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Discussion Starter · #1 · (Edited)
45Lc bullet dia. vs accuracy--Update

Maybe this is the right place to post this, had it in the wrong spot I think. I'm a newb. Sorry
Long story short. Shot a ruger 3 screw 45lc blk and colt 45lc many years, never a rifle. Picked up a marlin cowboy 20" 45lc just to have fun with, JM stamped barrel.
Tried my ruger loads in the rifle.
8.0 unique -255 rnfp .452 dia in the marlin--6 to 8" groups at 50 yds, buckhorn sights. hmmm

Little more research, picked up some imr4227

Mounted a scope good and tight so no errors with my old eyes
5 rounds each of 18.0gr--19.0gr--20.0gr--255 gr rnfp with (what I thought were the .452 lead) but they were the .454 lead for the colt.
Still got 6"-8" groups at 50yds
Loaded 5 ea 19.0 & 20.0gr imr 4227 with speer 260 gr JHP's, .451,---got around 4" groups at 50yds.

Any help would be appreciated to my problem.
Thanks​
 

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Morning, and welcome to the forum. Really need more information to bet a better handle on what may be going on with your rifle. Such as what exactly are the type of bullets your shooting. You said 255 gr. mfp…..what is a mfp? Flat point I’m sure but the "m". If these are cowboy bullets such as those made by Hornady or Magtech then they are pretty soft lead, powder coated and made for revolvers but may not work well for a trip of 20 inches down a rifle barrel. IMR4227 should work well in your rifle but it is temperature sensitive and a mag primer is a must for consistent ignition.

The .454 size cast should be a good match for your gun but the 4 inch groups at 50 yards using jacketed bullets points to a possible gun problem in my opinion. Have you inspected the crown on the barrel? Even the smallest imperfection to the crown will give you problems.

If you have never shot a lever action at the bench your technique is much more important than shooting other types of guns. You probable already know that but just as a example of how I shoot at the bench, is I load three into the mag tube and one in the chamber. The forward sand bag is placed under the receiver, never allowing the barrel or forearm to rest on the bag. I believe the mag tube hanging under the barrel changes the harmonics of the barrel with every shot fired and ejected. Resting the barrel on the sand bag scatters the shots all over the place.

What it boils down to is your gun pretty much has a mind of it’s own. It may not like certain types of bullets, powder, or even they way you shoot it.

The group below is one I shot at 50 yards using 22 grains of H4227 behind a 270 grain SWC which measured 0.60 inches. In all honesty I haven’t duplicated that group again, as usually it’s 1-1.5 inch 50 yards. But if I can get 3 inches at 100 yards with the 45 Colt I’m a happy camper.

Games
 

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Discussion Starter · #3 ·
Gohon,
Thanks for the info. The bullet is a Dardas 255gr r n fp. The r and n together looks like an m. What type primer do you use, rifle or pistol mag?

Looked at the crown with a 16x loupe and looks good and sharp. The rifle was new, unfired when I bought it.

Just pushed a .452 bullet through the barrel and with my digital caliper, get .4445 and .452. Will use a good starrett depth mic at work to be exact.

Will load up a few more rounds with the the .454 bullets and try imr 4227, unique, and may have some 231, and try your style of bench rest. I had the front rest under the forearm.

This has got me bummed out for sure. I've been shooting for near 50 years and can usually get them a running.

Thanks , and dang good shootin.
 

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Two things I'd do. Replace the sights with a standard marlin folding rear and a skinner front sight. Second is to shoot a larger diameter. Mine dotes on the Lee 255 as cast at .453. These things will likely shrink your groups dramatically.

Papalote
 

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I use CCI-350 which is a large pistol mag primer with H4227 and IMR-4227. The large rifle primer stands to tall so they are not interchangeable with a pistol caliber. You can swap the small pistol and rifle primers but not the large ones.

I cast my own so have no experience with Dardas but if they are sized at .454 they should shoot fine, unless your gun simply doesn't like that bullet and that sometimes does happen. I have a 357 mag rifle that simply will not group SWC no matter what I do. Others say their gun shoots them fine but not mine. That picture of the group I posted is of a RCBS 45-270-SSA casts and both my revolver and rifle loves them things. Even though they are plain base I still get 1446 fps and that's nothing to sneeze at for a 45 caliber 270 grain bullet. Are you getting leading in the barrel? If you are getting leading in the barrel then a gas check design would be in order or push the Dardas a little harder to get them to bump up and seal the bore.
 

