COL differentials for 45 Colt

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tomhenry

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I've just started reloading for 45 Colt for a Winchester branded (Miroku) 1873.

I loaded some rounds using 250 grain lead bullets and now am loading using 200 grain plated. The powder is VihtuVuori N330. VihtuVuori's website gives the minimum for the cartridge/powder combination as 8.0 grains for 876 fps. The maximum is 8.6 grains for 978 fps.

SAAMI specs for the lead bullets for max length is 1.600 inches. Minimum SAAMI length is 1.515 inches. Seating the 250 grain lead bullets to the bullet cannelure gives COL of 1.594 inches. VihtuVuori's website also gives the COL as 1.594 inches.

I've loaded a few 200 grain plated bullets with the same COL of 1.594 inches. There is considerable bullet protruding from the end of the case which makes me wonder about the space inside the case between powder and bullet base.

Suggestions?

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Try several OALs and use what works in your gun.

I don't know about the 1873 Winchester reproductions, but had a Miroku '92 in .45 Colt about twenty years ago. I had to seat the Lyman #454424 255 gr. cast SWC much deeper than I did for my revolvers if the cartridge was to work through the action of the '92.

In your case, as long as the bullet is held in place securely and functions through the action, I wouldn't be concerned about OAL, though a powder charge adjustment might be necessary to get the velocity you want.
 
I’d measure the length of the 250 gr bullet that sits inside the case and then duplicate that with the 200 gr.Make up a dummy round and see if it feeds properly first
 
From the beginning of my revolver reloading (1969) I have always seated bullets to the crimp groove and disregarded book OAL. I figgered the bullet designer knew where to locate the crimp groove and many, many times when seated to crimp groove my OAL didn't match the book OAL, besides the manual OAL is just what the lab techs got when they used the bullets they had. The (very) few plated bullets I loaded for my revolvers I used a guesstamate using the OAL of an equivalent weight/shape "proper" revolver bullet. I have never had any problems and recorded the handload specs so I wouldn't have to "re-figger" the load...
 
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Usually the cannelure on a bullet is correct for 97% of it's loads.
Mostly if a crimp is needed for full power loads.

Any OAL on the bullets cylinder will work if it is safe and works with
the weapon and powder used.

Accuracy & safety can come from "Odd ball" loads.
 
Cartridge OAL is critical in the Winchester 73 mechanism to make sure it feeds correctly from the tube to the carrier, and then so the carrier can lift the round w/o hanging up.

At least the orig design is that way, I don't know if the repros have changed anything.

The loaded cartridge should just fill the carrier by length so as to hold the next round in the tube from entering the carrier.
A little short is OK as the front edge of the carrier has a scalloped edge to push the next round in the magazine back into the mag as it moves upward should it be able to wander just a bit into the carrier.

Also a round that is too long will have the tip of the bullet hanging out of the carrier and into the tube and not allow the action to be operated.

Crimp the rounds to avoid the magazine tube feed from pressing the bullets back into the cases.
Don't try and make a magnum out of it and the '73 will hold up just fine. The repros are strong(er) with their modern steels and heat treat.
The entire original design is what is not so strong.
 
Seat them to the crimp groove , crimp and see if it functions .
When working with a lever action it's best to crimp the bullet well ...
You have the magazine spring pressing on them and the recoil from firing so you need a good crimp and the crimp groove is the best place to put it .
If the round won't feed I would look for another bullet . Lever guns in 45 Colt can be picky about what they feed . They were never originally chambered in that round ... Use a bullet it likes . Trying to get it to feed a bullet it isn't designed for leads to a lot of frustration . Bullets with no crimp groove or cannelure may not be the best for the 45 Colt in a lever action rifle ... a proper bullet might make life easier .
Gary
 
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tomhenry said:
I've loaded a few 200 grain plated bullets with the same COL of 1.594 inches. There is considerable bullet protruding from the end of the case which makes me wonder about the space inside the case between powder and bullet base.
Click to expand...

And why are you concerned about the empty space differences?

Seated to the same COAL", as you did & the manual suggests, will leave more space with the 200gr bullet because it's shorter.

The increased charge weight, over the heavier bullet, takes that into consideration.

If you find you need more of the 200gr bullet inside the case just reduce the powder charge a bit.

.
 
The original Winchester rifles were built for the bullets used in the day which were round nose flat points. The modern reproductions operate best with that same bullet profile and do poorly with semi wadcutter shapes. OAL is critical to smooth working. Also the 73 and 92 were never originally built in 45 Colt so careful bullet selection is important for function. I cast my own bullets for 45 Colt and use a Lee 255 grain RNFP mould. I cannot say if it will work in the 73. All my rifles are 92's.
 
BLUEDOT37 said:
And why are you concerned about the empty space differences?

.
Click to expand...

Secondary Explosion Effect A Reality - Sporting Shooter

Just asking people who know about such things. I've been reloading for 40 years, but I've been reloading the same cartridges with the same loads with the same powder.................

And the 1873 is an inherently weak action.

But based upon answers I've received, I think it'll be ok. Industry specs for the cartridge for the Colt SAA and the Win 1873 is 14,000 psi. Space in the case between powder and bullet doesn't appear to be a consideration here.

