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Mmmm, I'd say its more like saying a Dog and a Wolf are comperable.

Tethgar wrote:
see a .75 caliber round is a 20MM. I've held a 20mm and a 12 gauge.. The 20mm is significantly larger.

A 12 gauge shotgun is roughly .729 caliber according to the chart on wikipedia. A 20mm round is about 0.87 caliber.

The 12 gauge is closer in width than the 20-mil.

 Melissia wrote:

Tethgar wrote:
see a .75 caliber round is a 20MM. I've held a 20mm and a 12 gauge.. The 20mm is significantly larger.

A 12 gauge shotgun is roughly .729 caliber according to the chart on wikipedia. A 20mm round is about 0.87 caliber.

The 12 gauge is closer in width than the 20-mil.

I was taking length into consideration. Honestly I've always though of the bolter rounds as half sized 40MM rounds.

Bolter rounds, from the dimensions shown in the artwork linked earlier in the thread, aren't likely that much larger than 12 gauge shotgun shells.


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Based on the image above, the standard issue bolter round is 0.75x1.875 in inches, or roughly 19.05x47.625 mm.

Compare this to the 5.56x45mm NATO round used in M16s and the like.

Which puts the bolter's dimensions in inches at 3/4" by a little less than 2"

Not all that big when you consider all dimensions. Its pretty squat for a bullet though.

I thought the exact same thing when I calculated it.

Melissia wrote:The pattern number is the year it was made.

Wouldn't that leave out the millennium, making the number a bit useless?

Personally, I thought it just means something like "998th version of the Godwyn-pattern". I mean, the Imperium may not be big on advancement and inventions, but they do keep tweaking what they have. Sometimes necessarily so, for when the knowledge to manufacture part X of the 997th model is lost and the available stocks are depleted, the AdMech needs to come up with an alternative -> cue the new version, replacing part X with part Y and hopefully not being notably worse than the original.

I'd wager this is the same for all sorts of Imperial wargear, considering it has been in use for thousands of years.

Tethgar wrote:I was taking length into consideration. Honestly I've always though of the bolter rounds as half sized 40MM rounds.

How'd you get that idea? Look at the magazine sizes and the ejection ports.

But, if the minis are any indication, looking at CSMs might do the trick too. They often use belts instead of magazines, even on their boltguns - meaning you can perfectly see the exact shape of the rounds:

Yeap, bolter rounds are short and squat compared to most rounds in modern times. Closer to grenades than bullets.

 Tower75 wrote:

 Lynata wrote:

Tower75 wrote:This also got me thinking, as the magazine of a bolt pistol is basically underneath the barrel, does the barrel actually work as a chamber? I mean, a breech-bolt would strip a round from the mag and chamber it ahead of the magazine but the only place I can see the round being chambered into is directly into the barrel itself. I dunno, maybe the bolt pistol fires from an open bolt configuration.

I think the barrel may just be really short. It needs to be a chamber to actually take the round as well as eject the casing, doesn't it? From what I've read, both chamber and barrel pretty much merge into one another, anyways. Isn't it just a matter of definition?

I know it's not really in keeping with the OP, but no, a chamber and barrel are not a matter of definition. A chamber is a chamber, and a barrel is a barrel. In the firearm world those two definitions can never be interchanged.

However, upon saying that, I know what you mean, the round is chambered into the breech of the barrel; the chamber, and fired down the barrel. It just so happens that the chamber and barrel are so damn short that the latter might as well not be there.

It could be that the bolter uses a telescopic, or wrap-around bolt, so that when the bolt closes part of the barrel length is inside it - for a real-world analogy see the Uzi SMG. Of course, this is usually employed with the magazine in the pistol grip...

I stand by my 20mm grenade comment. TO ADMIT DEFEAT IS TO BLASPHEME AGAINST THE EMPEROR!


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long link is long
http://www.etsy.com/listing/97683600/single-scifi-bullet?ref=sr_gallery_1&ga_search_query=scifi+bullet&ga_view_type=gallery&ga_ship_to=US&ga_search_type=all

Tethgar wrote:

 Grey Templar wrote:
Comperable, not equivilant.

That's like saying a dog and a horse are comparable.

Under certain circumstances, they are comparable. Some types of horses are quite small, and some types of dog are huuuuuge.

https://www.google.co.uk/search?q=big+dog+small+horse&oe=utf-8&aq=t&rls=org.mozilla:en-GBfficial&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=6IVIUcKbCYfhOpn3gDA&biw=1222&bih=634&sei=6YVIUd-ULNGV0QWY8IHQAg

 Flinty wrote:

Tethgar wrote:

 Grey Templar wrote:
Comperable, not equivilant.

That's like saying a dog and a horse are comparable.

