If everything else with the gun is in good condition you should have NO issues shooting the surplus ammo on the market

 

Thanks jepari...do you mean the original ammo or the finnish D166?

 

The Finnish 'D' modification was done to the chamber to allow the use of the new Finn D-166 and Soviet 'D' rounds.

It is unlikely that a captured rifle would've received the 'D' modification as the chamber would be able to handle the D-166 round straight from the Soviet factory. The D-166 round had the same dimensions as the Soviet 'D' round introduced in the 1930s.

The barrel would still have been marked 'D' for the Finns peace of mind.

All surplus and modern commercial ammo will chamber and fire safely in your rifle.

 

+1, you should be able to use pretty much any surplus or commercial ammo without any issues

 

d166 in 1891

I have a mosin nagant tula 1891 made in 1906 that also has the "D" marking on the receiver. it has finnish capture markings, and has been modified by the finnish. is it safe to fire surplus 7.62-54r in this gun? could anyone tell me the difference between the D 166 round and the 7.62?

 

I have a mosin nagant tula 1891 made in 1906 that also has the "D" marking on the receiver. it has finnish capture markings, and has been modified by the finnish. is it safe to fire surplus 7.62-54r in this gun? could anyone tell me the difference between the D 166 round and the 7.62?

Finns did not put D on receiver.

 

Now I am confused, my Finnish Mosin is marked 1943 vkt with sa acceptance mark and the letter "d" stamped on the barrel. I had some of the same ammo questions until I read further. The reciever is an 1895 French made. But it is positively stamped "d" .... so if the finns did not stamp the "d" where was it marked?

 

The "D" stamping should be a "D", not a "d". The chamber area of the barrel is commonly called the barrel by the not-so-informed. Are you mistaking the barrel for the receiver? The barrel starts when the flats of the receiver end.

 

Here is a pic that shows the receiver, and the barrel. Not all D stamps were put on the barrel. Some rifles have the marking on the rear sight. Both of my 1942 Tikka M91s are D marked on the sight.

 

+1. The D mark is stamped on the rear sight base of the Konovalov re-numbered/ metricated sight on my 1943 Tikkakoski M91.

 

Look at the pics at the bottom of this page.

http://7.62x54r.net/MosinID/MosinAmmoID03.htm

 

I don't think the D on the sight is for the cartridge but I could be wrong in that the sights were graduated for the D-166 bullet. Basically they made the throat of the barrel ever so slightly deeper to accommodate the Finnish bullet in Russian guns. Thus the D designation. Often time the D-166 bullet in an unmodified Russian gun will engage the lands prior to the bolt closing making the bolt close very difficult. Yes you can fire surplus ammo in your rifle as it will handle any 54r cartridge now.

 

I believe IJ70 has explained ti perfectly. I have some Lapua D 166 bullets at home, and believe they are about .3105 diameter, with an unusual boat-tail base, but I'll have to re-measure when I get home and make an accurate report.

USMCsean, a question for you. i really don't know the answer so it is no criticism of what you posted.
I have a Winchester Model 54 carbine which I received as an inheritance from a close friend's father, and when I checked the barrel length from end of receiver to muzzle it came up a little shorter than the spec. But when I measured from the bolt face (closed bolt) to the muzzle it agreed exactly. Are there two ways to specify? I had always thought it was done as you say until this experience gave me pause to think. It does make some sense to measure from the bolt face as that would agree with the length of the barrel while sitting on the bench before installation. I'm going to call "my" gunsmith who knows everything (well it seems that way to me, and I have given him some real pain-in-the-ass jobs) and find out what method he uses.
Always ready to learn,
Kari

 

What I found out about D 166 bullets as made by Lapua today.

Just was is it about D 166 bullets? Where's the magic?
First, I did all my measurements except length with a 0-1" Mitutoyo digital micrometer zero'd with the thimble and checked on a supplied standard cylinder of known diameter.
I checked for comparison a 210 gr. Sierra MatchKing HP BT bullet, which measured exactly .308 dia. no matter where on the circumference of a circle around the bullet I measured it. Perfect uniformity.
The Lapua bullets were described as "7.62 D 166 13,0 g /200 gr. FMJBT Bullet"
Bullet diameter was given on the next line as (7.87 mm/.310).
My measurements of the bottom of the D 166 bullet, taken from the "driving band" part of the bullets:
Sample - .3096", .30955", .30950", .30945" and .30930". Not a stellar exhibition of uniformity of manufacture, and not quite .310" either.
The weight was the same pattern. Slightly over the listed 200 gr., the bullets I weighed clustered around 202 gr. plus or minus a few tenths of a grain, close to my scale's .1 gr. +- error range.
Length was measured with a Mitutoyo digital caliper, which is not as accurate as the micrometer but plenty accurate for overall length of the bullet. My lengths of bullets chosen at random from the same box, were 1.3365", 1.3355", 1.3360", and 1.3335". Bullet length can be variable and not significant if the bullet is measured from the same point on the ogive with a bullet comparator, which is what I really should have done, but I am getting tired so I just measured base to tip.

