6x45mm or 25-45 sharps?

[justin22885]

so i decided afterall that i will get an AR-15, however for reliability and longevity sake im sticking to a .223/5.56 based cartridge, but im looking for an upgrade to .223 itself, poor barrier penetration, little energy at extended distances, generally a poor selection of bullets above 55 grains (almost all FMJs or match ammo) so its not as versatile a cartridge as id like it to be

an 85 grain 6x45 cartridge will fly flatter and deliver more energy at distance than even 5.56/223 match ammo and i believe its also capable of handling up to 100 grain projectiles for a bit more long range energy retention, so between those two possible loads are a lot of potential and big improvement over .223

25-45 sharps is really starting to interest me though, it can handle bullets from 75 grains (which match the flight path of a 62 grain 5.56, but with more energy) up to 120 grains which offers pretty close to the same muzzle energy and barrier penetration is a 7.62x39 but with a higher ballistic coefficient and great distance and accuracy... in the middle is the 100 grain option

now, there are reasons im not considering .277 wolverine or 6.5 PCC and to put it very simply i just dont like the way those cartridges are designed, to maximize case capacity such as on the 6.5PCC you have almost no case mouth and the shoulders are nearly flat, .277 is almost as bad whereas the 6mm and 25 cal have a longer taper in the shoulder, full length case mouth and in my opinion are cartridges that will be more reliable in semi automstics

anyone with any experience on these two that could comment?

 

[Sunray]

Either one will be primarily a reloading only thing. Neither will be available in small places.
.25-45 Sharps ammo and brass($39.49 per 50) is only available from Sharps Rifle Co. in one bullet weight.
Quality Cartridge 6 x 45 brass you can buy from Midway. Nobody loads it though.
So find ammo and brass before you spend any money. And buy as much brass as you can afford when you buy the rifle too.

 

[Gtscotty]

You're almost at the conclusion of your long journey wherein you'll give up your obsession with having a homemade autoloader chambered in nonstandard or wildcat rounds, and finally lay some cash down on an economical and effective AR-15 in 5.56. You'll realize, as many have before you, that unless you actually plan on hunting or competitively target shooting with your rifle the small increases in power at ranges you probably won't be killing anything at offered by the less popular nonstandard rounds do not outweigh the economy, availability and supportability offered by a vanilla AR-15, and it's ubiquitous fodder.

.... At least that's my prediction given the slow change in direction indicated by your last several threads on this subject.

 

[justin22885]

You're almost at the conclusion of your long journey wherein you'll give up your obsession with having a homemade autoloader chambered in nonstandard or wildcat rounds, and finally lay some cash down on an economical and effective AR-15 in 5.56. You'll realize, as many have before you, that unless you actually plan on hunting or competitively target shooting with your rifle the small increases in power at ranges you probably won't be killing anything at offered by the less popular nonstandard rounds do not outweigh the economy, availability and supportability offered by a vanilla AR-15, and it's ubiquitous fodder.

.... At least that's my prediction given the slow change in direction indicated by your last several threads on this subject.

ill still have a 5.56 barrel when i want to shoot cheap and common so.. i'll have both worlds ;-)

 

[ironworkerwill]

I don't know what the big deal is. If its parent case is .223/5.56 you pretty much have an endless supply of brass.(I figure you reload) New AR barrel, dies and rock and roll.

I would go with the 6mmx45 or the 6.5TCU only because of bullet selection. I have not been impressed with .257 bullet selection.

 

[justin22885]

I don't know what the big deal is. If its parent case is .223/5.56 you pretty much have an endless supply of brass.(I figure you reload) New AR barrel, dies and rock and roll.

I would go with the 6mmx45 or the 6.5TCU only because of bullet selection. I have not been impressed with .257 bullet selection.

you are very right about the poor bullet selection with .257, so i can agree with that

can the 25-45 be loaded with 100 grain projectiles?

 

[crazysccrmd]

The 25-45 suffers from a lack of powder space when loaded with 100gr and heavier bullets. Sierra 70 and 90gr Blitzkings offer the best balance of BC and usable powder capacity. Speer 87gr will work well for deer and pig hunting. Sierra 90gr Gameking might be a good option as well.

The 6mm has a better bullet selection, especially for match type bullets. The Berger 90gr BT has a .409 BC which is better than anything you can fit in the 25-45.

 

[justin22885]

so, the 6mm can take up to 100 grain bullets but the 25 cal cant?.. also, the hornady 87 grain v-max has a BC of .400, is an expanding bullet, and about half the price of the bergers, if i were to get into 6x45mm as a performance upgrade to 5.56/.223, id go with 87 grain vmax.. either those or the 85 grain speer SP boat tail, plus it would share an identical trajectory with 150 grain .308

 

[crazysccrmd]

The heavier 6mm tend to have a much better BC than the heavier .257 bullets. Sierra 6mm 95 SMK has a .46 BC compared to the .257 100 SMK .376 BC in the velocity range of the 5.56 case. Not huge, but launched at the same velocity the 6mm stays supersonic about 100m further, drops and drifts less.

Add in the lightweight 6mm bullets and it makes a pretty solid all around cartridge for paper, varmint, and medium game.

