8x52R Siamese Mauser Paper Patch

[iuvenal]

So, after loading j-words for my type-46-(8x52R conversion), I decided to mess around with paper patching. Brass was re-formed from Starline .45-70 as per the directions in "The Siamese Mauser" (Banzai Press). The brass was flared in a Lyman 8x57 M-die to accept the bullet. Loaded with 45 gr IMR 4350, Winchester LR primers. The boolit on the left right is the Lee TL-312-160-2R and the boolit on the left is the Lee-C312-185-1R. I started with the 160s as its what I had lying around, its my go-to for the AK.

Turns out the throat on this Mauser is pretty long (big surprise there) and the 160 could not be seated anywhere near the rifling. The 185s were slightly better, but still not quite there, I'll need to explore some other boolit options. Paper is Great Papers Vellum Letterhead, 45 deg. angle on the patches. Both boolits are water-dropped wheel weights and dropped at .314 then subsequently patched up to .327. The paper-patched boolit was sized down to .325, which just ironed the patch on, upon disassembly it was found that the size of the boolit was unaffected by the final sizing. Rifles bore is .323, and the patch seems to fit the throat pretty well, we'll see how they shoot tomorrow, I'll give you an update....

[semtav]

Glad to see this thread !! I started to work up a paperpatch load for my SM too. Never got past the development stage, but figured out I did need to order a .315 approx sizer die and size down some of my longer bullets if I was going to continue.

[iuvenal]

Thanks semtav, I know these aren't common, but I figured there would be some interest! I think this line of experimentation will be very worthwhile....see below.

Okay, back from range day. As expected the 160 gr. pills didn't group very well at 50 yrds. BUT it may not be the load, I'll get to that.

I'm the kind of shooter that needs a tiny target to do anything resembling grouping, so I bought some orange/white sight-in targets to provide a small square to aim at. I placed it below a standard NRA slow-fire pistol target to give plenty of real estate to get a group on because this thing likes to shoot HIGH and though I estimate about 2300 fps, I really have no idea where the projectiles would hit. At 50 yrds, I found myself getting lost in the target, so I moved it to 100 to make the square smaller. Then I figured that since the 160 didn't perform well, I'd save the rest for plinking and use the 185s for actual testing.

At this point I should mention that I got some new tinted safety glasses and used them today, and realized at 100 yrds. that the tint was washing out the orange on the target, making acquisition difficult. After the first two shots vertically strung, I was on the verge of despair, but after removing the offending optics, shot the last three rounds. You will find them clustered together in the lower part of the picture.

Note that even the shots which had strung were dead-on in terms of windage, I must have had a hard time leveling the sights with the target due to the glasses. Also note that the final three shot group is about the size of the 1-inch squares on the sight-in target. I'm still learning to group well, so I'm very very happy with these results.

Next I intend to pull out the chrony and see whats what. I know IMR 4350 probably isn't the most optimal powder for this bullet weight, I may try some WIN 748 or 760 next, I'll let y'all know how it goes.

[CJR]

iuvenal,

A couple of comments:

1. Are you resizing your brass or using as-fired cases?
2. If using as-fired cases and flaring necks, are you "ironing-out" the flare? Non straightened neck flares can randomly push the CB laterally in the chamber.
3. Sometimes it takes a number of shots to "season" the bore in order to get consistent groups.

Nice group! Hang in there. It will all come together!

Best regards,

CJR

[iuvenal]

Hi CJR,
These are freshly produced cases, all my previously fired cases are otherwise occupied at the moment. I do knock the bell off by removing the seating plug from the seating die (helps me to view whats going on) and very gradually running the case into the die and bring the die down until the neck is straight.

That brings up an interesting point, the sizing w/ the patch is more for the benefit for getting it in the new brass. The fired brass doesn't exactly hold .325s in a slip-fit, so I am going to check this week with a chamber cast, but I think the throat/fired brass should accommodate a .327 (no sizing). I'll see how the rifle likes it.

I intend to keep this rifle a PP shooter for now while I develop a load, hopefully it will get even better with seasoned barrel and a few tweaks! I want all five in that 1" square, and then I want to do it again at 200!

Thanks for the comments!

-i

[bruce drake]

Why don't' you use a 8mm bullet mold and then resize it down to allow the paperpatch or use the slightly bigger 8x56 bullet mold that Lee sells to fit that .327 bore.

And yes, I also paperpatch some 30 cal bullets in my .311 bored rifles so I understand the draw to PP for the challenge.

Bruce

[iuvenal]

Hi Bruce,

Short answer is that to use an 8mm boolit, I would probably find or make a custom sizer. IF I can get the .327 PP boolits to work, there will be no sizing required whatsoever. Thats not to say that I won't mess around with it in the future. I will at some point be working on a GC cast round, I have the 8x56 mold, but I think that I can make a regular 8mm mold work as the bore is .323, I'm just using a larger diameter projectile for these PP loads.

