Lee 170gr FN PP for Mosin

[thirtythirty]

Leading appears to end 4" after the muzzle. Am I maybe just pushing this Boolit too fast?

[edwin41]

I don't think the bullets are pushed to hard , but the patch isn't up for the job in my opinion.
you could try to size the boolits after patching , with a Vaseline / beeswax lube , to nominal groove dia..
this will really tighten the patch and smooths it out.
the patch has become very though this way...
do necksize the fired case , then with a lyman m die set the correct necksize , and seat the bullet so that the bottom does not stick in the casing , but like the length of the neck or so..

it works for me...

[thirtythirty]

I don't think the bullets are pushed to hard , but the patch isn't up for the job in my opinion.
you could try to size the boolits after patching , with a Vaseline / beeswax lube , to nominal groove dia..
this will really tighten the patch and smooths it out.
the patch has become very though this way...
do necksize the fired case , then with a lyman m die set the correct necksize , and seat the bullet so that the bottom does not stick in the casing , but like the length of the neck or so..

it works for me...

Thanks Edwin. Unfortunately don't have a lubrisizer (yet ) Until then I'm thinking of just taking it down a notch or two. If I were to use load data for a 30-30 (i.e, like 29gr of IMR 3031) would that be safe? I've just heard a little bit about dangerously low loads (mostly in the context of faster burning stuff). I'm just wondering if the same principle holds true for slow burning stuff.

Happy Canada Day!

[arlon]

Some mosins have really rough pitted bores. It makes me wonder if the bore is just shredding the paper patch with one load and maybe not pushed as hard with the red dot load. I had one MN model 91 that had a really rough bore and was counterbored about an inch. It had something like a .314 groove (not much left for lands either). and it would just eat brass cleaning brushes and shredded cloth patches. It shot about 2ft groups at 50ft. I found that it made a really good tomato stake in the garden. Another m91 with a perfect .311 groove is one of the more accurate milsurps I own. A 2 groove 03A3 beats everything else though.

[thirtythirty]

Some mosins have really rough pitted bores. It makes me wonder if the bore is just shredding the paper patch with one load and maybe not pushed as hard with the red dot load. I had one MN model 91 that had a really rough bore and was counterbored about an inch. It had something like a .314 groove (not much left for lands either). and it would just eat brass cleaning brushes and shredded cloth patches. It shot about 2ft groups at 50ft. I found that it made a really good tomato stake in the garden. Another m91 with a perfect .311 groove is one of the more accurate milsurps I own. A 2 groove 03A3 beats everything else though.

Hmmm. Interesting. I checked the bore again, and there is a little pitting, but nothing stupid so I don't think its that. I just went out to test out the reduced loads (30, 32, and 34 gr of IMR 3031). I started with the 30gr loads intending to work my way up. Unfortunately there was severe leading after only five shots. I am patching to probably within 1/16 inch away from the ogive. I'm patching just past the driving bands on my 30/30 and they seem to be working fine, so I don't think that there's too little patch contact (correct me if I'm wrong?). Should I maybe try patching to bore size instead of to groove size? Could this cause too much neck tension (Boolits coming out at .313-.314 w patch, groove .312)

[edwin41]

could you post a picture of youre patched bullet ?

[edwin41]

Thanks Edwin. Unfortunately don't have a lubrisizer (yet ) Until then I'm thinking of just taking it down a notch or two. If I were to use load data for a 30-30 (i.e, like 29gr of IMR 3031) would that be safe? I've just heard a little bit about dangerously low loads (mostly in the context of faster burning stuff). I'm just wondering if the same principle holds true for slow burning stuff.

Happy Canada Day!

hmm.. I missed this one.
when a heavily reduced load is desired they are loaded with small amounts of fast powders , like alliant bullseye.
the real danger comes with the slow powders in small amounts in large casings , when the primer pushes out the projectile , but the powder hasn't ignited yet... it might implode the casing and the full pressure falls on the receiver...
its called the " secondary explosion effect " or "SEE " in short.
this "SEE" effect could very well blow up your receiver part , so be very , very carefull with the slow powders.

[edwin41]

also , you might try to contact 303 guy , who has done a lot of testing and experience with pitted bores in the past.

[thirtythirty]

I looked at several loads in my lyman cast manual for 30-06, .308, 30-40, etc to find starting loads for IMR 3031 with an equivalent Boolit and they all listed 30grs so I think I'm safe.

How great an effect does pitting have on a PP? I feel like the pitting in my bore in pretty insignificant however I'd love to hear from your/others experience.

[thirtythirty]

Will attempt to post pics of the next batch.

[Any Cal.]

Maybe wrap the patch past the ogive...

I haven't gotten great accuracy p patching, but never got leading.

[thirtythirty]

Hey, was cleaning the gun again today and decided to slug the barrel with a PP Boolit just to see what happened. I'm beginning to think that it may be a cleaning issue. Previously I've cleaned it until the bore looked shiny, however I'm beginning to think that the shiny lands are producing an illusion such that debris in the grooves may still be hidden. In any case, I slugged the gun to cover all bases.

3 of the 4 lands tore the paper, as you can see, however the 4th maintained its integrity.

Anybody know what this means? Is this a faulty test?

Thanks!

[Ricochet]

I think that pushing your patched boolits through the bore to see what they look like when they come out is a great idea!

[barrabruce]

Your better off to use say a 1/2 grain of bullseye or something to just get the bullet to drop out the end of the barrel.
I think the stop starting from hammering one through will obscure your results a little by stop starting and the fact that the base is getting hammered by a steel rod and not a column of gas.
Saying that I have done the same anyway.
Your bullet shows me the the patch is too small because of there is no grunge on the groove rub area.
You will continue to get gas cutting...and thou it might seal somewhere in the journey to get consistency it would be very hard to get.

Thats what I think anyway.
But then again I'm no expert.

[HABCAN]

At a guess, looking at those pics, I'd say your patch is 'way too thin and your boolit is cast 'way undersize. Good results have been had with with big fat projectiles: two wraps of wet copy paper unsized after drying on a nominal cast .312 LEE 185gr. or 160gr. in both Lee Enfields and MNs, on 18.0 grs. IMR4227, 24.0/28.7grs. IMR4198. These hand fit tightly into a fired case mouth and are then crimped in place with the LEE Factory Crimp die. The paper 'confettis' about 8' in front of the muzzle. Accuracy is acceptable to 200 yds. Of course, YMMV.

[thirtythirty]

Wow, thank you all for your replies. So it sounds like the consensus is that my PP is too thin. Hmm, ok. I've tried PPing up to .315 before however I had trouble closing the bolt as I think the throat was too narrow. However maybe if I try for .314 or somewhere's around there. Even so, isn't that a little weird that a Boolit that is .001 over bore is letting gas by?