Reduced loads for .458 Lott


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jamesicus
March 8, 2010, 06:28 PM
I have a surfeit of Hornady .458 DGS 500 GR Bullets. I intend to use a charge of 38 grains of Accurate 5744 powder with Hornady .458 Lott cases and Remington 9 1/2M primers.

Will I still need to crimp the cases in the bullet cannelure with this reduced load?

Intended usage is paper target shooting at 50yds.

Thank you for all responses.

James

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earlthegoat2
March 8, 2010, 07:23 PM
In Terry Weiland's book, Dangerous Game Rifles there is an appendix on the use of 5744 for practice loads of all heavy calibers.

You first need to determine how much powder your case can hold uncompressed with a bullet seated. Then you weigh the powder on your scale. After that is determined you take 40% of that value (multiply by 0.40) This is your starting point for a reduced load. It will give velocities around 40-50% of a full power load. You can usually safely go up to 48% for a maximum velocity and pressure with lead bullets and 60-65 for max velocity and pressure with jacketed bullets.

I would still crimp with that load as it is still about like a medium power 45-70. Unless you have a single shot rifle like a Ruger No. 1, then you dont need to crimp.

jamesicus
March 8, 2010, 10:30 PM
Thank you, earlthegoat2.

Remo-99
March 9, 2010, 09:54 AM
I really like shooting large calibres, but my shoulder can only take so much punishment(old injury).
Loading lead bullets with TrailBoss, I bet you couldn't remove the smile from your face with a towtruck after shooting it all day long. lol

jamesicus
March 13, 2010, 09:12 PM
It was off to the range today:

Rifle: CZ 550, American Safari, .458 Lott (/.458 Win. Mag.), Open iron sights, weight: 10lbs.
Ammunition: reloads using Hornady New Dimension dies, RCBS Rock-Chucker press
Brass: Hornady
Powder: Accurate 5744 - 38 grains (no fillers)
Primers: Remington 9 1/2M Magnum rifle
Bullets: Hornady 500 grain DGS - .458 dia.

Full length resized without crimping.

I shot twenty rounds in four five shot groups from the bench at 25 yds. This was mainly a function/performance test although the groups were nice and tight (3 inches high) given the handicap of iron sights and my diminished eyesight. The recoil was quite mild and the shooting experience pleasurable - I could have comfortably shot many more rounds during this range session. I single loaded cartridges directly into the chamber, overloading two dummy rounds that I kept in the magazine in order to check uncrimped bullet set-back resulting from recoil. After the first five round string I removed and checked the dummy rounds -- they had both set-back in the cases approx 3/16". I think I will crimp future loadings in the bullet cannelure. The powder performed flawlessly -- extraction of fired cases was easy and the fired cases were in excellent condition. I fired three factory loaded cartridges offhand before I departed the range -- just to remind myself how brutal the .458 Lott recoil can be!

An aside:

I was already a fervant fan of Western Powders after using their "Blackhorn" powder for my inline muzzleloading (Thompson Center .50 caliber "Bone Collector") -- it revolutionized the sport for me -- no bore fouling (you can shoot numerous rounds without cleaning between shots), easy breech plug extraction, easy cleaning of the bore upon completion of shooting using regular cleaner such as Hoppes #9. After the performance of "Accurate 5744" I am an even greater fan of Western Powders.

James

jamesicus
March 21, 2010, 01:48 AM
I hand loaded some cartridges using the following prescription: Hodgdon IMR "Trail Boss" powder - 18.2 grains minimum load (70% of carefully measured 26 grains of case capacity using once fired factory brass and new factory bullet) - based on this Hogdon (PDF) page (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf)

I shot the following groups from the bench at 50 yds this morning under very breezy conditions .....

http://jp29.org/lott07.JPG

..... bottom five shot group using 500 grain Hornady DGS bullets - top three shot group using 500 grain Hornady DGX bullets. This was a test of recoil effect (very light indeed) and grouping capability (no sight adjustment). CZ 550 American Safari Magnum rifle - .458 Lott caliber. Nikon "Buckmaster" 1x20 scope sight in Talley QD mounts.

Caveat: My handloads work in my rifle. You may not achieve the same results in your rifle using the same load and components.
Always refer to the data published by Hodgdon relating to their IMR Trail Boss Reduced Loads For Rifle and Pistol (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf)

James

GMFWoodchuck
March 21, 2010, 12:05 PM
My understanding is that the 450 marlin and the 458 win mags are the same basic cartridges as the lott but shorter. Can you interchange them like a 44 spec in a 44 mag firearms?

If you could you could have a very good way of getting reduced loads without any of that funniness with severely reduced loads.

Afy
March 21, 2010, 12:58 PM
36 grains of case capacity? I somehow always thought it would be a lott more... ;)

jamesicus
March 24, 2010, 08:39 PM
Short afternoon session at the range. Hand loads using 18.5 grains of Hodgdon IMR "Trail Boss" powder (minimum load plus .3 grains), Hornady twice fired brass, Hornady 500 grain DGS bullets, Remington 9 1/2M magnum rifle primers. CZ 550 American Safari Magnum rifle - .458 Lott caliber. Nikon "Buckmaster" 1x20 scope sight in Talley QD mounts/rings.