The only concern now is the plated bullets being pushed into the case from recoil in the tube mag. And a reloader has to be careful about the crimp with plated bullets cause of the danger of cutting the copper plate and leaving a sheath of copper in the barrel.

Etc.
 
"And a reloader has to be careful about the crimp with plated bullets cause of the danger of cutting the copper plate and leaving a sheath of copper in the barrel." (quote)

If you need to Crimp a plated bullet............

you spent your money on the wrong material.

I can see a taper crimp on plated bullets but not a crimp that damages the surface and lead in the bullet.
 
Nevada Ed said:
"And a reloader has to be careful about the crimp with plated bullets cause of the danger of cutting the copper plate and leaving a sheath of copper in the barrel." (quote)

If you need to Crimp a plated bullet............

you spent your money on the wrong material.

I can see a taper crimp on plated bullets but not a crimp that damages the surface and lead in the bullet.
Click to expand...

Dunno what you're talking about.

I've been using plated bullets for years for 44 mag cases, 357 mag cases, etc, and a roll crimp is fine. Like I said, one just has to be careful.

Taper crimp is fine as well and is what I use for 9mm and 45 acp.

Like as in all things reloading, one has to be careful.
 
tomhenry said:
Secondary Explosion Effect A Reality - Sporting Shooter

Space in the case between powder and bullet doesn't appear to be a consideration here.

The only concern now is the plated bullets being pushed into the case from recoil in the tube mag.
Click to expand...

If secondary explosion was your original concern on your load then correct, it's not a consideration with this one.

Adequate bullet-case tension is a common problem with plated bullets.

Use the tightest (smallest diameter) sizing die you have. Just bell-mouth/flair your cases minimally. Don't use a M-type expander plug. Let the bullet expand the case body when seating it.

If you still get bullet set-back in your rifle you'll have to change to a bullet with a cannelure.

.
 
tomhenry said:
Dunno what you're talking about.

I've been using plated bullets for years for 44 mag cases, 357 mag cases, etc, and a roll crimp is fine. Like I said, one just has to be careful.

Taper crimp is fine as well and is what I use for 9mm and 45 acp.

Like as in all things reloading, one has to be careful.
Click to expand...

Is the bullet ment for pistols............?
or is it the ones designed for revolvers & rifles?
The bullet maker and type was not mentioned.
 
First find what range OAL works with your Model 1873. The previously stated 14,000psi limit does not generate tremendous recoil. A few whacks with bullet puller can be used to easily determine how secure the bullet is.

Plated bullets in non-magnum revolver caliber cases that are properly expanded should be able to be taper crimped. If the bullet crimped at a cannelure or crimp groove won't feed, the roll crimp vs. taper crimp question is moot. There is usually a lot of bullet in the cases.

Magnum caliber loads, especially those approaching MAXIMUM are better served with bullets (including solids, lead and jacketed) that have cannelures or crimp grooves and roll crimps. In some instances the OAL may also be critical as far a pressure is concerned.

Cheers!
 
I stumbled onto Redding profile crimp dies looking for a way to crimp very thin Winchester 44/40 cases for a 92 Winchester. IMO this is the only way to go for the Winchester lever guns. Accuracy improved and the crimp is the most even I have ever gotten. I now use this type die in my 45/70 1886 and will get them in other calibers as they become available.
I understand you are using plated and in these times you use what you have. However if you can get them explore the cast RNFP options. They work really well and in the correct weight range have proper crimp grooves.
You might also get a copy of Mike Venturino's book"Shooting Lever Guns of the Old West". Good info in there about shooting the 1873.
 
My understanding of the secondary explosion phenomenon is that it occurs when using small charges of slow burning powder, not fast burning powders.
This secondary explosion phenomenon is so rare it can’t be made to occur under controlled laboratory conditions, therefore it can’t be studied with repeatable accuracy to make it occur on demand.

Your VV N330 powder is a fast burning powder (mid to slow for pistol use) compared to slow burning rifle powders.

My 2021 paper copy of the VihtaVuori Reloading Guide doesn’t show N330 powder listed in any recipe for 200 gr or 250 gr bullets (maybe it’s on their web site). The burn rate chart in the manual plots N330 parallel to Hodgdon’s HS-6 and Alliant’s Power Pistol powders.

I have a Miroku built M73 24” bbl in 45 Colt and use Hodgdon’s CFE-Pistol (one line on the chart slower) with great success at max load level and 250gr cast and CamPro plated bullets.
Next time you have the brass elevator out of the rifle place a cartridge into the elevator and observe and measure how much space above the bullet nose to the edge of the elevator.
Make a dummy ctg. That you can press the bullet in shortening the COL more and more until you learn the COL limits for your rifle.

Large extra space under the 200gr bullet means you can add powder to get the MV (and it’s associate pressure) back up to what it was when fired with the short COL.

45 Colt ctg works best with 250gr and heavier bullets.
The RCBS 270gr SWC might work just depends on the semi wad cutter ledge snagging on the chamber mouth.
I wouldn’t go as high as 300 gr.

I shoot my M73 often with 35 gr of Old Eynsford 2fg real black powder, that puts the fire back into firearms.
 
In my Winchester (Miruko) 1873 .45 Colt I usually use a COL of 1.6" for all loads and feeds just fine with JHP, cast, plated and FTX.
 
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