.45 "Marine Load"

[cnnhead]

I came across the article about the famous .45 Marine Load and decided to replicate one. I don't have Winchester brass at hand so I used brand new GECO cases primed with CCI300 primers and this resulted in such a cartridge:
COL: 1.200"
projectile: Nosler 185gr JHP CC
powder: VV N310 4,1gr
case: GECO (0.894")
primer: CCI 300

After first tests with my venerable STI Trojan 5" the results didn't meet the expectations though. The best 10-shot group was ca. 2" wide at 25m and some series were even wider.
I measured my ammo with Labradar and here came another surprise. According to the source the Marine Load should measure around 770fps up to 830fps. Mine was barely 700fps! (min 679; max 732; es 52; std 14). I tried to boost it a little bit going up to 4,5gr but all I got were bullets racing at 770fps and forming a group wider than 3".

Any idea why I got such different results and what to do next?

[Rover]

Every gun is unique in its load preference.

[Christopher Miceli]

4.2-4.5 VV N310
1.205-1.21 OAL
try .470 -.472 crimp

here is a load for one of David Sams match 1911s. Test at 50yards with a machine rest.

[davekp]

Maybe it's the gun. Does it group any better with any other ammo?

[GOVTMODEL]

I came across the article about the famous .45 Marine Load and decided to replicate one. I don't have Winchester brass at hand so I used brand new GECO cases primed with CCI300 primers and this resulted in such a cartridge:
COL: 1.200"
projectile: Nosler 185gr JHP CC
powder: VV N310 4,1gr
case: GECO (0.894")
primer: CCI 300

After first tests with my venerable STI Trojan 5" the results didn't meet the expectations though. The best 10-shot group was ca. 2" wide at 25m and some series were even wider.
I measured my ammo with Labradar and here came another surprise. According to the source the Marine Load should measure around 770fps up to 830fps. Mine was barely 700fps! (min 679; max 732; es 52; std 14). I tried to boost it a little bit going up to 4,5gr but all I got were bullets racing at 770fps and forming a group wider than 3".

Any idea why I got such different results and what to do next?

(a) If you used a Ransom Rest, know that it is very sensitive to operator technique.

(b) Load either some 200 grain LSWC's over 4.0 grains of Bullseye or get a box of Federal GM45B and repeat the test. If your pistol won't shoot those loads, it's likely the pistol.

[Christopher Miceli]

he is shooting @ 25m. I've never shot a STI trojan but any bullseye worthy 1911 should keyhole @ 25yards with a box of rocks... well at least 1/2 in group.

[GOVTMODEL]

he is shooting @ 25m. I've never shot a STI trojan but any bullseye worthy 1911 should keyhole @ 25yards with a box of rocks... well at least 1/2 in group.

Agreed!

[cnnhead]

I've been using this gun for IPSC/IDPA only until now and its accuracy wasn't my first concern. I've been using cheap factory ammo mostly. It has changed now and I'm trying to squeeze something out of it. I don't have a proof that a gun is capable of shooting tight groups but on the other hand I have also no proof against.

I don't have a Ransom rest, I simply use a sandbag (not very precise approach, but I can achieve sub inch groups with my 9mm @25m this way, so why not with .45?).

All fired cases are heavily charred on one side (12 o'clock). Does it indicate anything?

[Rover]

Yes, it tells you that the round is laying on the bottom of the chamber, allowing gas to blow by on the top. Very common. Bigger chamber, more blowby.

[GOVTMODEL]

All fired cases are heavily charred on one side (12 o'clock). Does it indicate anything?

It indicates that your load is very low pressure and the case isn't expanding enough to make a tight seal in the chamber. Gas is leaking.

[Misny]

There is definitely something wrong with your load. In my experience the Nosler 185 gr. JHP load with shoot very well in any good pistol. Many years ago, I got some good advice from Dave Salyer, who with Al Dorman, developed the "Marine Load". Since I didn't have any VV powder available, Dave said in their tests that Bullseye worked very well and he suggested the following: Starline virgin brass, WW primer, 4.5 gr. of Alliant Bullseye, 1.25" COAL and a taper crimp of .470". I've machine rest tested several different pistols at 50 yards and even well used workhorses gave 2" center-to-center 10 shot groups. With that load, I get 828 fps. out of an accurized 1911 with 5" barrel. Dave also told me that COAL, in their tests, didn't really make an appreciable difference in accuracy. Years ago, when I passed on this load to shooting buddies, one of them had purchased a new Rock River accurized pistol. He immediately took it to the range for Ransom Rest testing and couldn't wait to show me his 10 shot group out of his new pistol. He used 4.6 grains of Alliant Bullseye (everything else the same as above) and had a sub 1" one hole ten shot group at 50 yards! Recheck your powder, scale accuracy and crimp (measured at the case mouth). I have no experience with GECO brass, but if it is decent brass, you should still get good groups (under 3" at 50 yards) with an accurate pistol.

