Correct bullet size question

[7.62Man]

Hi All,

I just finished slugging the bore of my mosin nagant "scout" project rifle and am now looking for the correct bullet diameter. Groove to Groove measures 0.303" and land to land measures 0.313".

My first question is a 0.312 cast bullet (LeeC312-185-1R) the right bullet, or is it too small? Could I also use the Lee CTL312-160-2R?

I plan to use this rifle as my deer hunting (Moose/Bear?) rifle. I have only cleaned it up and have yet to fire it. Dam April snow storms in NW Ontario!

Thanks
Bill

[mag_01]

Ideally you would like to be .002 Th's. over bore or larger if throat is larger--- The Lee .312 is worth a try depending on alloy it will drop ..313 plus--- If boolit tumbles then larger Dia. is required or a filler will help (filler as last resort)---Reduced charge----- when using a filler. And the 185 is a good choice.---Mag



-18grs. of 2400 and the 185 work well in all my MNs

You will probably want a stronger load for hunting

[Larry Gibson]

Almost all COMBLOC MNs have the Soviet chamber; the throat leade to the lands tapers from the outside of the chamber's neck mouth. American and European chambers neck mouths have a step before the leade starts. Finn MN M39s built with Sako barrels also have this step. Essentially what this means is the leade to the lands is a very large taper in most MNs. I get the best accuracy with the largest cast bullets that will still allow the neck to chamber. All of the russians I've dealt with shot well with .314 sized bullets though a couple would only take .312" bullets. I mostly use Norma cases and the necks are thinner than most other reloadable cases. My Lee 312-185 drops at .313" from the mould when cast of WWs. I crimp on the GC and lube in a .314" die. That bullet shoots very well in every MN with a decent bore I've shot it in as does 314299.

Larry Gibson

[Buckshot]

...........7.62Man, you've got it backwards. Land to land (bore) is .303". Groove to groove is .313". There are a few boolit designs out there that will allow you to meet or exceed your groove diameter. Your problem is in meeting your land diameter. Probably your best bet will be the Lyman 314299 as it is designed to drop a slug of .314" drive band (groove) diameter. It may miss the mark for the bore, maybe not.

There can be accuracy issues with bore riders NOT riding the bore, so you lack guidence for the boolit as it travels down the barrel. Boolit moulds are different, and even moulds from the same manufacturer carrying the same number can vary a bit from batch to batch. My Lyman 314299 WILL drop slugs of .314" & .302". My Lee C312-185R will go .313" on the bands and a full .303" on the nose.

Naturally things can alter these dimensions to one degree or another such as alloy, casting temp, block temps, alloy delivery, etc. Large bore diameters are the killers in some rifles. Mould designs for boolits over .313" are scarce.

................Buckshot

[7.62Man]

So I guess my other mosin-nagant at 0.316" is a lost cause?

Would it be worthwhile for me to make a custom mold from mountain molds for this rifle? Or is a 0.316 barrel shot out?

Thanks for the info

[Ricochet]

No, it's not shot out, it was made that way. Oversize bores are common in military rifles from lots of countries. Starting with tools to cut a larger bore gave more useful life before the tool had to be replaced, I imagine. They weren't too concerned with gilt-edged accuracy, they just needed it to shoot reliably with military ammo.

Use the fattest boolit that will fit in the neck and let the cartridge easily chamber and extract. May work well, may not.

[4570guy]

It looks like you guys have answered the question I posted over in the Military forum: http://www.castboolits.gunloads.com/showthread.php?t=15148.

It sounds like I'll be okay so long as the loaded round chambers smoothly -- and it does that.

[Junior1942]

So I guess my other mosin-nagant at 0.316" is a lost cause? Nope. Mine measures .316"on one side and .317" on the other side. As per Buckshot's example, I reamed a Lee push-through .314" die to .3155" and LLA lubed some .323" #323471 bullets (220 grs) and they swaged down just fine. Shoot just fine, too, at 1821 fps.

The I.D. of my fired cases is .316" so I reamed the Lee die to .3155" so the sized bullets can be hand seated. A coat of LLA on them provides just enough extra diameter to prevent a loose fit. I seat them and give them a light crimp. I figure my non-sized cases ought to last about forever.

Below is a group. I load them with a whack-it Lee Loader.

http://www.castbullet.com/shooting/photos/mn01.jpg

[Junior1942]

PS: the Lee Loader is for .308" bullets, so you can't use it to neck size cases for .311+" bores. Also, you can't drop a .3155" bullet down through the die. BUT you can start a bullet in a case neck and THEN place the die over the bullet/case, and it will seat perfectly in the normal whack-it way. What that gives you is a cheap loader with an inline bullet seater.

[Bullshop]

7.62 man
hang in there bud it aint lost yet. There had been a smle 303 getting passed arround at the gun shows and everybody had it for awhile but nobody wanted to keep it. I finaly got it for $50.00. I wanted it for parts as it had the milled micro rear sight and a good clip which was worth the 50 to me. Found out why nobody wanted it when we shot it and .314" tumbled out of it. We slugged it and got .318" grooves. All we done was run sone case necks over a 32 special expander and seat some 32/8mm boolits at about 321/323" and bingo we got a shooter. Instead of looking for a real fat 30 you need to look for a slim 32. There ya go!
***He has risen*** arent you glad? Blessings to all!!!!!
bic/bs

[leftiye]

7.62 Or, you could lap out your mold a thou. or two.

[7.62Man]

I like the thriftiness of lee molds, so I think I will try a Lee C324-175-1R have the nice folks at Lee make me a push thru sizing kit for .317 for $25. I will order myself one of those wack it loaders and hand seat the bullet.