Under certain circumstances, they are comparable. Some types of horses are quite small, and some types of dog are huuuuuge.

https://www.google.co.uk/search?q=big+dog+small+horse&oe=utf-8&aq=t&rls=org.mozilla:en-GBfficial&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=6IVIUcKbCYfhOpn3gDA&biw=1222&bih=634&sei=6YVIUd-ULNGV0QWY8IHQAg

But then, you do get some pretty big horses too.
Dogs are generally smaller

https://www.google.co.uk/search?q=Big+Horse&hl=en&rlz=1C1TEUA_enGB507GB507&source=lnms&tbm=isch&sa=X&ei=1YpIUa6fJsTK0AXOm4DwBQ&ved=0CAoQ_AUoAQ&biw=1366&bih=643

Especially this horse: http://www.thesun.co.uk/sol/homepage/news/2660003/Horse-is-shoe-in-for-world-record.html

 Grey Templar wrote:

 Melissia wrote:

 Grey Templar wrote:
Yes, the sculpts are out of proportion.

Bolters are .75 caliber and have been for the longest time.

Yep.

Boltguns and boltpistols are .75 caliber, and heavy bolters are 1.00 caliber.

While that is undoubtedly a big round, it's not impossibly big. It's comparable to shotguns, IIRC.

Indeed, its 50% larger than a .50 cal. And thats a huge round.

Yeah, but the little guy three from the left is .50 as well.



.50 is the width. But, as you can see there's a huge difference between 12.7mm(.50)x33mm and 12.7 x 99.

A 12 gauge shotgun shell is ~.73' in diameter. Probably the closest approximation for a bolt round.

An AA battery is about .55'

 Veteran Sergeant wrote:

 Grey Templar wrote:

 Melissia wrote:

 Grey Templar wrote:
Yes, the sculpts are out of proportion.

Bolters are .75 caliber and have been for the longest time.

Yep.

Boltguns and boltpistols are .75 caliber, and heavy bolters are 1.00 caliber.

While that is undoubtedly a big round, it's not impossibly big. It's comparable to shotguns, IIRC.

Indeed, its 50% larger than a .50 cal. And thats a huge round.

Yeah, but the little guy three from the left is .50 as well.



.50 is the width. But, as you can see there's a huge difference between 12.7mm(.50)x33mm and 12.7 x 99.

A 12 gauge shotgun shell is ~.73' in diameter. Probably the closest approximation for a bolt round.

An AA battery is about .55'

Has ANYONE ever realized they make 20mm rounds that AREN'T giant tall cannon shells?

20mm rounds are still much thicker than .75 caliber rounds.

20mm flares were what I had in mind.

I think it depends on the ammo.

Standard bolts comprise the following components: outer casing, propellant base, main charge, mass reactive detonator cap, depleted deuterium core, diamantine tip. The calibre of the standard round .75 and it possesses a super-dense metallic core.

To me, this sounds like the detonator cap is less designed to blow up inside the target as it is to punch a hole in armor and let the rest of the bolt through.

That's not really how it's described in the lore, however. It's an explosive charge meant for damage, not for penetration-- it assumes penetration before it explodes.

But the lore varies wildly based on author's flare for the dramatic. Saying someone is shot and falls over is nowhere near as exciting as saying someone was shot and exploded from the inside out.

Agreed. I never said it was a HUGE explosive charge either. But it IS explosive.

Basically it works on the same concept as the old firecracker metaphor-- hold a firecracker in your open palm, and when ti blows up you'll just burn your hand. Hold a firecracker in your closed fist, and you'll lose your fingers.

http://www.defensereview.com/exclusive-video-aa12-machine-shotgunfrag-12-grenade-weapon-system-test-fired/

That is not a bolter shell . It's merely a grenade, nothing more.

Its a piece of the puzzle.

Combine it with Gyrojet technology, put it in a casing, and you practically have a Bolt round.

The actual calibre of the bullet head is on relevant to the bore of the barrel, the rest of the cartridge contains the primer and the proppelant. as you can see in the pictures above the .50 BMG (a dedicated HMG round or Anti Material round) that there is a much bigger charge behind it than the .50AE round, this is more because of the purpose of the round itself, the .50AE im guessing is to punch through kevlar, im not familar with this round. The .50BMG though relies on its charge to penetrate armoured targets.

Anyway back on topic, as bolter rounds utilise rocket propellants (dont ask me how the recoil isnt as bad as it should be cause i dont have a clue) and use the conventional powder based proppellants to activate the rocket motor inside the bolt, the powder charge only needs to be sufficient to propel the bolt out of the barrel before the rocket motor can activate fully. Thats probably why the cartridges are so squat because the main proulsion systems are in the bolt itself rather than the case with the converntional charge, which is practically an oversized primer. Shotgun cartridges like the 12 bore only require 1.5" or so to hold the charge, the rest of the cartridge is composed of wadding, to push the shot out of the chamber into the bore, and the shot itself.

Cannot believe I put that in the quick reply text box...

It's .75 caliber but it is not a large round.

Yeah, the Bolt round as a whole would be smaller than the 50cal BMG round.

Still pretty big for an SMG though.

Are there any SMGs thats have 50cal ammunition?

I think there's SMGs that fire .45 colts, but dunno about bigger than that.

 Grey Templar wrote:
Its a piece of the puzzle.

Combine it with Gyrojet technology, put it in a casing, and you practically have a Bolt round.

Precisely.

Also no fragmentation (bolter shells aren't frag grenades ). And probably a few other changes as well.

 Melissia wrote:
Also no fragmentation (bolter shells aren't frag grenades ). And probably a few other changes as well.

Still has the 2 stage trigger.