Cast boolit for 7.62x25 sabot loads

[AP30N]

Hello, first time here, so be gentle on the newbie!

Been reloading all my life but only cast boolit when I need to, now it is such time.....

I have been toying with the idea of loading a 22cal boolit in my 7.62x25 TT33 clone, just because people around me have been going on about their new FN 57 and I kinda said to them, yeah, I bet I could do it in my $500 TT clone.

After working on in a bit, I got it right (kind of), I got some locally manufactured (Taipan in Aus) 45gr .224 JHP and loaded them in 30 carbine sabots from Sabot Reloading Pro. 5.8gr of AP50N (very very very similar to International in terms of bulk density and burning rate) loaded to OAL of 35mm got me 1800 pfs. There I go, beats FN 57! Anyway I think this is as hot as I can get without risking losing body parts. As a matter of fact I don't recommend people to try it (usual disclaimer haha).

The problem is that the recoil is so soft that I struggle to get it to cycle 100%. I got it to eject with a 6lb 1911 spring and a cut down mainspring that would only ignite Fed primers but sometimes gets failure to feed. My thought is only if I can get it to eject on a 7lb spring, I should be good to go. Adding more powder is out of question as I am starting to get pressure signs

The other option is to load a heavier boolit and work up another sensible load. Oh by the way, the 7lb spring set up works like a dream with boolits from 93gr Lee 311 mold, sized to 309, in front of 4.7gr Trial Boss (yes it is a compressed load the powder is filled all the way to the brim), or 3.5gr AP50N. It would be good if I can have the Tok set up for both loads.

Now that is where the cast boolit comes in. I don't think I can find a heavier JSP/JHP that will not reduce my already small case capacity, but maybe a 50 or 55gr cast boolit with a fat, blunt nose AND no lube grove (ok, 1 is fine), flat base would be better than boat tails too. Are there such animal out there? Any suggestion? Or maybe some one has done that before and would like to share.

Another problem is that I can't get the sabot to release the boolit 50% of the time. When I shoot at 40 meters, I would get two groups, a higher 22 cal group and a lower 30cal group. I am sure the 30 cal group wasn't just empty sabots, the was no sign of petals opening. Maybe if I can lube the inside of the sabots, or maybe sizing to 223/222 may help..... I am open to any suggestion too

Jon

[Dan Cash]

At the velocities you are achieving, a flat point bullet is probably not your best choice but you don't say what you want to ventilate with this pistol. Accurate Mold will make a nice flat nosed custom bullet for you but he has a minimum meplat of .18 inch.

Sabot release of sub projectiles has always been a problem, one which the military seems to have solved for their tank ammo. You might try using a razor blade or scalpel to make a radial cut at the base of the petals so that they are not quite so durable, giving centrifugal force and wind resistance a better opportunity to separate the sabot. Don't cut clear through the petals, just enough to weaken them. Keep us posted on your progress and remember....PICTURES.

[AP30N]

Only ventilating paper here (sport only, no carrying or handgun hunting in Aus and no shooting an unmodified tt33 neither, barrel length must be at least 120mm, so I am stuck with Zigana P9). Its just that I have told some mates that I would be loading my Turkish TT33 clone to match/better their FN 57s' ballistic so I must do it.

I will try the sabot mod and post some pic in the next two weeks or so. This weekend is for working up load for my 38 Webley that I have just purchased

[jcren]

Lee's new 225-55 rf should be about right. It is A gas check design, but that wouldn't matter with the sabot and the gc cut back may help with sabot release. It is listed under new products on the lee site.

[AP30N]

Ohhhh the Lee 225 mold looks good, do you by any chance know the length of the boolit? My Sabot looks like this so prevents me from loading any thing over 16mm in length if I am to load it to a OAL of 35mm and crimp at where the petals starts



As I said I would post some pics, found some recovered boolits I shot a few weeks ago, here is what they look like. I shot them into cake icing block, it is somewhat denser than ballistic gel I believe, this is just to see how they look like when shot into something.



Left to right: 1)35gr Max, blew up on impact, 2 inch deep.
2) Hornady 45 JHP, 3in deep
3) Taipan 45 JHP, most shot thru 8 inch of stuff, the only one found looked almost good enough to be sized and loaded again



Some recovered sabots didn't even look like the patels opened at all, and that's after a few inches of penetration, one actually fused into the Hornady and never came off



Some 78gr store bought, 93 gr lee 311 mold sized to 309 and solid brass HP made out of 8mm fish sinker from ebay (I plugged the bottom with a bearing ball pressed in), took me about 3hr to make 10 as they don't size well, final sizing was done with a 304 sizer die so that the brass would bounce back to 308




The middle die is a plastic sobat seating die from the supplier of the sabot, pretty handy for $10 or so. The small grey thing is the "shell holder"