Shooting from the bench under calm conditions - 70 F temperature - bright sunshine - Caldwell rifle rest.

http://jp29.org/lott11.JPG
Three shot group at 50 yards (after two sighting-in shots).


http://jp29.org/lott10.JPG
Five shot group at 50 yards (sight adjustment verification).


http://jp29.org/lott12.JPG
Three shot group at 100 yards (3" POI drop from 50 yards).


I don't think the groups are too bad - considering my diminished eighty year old eyesight and accompanying trigger finger tremor.

I will shoot strings using this loading (and components) through the Chronograph this coming weekend

Caveat: My handloads work in my rifle. You may not achieve the same results in your rifle using the same load and components.
Always refer to the data published by Hodgdon relating to their IMR Trail Boss Reduced Loads For Rifle and Pistol (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf)


James

jamesicus
March 29, 2010, 06:24 PM
.......... Hand loads using 18.5 grains of Hodgdon IMR "Trail Boss" powder (minimum load plus .3 grains), Hornady twice fired brass, Hornady 500 grain DGS bullets, Remington 9 1/2M magnum rifle primers. CZ 550 American Safari Magnum rifle - .458 Lott caliber. Nikon "Buckmaster" 1x20 scope sight in Talley QD mounts/rings .......... I will shoot strings using this loading (and components) through the Chronograph this coming weekend.

Twenty shot string from the bench using a Caldwell rifle rest through a "Pro-Chrono" digital chronograph positioned 15ft in front of 25" barrel muzzle -- High velocity: 729fps, Low velocity: 691fps, Average velocity: 710fps.

Calm weather conditions, 75 F temperature - bright sunshine.

Clean, complete powder burn.

The components:

http://jp29.org/lott09.jpg
Hornady thrice fired brass (cleaned) - Hornady 500 grain DGS bullet -
18.5 grains of Hodgdon IMR "Trail Boss" powder (minimum load plus .3 grains) - completed cartridge

Note the bulky, "fluffy", "cheerio shaped", powder.

Caveat: My handloads work in my rifle. You may not achieve the same results in your rifle using the same load and components.
Always refer to the data published by Hodgdon relating to their IMR Trail Boss Reduced Loads For Rifle and Pistol (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf) prior to formulating your own handloads.

James

jamesicus
April 6, 2010, 04:19 PM
My own goal is to produce safe hand loads that are comfortable to shoot from the bench for prolonged periods; will produce consistent, reasonably accurate, target groups; serve as suitable close range light game hunting loads. The near minimum (Hodgdon data) loads I am presently using in my CZ 550 American Magnum Safari .458 Lott rifle fall short of the "light game hunting suitability" criterion. I want to achieve approximately 1000 fps muzzle velocity with 500 grain bullets which will produce 1100 foot lbs of muzzle energy. I will work slowly to that end.
Early morning Range session -- very light breezes -- ideal for chronograph usage.

Hand loads using Hodgdon IMR "Trail Boss" powder; Hornady five times fired brass; HSM 405 grain lubricated, cast bullets (.458 diameter); Remington 9 1/2M magnum rifle primers; CZ 550 American Safari Magnum rifle - .458 Lott caliber.

Shooting from the bench under calm conditions - 70 F temperature - bright sunshine - Caldwell rifle rest. Bullet velocity measured using a ProChrono chronograph positioned 12 feet from the rifle barrel muzzle.

I opted for 405 grain bullets for better ballistic balance and cost savings. I loaded four groups of five cartridges (using Hodgdon IMR Trail Boss powder data) in 2 grain increments from a near minimum of 19 grains to a near maximum of 25 grains (I never use maximum loads as a matter of principle). Bullets were seated to the crimping groove but were not crimped -- I believed the very light recoil produced by these loadings would not result in bullet set-back in the box magazine -- this proved to be the case as rounds were chambered via the magazine (flawlessly), two and three, without any set-back.

Below:

HSM 405 grain lubricated cast lead bullet (top)
Fired Hornady cartridge case (middle)
Hornady 500 grain DGS factory jacketed bullet (bottom)

Showing relative OL lengths of bullets, seating position in case and location of crimping grooves (seated to this index)

http://jp29.org/lott16.JPG

I used magnum rifle primers to insure optimum powder burn -- fired cases were clean with no evidence of unburnt powder granules. The 19 grain (near minimum) loading produced the best target groupings and the most consistent velocities:

1165 fps
1157 fps
1160 fps
1169 fps
1169 fps

1164 fps average - 1157 low/1169 high

This average velocity with 405 grain bullets equates to 1219 ft/lbs energy (at 12 feet from the rifle muzzle). The oft quoted minimum striking energy for taking white tail deer and other thin-skinned animals is 1000 ft/lbs -- therefor I believe this loading meets my requirement for a suitable close range light game hunting load.

Caveat: My handloads work in my rifle. You may not achieve the same results in your rifle using the same load and components.
Always refer to the data published by Hodgdon relating to their IMR Trail Boss Reduced Loads For Rifle and Pistol (http://www.imrpowder.com/PDF/Trail-Boss-data.pdf) prior to formulating your own handloads.

James

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