First time reloading .45 ACP 185g LSWC by Rocky Man Bullets

[nvdwarrior]

I am having a hard time finding a measured OAL for these new Rocky Mountain (RMR) .45 Cal (.482) 185grain LSWC bullets I purchased. It appears that folks set these bullets by visual depth of the bullet collar being just above the cartridge rim. It has been described as a fingernail or matchbook sized lip. My question is, these bullets appear to be the longer type of a LSWC. It looks like an OAL measurement would be more appropriate than the visual method. I am not too worried about overpressure using a very light load of Bullseye (4.6g). Its for plinking at no more than 50 feet. So has anyone developed an average OAL for this bullet or does this learned group agree that visual seating coupled with functioning will be OK. thanks in advance for any advice. I have been reloading only round nose plated .45 230g and 200g. up to this point.

 

[Unclenick]

Not for that particular one. The look like the noses are copying the 200 grain H&G #68 profile, which is very popular with target shooters.

I shot bullseye matches for a number of years and experimented a lot and found that adapting the load to the chamber of a self-loader could reduce groups by 40% and reduce leading. Revolver loading is different, but also less common, so I will assume you are using a self-loader or a single-shot here. I set the round up for the chamber by seating the bullet out so the cartridge headspaces on the throat of the barrel instead of on the case rim, as it was designed for. Too many .45 Auto chambers are too deep, and the cartridge actually winds up stopping on the extractor hook instead of the mouth finding the end of the chamber anyway. With jacketed bullets that doesn't seem to cause a problem, but with lead it angles them to distort slightly and shave lead, so it spoils accuracy an makes the gun more trouble to clean.

The way to headspace on the bullet is to use your barrel as a gauge. See the illustration third from left.

The only problem I've run into with that has been with one odd barrel that had a super long throat. That one required that I seat the bullet out so far that the cartridges didn't feed reliably. If that happens to you, our you have trouble with magazine fit, then nudge the bullets deeper 0.010" at a time until the problem clears up.

You will note that in rifle, seating a bullet to contact the lands raises pressure. I have seen no sign of that in the 45 with lead bullets seated to touch the lands, possibly because, in this small powder space cartridge, primers frequently unseat or start the bullet moving forward anyway.

 

[nvdwarrior]

Thanks Uncle Nick. Yup I did forget to mention the firearm is a Remington R1 in .45 caliber. Good info you provide. I am keeping powder charge low to keep velocity down so as to NOT lead the barrel. I have had great luck shooing Missouri Bullet Co LRNs and the barrel stays clean. What started me down this road was a recent purchase of some 1970 vintage .45 LSWC that was used in competitive Bullseye shooting. The bullet is much smaller than these Rocky Mountains but it is seated as I described...a matchbook thickness above the case rim. I am more concerned about leading the barrel versus too much seating and high pressure. Thanks again and the pictures are great. I will try using the barrel versus my case gauge which of course only measures to the rim....

 

[Nick_C_S]

They look like the noses are copying the 200 grain H&G #68 profile

I think so too.

I load a lot of 200gn "H&G #68" LSWC bullets. I have three 1911's and have plunked tested them all. I set my OAL to 1.240 +.000 /-.005. I would suspect that most arrive at a similar measurement. As described, it leaves about 1/32" (ish) of bullet shoulder above the case.

Just mentioning so you have some reference. Do your plunk test. Your Mileage May Vary.

 

[noylj]

All the COL in a manual tells you is what COL they used for their gun with a particular bullet for testing. It is NOT a recommendation. Never forget that chambers vary and what works in one gun may not work well in another.
For any SWC: get a seating stem that ONLY contacts the bullet shoulder. Once that is set for one SWC, it is set for ALL SWCs, no matter the nose length--at least for that gun. Most Bullseye shooters reference the case head to shoulder distance for this reason (0.928-0.930" is a general base to shoulder length).

Per Ramshot:
"SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as
1) magazine length (space),
2) freebore-lead dimensions of the barrel,
3) ogive or profile of the projectile and
4) position of cannelure or crimp groove.
• Always begin loading at the minimum ‘Start Load.’"

Your COL (OAL) is determined by your barrel (chamber and throat dimensions) and your gun (feed ramp) and your magazine (COL that fits magazine and when the magazine lips release the round for feeding) and the PARTICULAR bullet you are using. What worked in a pressure barrel or the lab's gun or in my gun has very little to do with what will work best in your gun.
Take the barrel out of the gun. Create two inert dummy rounds (no powder or primer) at max COL and remove enough case mouth flare for rounds to chamber (you can achieve this by using a sized case—expand-and-flare it, and remove the flare just until the case "plunks" in the barrel).
Drop the inert rounds in and decrease the COL until they chamber completely. This will be your "max" effective COL. I prefer to have the case head flush with the barrel hood (see unclenick's pretty picture). After this, place the inert rounds in the magazine and be sure they fit the magazine and feed and chamber.
You can also do this for any chambering problems you have. Remove the barrel and drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth.
Remove and inspect the round:
1) scratches on bullet--COL is too long
2) scratches on edge of the case mouth--insufficient crimp
3) scratches just below the case mouth--too much crimp, you're crushing the case
4) scratches on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit
5) scratches on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.