[reed1911]

Okay, you have a problem. The intent is for the sabot to only hold onto the bullet long enough to get out of the bore and then fly off shortly in front of the barrel. If it does not, your accuracy will be terrible. Look up the .223 Timms; That was the development of a .22 in sabot for the x25 before we came out with the .22 Reed Express. Running the .22 in a .30 sabot can be done, but you have to get your velocity up enough to get rid of the plastic before your accuracy will begin to develop.
I never could get it accurate enough for my needs hence why we brought out the new round, this was back in 2000-2001 before the advent of the .22 TCM. Oddly enough we worked with some of those that ended up on the TCM project, but I cannot say with any degree of confidence that our work had anything to do with Armscorp's research. Just a coincidence I suppose.

[tmag97]

Im lost what is pfs.

Thanks Mike

[BCRider]

Um.... since you're shooting with a sabot you realize that a lube groove on the bullet is totally superfluous right? The lube is inside the sabot where it can't reach the bore wall so it's just along for the ride. In your case a simple direct smooth wall boolit would be just fine.

It would be a little more work but if you could find someone that could make sabots for you then you could use the longer and heavier bullets too. The sabot and extra length would stick back into the case a little more though.

[AP30N]

Im lost what is pfs.

Thanks Mike

I suffer from a condition called typoitis, usually happens late in the evening or when I am in a hurry.... thus ft/s became PFS

[AP30N]

Okay, you have a problem. The intent is for the sabot to only hold onto the bullet long enough to get out of the bore and then fly off shortly in front of the barrel. If it does not, your accuracy will be terrible. Look up the .223 Timms; That was the development of a .22 in sabot for the x25 before we came out with the .22 Reed Express. Running the .22 in a .30 sabot can be done, but you have to get your velocity up enough to get rid of the plastic before your accuracy will begin to develop.
I never could get it accurate enough for my needs hence why we brought out the new round, this was back in 2000-2001 before the advent of the .22 TCM. Oddly enough we worked with some of those that ended up on the TCM project, but I cannot say with any degree of confidence that our work had anything to do with Armscorp's research. Just a coincidence I suppose.

Thanks for the info, just spent some time reading up on .223 timms and .22 Reed.... Looks like it is intended for the stronger CZ52 action too (something on my wishlist anyway).

It also got me thinking..... What if the petals were skinnier? From the recovered sabots, I could clearly see that the petals with rifling marks on so they weren't just riding on the land. If I reduce OD of the front half of the sabot to just short of riding the bore, I could actually load a short boolit (like a 35gr V max) further out for more velocity (and more recoil to cycle the action), there should also be a bigger air gap between the boolit and the petals so there is more air resistance. Along with weaker petals, they much just peel back easier...... Chances are you have done all these before, but worth a try



Still don't have a boolit mold for it, so I think I will try pulling out some 22lr bollits to try so long.

[AP30N]

Um.... since you're shooting with a sabot you realize that a lube groove on the bullet is totally superfluous right? The lube is inside the sabot where it can't reach the bore wall so it's just along for the ride. In your case a simple direct smooth wall boolit would be just fine.

It would be a little more work but if you could find someone that could make sabots for you then you could use the longer and heavier bullets too. The sabot and extra length would stick back into the case a little more though.

Think I wasn't clear enough on what I was trying to do .... it was late at night....

I am thinking of adding some lube to make the boolit/ Sabot separation a bit easier, the sabots fail to release the boolit half of the time.

The whole lube grove thing has to do with me wanting to have as much weight in the boolit as possible, as long as I can have it under 16mm. That was why it was trying get have a blunt nose, flat base and no lube groves. I that I think of it, the flat base would however counter productive, as there will be more surface for the sabot to hold onto. A base meant for a gas check (but without gas check) would probably be the best, as it is heavier than a boat tail but hasn't got surface for the sabot to hold onto. I should probably try sizing the boolits down to see how small I can go before the sabot stops to securely hold onto the boolit whilst under recoil and/or spinning in the bore.

[badbob454]

After working on in a bit, I got it right (kind of), I got some locally manufactured (Taipan in Aus) 45gr .224 JHP and loaded them in 30 carbine sabots from Sabot Reloading Pro. 5.8gr of AP50N (very very very similar to International in terms of bulk density and burning rate) loaded to OAL of 35mm got me 1800 pfs. There I go, beats FN 57! Anyway I think this is as hot as I can get without risking losing body parts. As a matter of fact I don't recommend people to try it (usual disclaimer haha).

quote above..
seeing that it is only a 150 fps difference from 1650 fps of standard 7.62x25 i would stick to the 30 cal boolit i have found sabots are not very accurate as well ... my 2 cent's