for me in this group, I drew some correlations based on my experience ( .50 cal only- Knight with 1:28 twist, your mileage may vary). Bullets that require a faster rate of twist than specified as optimum will take a powder charge greater than say a 100 gn Volume ( Triple 7 and Blackhorn 209 velocities) to shoot accurately. Bullets that required a slower rate of twist, will shoot better with lesser powder charges than 100 gn Volume. This is theory only and I know some guys are shooting bullets like the 250 XTP out of Savages with great accuracy. So Greenhill may be just a guide. Sorry so long winded.

 

[NimrodRx]

Re:

Wayles, let us know how the 200gr pro hunter works out. I have played around with paper patching some Barnes bullets but did not have great success. I know that others have and are doing it with positive results.

Notice that the twist MQ calculated for the 200gr Pro Hunter is the same that is recommended for the 200gr SST ? 1:25. Push it a little faster out of a 1:28, say with 120gr of BH and you should be in business ? just like you are with the 200gr SST. The sabot remains the fly in the ointment.

I agree, the 0.40/200gr SST out of the 1:28 twist Green Mountain bbl is scary accurate. If only it were bonded or the jacket was thicker?

 

[alphaburnt]

Nimrodrx, the problem with the SSTs and Shockwaves holding together is the primary reason I began looking at the .375. Being smaller in diameter than the .40 gives it a small game performance advantage already, but it is a RIFLE bullet and I suspect the SSTs and Shockwaves are made-over pistol bullets. Sectional Densities of the two- Speer .239 and TC SW .179. Next I looked at energies, affects by wind and bullet drop. This is why it seems so good, using the information from the Speer SS 235 grain mentioned above with a BC of .317 and plugging it into Hornadys Ballistics Calculator with 35 degree temp, a 150 yard Zero, 10 mph crosswind and approximated velocity of 2100 fps equals 1.9" high at 100, 1.7" wind drift and 4.8" low at 200 yards, 7.0" wind drift-with 1370 ft lbs of energy. Compare this with the .400 Shockwave using the same values above with the exception of a 2300 fps muzzle velocity and a BC of .220, 1.7" high at 100 with 2.1" wind drift and 4.6" low at 200 yards with 9.4" wind drift- with 1125 ft lbs of energy.
One of my biggest fears with the .375 ( other than if it will shoot accurately) is that there are rifles ranging from .375 Winchester to .375 H&H Mag and different bullets made for different applications- my goal is choosing the RIGHT .375 bullet for deer-sized game. I seriously doubt the bullets made for the .375 H&H Mag would perform desirably on deer sized game, but if made for .375 Winchester, it should be right there. Looking at reloading manuals, the velocities for the Winchester and 200/220/235 gn bullets I believe could be duplicated or topped with Blackhorn 209. It must prove itself as a shooter first. I did call Harvester yesterday and spoke to a great guy (sorry, forgot his first name but last name Beard) at length. He said they do not make such a sabot and the process of doing so could be $4000 to 5000 for custom mould, machining etc. I did not have any idea it would be that expensive, so it appears that if I try them- they will be paper patched. Long winded again, sorry, I am obsessed.

 

[NimrodRx]

MQ, why don't you just pony up and pay for the start up fee at Harvester. Consider it a Christmas present to the rest of us

Seriously though, even if you did have the sabot, I don't think you can push it fast enough to compensate for the slow twist. Isn't a .375 Win right around a 1:16 or 1:14 twist?

IMHO, the only way to get where you're going is with a custom smokeless.

 

[alphaburnt]

Nimrodrx, wouldnt that be a Merry Christmas!...but...No.

You are correct, my dream load out of the .45 is just that. Minutes ago, I found a length reading for the Speer bullet I used in the example above. You can see it here: http://www.realguns.com/archives/143.htm
Sadly, it is 1.058" long. Using that and the diameter they measured at .3754", Greenhill formula states 1:19 :cry: . Im afraid, paper patching or even with a sabot, to push it fast enough to be accurate in a 1:30 twist bore would be an impossibility for the sabot to hold up to that punishment. Perhaps if someone had an older TC with a 1:20 twist, they could try it :wink: . Oh well, on the brightside, I believe Wayles bullet might be a prospect.

 

[NimrodRx]

Been there done that. Tried it in a 1:20 twist TC. No dice.

 

[alphaburnt]

Nimrodrx, did you try the .375 or the .358 in that gun?

 

[wayles]

.375 in the .45?

MQ..... I found the material in an unlikly place. Its fine emory cloth in the sheet form. Cut the material into the correct width strip.[measure the sabot depth] . Now cut it into the correct length to where it almost wraps around the bullet. Insert the strip into the sabot grit out. This helps the emory grip the inside of the sabot. Insert the bullet into the sabot . As it is pushed in it pushes down and out holding the strip in place. Store in an [old] hornady XTP box or a drill a board to the correct dia.
NimrodRX .......which bullet did you try and how fast did you push it? The sierra pro hunter tapers down to a flat exposed lead tip and and is only .837 long. It only weighs 200 gr. It should have no problem opening up. I plan on shooting 110 to 130 gr of BH209. Please expand on your experience.
Wayles

 

[alphaburnt]

Wayles, is this the same stuff used for cleaning copper pipes before soldering, comes in rolls?

 

[wayles]

emory cloth

Yes , I did not measure the stuff in rolls . What I had available was in the sheet form [Fine emory cloth ][not the paper stuff] This stuff provides a very tight fit, but I don't think its excessively tight.
Wayles

 

[alphaburnt]

Gotcha, thanks.

 

[NimrodRx]

Guys,
Keep in mind, I was working with the .358 (.358 Win) dia bullets. in the MMP and PR .357/45 sabot. I tried bullets in weights ranging from 180 gr to 220 gr. Out of the 1:28 twist GM bbl, I had a real nice snug fit and great ignition with BH209. However, I could not get any of the bullets to stabilize.

I think the 1:20 twist TC would have worked, but I had some serious ignition problems with BH209. I won?t use any other BP sub anymore, so I gave up on the idea.

Wayles, you may be onto something with the .374/200 gr Pro Hunter. Paper patching it with the emory cloth into a .40/45 sabot could be the ticket for one heck of a long-range performer. I have no doubt that it will hold together even at 2500 fps. I agree, expansion should also be sufficient. Even if its not, you?re still talking about a hole that is larger than a .243 round that expands to an additional 50% of its diameter.

.374 to .40 just seems like a long ways to go. I hope it works. Please keep us posted.

 

[wayles]

.375 in the .45?

when hunting season is overand the weather moderates a little in western NE I will wring it out
Wayles