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Discussion Starter · #6 ·
Went to the range this morning, 50 yds, with scope mounted. Receiver laying on front rest, bag, not forearm, with a good solid bag on the rear.
Here's the results, 8.5x11 paper with 1" diamonds. IMR4227, Unique, and ww231. Dardas 250 gr RNFP .454, 260 gr JHP .451 Speer
Shot a few more loads than shown, most were 6"-8" groups, Guess I need to try a different bullet, and go from there. This is the chits.
Any more ideas out there?
Thanks

IMR 4227--250gr

WW231--250gr

Unique--250gr

IMR4227---260gr JHP Speer
 

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From what I see, your rifle seems to show signs of liking the 4227/.451 Speer 260 JHP combo. If it was me, I'd spend some time fine tuning it before I gave up on it. My LSI PUMA, (Rossi mfg'd) 1892 likes the .451 Speer JHP, too. BTW, I lived for a time in Tulsa with my cousin in the early '90s. Nice town. Good luck with this, jd45
 

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From what I see, your rifle seems to show signs of liking the 4227/.451 Speer 260 JHP combo. If it was me, I'd spend some time fine tuning it before I gave up on it.
That's what I see also.....except for the one flier that last group appears to be about a 4 shot one inch group at 50 yards. Nothing wrong with that. Even the third group shows some tightening up of the cast bullet with Unique.

As to the first group with the vertical stringing, here is something to think about......." Realizing there's no such thing as "always", but, generally, vertical strings result from forearm bedding problems. Horizontal strings generally result from a slight canting of the rifle from the vertical. If you sight in without canting, you get a known point of impact. If you shoot a group with uniform canting, you'll get a tight group but off to the side. Using targets with one-inch grid lines allows alignment of the scope's crosshairs uniformly for all shots". You might try switching to a target that has a true vertical and horizontal line connected to the diamond Or simply use a ruler and thick felt pen to draw the lines to ensure proper alignment of the crosshairs. I think your gun is alright.....it's just a matter of finding the combination of bullet and powder it likes and working on the sight picture.
 

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One thing to keep in mind is switching back and forth between Lead and Jacketed bullets can weld the residue to the inside of your barrel.
Clean well between the 2.
Also speed helps in the Marlin rifles with the right size projectile.
 

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Discussion Starter · #10 ·
I may give up on the lead loads, at least the warmer ones. I like to never got the bloody lead out of the barrel. Maybe the 8.5gr unique didn't lead, but I bet the 4227 did.
Wanting to shoot lead, cheaper. Guess I'll be searching the web for some jacketed for sure.
Any good leads on where and which .45lc jacketed bullets work good?
2 B continued. lol
 

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Both Gohon & I have recommended you keep the 260 Speer as one of your jacketed bullets. If you have a slow twist rifling in your barrel, I wouldn't go heavier than that...they won't stabilize. You might also try the Hornady 250GR XTP. Keep checking online sources for in stock availibility. jd45
 

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Discussion Starter · #12 ·
I appreciate all the ideas and recommendations. Gonna pick up a box of 250 xtp's and give them a shot and more testing with the 260 speers.

Here's what the website says on the barrel, twist, but I don't think it's right. Looks more shallow cut, maybe microgroove, I don't know.
Barrel------Tapered octagon with deep-cut Ballard-type rifling (6 grooves).
Twist Rate----- 45 Colt - 1:38" r.h.
 

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In my 45 colt Winchester I use 9 gr of Unique with a Hornady 250 gr xtp and it will stop a deer right there. When playing around I use the Berrys Plated bullets or the Rainers plated all 250 gr. If I am shooting hard cast which is a lot cheaper I drop my charge down to 6 or 7 grains of Unique. I get better groups by firing 3 shot groups and letting the barrel cool some between strings. The 6 grainers are great for wife and Grandkids. I always try to clean well before switching between cast and plated. But really you would have a hard time leading the barrel with hard cast and 6 or 8 grains of Unique. Don't give up your last couple of groups look very promising.
 

