My .45 Colt 1873 has bench accuracy of about 4" at 50 yards; hand load Star brass, 250 .452 MO bullets, 8 gr. Unique, Winchester large pistol primers and 1.55 OAL. Plenty of accuracy for a deer's chest area however, would not mind tighter group performance. The rifle may be maxed for the design and that is OK - but, if going to change the variables for this rifle/ cartridge to (possibly) tighten the groups, which loading component is the best to start with/ change (ie. power charge?, primer?, etc). Thanks for your help.
Loading Variables Question
- Thread starter Steve S.
- Start date
- Status
Reloadron
Contributing Member
My best guesses would be powder followed by powder charge weight and bullet. That has been pretty much my experience but there is really a handful of variables including as you mentioned primer, brass and things like crimp. So if it were me I would start with powder followed by charge weight and then bullet. Just keep in mind to only change one variable at a time.
Ron
Ron
Sam1911
Moderator Emeritus
First, I'd slug your bore and measure to see what your diameter really is. Could be you need a larger bullet diameter. And, especially if you've fired a lot of lead that really didn't fit well, you might have a lot of leading in there that needs to be scrubbed out.
Then, I'd make sure the crimp is firm and consistent (you might even consider trimming your brass to uniform length for a situation like this), and then work on the powder charge. Go up by a few 1/10ths of a grain at a time, working from low to high across the published load range until you find the charge that seems to give you the tightest groups.
If you can't get better than 4" at 50 yds with Unique, try another powder.
Then, I'd make sure the crimp is firm and consistent (you might even consider trimming your brass to uniform length for a situation like this), and then work on the powder charge. Go up by a few 1/10ths of a grain at a time, working from low to high across the published load range until you find the charge that seems to give you the tightest groups.
If you can't get better than 4" at 50 yds with Unique, try another powder.
TimSr
Member
Bullet weight and shape is number 1 on my list, followed by the bullet/powder combo, and the powder charge is for fine tuning. Cast bullets in your weight range and Unique are usually a pretty compatible combo. You might try some 255gr SWC Keith types bullets. May or may not be any better than RNFP. I get great accuracy for 255grSWC but get even better from Hornady XTPs from a revolver.
witchhunter
Member
Bullets first, but you may need to try everything. Make sure the bore is cleaned between tests.
Something to consider...
An appropriate charge of Unique in the large 45 Colt cartridge is position sensitive when fired. In my revolvers, the velocity varies 10-12 percent whether the powder is against the primer at firing or against the bullet.
I do not see a difference in grouping, that may be a shooter thing, but i suspect that it would be more noticeable when fired from a rifle at longer ranges.
As much as I like Unique, I am trending away from it in larger cases such as 45 Colt, 44 Special and 44 Magnum.
An appropriate charge of Unique in the large 45 Colt cartridge is position sensitive when fired. In my revolvers, the velocity varies 10-12 percent whether the powder is against the primer at firing or against the bullet.
I do not see a difference in grouping, that may be a shooter thing, but i suspect that it would be more noticeable when fired from a rifle at longer ranges.
As much as I like Unique, I am trending away from it in larger cases such as 45 Colt, 44 Special and 44 Magnum.
- Status