I guess one of the other major reasons I'm going to the trouble is I never have seen it done for this cartridge, so I kind of wanted to see if I could get it to work.

-i

[UBER7MM]

Iuvenal,

I'd say by the size of your group sans glasses, you're on the right track. All things being equal, which they're not, IMR-4895 works in the 8x57 with a wrapped Lee C312-185-1R. You might try that powder. Your mileage may vary. Dacron filler saves powder from spilling into the chamber and magazine if the wrapped bullet gets stuck in the leade or rifling when you try to extract it.

Enjoy,

[iuvenal]

Hey Uber7mm,

Thanks for the suggestion, I'll have to try 4895. I'll definitely look into the filler too, especially going up to .327

-i

[UBER7MM]

Hey Uber7mm,

Thanks for the suggestion, I'll have to try 4895. I'll definitely look into the filler too, especially going up to .327

-i

The experts will tell you that just enough fluffed (pulled apart) Dacron is needed to replace the air space between the powder and the boolit:

http://castboolits.gunloads.com/show...use-of-fillers

One can also explore Cream of Wheat and other media.

I'm conservative when working up a load.

Be safe and enjoy,

[iuvenal]

Thats a very interesting thread, I hadn't thought about filler much in the past but seeing how its done properly laid out with everything explained so well, I think I'll give it a go.

-i

[303Guy]

I'm watching with great interest. 4350 should be a great powder in your cartridge. You may find boolit base peening with it - or not. I did but that was with a softer alloy. Some Dacron filler may help with that. Then again, your group doesn't indicate any problem so why fix it? I'd be inclined to keep on with the same powder. Mind you, it's best to experiment as much as possible - more fun! I solved my boolit base peening problem by going to W748 but didn't chrony the load and have actually lost the load data! We'll, it's still there but I'm not sure which one it was.

On powder choices, the theory is that a slower ball powder is better because it produces a gentler launch into the bore. 760 would be in the same ball park as 4350 so might be a good place to start if you have some. I've had good results with H4227 with Dacron filler (in a 303 Brit). Velocity is lower though but it's a nice shooting load (22gr under a 208gr boolit) but may be unsuitable for your larger case.

[iuvenal]

Yeah I need to touch a couple off into a sand bucket to see whats going on with the boo lit itself. I think this paper is substantial enough to maybe prevent base peening, I'll find out. You make a good point, maybe I'll stick with 4350 and add some dacron. I do have some 748 and 760 that I might try. I'm going to decide what parameters I'm going to change tonight (maybe make some more brass too) and test them on the weekend. Maybe get a crony put on them too, I think I can get a little more velocity out of them without losing too much accuracy.

[semtav]

Iuvenal
I just broke down and sent buckshot a check for a .315 die. I'm going to rezsze a couple of my 8mm bullets and see how that works.

[iuvenal]

Great! Let me know how it works out, I'll be interested to see what you develop!

[iuvenal]

Okay, guys time for an update. I know I said i'd update last weekend, but inclement weather prevented me from following up. So I didn't size the patched bullets at all this time, just wrapped them and set them in the case with a slight roll crimp (big throat, not a slip-fit w/ fired case). I also loaded some cases w/ 47 gr of IMR 4350.

Wasn't in my greatest shooting form today, had trouble focusing on the target again (even without shades), so the vertical stringing was back. I do however fully believe that I am totally responsible for this, not the load nor the gun. The hotter loads did seem to wander more laterally, so maybe I'll just keep it nice and "slow" (I still need to chrony). Anyway, I think not sizing the wrapped boolits is a-ok, I will continue to develop this load or the next week.

-i

P.S. Hows your load developing going semtav?

[semtav]

just got my .315 die yesterday. by the time I got off work it was 100 + and my reloading room was hotter. so as soon can resize some bullets I'll give it a try.

[semtav]

cast up a bunch of bullets in the .324-327 range today but couldn't get them thru the 315 die in one step, so i'm going to have to do it in a couple steps.

[iuvenal]

Cool, I actually just lapped the mold I've been using, upon checking it again it drops in the .313-.3135 range. I ran it through the Mauser barrel and didn't really like how the land were engraving, so today I lapped and polished the mold, it drops around .314-.315 now with WDWW. Enough to to engrave about .001-.0015 Hopefully that will give me some increased accuracy and consistency. I'll wrap some up and use my sled on sunday, take myself out of the equation as much as I can.

I feel your pain on the sizing, I'm playing around with a PP mosin load, the bullets drop at .310 and need to be taken to .305. They won't go through the die as dropped, but go through like butter if I size down to .309 first. Let me know how it goes.

[semtav]

I just screwed up. They will go right thru a .313 RCBS style resizing die. should have had one of those made instead of the lee push thru die.