25-2 Revolver Accuracy with Autorim vs. ACP Ammo

[wallyccspd]

Good Evening:

I picked up a 6" 25-2 revolver in .45 ACP.

I was curious to see if anyone had an opinion on accuracy while using .45 Auto rim brass versus using .45 ACP brass loaded into full moon clips? Meaning, do you find that ammo loaded in auto rim brass shoots better in the 25-2, or do you find the ACP brass to shoot the same? Or do you see no difference at all?

In my Wadcutter and hardball gun (both Rock Rivers) I run 3.8 grains bullseye with a 180 grain flat base LSWC (by Brazos Bullets); .468 crimp and seated .925 from the bullet shoulder to the case head. I run this at 50 yards. At 25 yards/indoor matches, I run the 160 grain Brazos with 4.0 Bullseye. Both loads feed and shoot well for me.

I have a small supply of Remington auto rim brass, but I have a larger supply of ACP brass.

Your thoughts?

Regards,

Wally

 

[SnidelyWhiplash]

As far as I know…Remington was the only company to produce the Auto-Rim cartridge while everyone and their brother has loaded numerous loadings in .45 ACP. So it’s difficult to make valid comparisons. If I remember correctly…the Remington Auto-Rim round was a 230 grain lead bullet while .45 ACP rounds are usually jacketed.

The differences are probably minor but it’s far easier to find an excellent shooting ACP round than the one selection of Auto-Rim without hand loading.

A correction…I understand Cor Bon lists the Auto Rim but don’t know anything about it beyond that.

 

[Rpg]

On the few occasions I’ve run into auto rim ammo, I’ve never seen a difference, but I’ve never done a real comparison.

You’d have to hand load to produce comparable loads then test them side by side.

 

[series guy]

The bullet contributes way more to accuracy than the brass. I think you’ll find jacketed or plated bullets to be the most accurate.

 

[rockquarry]

The bullet contributes way more to accuracy than the brass. I think you’ll find jacketed or plated bullets to be the most accurate.

If you use a well-fitted cast bullet of the right alloy for the load, it will shoot at least as well as a jacketed or plated bullet. An H&G #68 cast bullet design is a good place to start for anything chambered in .45 ACP or Auto Rim.

There may be a difference in accuracy between ACP brass and Auto Rim brass, but like others here, I have done no side-by-side benchrested accuracy comparison.

 

[pasound]

I had a 25-2 45 Colt/45 ACP. I handloaded Bullseye and both jacketed and cast lead for all three, and all I noted was it shot the Colt a little better than either Auto Rim or ACP.

 

[StrawHat]

With comparable handloaded ammunition, I have found no difference. I use a variety of headstamp in ACP and Star-Line Auto Rim. Even when I run one specific headstamp ACP, not enough difference from my hands.

Kevin

 

[sjmjax]

I like using Auto-Rim brass. But, I’ve not seen a difference in accuracy between the two using otherwise the same load.

Biggest impact on accuracy in my experience has been the bullet. My guns have the oversized throats. FMJ is excellent for accuracy. Plated okay. Plain lead awful.

 

[biku324]

I have a 625-8; no difference that I can see. I use AR brass mainly for 250 grain bullets, cast and jacketed.

 

[rockquarry]

I like using Auto-Rim brass. But, I’ve not seen a difference in accuracy between the two using otherwise the same load.

Biggest impact on accuracy in my experience has been the bullet. My guns have the oversized throats. FMJ is excellent for accuracy. Plated okay. Plain lead awful.

Are you using commercial cast bullets or your own cast bullets? if cast don't shoot well, they are likely undersized and possibly of too hard an alloy.

 

[6string]

Case fit beats out case type!!!

Brass choice and prep is critical with these 45 revolvers! If you use Auto Rim, check case length carefully. You want the casemouth all the way to the chamber shoulder, but not too long that if forces the case head to bind on the recoil shield. Many auto rim cases are too short. (Trick. Make your own cases out of .45 Colt brass, but trimmed so they headspace off the case mouth! They will look funny because, when seated, the rim will be about 0.030” proud of the cylinder face. But, that’s OK! The rim, in this case, is only for extraction!
For ACP brass, the golden rule is that moon clips are for extraction only! Don’t let them be part of the headspacing equation, otherwise accuracy will suffer and/or you’ll have binding issues. Again, case length is critical! In a properly cut chamber, you should be able to get reliable ignition without moon clips. If not, check your case lengths and the depth of the chamber cuts combined with the gap between the rear of the cylinder and recoil shield.
With ACP cases you want to have the case mouth headspace on the chamber shoulder and have the rear of the case within a couple thousandths of an inch to the recoil shield. This gives you consistent ignition and best accuracy.
Unfortunately, many 25-2s have chambers cut a little too deep. There’s a trick to deal with this, but it’s too much of a hassle for most folks. You can use longer cases like 45 Win Mag or 451 Detonics Mag, trimmed to the specs I have recommended.

If you use moon clips, check them very carefully. Make sure they are dead flat. Make sure they are not too thick so as to mess up your carefully controlled headspace efforts. If necessary, lap your moon clips on a flat reference surface. (You’ll be amazed how inconsistently metal is removed! These clips really are not made with precision in mind.)
In any case, regardless of what brass you use (or fabricate) you want to consistently fill the distance between the chamber shoulders and the recoil shield as close as possible without binding.

Your other 25-2 issue will be chamber mouths. If they are large (.456-.458”), like many are, accuracy will be a struggle.
The “old pre-model number” 1950 and 1955 Target revolvers tend to have tighter chamber specs. They were built to actually be winning target revolvers, not just range toys.

Remember, .45 ACP revolvers don’t have the tapered leade in the chambers as found in rimmed case cartridge revolvers. So, they are very unforgiving of lackadaisical reloading practices.

 

[SGT ROCK 11B]

Your thoughts?

Regards,

Wally

Wally, just for plinking and having fun with light loads I like using the Auto Rim brass. That way I do not have to worry about mooning up and de-mooning the brass.

I prefer 200 grain LSWC. Sarge

 

[STORMINORMAN]

In addition to years worth of 45acp brass I purchased 1K once-fired Speer 45acp +P nickel plated cases with SPPs and have never looked back..?

They shoot well (with both hot or "cool" reloads?) out of my 1911s, Ruger American, Springfield XDM Elite Compact & the Model of 1955 (with or without moon clips)...

Never really noticed any material performance differences with 45acp brass, SPs or LPs: have a couple hundred Starline Auto-Rim cases for "special" projectiles and loads. Starline says they are pretty stout.

Cheers!

P.S. Small Primers just seem SO much easier to find and the Rifle ones work just great in 45acp (and in 10mm, I might add) in my experience.