Hello,

I've just started researching reloading because of a purchase of Mosin Nagant m44 (7.62x54r)in very good shape. Vareity and availibilty of rounds are often quite lacking so reloading seemed to be the logical next step and after talking with my brother I found it was cheaper to get into than I thought. Before I purchase the equipment I wanted to make sure that bullets would be availible as well as brass. That brings me to my question...

It seems these rifles were produced with varying size bores according to many sources on the internet. I found on site that was particularly helpful in describing the process of slugging the barrel to determine what size of bullet to use, however after searching here I've found some contradictory information with regards to what size bullets I should use. The site that gave directions stated that for jacketed bullets the bore size should be used and for cast bullets the groove size should be used. From what I have been able to glean from the posts here it seems that the groove size should be used for both types of bullets.

Is this correct? From slugging I found the bore to be .3010 and the groove measurement to be .3125. I'm worried about using a too large bullet and causing high pressures... The 7.62 ammo I have been able to find (HotShot brand, reloadable boxer primed brass) measures .3095.

Basically my questions is should .308 slugs be used or .303 british (.311) slugs? Thanks for all the help. Am looking forward to where I can on your great site.

Shawn

Can you direct me to the site that describes slugging the barrel? I need to do that myself on a gun. Sorry I can't be of help in your guery.

Thanks.

You will want to use a .312 bullet (.311 bullets would also work, both sizes are available for 303Brit reloaders), IF and it's a big IF, the neck portion of the chamber is large enough to all free bullet release (the opposite "pinching" will cause you big problems). If not your stuck with using standard .308 bullets (flat base prefered for better opturation in the larger barrel).

Jacketed bullets are normaly sized at nominal groove diameter, and lead bullets are normaly .001 OVER actual groove diameter.

Slugging can be done several ways, the most common is to push a slightly oversize piece of lead (IE: fishing sinker, 00 Buckshot etc.) thru the barrel and measuring it.

Thanks Tailgunner, sounds like the site was incorrect in sizing a jacketed bullet... I think the confusion comes in in their desription of lands/grooves... (Quoted from the site...)



"Using your micrometer or caliper, you should measure land to land (that is ridge to ridge) to give the correct diameter of the barrel. If you measure groove to groove, this will be too small."



The high points on the slug should be the groove measurement of the barrel not the lands measurement correct?



I'll be trying the .308 slugs to be on the safe side and if accuracy suffers I'll take it into a gunsmith and have them make sure pinching won't occur. Thanks for the tip on a flat backed bullet.



KynaDog, the site I had found is:



http://www.surplusrifle.com



Here's a direct link to the article I was refering to.



http://www.surplusrifle.com/reloading/slug/index.asp



As tailgunner said it is a pretty simple process. Cost is pretty insignificant. I think 10 #9 lead egg sinkers were about 80 cents and then the 1/4 oak dowels about 50 cents a piece. The large cost will be a precise enough caliper/micrometer. I used one of my engineer buddies digital calipers which was good down to .001 and representation down to .0005. That will be one of my first purchases along with my reloading set. Decent digital calipers can be had for around 50 bucks... That will almost double the initial start up cost, but I think the ability to make measurements that you can trust is worth the extra cost. Thanks again for the help.



Shawn

"The high points on the slug should be the groove measurement of the barrel not the lands measurement correct? "
Correct. Bore is the size of the hole BEFORE the grooves are cut in IE: the "land" diameter. The "slug" is a reverse image of the bore, so it's largest diameter corosponds to the "groove" dimention.

A low-rent way to see if bullet release problems exist in your rifle's chamber......take a fired factory round's case, and see if your intended component bullet is a slip-fit into the case mouth. .002" inch clearance is about ideal, sometimes it will be more, once in a while less.

If less, most case trimmers have reamer attachments or neck turners that can remedy the "too-thick" case neck problem.

General rule here--with jacketed bullets, attempt to match the barrel's groove diameter. With cast bullets, attempt to match or exceed by .0005" to .001" the throat diameter.

My Romanian M-44's throat is .314", and its groove diameter is .313". I just got a semi-custom mold for it and my SMLE that casts at .315"-.316" to service their respective diameters.

Hey Deputy Al,

Thanks for the heads up. That will be a simple way and low cost method for me. Only cost involved would be to buy a box of .311 slugs. If they fit I'll try both .308 and .311 slugs to see which performs the best. Thanks again for all the help. Hope to get my reloading equipment next weekend and my membership at the local range should be processed by then as well.

Shawn