LLA is that lee liquid alox? Also what size gas checks would I use or do I need to use gas checks when the bullets are cast from wheel weights and water dropped to harden?

Thank-you again for the info

[mike in co]

go back up and look at the post on NECK dia. a full dia bullet may not let the case chamber. get an measurement on a fired case. 317 may be too big for the case neck/chamber.

[Junior1942]

You'll need an 8mm/323 gas check for an 8mm/323 mold bullet. The .317" die will swage them down along with the bullet. Run the .323" bullets through the .317" die while they're wet with LLA (Lee Liquid Alox).

If your chamber neck is tight you might not be able to use a .317" bullet. I don't think I could.

[7.62Man]

So I need to fire a fire rounds thru the old wardog measure the ID of the fired cases. That should give me the diameter of bullet to size down to 0.315"-0.317".

If I use the expander from a 303 die set and use a lee universal case expanding die, think it will give me a 0.315-0.317 case ready to seat my cast bullet? Anyone know where custom sizing dies can be purchased from?

Or is it easier (cheaper) to follow junior1942 method of hand seating the bullet and just using the die to finish seating the bullet. By slipping the die over and tapping the bullet home with the bullet seater.

[7.62Man]

I see now that Lee will make me a custom collet die set for $50 plus the cost of shipping. All they require to make the set is my money and two fired cases.

:)

[Buckshot]

So I guess my other mosin-nagant at 0.316" is a lost cause?

Would it be worthwhile for me to make a custom mold from mountain molds for this rifle? Or is a 0.316 barrel shot out?

Thanks for the info

.............Nope. Before you do anything else or spend more money, upset a lead slug in the throat/chamberneck area to see what you have to work with. If it turns out you CAN utilize a .316/.317" boolit, with the caseneck allowing release, you now know what options you have.

Cheapest is to buy a standard Lee .314" push through size die. Hone it out to something between .316" and .317". Buy a Lyman 323470 mould. This is a 2C dropping Loverin 165gr GC slugs. TL them, seat GC's and then run them up through your reworked die.

You will now have full body diameter .317" boolits and the bore becomes of no consequence.

"I like the thriftiness of lee molds, so I think I will try a Lee C324-175-1R have the nice folks at Lee make me a push thru sizing kit for .317 for $25. "

Save your $25 and hone your own $12 Lee die this way: http://www.castpics.net/RandD/hone_a_die/hone_a_die.htm

Or you can use a split dowel with wet or dry paper spun with your drill motor. Clamp the drill motor in your bench vise to make it very simple. The Lee push through die has only a narrow band where the sizing takes place, so it's not a lengthly process. Your split dowel can be wood but for this size it won't be real reliable or long lived. Better would be a piece of 1/4" steel rod. A 2" piece would suffice so you don't need to buy a whole 3' piece at the hardware store (although the remainder might be handy for other stuff).

You can just buy a 1/4" bolt and cut the head off. Use a hacksaw to cut the split about 1" long. Also get 1 sheet of 320 grit and one sheet of 600 grit. With these items on hand you're now set up to do several dies. You're only removing at the most .003" from the die. The whole operation should take less then 1 hour of your time.

...................Buckshot

[7.62Man]

I could lapp out my wack it lee loader that way too. Thanks!

I am off to slug my chamber and see what it gives me.

[7.62Man]

Ok slugged chamber and got 0.323"? I must be doing something wrong? I took a 1/4 oz egg shaped sinker and dropped it into the chamber, then I beat it into the bore for a while about 1/2 the length of the sinker and gave it a lite tap from the other end and measured.

I got the idea to try dropping a .310 jacketed bullet and it got stuck right away in the bore. Then tried a .308 bullet and again it got stuck. What gives When I slugged the bore with a 00 buckshot i got 0.316". I am really confusing myself, how can a .310 bullet get stuck in a .316 bore or for that matter how can a .308 one.

[Buckshot]

Ok slugged chamber and got 0.323"? I must be doing something wrong? I took a 1/4 oz egg shaped sinker and dropped it into the chamber, then I beat it into the bore for a while about 1/2 the length of the sinker and gave it a lite tap from the other end and measured.

I got the idea to try dropping a .310 jacketed bullet and it got stuck right away in the bore. Then tried a .308 bullet and again it got stuck. What gives When I slugged the bore with a 00 buckshot i got 0.316". I am really confusing myself, how can a .310 bullet get stuck in a .316 bore or for that matter how can a .308 one.

................Well, first of all we need to get our terms right way out :-) (one of my little pet peeves, sorry). The bore can be the land diameter, or bore can be talking about the entire inner surface of the barrel. The GROOVE is only one thing, and that is the groove, and the GROOVE is NEVER the bore unless you're using bore to talk about the whole shebang, HA!

So, your GROOVE is .316", but the BORE is probably something like .302"/.303" or similar so no, you'll not get a .308" slug to fall through. There is a little matter of .005" interference.

If you got a measurement of .323" then something IS wrong. We'll assume the caseneck walls are .010" thick (makes it simple for me, and I'm pretty simple) and if that is the case (no pun) and you have a .316" GROOVE, then that fishing sinker orta mike about .336" to maybe .340". You may be reading the throat at .323" but I hope not because thats a bunch!

With a .316" GROOVE :-) ideally the throat should be maybe .318" on that military rifle. Your measurements for that rifle might look like this:

Chamber neck: .340"
Throat: .318"
GROOVE dia: .316"
LAND dia: .303" (say)

Or somewhere within a few thousandths give or take.

...................Buckshot

[7.62Man]

Going to try again to measure the chamber neck. Must have got it wrong (I hope!)