Name that firearms related item

[Moccasin]

Ok, not a part this time but a firearm. What is it?

[zephyp]

Looks like a 20mm anti tank rifle. Russian or German maybe?

[Moccasin]

It is an AT rifle but which one?

It is not 20mm and not Russian or German.

[allingeneral]

Is it a...

14 mm pst kiv/37:

(14 mm antitank rifle M/37)

(0.55 Inch Boys Anti Tank Rifle Mark 1, "Boys")

PICTURE: Boys antitank rifle. The muzzle brake is not the original design. (Photo credit Gun Pictures.net website). CLICK THUMBNAIL TO SEE LARGER PIC (39 KB).

Calibre:
13,9 mm x 99 B (.55) Boys

Length:
161 cm

Barrel length:
92 cm

Weight:
15 kg / 16,6 kg

Rate of fire:
5 - 7 shots/minute

Muzzle velocity:
745 - 760 m/sec (with Mk I ammunition)

Magazine:
5, removable

Bullet weight:
60,3 g

Ammunition weight:
150 g (whole cartridge)

Ammunition types:
AP

Basic principle:
repeater, cylinder lock (bolt action)

Country of Origin:
Great Britain


Finnish use: During Winter War 100 used in Finland, from these 70 were used by Finnish frontline troops and 30 used by Swedish (SFK) volunteer unit. Finns managed to get about 300 more before Continuation War. These about 400 were issued to Finnish troops in start of Continuation War. They remained in frontline use until being replaced with L-39 AT-rifles around 1942 - 1943. After this some of the Boys at-rifles were issued to coastal troops.

This British at-rifle completed in 1936 was first called "Stanchion", but after death of one of its designers it was renamed as Boys after him. Boys at-rifle was first issued to British Army in 1937 and used both by British Armed Forces and troops of Commonwealth during early part of World War 2. Around year 1942 the British delivered these antitank rifles also to Soviet Union, but the Soviets were so unimpressed for their poor armour penetration capabilities that they never bothered to issue them. The large differences in measured muzzle velocities could be explained by different ammunition designs. Two British ammunition models existed for this weapon: Mark I and Mark II. The non-Finnish armour data is probably for Mark II ammunition. But according "Finnish Military Cartridges 1918 - 1944" ammunition delivered to Finland seems to have all been Mk I, so Finnish statistics are for this ammunition. Mk I ammunition had 60,3-gram (930-grain) bullets and steel jacket covered with cupro-nickel. Core of the bullet was special steel and thin layer of lead had been applied between core and jacket. Muzzle velocity was around 745 - 760 metres/second.

PICTURE: Boys antitank rifle. Notice the bolt and the off centerline sights (the rear sight has be turned up in this photo). The muzzle brake is not the original design. (Photo credit Gun Pictures.net website). CLICK THUMBNAIL TO SEE LARGER PIC (63 KB).

During Winter War Great Britain donated 100 Boys at-rifles to Finland, they arrived in January of 1940. 30 rifles of this first batch were issued to Swedish volunteer force and the remaining 70 saw front-line use in Finnish hands during Winter War. Only 6 of the 100 rifles were lost during Winter War. During Interim Peace another batch of 100 Boys at-rifles arrived from UK and later during it Finland also bought 200 more from the Germans (who called them "Panzerabwehrbusche 782 (e)"). The 200 Boys at-rifles bought from Germany arrived 10th of December 1940. When Continuation War started these at-rifles were issued to Finnish front-line troops, who used them until domestic 20-mm L-39 at-rifles replaced them around 1942 - 1943. M/37 at-rifles didn't impress Finnish soldiers that used them, their armour penetration capability proved to quite small and after armour effect was not too remarkable either. When Boys at-rifles had been gathered off from frontline troops some of them were issued to coastal troops and the rest were warehoused. Losses of these weapons had been remarkably low as in summer of 1944 still 336 of the original 400 remained. After WW2 they remained warehoused until being sold to United States in 1956.

The rate of fire for this at-rifle varied around 5 - 7 shots/minute. Empty magazine weight 450-grams, while fully loaded one weight 1.2 kg. Rear sight was diopter-type with settings to 300 and 500 yards/meters. Equipment of the weapon included magazine box, which contained 8 magazines for it. Practical after-armour effects were so small that bullets had to be aimed to crew members of the targeted armour vehicle. As typical to weapons of its class this antitank rifle had both bipod and muzzle brake. But even with the muzzle brake the muzzle flash was visible enough for Finnish military manuals to especially warn about that. Manuals also contain warning informing that the bolt didn't close on top of the empty magazine and replacing magazine demanded first pulling bolt as far back as it goes.

[Moccasin]

See Rick, you can make a good guess every now and then.

Boys MKI .55in Anti Tank Rifle. Probably the only rifle I'd want more than a Barrett.

[allingeneral]

w00t! My turn then!

[Moccasin]

Mossberg 500 trigger assembly

[wbtrunx]

Mossberg 500 trigger assembly

I'm with Moccasin.

[allingeneral]

Yep - you win!

[Moccasin]

Here ya go, a little tougher one. It has nothing to do with black powder or muzzleloaders.

[goodoleboy]

I have no earthly idea what this could unless it's a powder holder, and since you says it has nothing to do with black powder that rules out my answer completely.

[allingeneral]

Is it Captain Hook's hand with the hook removed?

[wbtrunx]

Best guess is some sort of palm pistol.

[Moccasin]

It goes to a crew served weapon (that's a machine gun for you Navy guys).

I won't let this go too long before I tell what it is.

[allingeneral]

Hmm.. is it for a cannon?

[Moccasin]

Hmm.. is it for a cannon?

No, see my post immediately before yours.

[wbtrunx]

Well, whatever it is, we don't use it on our M2s, M240Bs, Mk19s, or TOWs...what else is there?
Ol' WW1/2 MGs I guess. Don't know which.

[Moccasin]

Leather filling cup for an M1917 water cooled machine gun.

Here's an easy one.

[Hiwaytahell]

Adjustable rear sight for something I don't know about yet.

I really suck at this

[Moccasin]

Adjustable rear sight for something I don't know about yet.

I really suck at this

It is an "adjustable rear sight" but it is a specific kind of rear sight. The one pictured is universal so it doesn't fit a specific rifle.