Summary - I was not as impressed by the Lapual bullets as I expected to be. I sometimes use the cases and they are very nice indeed! At the diameters I measured those bullets should shoot safely in any Mosin, Finn or Russki, as long as they are not jammed up against the rifling. If you are handloading check with a home-made dummy round to be sure they are not. They may not be quite as accurate as expected because their diameters are a little smaller than advertised. I think it is quite possible that with an exposed lead base, they may obturate to fill larger diameter bores and
engage the rifling. Just a theory.
I think I will try them in my best shooting models - 39, 28, and 24, and maybe 28-30 and 28/76.
Might as well load them up and shoot them more often

(Don't go to the range without checking this, or when they call a ceasefire just after you have chambered a round, you may pull out the case, leave the bullet stuck in the throat, dump the powder in the action, and leave the bullet jammed in the rifling if you seated it out too long. Always try these at home, first. If you do think you are going to yank the case off the bullet, point the rifle straight up in the air and slowly withdraw the bulletless case until you can remove it by hand, keeping the powder in the case and not all over your bolt recesses, bolt ways, magazines, etc.)

The smaller than advertised diameter of the bullet, the slight variations in weight, length, etc. - none are significant in my opinion to make the bullet unsafe to use in appropriate handloads in any Mosin, as long as the bullet is not seated too long in a short-throat (non "D" marked) chamber. They are small enough in diameter to use in a 28/30, IMHO, and certainly no danger if they go rattling down a .313" Russian bore, just don't expect famous accuracy from that combination. Let common sense be your guide.
Interesting topic. I'm happy to learn anything I can from the comments of others.
Kari
PS USMCSean, don't forget my question.
Kari Prager

 

...

Summary - I was not as impressed by the Lapual bullets as I expected to be. I sometimes use the cases and they are very nice indeed! At the diameters I measured those bullets should shoot safely in any Mosin, Finn or Russki, as long as they are not jammed up against the rifling. If you are handloading check with a home-made dummy round to be sure they are not. They may not be quite as accurate as expected because their diameters are a little smaller than advertised.

I have three M39's, and it is impossible to load a round with the D166 and get anywhere near the leade, or forcing cone where the tapered lands begin in the throat. I have used a Hornady seating gauge, and the D166 is about ready to fall out of the case when it contacts the lands. With the D166 seated in a Lapua 7.62X53R case to its crimp canelure, the M39 is the "long jump" champion of all of my "Cold Warriors" - Finn, Swede, and Swiss.

I think it is quite possible that with an exposed lead base, they may obturate to fill larger diameter bores and
engage the rifling. Just a theory.

The D166 has a stepped boat tail. A flat base FMJ, e.g. US 150 gr M2 ball, British 174 gr Mk VII, will expand to obturate in the bore. That is why an Enfield No 4 can shoot cordite ammunition.

I think I will try them in my best shooting models - 39, 28, and 24, and maybe 28-30 and 28/76.
Might as well load them up and shoot them more often

Shoot the Lapua D46 in your M28/30 and M28/76 (if built with an M28/30 barrel. There are M28/76's built with M39 barrels too.)

 

Barrel length

Typically any barrel length is measured from the bolt face to the muzzle. Although some will try to measure from the receiver face to muzzle and some from chamber end to muzzle, but this could be a variable due to the length of the barrel tenon and or cartridge chamber length.

Donald

 

I have a few messages from Kari in my inbox that I can never bring myself to delete.

 

In light of the D-166 discussion, I am attempting to research what the ballistics of this heavy ball ammo using the d-166 bullet is, in an attempt to duplicate or at least closely (safely) as possible.

I have just started researching, but not having much luck with it. Does anyone have any pointers or leads?

 

2300fps muzzle vel. BC: 0.483.

You can plug this into Hornady ballistics calc on their website.

Daniel39

 

Perfect, so a 200 gr bullet @ 2300 fps. Thank you.

I plan on working up a load with the 180 grain bullet to duplicate those ballistics as well.

 

RIP Kari

RIP Kari