[cnnhead]

Thanks a lot for the invaluable remarks. I'll keep working on my loads.

Here, on the other side of the pond, it's much easier to get VV powder than Bullseye. I'll stick to VV for a while.
.45ACP is not a very popular caliber down here, so the choice of brass is also quite limited. GECO is known for pretty decent budget ammo, but I don't have too much experience with their cases (I use Lapua brass for all my other loads). I'll try to get some WW or Starline brass instead.
The case mouth measures .471" right after bullet seating and .470" after crimp.

I'm pretty confident of my scale accuracy - I produce 32S&W rounds based on the same powder N310 and I'm able to get 1/2"@25m. BTW, N310 measures really well.

It may be a gun of course, especially that it was never properly tested for its accuracy (rather for reliability). Even though it's not strictly a Bullseye gun, I'd expect better from STI.

I'm still very surprised with very low velocity of 4.1gr rounds - barely 700fps! I'm not sure what it could mean, so I keep looking for a solution.

[Misny]

I've been using this gun for IPSC/IDPA only until now and its accuracy wasn't my first concern. I've been using cheap factory ammo mostly. It has changed now and I'm trying to squeeze something out of it. I don't have a proof that a gun is capable of shooting tight groups but on the other hand I have also no proof against.

I don't have a Ransom rest, I simply use a sandbag (not very precise approach, but I can achieve sub inch groups with my 9mm @25m this way, so why not with .45?).

All fired cases are heavily charred on one side (12 o'clock). Does it indicate anything?

This is quite common with light loads, not allowing the cartridge case to expand completely into the walls of the chamber. With a "Marine Load" you should be getting enough pressure for full expansion. Here is an article that might give you some ideas. One I came away with was maybe your chamber isn't very tight. The Marine Corps got velocities of 770 - 830 fps with 4.1 grains of VV 310. They said the tighter match chambers (Bar Sto barrels) got velocities in the upper part of that range. https://www.ssusa.org/articles/2016/4/0 ... h-45-load/

[CR10X]

Before you get wrapped up in too many variables, please remember that it is also reported that the original 4.1 gr VV310 was from over 10 years ago (closer to 15 maybe?). It is reported that the current formulation of VV 310 will require a few tenths more grains of powder to achieve the original velocities. That was my experience.

Do not worry, simply increase by a tenth or so and keep testing. Nosler 185's and Zero 185's will generally get better grouping the faster they go. Bullseye shooters simply stop increasing when groups are optimum with the least recoil for their shooting.

Next, be sure the crimp is is consistent and appropriate, this varies with brass manufacture to some extent.

[BenEnglishTX]

here is a load for one of David Sams match 1911s.

This will probably be a dumb question but it's bugging me so I'll go ahead and show off my ignorance again.

The load data written on the target in that picture clearly says "Fed. LR primer".

Large rifle primer?

I'm confused. Is that a mistake in the notes or do some of y'all use LR primers? If so, why? Or does LR stand for something else?

[Rover]

Speaking of primers, why not try magnum pistol primers and try to get your pressures up a little. It may improve accuracy as well. Winchesters are nice and hot.

[Gort]

I would caution against using any large rifle primer in a small capacity pistol cartridge. Pressures can become erratic, accuracy may suffer vertical stringing from the primer driving the bullet into the rifling prior to the powder starting its burn. Lastly, rifle primer cups are thicker and have a higher brinell hardness to survive in a 60,000 psi environment and many pistols ignition force is inadequate to fire them reliably. The manufacturers make rifle and pistol primers for a reason, use them appropriately.
Gort

[C. Perkins]

Winchester large pistol primers are designed for standard and magnum loads.
All that I use in the .45 using 4.6-4.8 grains of Bullseye under a Nosler 185 grain Custom Competition for the long line and Hornady 185 grain button nose for the short line.

Clarence

[cnnhead]

Interesting lead. Winchester and Federal LP primers seem to be suited for both regular and magnum loads at the same time. CCI on the other hand offer two separate products.
I'll try to get some WW primers and check if there's any difference. On the other hand I won't dare to use primers which are specifically designed for magnum loads only (or at least advertised as such).

[Rover]

"On the other hand I won't dare to use primers which are specifically designed for magnum loads only (or at least advertised as such)."

Why the hell not? The point is to get MORE pressure and more complete powder burning.