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I think the twist rate in your barrel is probably right, tho I am at a loss as to why they put such a damned slow twist in it. My Puma also has a 1-in-38 twist barrel, the one that likes the 260 Speers. Wish I could get a hold of more. Now you've got 3 people opining the 260 Speer is a good bullet for your gun, but those 250 XTPs may work just as well. jd45
 

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I may give up on the lead loads, at least the warmer ones. I like to never got the bloody lead out of the barrel. Maybe the 8.5gr unique didn't lead, but I bet the 4227 did.
I certainly wouldn't give up on casts and if you're getting a leaded barrel with a .454 cast then you simply aren't pushing those Dardas casts fast enough for them to obsturate and seal the bore. 8.5 grains of Unique is by no means a warm load for the Marlin rifle. For a Colt SSA it might be but since your casts are in the 16 plus BHN range you need at least 20,000 psi pressure to get them to bump up and seal the bore.

If it were me I would scrub the bore clean of all copper and lead, load up some loads with 11 grains of Unique and have a go at it. That's a Ruger/TC load but your rifle will take it and much more.....your shoulder might not but the gun will. If you want plinking loads with a plain base bullet then you will need to go with a softer bullet, around 10-11 BHN of at least .454 and load up to the Colt SSA standards. I haven't looked at them but if the Dardas casts are of a bevel base design then that also may be part of your problem.

BTW....pushing a .452 bullet through the bore isn't going to tell you much as to the specs of your bore. You really need pure soft lead sized .456-457 to get a true reading. If you can find pure lead #8 egg sinkers (Southbend still makes them) then you can squeeze them in a vice to fatten then up and they work great. Your gun will shoot cast successfully and without leading the barrel.....you just gotta get the right ingredients put together.

Bottom line for me is if non gas check then flat base only, no bevel base bullets with a minimum of .454 dia. 15-16 BHN is the hardest casts you will ever need for the 45 Colt with 11-12 even better but still at a minimum of 454 dia. Above 1500 fps....go with a gas check bullet, again at .454 dia minimum. Obviously as you can see, I think bullet to bore fit is the most important thing to prevent bore leading. My experience is leading of the barrel is usually improper fit of bullet to bore and to hard of a cast as second.

Where was most of the lead concentrated in your bore?

Tell ya what......PM me your address and Monday I'll send you some of my casts and load data.
 

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Discussion Starter · #16 ·
Well, been to the range to test some more loads. More jacketed and some cast bullets that Gohon was nice enough to send me to try out that worked great in his rifle. Dismal results at best. Most were 4" to 5" groups at 50 yds.
One jhp load was decent, but all the loads should have been just as good. No dice. Has to be a barrel problem, ( I guess). I am stumped. May be looking for a 1873 in 357/38. Wife needs a lighter recoiling caliber anyway, with shoulder
surgery coming up.
Thanks to all for your help, ideas.
Here's the pics, 1" diamonds, 50 yds, scope
260 JHP

260JHP

Best of the cast loads


 

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Not a Marlin, but my Rossi trapper likes .452" and heavy GC lead bullets. The faster the better it seems but my loads with Lil Gun are way into Ruger only territory.

FWIW mine also likes the Nosler 250SJHP with high end Colt loads as well as Ruger level loads. It doesn't shoot Unique plinkers worth a darn.
 

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Midway had the 250 grain XTP back in stock today. A trigger job makes a big difference on group shooting as you pobably know. I have a 1894 round barrel 45LC made in 1989 that I had my gunsmith work on last week and he brought the trigger from 7 poinds down to 2.5 pounds and it made a big difference.
 

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I'm not trying to throw doubt on the shooter, but I'm wondering how much of what we're seeing isn't a cleaning issue. I know I thought I cleaned my FG well before shooting factory cast, Grizzly and BB, and they only shot so-so and I thought I cleaned well after shooting those cast, but my known jacketed groups opened up noticeably. I opted for course stainless scrubbing pad pieces wrapped around a patch and jag and was amazed at what came out. About 30 minutes of elbow grease and various solvents my bore looked like new. After that the jacketed bullet grouping came back together. I know this is shooting factory ammo versus loaded, but the groups just tickled a memory for me.
 
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