Big bore load development process

nksmfamjp

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OK guys, I had the 458 Lott out yesterday with min loss to get a feel.

The first feeling I got was ,”how the hell am I going to develop safe accurate loads with all this recoil?”

I would normally load develop by ocw method shooting 50-100 rounds. This would take a year with heavy loads to get enough down range.

so, what shortcuts are there to this?

im thinking shoot a velocity ladder maybe to find a sweetspot...
 
For a lot of shooting of a heavy recoiling rifle you may need to pick up a Lead Sled.
 
A lead Sled... Do you need that ?

I use in sitting position the usual normal equipment with sandbags , whether it's going to develop a load for a big bore rifle or zeroing a scope for the same rifles. This is also part of the training and preparation for the handling of such rifles in the terrain.
 
A .458 Lott is not designed as either a long distance sniper rifle or as a varmint rifle. It's designed for in close at dangerous game. Refer to a reliable data from Hodgdon and/or other manufacturers, select a projectile to suit the task and then enough rounds to confirm function, reliability and zero. Don't over do it. A few rounds at a time only otherwise all you'll develop is a flinch. Do your shooting from either standing unsupported or standing with sticks. Remember you're after minute of buffalo not sub-minute of angle.

Use a smaller calibre rifle, of similar configuration, for lots of practice.
 
With a lot of training normally you don't develop a flinch. Thats my opinion , but may be i am not a good example. I am shooting all the times with rifles caliber 458 and more.

I would not train with rifles smaller caliber , IMHO that does not prepare for shooting with big bore rifles.
 
I sort of followed the method talked in this video, which is OCW-ish, with the first pass of developing my 404 Jeff loads. Full disclosure, I had a favorite load that was given to me, so we had a certain load in mind when we started. But as pointed out in this video, and what I did, was loaded a total 10 rounds of 5 loads and shoot them into a dirt bank and simply chrony the shots. I used a friends magneto type chrony. We had 2 rounds of each load and 5 loads to test. Since Swift A-Frames aren't cheap, this was an economical test. We simply looked for the for the SD and ES from two shots on each and found the node.

 
Well, I do have a lead sled, but it won’t be enough for 500gr loads!

i think I will just confirm max pressure and keep building my ability to handle it!
 
I use these for zeroing and load development of big bores, you shoot standing yet have a stable platform. Mine are made by Primos.
IMG_1664.JPG
 
As mentioned earlier, you must re-define "accuracy" for your Lott. It is not the same as accuracy for your 7mm-08 that you use on Sheep.

Regarding the practice with the smaller caliber rifle...better than nothing, but be sure to put plenty of rounds through the big guy...it is the only way I know to get used to shooting them in the field.

I am not a fan of the sleds...I think you can adequately sight and test a big bore standing with your hand between the rifle and a sand bag. This allows you to roll with the recoil and continues to reinforce proper big-bore technique.

I would do initial shooting and training at 25 yards to build confidence and allow you to quickly see improvement.

As you master the rifle, you can move out...but 50 yards is a good long poke with a DG rifle. Tell your PH you want to kill your critter close! It is more fun that way. :)
 
Using the shooting sticks from my previous post above you can shoot reasonably accurately. Here are two targets I shot the other day. Both rifles open sighted, distance 50metres. Right target Winchester M70 in 416Rem three shots. Left target Krieghoff double, 470NE one shot from each barrel. The red dots are very hard to see with irons at that distance and are a limiting factor.
Image1574521457.913492.jpg
 
This KencoOutdoors rest is the most stable standing rest I have seen and it lets you "roll" with the recoil.
DSC03696.jpg
 
Just shoot normal type hunting loads. Use a sissy pad. Shoot off a good rest for accurate shooting. Don’t shoot too much to begin. Sit more upright and don’t tighten up muscles too much. If using scope don’t crawl the stock and make sure scope has enough eye relief.. 4.75-5” at least. Practice off sticks once in a while.
 
Don't overthink it. Velocity ladders or target ladder methods at various range increments for finding sweet spot accuracy... not necessary. If you have a "normal" rifle of 24-25" bbl with more or less normal chamber and bore you can expect normal velocities as are published in pressure tested load manuals and sources. I have shot this type rifle a lot and worked up loads a lot in these type guns. They do recoil.

Don't
use a big soft thick sissy pad. Use a large wide fairly thin stiff one of sorbothane or hard rubber sandwiched between layers of thick leather. If you need extreme protection then use a thin sand bag. The idea is to spread the recoil over a larger area. Use a chronograph to approach your objective velocity. Watch for pressure signs. Don't creep up from 5 grains below listed max in .1 grain increments.... silly. Go maybe 5-10 % below max and load in increasing 1 grain increments. It only takes about 5 shots thru the chronograph and on paper at same time to get a good indication if the load is worthy or not. When first starting the process of learning how to shoot these heavy recoilers, limit number of shots for each range session to about 5. If you start flinching or are afraid of the recoil, you may be able to get good chronograph data for load development but will not learn much about inherent accuracy of the load. And in the field without ideal conditions you need to have some ability for accurate shooting even for big targets. Yanking that trigger (flinching) even on a large DG animal at fairly close range is not good at all! These big guns have the potential to shoot extremely well. Doing so in practice has a huge positive effect on your confidence in both shooting ability and the rifle/load.... good things.

Most manuals and published data sources list top Lott vels with 500 grain bullets ranging from about 2200 to about 2250. Use that as an objective velocity range to approach. Some guns will show pressure signs before that and some may go well beyond. If you plan to hunt serious DG game in the heat, use a temperature insensitive powder like one of the Hodgdon extreme types. I have used both Varget and Benchmark with good results in the Lott's bigger close cousin the 450 Watts. Don't overlook good premium and proven bullets in the 450 and 480 grain weights either.
 
Good points....I feel like with open sights and 458 Lott recoil, I’m shooting more for what can I handle and give safe pressure with minute of buffalo accuracy!
 

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