TargetTalk

What dies are you using and what crimp are you using for your 45ACP's?

Here is why I'm asking.

I just switched to the Redding competition micrometer die. I was using RCBS dies. I have almost eliminated rounds that don't gauge OK. This die straightens and centers the bullet. I'm still using the RCBS die to crimp. I Chronograph some loads last week. Seating and then crimping with the RCBS dies and seating with the Redding and crimping with the RCBS. Muzzle velocity didn't change but SD went from 19 to 15. But more impotent, no more crooked bullets.

Almost forgot. I'm using a .467-8 crimp.

Rounds that don't gauge ok are generally the result of brass (glock fired), re-sizing issues, not enough crimp or OAL issues. Rarely anything to do with the actual dies.

Crooked bullets are generally the result of not enough flair or the need for a better seating stem. I have insert to seat LSW bullets by the shoulder and ground the round nose stem out so the bullet seats off about halfway down the ogive, not the nose. There are always imperfections around the tip, especially with JHPs. (for pistol the shoulder measurement LSWs and consistent ogive distance to the leade for JHP are more important that the actual OAL and its variations due to the bullet nose. (look closely at the nose of cast and JHP bullets and don't get lost in the 1/1000's variations there).

The Redding Comp seating die may need some tweaking if you are using lead bullets or not resizing the case enough. The bullet stem guide spring is very strong on some of those and the die must be kept very clean. (sometimes so strong it can push the bullet into a case before the actual seating limit is reached.

While chronos don't make groups, they can give some indication. The real question when going from 19 to 15 SD is if that was the result of the elimination of the velocity outliers or simply a slightly better grouping around your average velocity.

you did not say if you were using lead or JHP bullets. (Don't even attempt 50 yard accuracy with plated bullets.) Crimp is +/- 0.470 average for JHP's and LSWs are about +/- .469 depending on the specific bullet and brass. (Some lead bullets require a little more crimp.)

I use Dillon dies, reload on a 650 and get single digit SD with 200 gr LSW and 185 JHP loads using VV310 and crank them out about 1,000 per reloading session. But I was just going by the group testing (1.5 to 2.0 inches from Ransom at 50) for my loads and never knew what the actual velocity or SD was until years later when a friend was testing some loads and wanted to shoot my gun at the range. (He kinda packed up his chrono and left after firing about 50 rounds of each load.)

CR

Having suffered through three statistics classes, I wonder if there is any real difference between a variance of 15 and 19? The only way to tell is to repeat the loads to see of the difference in SD trends.

A note on belling: a common mistake is to over-bell case mouths, which makes bullet center-seating more difficult. I use a Dillon 550B with Dillon dies for the 45; their seating die has a useful quick change plug for flat nose or round nose bullets. I prefer flat bottomed bullets as I think these are easier to center versus bullets with a beveled bottom. I know that seems illogical, but if the bevel angle doesn't match the belling angle, centering beveled bullets is more difficult in my opinion. The most accurate bullet available in 45 ACP is the Nosler or Zero 185-gr JHP and these are flat bottomed bullets.

I don't used the primer seating function of the 550B but hand seat using an RCBS priming tool, which allows me to feel when the primer is seated flush. When loading, I start at the powder drop station using cleaned brass with seated primers. Flush seated primers will increase ignition consistency and if you wish, allow use a lighter hammer spring (factory on a full size 1911 is 23 lbs but you can get reliable ignition with 18 lb springs, especially with Federal primers). I don't recommend this for a defense carry pistol but all day long for a target pistol. Hope this help, dipnet