 

[justin22885]

from my understanding after doing a bit more research on the 25-45 sharps is that given the case length and COAL length there isnt enough space to seat larger 25 cal bullets due to the ogive, it would lead to the bullet being narrower at the case mouth than the mouth itself, and its not easy to sqeeze enough COAL out of the AR-15 mags to make it possible

the 6x45mm bullets though seem to have no issues seating longer bullets.. seems they were both designed around an 85 grain cartridge and physics dictate that both bullets being the same weight, the one smaller in diameter must be longer, more aerodynamic giving the edge to the 6 mil

 

[R.W.Dale]

7.62x39-30HRT-450 bushmaster-300blk

I've had my share of alternative caliber AR15's

Now I just have one simple 603 retro ar because I figured out something along the way.

223 with a good bullet kills deer and punches paper just fine.

 

[justin22885]

7.62x39-30HRT-450 bushmaster-300blk

I've had my share of alternative caliber AR15's

Now I just have one simple 603 retro ar because I figured out something along the way.

223 with a good bullet kills deer and punches paper just fine.

finding a good bullet for the task is not so easy in .224 and in many places its not even legal

anyway, i was really hoping to find a good option in the 100-120 grain category

 

[R.W.Dale]

Then grab a bolt action hunting rifle in a RIFLE caliber like a MAN ;-)

Finding a good bullet is easy. They are called nosler partitions or Barnes TSX

I will guarantee finding a good 5.56 deer bullet is easier than finding one in 6mm or 25 caliber that will run through an ar15 magazine with a 45mm case

 

[justin22885]

Then grab a bolt action hunting rifle in a RIFLE caliber like a MAN ;-)

Finding a good bullet is easy. They are called nosler partitions or Barnes TSX

I will guarantee finding a good 5.56 deer bullet is easier than finding one in 6mm or 25 caliber that will run through an ar15 magazine with a 45mm case

i have larger caliber weapons, used to own an M1A, and a PTR-91, now i have a MAS 49-56 in .308, as well as a couple surplus bolt actions, 8mm mauser and 7.62x54R are no slouch.. however, they dont have what im looking for

if i could find an expanding bullet in the 75 grain range for 223 that was actually inexpensive enough to load larger qnantities of that would be perfect

 

[R.W.Dale]

i have larger caliber weapons, used to own an M1A, and a PTR-91, now i have a MAS 49-56 in .308, as well as a couple surplus bolt actions, 8mm mauser and 7.62x54R are no slouch.. however, they dont have what im looking for

Take it from me. You will NEVER have what your looking for. There's always that next "I need a rifle for..."

Heed my advice adding caliber weirdness only makes this eternal quest cost more.

I have had my own proprietary wildcats (30ppc largo) and every military cartridge that participated in ww2. Now my "weird" cartridge is 35rem.

Because at the end of the day they ALL just make a loud BANG and put a bullet hole in something

 

[R.W.Dale]

My longest shot on game was 278 yards with a 20" 7.62x39 ar15

I don't and I suspect nor do you have any business shooting at game farther than 300yds. As such more performance brings NOTHING to the table.

Shoot something simple, shoot it a lot at many ranges so you know the drop and have a rangefinder handy.

 

[Gtscotty]

My longest shot on game was 278 yards with a 20" 7.62x39 ar15

I don't and I suspect nor do you have any business shooting at game farther than 300yds. As such more performance brings NOTHING to the table.

Shoot something simple, shoot it a lot at many ranges so you know the drop and have a rangefinder handy.

This is sage advice, the differences between most similar cartridges are largely academic for 90% of uses... Once you get a rifle that is reasonably well suited to your needs, what really matters is how good you are with what you have.

 

[justin22885]

i guess 6mm then as far as cartridges that can be used without fireforming, just running through a die and reloading like normal

 

[rayatphonix]

Converting .223 brass to 6x45 has not been nearly as easy as I expected, at least with once fired brass. Lots of ruined cases when expanding the mouth no matter what lubricant i try. I had to anneal the brass to have consistent success. Expect my brass was case hardened. Btw I was using Redding dies. Perhaps another brand would work better.

 

[justin22885]

Converting .223 brass to 6x45 has not been nearly as easy as I expected, at least with once fired brass. Lots of ruined cases when expanding the mouth no matter what lubricant i try. I had to anneal the brass to have consistent success. Expect my brass was case hardened. Btw I was using Redding dies. Perhaps another brand would work better.

i thought annealing first was a given when doing such a change to the brass?

 

[rayatphonix]

Converting 243 to 260 I never had that issue.

 

[Jim Watson]

But wait, Justin, how are your previous two projects going? The .223 to 9mm Super Duper and .308 to .45 Amazing? And wasn't there one before that? I forget details.

 

[justin22885]

But wait, Justin, how are your previous two projects going? The .223 to 9mm Super Duper and .308 to .45 Amazing? And wasn't there one before that? I forget details.

i actually convert .308s into 45 super regularly, need to ream the inside a bit, but it works.. i only do it to .308 brass that doesnt exactly make the cut to be reloaded as .308 (mouth tears, dings, etc)

 

[justin22885]

hmm, what does more damage to medium size targets, an 87 grain .243" v-max at 6x45mm velocities or a 150 grain .308" non-expanding FMJBT at x39 velocities?

 

[R.W.Dale]

hmm, what does more damage to medium size targets, an 87 grain .243" v-max at 6x45mm velocities or a 150 grain .308" non-expanding FMJBT at x39 velocities?

Does it matter?

There are no varying degrees of DEAD

Why would you arbitrarily limit yourself to FMJ with x39 anyways? They make 125 grain ballistic tips ya know.

You sir have an acute case of paralysis from analysis. At this point in metallic cartridge development you are not going to discover anything even remotely new or revolutionary so you can just get that fantasy out of your head now.

Now excuse me I'm gonna go to the range and shoot groups from my 17" 9mm Luger TC encore.