Caliper mystery
-
- Posts: 25
- Joined: 23 Dec 2018 08:56
- My Press Choice: Single Stage
- Location: New England
- Been thanked: 1 time
Caliper mystery
I seated twenty 44 spls (at the cannelure) and they all measured 1.450. The minimum COL is 1.495. Then I crimped them and re-measured. Now they’re all measuring about 1.490. What’s going on? Anyhoo, I wonder if .005 under would create unsafe pressure. I’m also wondering if my calipers are off, or I’m forcing the thumbwheel without realizing it. Any thiughts?
- Ranch Dog
- Site Admin
- Posts: 6458
- Joined: 22 Jun 2013 17:16
- My Press Choice: Progressive
- Location: Inez, TX
- Has thanked: 1617 times
- Been thanked: 2851 times
Re: Caliper mystery
The way I read it is that they grew longer so that will reduce the pressure.bluetick wrote:Now they’re all measuring about 1.490.
Michael
- Macd
- Supporter
- Posts: 1009
- Joined: 16 Oct 2017 16:12
- My Press Choice: Single Stage
- Location: Far East
- Has thanked: 362 times
- Been thanked: 403 times
Re: Caliper mystery
If you give bullet weight and make, powder and amount I will run a Quickload check. The growth could just be the case mouth pushing the bullet forward to get into the cannelure (Assuming roll crimp). Pressure change in the .44 calibre with a slight decrease in C.0.L. should be insignificant unless you are compressing a powder like L'l Gun. If you want to check the accuracy of your calipers or your technique use a set of clean flat feeler gauges. To check if it is consistent along its scale you can use some bond paper. Measure a sheet, fold it over and measure again and repeat several times. The measurement should increase in line with the number of folds at least within the error tolerance of your calipers.
-
- Posts: 25
- Joined: 23 Dec 2018 08:56
- My Press Choice: Single Stage
- Location: New England
- Been thanked: 1 time
Re: Caliper mystery
.44 spl, 200 grain hornady jacketed, and 6.7 grains of Unique to send it back on its way. Minimum COL is 1.495.
-
- Founding Member & Supporter
- Posts: 674
- Joined: 30 Jun 2013 09:30
- My Press Choice: Turret
- Location: S. Oregun
- Has thanked: 203 times
- Been thanked: 371 times
Re: Caliper mystery
Am I right; you seated bullets, measured OAL, then crimped and remeasured, the OAL grew .040"? Since my first revolver reload (1969), I have just seated to the crimp groove/cannalure and disregarded book OAL. I've reloaded a bunch of 44 Specials but none grew with crimping, some shrunk a few thousandths, but none grew. What set up are you using (press, dies, etc.)?
- Ranch Dog
- Site Admin
- Posts: 6458
- Joined: 22 Jun 2013 17:16
- My Press Choice: Progressive
- Location: Inez, TX
- Has thanked: 1617 times
- Been thanked: 2851 times
-
- Founding Member & Supporter
- Posts: 674
- Joined: 30 Jun 2013 09:30
- My Press Choice: Turret
- Location: S. Oregun
- Has thanked: 203 times
- Been thanked: 371 times
Re: Caliper mystery
C'mon back bluetick. Nobody's gonna laugh at you for misreading yer calipers. BTDT on many occasions...
- Macd
- Supporter
- Posts: 1009
- Joined: 16 Oct 2017 16:12
- My Press Choice: Single Stage
- Location: Far East
- Has thanked: 362 times
- Been thanked: 403 times
Re: Caliper mystery
QL Predictionsbluetick wrote:.44 spl, 200 grain Hornady jacketed, and 6.7 grains of Unique to send it back on its way. Minimum COL is 1.495.
I used Hornady XTP as it was the only one I could find for the .44 spl at 200 grains.
Pmax SAAMI = 15,500 PSI
1.490 = 13,206 PSI
1.495 = 13,095 PSI
At 1.450 QL predicts 14,196 PSI or 92% of SAAMI max. My own preference is to keep handgun loads below 90% as it is easier on the gun and usually on my arthritis.
I couldn't find a similar load to the one you describe in any of my manuals nor on the Alliant site. 6.7 grains of Unique is below minimum for a COL of 1.490 in all the references.
- mr surveyor
- Founding Member
- Posts: 650
- Joined: 30 Jun 2013 09:30
- My Press Choice: Hand Press
- Location: NE Texas
- Has thanked: 386 times
- Been thanked: 231 times
Re: Caliper mystery
I would ask that bluetick verify his numbers stated in the original post. Something about those numbers just don't seem to click with my brain.
just trying to follow
jd
just trying to follow
jd
--------------------------------------------------------------------------------------
There's just some things best left unsaid on the internetsuperhighway.
There's just some things best left unsaid on the internetsuperhighway.